Dark matter vs modified gravity: which team are you on?

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- <silence>

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Physics

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- World.

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Hello and welcome to the
Physics World Stories Podcast.

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I'm Andrew Lester. And in this episode,

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we're gonna be exploring the debate raging

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between dark matter theorists

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and modified Newtonian
dynamics or mon theorists.

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The debate centers around
two competing theories,

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which are proposed to
explain the discrepancies

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between the observed gravitational
effects in the universe

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and the predictions made
by Newton's laws of gravity

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and general relativity.

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There are particular issues in
the way that galaxies behave.

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For example, the rotation curves

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of galaxies are faster
than you would expect.

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Dark matter theory suggests

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that the missing mass causing
these gravitational anomalies

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is due to this unseen form of matter.

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Dark matter doesn't emit absorb

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or reflect light, meaning it's invisible

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and detectable only through
its gravitational effects.

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Dark matter is thought
to make up around 27%

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of the universe's mass energy content.

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Mon, on the other hand, suggests

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that these discrepancies
can be explained without

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invoking unseen matter.

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Proponents of mon propose
modifications to Newton's laws

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of motion and gravity at
very low accelerations,

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which are typical of the
conditions found at the outer

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regions of galaxies.

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According to mon,

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the gravitational force behaves
differently at these low

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accelerations of gal rotation
curves without requiring

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the unseen dark matter in
the astronomical community.

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There is something

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of a tribal debate about it
on the physics world website.

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There's the first of three features

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by Keith Cooper exploring
this topic, cosmic combat,

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delving into the battle
between dark matter

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and modified gravity.

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Having read that article,
I wanted to find out more.

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So in this podcast, we'll
hear from two researchers,

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one who's moved from the mon
camp to the dark matter camp,

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and first Professor Stacey
Magor, who moved from dark matter

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to be a supporter of mon.

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- I am, uh,

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on the faculty at Case
Western Reserve University in

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Cleveland, Ohio and the United States.

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Uh, I work on galaxies and cosmology, and,

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and those things have sort of brought me

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to be interested in the
dark matter problem and,

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and the modified Newtonian
dynamics of Milgram.

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So in, um, both of those,
uh, astronomical objects,

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I mentioned galaxies and cosmology.

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You find that things don't add up.

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What you see is not what
you get in the sense

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that if you use the law of
gravity as taught to us by Newton

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and Einstein, um, applied

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to the visible matter, uh,

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things don't work out in galaxies.

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Stars and gas are orbiting
faster than one would predict.

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Um, the cosmology as a whole, um,

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doesn't really add up unless
you have both some extra mass

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and, and for that matter,
some extra, um, dark energy.

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Uh, and in particular in the
case of cosmology, we know,

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uh, from the early universe
that the abundances

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of the light elements, um,
the isotopes of hydrogen, uh,

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helium and lithium, uh, we
can understand that as, uh,

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the universe having
passed through, uh, a, a,

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a phase in which it was
one giant nuclear reactor.

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And we get the, uh, observed
elemental abundance, right,

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for a particular density of,
uh, bariums, uh, neutrons

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and protons, normal matter
that make up most of the mass.

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Uh, and that is maybe 5%
of the critical density,

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which is the over under, uh,
between expanding forever

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or relapsing.

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And yet, if we go out as astronomers

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and move, measure how things
move, and large scales

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and try to estimate the total
gravitating mass density, uh,

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then it's much bigger
than that, uh, density

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of normal matter.

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Uh, so we infer that there
is extra mass in both kinds

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of systems and that mass visible to us,

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and it have participated in this, uh,

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early big bang nucle synthesis.

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So we infer that it is some
kind of new particle outside

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of the standard model of particle physics.

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- So where does the modified
new dynamics come into

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- This?

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So, um, so that,

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that background about the
dark matter is sort of

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where I came to the problem from

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and where I, where I think
most, uh, scientists come to it.

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Um, but I was mostly interested in those

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astronomical objects.

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In particular, a class

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of things called low surface
brightness galaxies, which, uh,

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when I was a young
scientist, were, were new

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and not much was known about them.

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Uh, and I,

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and so a low surface
brightness galaxy is just a, a,

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if you think of a pretty spiral
galaxy, it's, it's just take

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that and stretch it out.

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It's, uh, has a much lower
average surface density of stars.

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Um, and so it's not as
pretty, but still a galaxy.

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And so, um, I had ideas
about how those, uh,

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would form in terms of dark
matter other people did too.

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And, um, none of those
ideas proved correct.

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And so in studying those things, I,

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I really got concerned
about whether we understood

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dark matter or if it could
even explain these galaxies.

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And, and that's a long story

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because one doesn't
consider, uh, something

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as radical as the, uh, a
modification of gravity, the,

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the so-called modified Newtonian dynamics

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until you're really convinced
that there's a problem

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with the dark matter picture.

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Um, and I became aware of that, or,

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or I become concerned for
the, the dark matter, um,

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before I became aware that,
that anybody had really even

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hypothesized that, um,

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at the time I was a postdoc in Cambridge

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and, um, uh, ma Mai Milgram,

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who was the person

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who hypothesized the modified
dynamics happened to come by.

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Uh, so it was a sort

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of a chance meeting in
middle Earth, as it were.

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And, and at a critical time when I was,

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um, already concerned about
whether the dark matter

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picture was viable.

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Um, and like I say, there's
a huge backstory just to

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that statement, but I'd
gotten worried about it.

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Um, nevertheless, I was
still convinced that

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that had to be the case.

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And so when I saw his talk
advertised on a poster, uh,

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something about modified gravity,
I was like, oh, who wants

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to hear that nonsense?

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It can't possibly be right.

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Um, and so I did go anyway.

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And, uh, he basically
not knowing who I was

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or what I did, derived in a
few lines on the board, um,

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a prediction for

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what low surface bytes
galaxies should do in

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his modified dynamics.

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Uh, that was exactly what I was observing

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and, uh, was part of what
had caused me deep concern

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for whether or not, uh,

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we could explain it with dark matter.

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And it was basically
a fine tuning problem.

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So, um,

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what the modified dynamics
hypothesize is that rather than

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there being a whole lot of
dark matter in the universe,

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that all the discrepancies
that we observe are

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because Newton and Einstein
didn't teach us everything.

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And so there's a change the force law.

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Um, and then his hypothesis
is change happens

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at a particular acceleration scale.

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Um, that's already kind of
hard to wrap our heads around

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because of course,
people, uh, early on when,

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when the dark matter
problem became obvious, um,

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people did think, well, maybe
it's a change in gravity.

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Uh, and the first thing our
brains think of is size, right?

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Cosmic scales are huge.
The galaxy is huge.

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The solar system is huge,

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but it's tiny compared
to those other things.

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So it's easy, uh, to imagine that, okay,

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Newton's inverse square law law and,

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and Einstein's additions

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to it work perfectly in the solar system.

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But maybe when you get to
the much, much bigger scales

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of galaxies, some
intermediate scale there, the,

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the force law changes,
um, that does not work.

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Um, you, you cannot make a,

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a length scale dependent
modification, uh, to the law

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of gravity and, and
fit it to all the data.

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Um, so people pretty much gave
up on that pretty quickly.

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But, but Milgram like, I
guess he suggested, well,

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there are other scales,
and the one that seems

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to work is this very
low acceleration scale.

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Um, and so he had hypothesized,
um, basically he wanted to

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cook up a theory that
made rotation curves flat,

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which was the, the hot topic at the time.

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Uh, but once you do that,
once you write down a,

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a modified force law,
it's, it's an equation and,

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and you're stuck with it, and
it makes lots of predictions

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and, um, acceleration
follows from surface density.

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So I had inadvertently done
the perfect, um, experiment

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to test this theory.

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<laugh>, I didn't know
about the theory when I,

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I was <laugh>, I was
interested in the low surface

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brightness galaxies, um, but
they were low surface density,

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and so that meant low acceleration.

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So they were strong
tests of, uh, his theory.

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And in fact, after, uh, I
hearing his talk, I went back

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and read his original papers,

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and I found a, a quote in there that said,

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low surface brightness
galaxies will provide

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particularly strong tests.

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And I was like, wow, I have now the data

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to falsify this stupid
theory, <laugh> <laugh>, that

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that was my first thought,

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because I was coming at it
from this dark matter picture

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where that had to be true.

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And even though I was already
worried about whether it,

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whether it could work

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or not, I still assumed that this,

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this strength theory had to be wrong.

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Um, now the concerns I had were
because of the fine tuning,

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and again, a long story short,
that fine tuning comes about

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because galaxies, uh, turn out

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to obey this modified force
law that Milgrim wrote down.

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And not just in terms of
having flat rotation curves,

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but in being able to map the details

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of the observed mass
distribution to the kinematics.

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That is how the entire shape
of the rotation curves was,

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how, how stars and gas moved in galaxies.

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Um, and so what I said

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before is that, you know, we
have the dark matter problem

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because what we see is not what you get.

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Um, but it is in this modified force law.

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Um, and what since then
is, you know, 20 years

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of hard work.

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But, um, we've been able to show that

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that's true empirically in
galaxies, um, without reference

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to, to milgram's particular theory,

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that if you measure the
mass distribution, uh,

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of the stuff you can see,
then it maps, uh, directly

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to the total kinematics.

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Whether that's dark matter
or this modified gravity

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or something else, we
have not yet dreamt up.

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Uh, and that's a critical part

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of understanding what's going on.

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That is unanticipated
in dark matter theory.

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And as yet, not satisfactorily
explained by it,

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- We'll hear much more from
Stacey later in the podcast.

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But while Professor Magor
has moved from studying dark

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matter towards mon, Dr.

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Adrian Nik has moved
in the other direction.

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- So, um, I am a postdoc
in the, uh, department

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of, uh, physics and astronomy at St.

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Andrews. Um, I work on, uh,

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right now I work on testing the idea

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that we are living in a
local under density or void,

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and this could, um,

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perhaps solve the Hubble
tension in cosmology.

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Um, but originally this,
this postdoc was about, uh,

248
00:12:50,565 --> 00:12:54,325
implementing the, um, wide binary test

249
00:12:54,385 --> 00:12:56,805
of gravity at low accelerations.

250
00:12:57,465 --> 00:13:01,525
Um, and that took, uh,
first couple of years.

251
00:13:02,225 --> 00:13:04,645
Um, and that's something
I've been working on for

252
00:13:05,275 --> 00:13:09,525
much longer is the idea of
grooving dynamics Ormond, um,

253
00:13:10,815 --> 00:13:13,535
which, uh, is about, um,

254
00:13:14,675 --> 00:13:16,535
galaxy rotation cuffs, perhaps being

255
00:13:17,205 --> 00:13:20,745
understandable without
any dark matter at all.

256
00:13:22,365 --> 00:13:23,945
- You've changed your mind, right,

257
00:13:24,205 --> 00:13:25,465
as a result of the evidence.

258
00:13:26,605 --> 00:13:30,665
- So if, if I just work o outwards on

259
00:13:31,255 --> 00:13:33,065
from the smaller scales
to the larger ones,

260
00:13:33,365 --> 00:13:35,025
and that, that I think
will make most sense.

261
00:13:35,445 --> 00:13:38,465
So, uh, the first thing,
um, well, uh, the,

262
00:13:38,485 --> 00:13:43,475
the smaller scale thing,
uh, failure was with regard

263
00:13:43,475 --> 00:13:45,835
to the solar system FM fides.

264
00:13:46,335 --> 00:13:50,355
So, um, because modern
acceleration dependent sort

265
00:13:50,355 --> 00:13:52,675
of theory, um, the

266
00:13:53,225 --> 00:13:56,755
deviation from Newtonian
mechanics sets in at only about a

267
00:13:56,755 --> 00:13:58,875
10th of a light year
for an individual star.

268
00:13:59,415 --> 00:14:01,835
Uh, it, it's, yeah, uh,

269
00:14:01,835 --> 00:14:04,395
which is still very far
compared to all the planets.

270
00:14:04,535 --> 00:14:08,315
But the thing is, um, it's not
that much further out than,

271
00:14:08,455 --> 00:14:09,995
uh, the gas giants.

272
00:14:09,995 --> 00:14:12,395
It's like 7,000 astronom units.

273
00:14:12,655 --> 00:14:13,715
Um, whereas, uh,

274
00:14:14,215 --> 00:14:16,435
in particular Saturns
are 10 astronom units.

275
00:14:17,095 --> 00:14:19,035
Um, so you could imagine
that if you're able

276
00:14:19,035 --> 00:14:21,355
to make very precise
measurements, you might be able

277
00:14:21,355 --> 00:14:23,395
to notice some, some mon effects.

278
00:14:24,135 --> 00:14:25,835
Um, and it turns out that, uh,

279
00:14:26,035 --> 00:14:29,475
a certain anomaly is predicted in mon, um,

280
00:14:31,505 --> 00:14:35,255
which, uh, is inconsistent
with the observations

281
00:14:35,255 --> 00:14:36,855
that nine Sigma confidence.

282
00:14:37,355 --> 00:14:39,775
Um, this is based on a precise, uh,

283
00:14:39,945 --> 00:14:42,815
radar pulse is being sent to
the Cassini spacecraft with,

284
00:14:42,995 --> 00:14:44,375
or which is Saturn for many years,

285
00:14:44,835 --> 00:14:46,855
and finding exactly the
distance between Earth

286
00:14:46,855 --> 00:14:49,815
and Saturn, uh, which basically I is, uh,

287
00:14:50,495 --> 00:14:52,605
constraining the sunset and distance.

288
00:14:53,145 --> 00:14:57,365
Um, so yeah, we, uh, that, um, the,

289
00:14:57,655 --> 00:14:59,565
there was a very detailed
study on this recently,

290
00:14:59,565 --> 00:15:03,685
looking at different possible
adjustments to the mon, uh,

291
00:15:03,685 --> 00:15:04,845
theoretical parameters

292
00:15:04,945 --> 00:15:07,765
and getting the consistency
between rotation curves

293
00:15:07,765 --> 00:15:09,005
and solar system IFM rights.

294
00:15:09,345 --> 00:15:11,445
And yeah, this, this can't be done.

295
00:15:12,185 --> 00:15:16,255
Um, this, uh, um,

296
00:15:18,315 --> 00:15:21,455
uh, the, the other thing, um,

297
00:15:23,525 --> 00:15:26,415
that came up, uh, so I'll talk
about the white binaries last

298
00:15:26,415 --> 00:15:27,975
because that's more complicated,

299
00:15:28,355 --> 00:15:31,335
but the other thing that
came up was the, uh,

300
00:15:31,835 --> 00:15:36,455
galaxy clusters, um, galaxy clusters, um,

301
00:15:38,085 --> 00:15:41,585
of course, uh, one, uh, already
problematic in the sense

302
00:15:41,585 --> 00:15:42,865
that they needed extra mass.

303
00:15:43,365 --> 00:15:46,465
Uh, but, uh, this argument
didn't really convince anybody,

304
00:15:46,465 --> 00:15:49,985
because generativity also
requires galaxy clusters

305
00:15:49,985 --> 00:15:53,545
of extra mass or nutrient
gravity can't work either in.

306
00:15:53,805 --> 00:15:55,265
But, uh, the thing is, um,

307
00:15:56,605 --> 00:15:59,825
galaxy clusters have less
gravity than predicted

308
00:15:59,825 --> 00:16:01,585
by mon in their outskirts.

309
00:16:02,145 --> 00:16:04,125
Uh, and that's only become clear recently

310
00:16:04,125 --> 00:16:07,205
because we've sort of got
observation extent out further.

311
00:16:07,825 --> 00:16:10,845
But, uh, uh, there've been
a few studies now which show

312
00:16:10,845 --> 00:16:14,125
that essentially galaxy
clusters seem to follow the

313
00:16:14,675 --> 00:16:19,005
inverse square law, even in
the low acceleration regime.

314
00:16:19,265 --> 00:16:20,885
So until recently, we didn't have data

315
00:16:20,915 --> 00:16:22,485
that went sufficiently
far out from a cluster

316
00:16:22,545 --> 00:16:25,485
to get into the low acceleration
regime, but now we do,

317
00:16:25,905 --> 00:16:27,325
and it's clear that they're following

318
00:16:27,325 --> 00:16:28,405
the inverse square law.

319
00:16:28,585 --> 00:16:29,605
Um, not only that,

320
00:16:29,665 --> 00:16:32,645
but they're following the inverse
square law with, uh, with,

321
00:16:32,745 --> 00:16:36,045
uh, but the wrong sort of
normalization, if you will.

322
00:16:36,345 --> 00:16:37,725
So they're following it, uh,

323
00:16:37,745 --> 00:16:40,205
as if the Galaxy cluster has six times

324
00:16:40,225 --> 00:16:41,765
as much mass as the visible.

325
00:16:42,225 --> 00:16:44,765
Um, however, in the standard
cosmological paradigm

326
00:16:44,805 --> 00:16:46,485
that makes total sense
because it's supposed

327
00:16:46,485 --> 00:16:48,325
to be five times as much
dark matter as a visible.

328
00:16:49,025 --> 00:16:52,765
Um, so, uh, in the outskirts
of galaxy clusters, which are,

329
00:16:52,985 --> 00:16:56,285
by the way, it's so far
out that, um, there a

330
00:16:56,875 --> 00:16:58,885
mass enclosed interior to that radius.

331
00:16:59,425 --> 00:17:01,805
Uh, it, I mean, the
proportions of variance to,

332
00:17:02,265 --> 00:17:05,325
to dark matter should be
the same as the cosmic one.

333
00:17:05,865 --> 00:17:08,445
Um, it's not realistic for
bar to have been blown out

334
00:17:08,445 --> 00:17:10,445
of a whole cluster, uh, even though

335
00:17:10,445 --> 00:17:12,005
for individual galaxies that could happen.

336
00:17:12,585 --> 00:17:15,365
Um, but for whole class it's unrealistic.

337
00:17:15,585 --> 00:17:17,965
So, so it is always known
that galaxy clusters, uh,

338
00:17:19,275 --> 00:17:22,095
should get sort of around this, uh, bar

339
00:17:22,615 --> 00:17:25,175
feedback issue if you
had measurements far out,

340
00:17:25,175 --> 00:17:26,815
which recently can be available.

341
00:17:27,315 --> 00:17:29,295
Um, the other thing to
realize of course, is that

342
00:17:29,295 --> 00:17:32,455
because in qualo, even if the
normalization is higher, uh,

343
00:17:32,815 --> 00:17:35,855
ultimately the in qualo will
end up like giving less gravity

344
00:17:35,885 --> 00:17:38,695
than the sort of inverse
distance operation in wand.

345
00:17:39,155 --> 00:17:44,035
Um, so because of this,
um, ultimately, uh,

346
00:17:44,055 --> 00:17:45,315
it recently has become clear

347
00:17:45,315 --> 00:17:47,995
that there's less gravity in
the outskirts than than one

348
00:17:47,995 --> 00:17:50,045
predicts just on the, the
basis of the visible mass.

349
00:17:50,305 --> 00:17:51,965
But because you also need to add a lot

350
00:17:51,965 --> 00:17:55,485
of dark matter e even in m to
explain the central regions,

351
00:17:55,985 --> 00:17:59,045
um, it's clear that mon
substantially over predicts the

352
00:17:59,045 --> 00:18:02,765
gravity in the outskirts, and
that cannot be, uh, reconciled

353
00:18:02,765 --> 00:18:05,165
because you'd have to
add like negative, uh,

354
00:18:05,165 --> 00:18:06,405
dark matter for that to work.

355
00:18:06,805 --> 00:18:09,645
H historically, actually the
cluster result came first

356
00:18:09,865 --> 00:18:12,205
and then the wide binary result,

357
00:18:12,205 --> 00:18:13,685
and then the solar system one, uh,

358
00:18:13,825 --> 00:18:14,965
in case people are wondering.

359
00:18:15,145 --> 00:18:17,845
Um, but, um, of course
they're all in a very

360
00:18:17,845 --> 00:18:19,365
short, uh, period.

361
00:18:19,785 --> 00:18:23,965
Um, but, uh, regarding the
wide binary results, um, so

362
00:18:24,485 --> 00:18:28,975
this is look at an intermediate
scale of, uh, about, um,

363
00:18:29,225 --> 00:18:32,335
0.1, uh, light years.

364
00:18:32,955 --> 00:18:37,495
Uh, the idea here is
that, um, binary stars,

365
00:18:38,155 --> 00:18:40,655
uh, with reasonably wide separations, um,

366
00:18:40,835 --> 00:18:43,495
in the solar neighborhood,
uh, should orbit

367
00:18:43,495 --> 00:18:47,175
around each other 20% faster
than the neuturing expectation,

368
00:18:47,715 --> 00:18:48,975
uh, if mon is correct.

369
00:18:49,675 --> 00:18:53,285
Um, so, uh, that's, um,

370
00:18:53,575 --> 00:18:55,885
quite a lot compared to
the planetary separations,

371
00:18:56,105 --> 00:18:57,445
but it's much smaller than the typical

372
00:18:57,445 --> 00:18:58,885
separation between stars.

373
00:18:59,425 --> 00:19:02,645
Uh, so there's, uh, plenty
of, um, wide binaries.

374
00:19:02,745 --> 00:19:03,885
Uh, in fact, the nearest start

375
00:19:03,885 --> 00:19:07,325
to the sound is actually
itself part of a white binary.

376
00:19:07,865 --> 00:19:09,805
Um, so these are not that, um, rare.

377
00:19:10,025 --> 00:19:12,365
- The European space agency's
Gaia mission has been

378
00:19:12,395 --> 00:19:16,165
surveying the stars and giving
much more precise data than

379
00:19:16,165 --> 00:19:18,485
has ever been available before Ira

380
00:19:18,545 --> 00:19:20,525
and his colleagues have
turned to that data.

381
00:19:21,145 --> 00:19:24,565
- So, uh, what we did is we
built like a detailed sort

382
00:19:24,565 --> 00:19:28,285
of statistical model for
wide binaries, which, uh,

383
00:19:28,285 --> 00:19:31,205
I've been working on and
off towards since like, uh,

384
00:19:31,795 --> 00:19:36,525
late 2017, um, calculating the, in detail,

385
00:19:36,525 --> 00:19:37,725
the mon predictions for

386
00:19:37,725 --> 00:19:39,845
how wide binary orbits
should behave in mon,

387
00:19:39,875 --> 00:19:43,685
also in the Newtonian case,
uh, then we had to add, um,

388
00:19:43,785 --> 00:19:47,925
the possibility of a
third star orbiting one

389
00:19:47,925 --> 00:19:50,445
of the two stars in the binary,
and actually a fourth star,

390
00:19:50,445 --> 00:19:52,525
because there could be a
closed binary around both

391
00:19:52,525 --> 00:19:53,645
of the stars in the wide binary.

392
00:19:54,185 --> 00:19:56,325
Uh, but these would be
on, on very short orbits,

393
00:19:56,325 --> 00:19:59,245
and you could just focus
on this motion of the sort

394
00:19:59,245 --> 00:20:02,605
of closed binary as a whole,
uh, around the more distant,

395
00:20:02,715 --> 00:20:04,125
like wide binary companion.

396
00:20:04,585 --> 00:20:06,765
Um, and this only in the cases

397
00:20:06,765 --> 00:20:08,645
where you're not actually
detecting the closed binary,

398
00:20:08,645 --> 00:20:09,685
because if you are, then

399
00:20:09,685 --> 00:20:12,005
that would be removed from
the sample anyway, um,

400
00:20:12,145 --> 00:20:15,695
but still, um, by doing
a very detailed analysis.

401
00:20:15,695 --> 00:20:19,015
So we, we fixed the, uh,
analysis protocol as much

402
00:20:19,015 --> 00:20:21,175
as possible in advance of
getting the actual data.

403
00:20:21,675 --> 00:20:25,415
Um, we posted like a detailed
like, uh, blueprint for

404
00:20:25,435 --> 00:20:28,335
how the test should be
done in autumn 2021.

405
00:20:28,995 --> 00:20:31,705
Um, and we were able to more

406
00:20:31,705 --> 00:20:33,345
or less prepare for the actual data

407
00:20:33,345 --> 00:20:35,945
because there were previous
guide data releases,

408
00:20:35,945 --> 00:20:37,305
which weren't quite accurate enough.

409
00:20:37,805 --> 00:20:38,905
Uh, and these more

410
00:20:38,905 --> 00:20:41,785
or less showed us like how to
get, how to do the analysis.

411
00:20:41,785 --> 00:20:45,745
Like, um, the actual
analysis, uh, was sort

412
00:20:45,745 --> 00:20:49,165
of something we did as quickly as possible

413
00:20:49,165 --> 00:20:52,325
after the guide h release
three came out in June, 2022.

414
00:20:53,105 --> 00:20:56,045
Uh, and I explained to
the other authors that

415
00:20:56,585 --> 00:20:59,525
we would most likely have
clear results by the end

416
00:20:59,525 --> 00:21:01,845
of the year, um, that

417
00:21:01,845 --> 00:21:03,485
that actually turned out to be the case.

418
00:21:03,705 --> 00:21:06,365
So on fifth November,
we found out that, uh,

419
00:21:07,015 --> 00:21:10,405
there was an approximately
20 Sigma failure of mon, um,

420
00:21:10,465 --> 00:21:13,445
but the observations were
consistent with the Newtonian, uh,

421
00:21:13,495 --> 00:21:16,565
prediction within one or
two standard deviations.

422
00:21:17,105 --> 00:21:19,765
Um, so that was then
written up, uh, subsequently

423
00:21:19,765 --> 00:21:21,605
and, uh, that's been
published, uh, recently.

424
00:21:22,265 --> 00:21:25,645
Um, so there were, uh, there
was also another study by, um,

425
00:21:25,965 --> 00:21:28,565
a couple of researchers
in Queen Mary that, uh,

426
00:21:29,075 --> 00:21:31,645
were authors on, on my paper, but

427
00:21:31,705 --> 00:21:35,685
before I did that they managed
to publish their own, like

428
00:21:36,435 --> 00:21:38,805
much faster, uh, sorry, much simpler and,

429
00:21:38,805 --> 00:21:43,005
and much faster analysis, um,
which should have, um, got

430
00:21:43,065 --> 00:21:46,655
to the, uh, it should
have captured the physics,

431
00:21:46,915 --> 00:21:51,115
but, uh, effectively it's
like calling someone on a,

432
00:21:51,115 --> 00:21:53,195
on a break phone instead
of like a smartphone.

433
00:21:53,645 --> 00:21:55,355
It'll probably still work, um,

434
00:21:55,575 --> 00:21:57,475
but it's, it's a bit less, uh, ideal.

435
00:21:57,815 --> 00:21:58,875
Um, so essentially

436
00:21:58,875 --> 00:22:01,355
what I did is we explored
the parameter space much more

437
00:22:01,435 --> 00:22:02,955
thoroughly, whereas they just found like

438
00:22:02,955 --> 00:22:04,995
what was like the best model.

439
00:22:05,495 --> 00:22:06,965
Um, but,

440
00:22:07,065 --> 00:22:08,725
but still this was sufficient to see

441
00:22:08,725 --> 00:22:11,325
that there was a very
strong preference for, uh,

442
00:22:12,075 --> 00:22:13,725
Newtonian gravity of a wand.

443
00:22:14,105 --> 00:22:16,325
Um, that's why my results were not, uh,

444
00:22:16,855 --> 00:22:18,885
completely surprising.

445
00:22:19,465 --> 00:22:21,645
Um, but nonetheless, it wasn't clear

446
00:22:21,735 --> 00:22:24,285
until we did the analysis, uh, uh,

447
00:22:25,195 --> 00:22:27,485
that we would actually
get the same results.

448
00:22:27,485 --> 00:22:29,205
It's always a possibility
that it would somehow

449
00:22:29,465 --> 00:22:30,565
be different.

450
00:22:31,105 --> 00:22:33,285
Um, but no, it, it is
all quite consistent.

451
00:22:33,505 --> 00:22:38,145
Um, we also like, um, found
out, uh, the main problem

452
00:22:38,145 --> 00:22:40,465
with some other groups that
claimed there was actually a

453
00:22:40,465 --> 00:22:42,665
signal in the white binary
test that looks like Bond.

454
00:22:43,205 --> 00:22:45,225
Um, we borrowed the dataset from them,

455
00:22:45,285 --> 00:22:47,825
and, uh, we identified
like what the problem was.

456
00:22:47,845 --> 00:22:51,065
And that's explained in, um,
one of the sections in a paper,

457
00:22:51,155 --> 00:22:55,065
which is, um, uh, titled what
comparison with other, uh,

458
00:22:55,805 --> 00:22:58,105
you know, implementations
of the White binary Test.

459
00:22:58,405 --> 00:23:00,785
So, yeah, um, the, uh,
it's, it's very clear

460
00:23:00,785 --> 00:23:02,985
that wide binaries are Newtonian, uh,

461
00:23:03,125 --> 00:23:06,465
to quite high precision
about like a percent or so.

462
00:23:06,885 --> 00:23:09,785
Uh, and that's why the mon
prediction is completely

463
00:23:09,785 --> 00:23:11,545
incompatible with the observations.

464
00:23:12,045 --> 00:23:14,985
Um, it's also totally in line
with the solar system result.

465
00:23:15,245 --> 00:23:18,505
If you were to as believe
mon is correct, uh,

466
00:23:18,645 --> 00:23:20,905
and ignore all the rotation curve results,

467
00:23:20,965 --> 00:23:25,825
but just, um, believe the
casini radio tracking result,

468
00:23:26,255 --> 00:23:29,665
that would automatically
show that wide binaries need

469
00:23:29,665 --> 00:23:32,745
to be Newtonian, um, to
like within a percent

470
00:23:33,045 --> 00:23:36,785
or so, um, that wouldn't
by itself disprove bond in

471
00:23:36,785 --> 00:23:39,585
that case, that would simply
prove that wide binaries need

472
00:23:39,585 --> 00:23:40,825
to be close to Newtonian.

473
00:23:41,325 --> 00:23:44,105
Um, but then if you combine it
with rotation curve results,

474
00:23:44,645 --> 00:23:49,565
um, then you would see, uh, the
failure of, of mon um, yeah.

475
00:23:49,825 --> 00:23:52,205
So it's these three
failures, like essentially,

476
00:23:52,595 --> 00:23:55,645
like in in context, what that
means is you can't extend mon

477
00:23:55,645 --> 00:23:56,805
to even slightly smaller

478
00:23:56,825 --> 00:23:58,285
or larger scales in the Galaxy

479
00:23:58,285 --> 00:23:59,885
regimes for which it was designed. Okay,

480
00:24:00,105 --> 00:24:04,485
- But so you were
previously a proponent of,

481
00:24:05,085 --> 00:24:07,845
I mean, you were looking at it,
uh, uh, tell me how it feels

482
00:24:07,905 --> 00:24:10,445
to you when you start looking
at it at something like that

483
00:24:10,465 --> 00:24:12,005
and you go, oh, hang

484
00:24:12,005 --> 00:24:13,005
- On.

485
00:24:13,005 --> 00:24:15,045
Well, this is quite a shock
when we found out like, uh,

486
00:24:15,155 --> 00:24:18,565
that, uh, it, it didn't
fit the wide binary test.

487
00:24:18,745 --> 00:24:19,925
The, the thing is like, uh,

488
00:24:20,235 --> 00:24:22,485
because I, I knew sort of the risk

489
00:24:22,485 --> 00:24:25,725
of moral hazards was very
high, that's why we, uh, tried

490
00:24:25,725 --> 00:24:28,845
to take mitigating measures,
you know, so we'd agreed, like,

491
00:24:28,865 --> 00:24:32,405
um, so basically there's a
Gravity law parameter in the

492
00:24:32,405 --> 00:24:35,685
code, which is like zero
for Newton and one for one,

493
00:24:36,025 --> 00:24:37,965
but it's not like an inte,
it's a floating thing.

494
00:24:37,965 --> 00:24:41,125
So it, it, it could have
values between minus two

495
00:24:41,125 --> 00:24:44,485
and plus, uh, four, uh, plus 3.6.

496
00:24:44,985 --> 00:24:48,005
So, uh, what we decided in
advance is basically I either

497
00:24:48,005 --> 00:24:49,525
would give zero, it would give one,

498
00:24:49,825 --> 00:24:52,565
and the other value would
suggest this something not

499
00:24:52,565 --> 00:24:53,685
quite right with analysis.

500
00:24:54,075 --> 00:24:56,125
Also, we agree on what
some kind of variations

501
00:24:56,125 --> 00:24:57,565
to the analysis that should be done.

502
00:24:58,145 --> 00:25:00,205
And obviously if the result, um, more

503
00:25:00,205 --> 00:25:02,685
or less holds up when we
change these assumptions,

504
00:25:03,225 --> 00:25:04,325
um, that would be good.

505
00:25:04,665 --> 00:25:06,845
Uh, then some other authors
suggested some other,

506
00:25:07,035 --> 00:25:10,485
like less complicated,
uh, simple sort of ways

507
00:25:10,485 --> 00:25:11,645
of looking at the data,

508
00:25:11,815 --> 00:25:15,005
which should also clarify if
Terrine mechanics is preferred

509
00:25:15,065 --> 00:25:16,525
or, or of Mons preferred.

510
00:25:16,945 --> 00:25:19,845
Um, and all these things
gave very consistent results.

511
00:25:20,385 --> 00:25:23,325
So, um, yeah, for, in terms
of how it felt like, uh, yeah,

512
00:25:23,325 --> 00:25:27,765
this, this was quite bad <laugh>,
um, I mean, there's no way

513
00:25:27,785 --> 00:25:30,725
to describe it any other,
this was, um, yeah,

514
00:25:30,855 --> 00:25:33,245
especially in this scenario where, uh,

515
00:25:33,245 --> 00:25:35,645
it wasn't really clear what,
uh, I would work on next.

516
00:25:35,745 --> 00:25:39,205
And, uh, um, but more generally like, um,

517
00:25:40,615 --> 00:25:45,325
because, uh, it seemed likely
that other problems would come

518
00:25:45,425 --> 00:25:48,485
and, uh, yeah, that, that this was

519
00:25:49,435 --> 00:25:50,525
very bad situation.

520
00:25:50,985 --> 00:25:52,525
- Is that kind of like an overnight thing?

521
00:25:52,565 --> 00:25:54,085
I mean, how long was it in that process

522
00:25:54,185 --> 00:25:57,125
before you were sort of going,
okay, I've really gotta stop?

523
00:25:57,265 --> 00:25:59,325
- No, no, it's, it's basically
an overnight thing on the

524
00:25:59,325 --> 00:26:00,965
5th of November, 2022.

525
00:26:01,385 --> 00:26:03,885
- Really? Okay. Did you
sleep well that night?

526
00:26:04,305 --> 00:26:07,725
- Um, <laugh>, well, uh, I, I
I, I can't remember like, uh,

527
00:26:07,785 --> 00:26:09,565
but ba basically, um,

528
00:26:09,675 --> 00:26:12,125
because we'd agreed like the, all the, um,

529
00:26:13,125 --> 00:26:14,125
analysis procedures in advance

530
00:26:14,185 --> 00:26:18,965
and there was a very clear
result, um, then, um, there was,

531
00:26:19,025 --> 00:26:22,045
um, essentially no way around it.

532
00:26:22,145 --> 00:26:26,965
Um, it was just very precisely
on the Newtonian value, uh,

533
00:26:27,185 --> 00:26:29,245
rather than the mod one in principle,

534
00:26:29,265 --> 00:26:32,525
any other value could have
risen theoretically, um,

535
00:26:32,835 --> 00:26:35,285
like if there were problems
of some sort of the test or,

536
00:26:35,285 --> 00:26:36,725
or if something else was going on.

537
00:26:37,225 --> 00:26:41,945
Um, but, um, in that scenario,
uh, why the code just sort

538
00:26:41,945 --> 00:26:44,765
of prefers the, the Newtonian result, um,

539
00:26:45,055 --> 00:26:47,445
especially given there
was some previous hints

540
00:26:47,445 --> 00:26:49,965
that the outcome would be Newtonian, um,

541
00:26:50,115 --> 00:26:54,965
because of this, um, yeah,
there, there wasn't really any,

542
00:26:55,345 --> 00:26:59,805
uh, way to like, it, it was
clear at that point that, uh,

543
00:27:00,035 --> 00:27:01,045
this, this couldn't have been,

544
00:27:01,745 --> 00:27:03,325
the mon couldn't have been correct

545
00:27:04,075 --> 00:27:05,075
- Clearly.

546
00:27:05,075 --> 00:27:07,645
I wanted to know Stacey's
response to this study

547
00:27:07,745 --> 00:27:10,245
of the binary stars from the Gaia data.

548
00:27:10,635 --> 00:27:13,605
- Okay, so let me provide
some broader context,

549
00:27:13,955 --> 00:27:16,885
because like I said, my
first thought was this,

550
00:27:16,995 --> 00:27:19,685
this stupid theory I will falsify.

551
00:27:19,825 --> 00:27:23,685
And then when I actually
went through the predictions,

552
00:27:23,785 --> 00:27:25,685
it was like, check, check, check, check.

553
00:27:25,745 --> 00:27:29,485
And, and, and I had
corroborated all the predictions

554
00:27:29,485 --> 00:27:32,325
that Milgram had made
while falsifying my own.

555
00:27:32,445 --> 00:27:35,325
I had my own dark matter based
theory, and it was wrong.

556
00:27:35,545 --> 00:27:36,805
It did not do the right thing.

557
00:27:37,625 --> 00:27:40,285
And so, you know, what
was I supposed to say

558
00:27:40,395 --> 00:27:41,525
that, that he was wrong?

559
00:27:41,905 --> 00:27:45,725
Um, but there are lots
and lots of other things

560
00:27:46,115 --> 00:27:48,205
besides individual galaxies.

561
00:27:48,385 --> 00:27:50,765
So I spent several years

562
00:27:51,515 --> 00:27:53,525
reviewing all the evidence,

563
00:27:53,985 --> 00:27:57,485
and I mean all the evidence I
did, uh, a tremendous amount

564
00:27:57,505 --> 00:27:58,965
of, of work about this.

565
00:27:59,825 --> 00:28:02,685
Um, and for the most part, not all of it,

566
00:28:02,945 --> 00:28:06,605
but for the most part, all the
systems in which we inferred

567
00:28:06,675 --> 00:28:10,965
dark matter ma worked perfectly
well, sometimes better.

568
00:28:11,705 --> 00:28:13,725
Um, and I would say in fact, well,

569
00:28:14,085 --> 00:28:18,285
I had been working really
hard to explain my way out

570
00:28:18,285 --> 00:28:19,285
of the hole.

571
00:28:19,445 --> 00:28:22,285
I had dug with the data
in terms of dark matter.

572
00:28:22,705 --> 00:28:24,805
And as soon as I allowed myself to think

573
00:28:24,805 --> 00:28:26,685
of all these problems in terms of mon,

574
00:28:27,405 --> 00:28:28,925
I found I was working less hard.

575
00:28:30,425 --> 00:28:31,925
And so what I found at the time,

576
00:28:32,065 --> 00:28:34,325
and this was the nineties basically, um,

577
00:28:35,555 --> 00:28:38,215
and I've reviewed it
many times since then.

578
00:28:38,395 --> 00:28:43,295
So the statement still holds
that you can explain maybe 80%

579
00:28:43,295 --> 00:28:46,175
of the data with ma depending
<laugh> on how you want

580
00:28:46,175 --> 00:28:48,335
to define, uh, percentages.

581
00:28:48,335 --> 00:28:49,415
And it really depends on

582
00:28:49,415 --> 00:28:52,295
how you choose the way the
various lines of evidence.

583
00:28:53,795 --> 00:28:56,255
And so the other 20% just didn't work.

584
00:28:56,755 --> 00:28:59,455
And the big thing that
didn't work at the time was

585
00:28:59,535 --> 00:29:00,895
clusters of galaxies.

586
00:29:01,555 --> 00:29:03,535
Um, and that's, that's still true.

587
00:29:04,235 --> 00:29:05,775
Um, and that, you know,

588
00:29:05,775 --> 00:29:08,055
that gives me concern about
whether or not it can be true.

589
00:29:08,835 --> 00:29:11,935
But what I don't accept is that we have

590
00:29:12,135 --> 00:29:14,095
to automatically default to dark matter.

591
00:29:14,365 --> 00:29:16,415
That just was the first
thing we thought of.

592
00:29:16,755 --> 00:29:21,295
Um, and we do have to
understand why mon gets

593
00:29:21,355 --> 00:29:22,655
so many predictions, right?

594
00:29:22,845 --> 00:29:24,575
Even if it's wrong as a theory,

595
00:29:25,075 --> 00:29:27,495
and we're not really engaging
with that as a community.

596
00:29:27,755 --> 00:29:32,055
Um, most people seem to retain
the attitude that I had,

597
00:29:32,125 --> 00:29:33,935
that we know it's dark matter.

598
00:29:33,935 --> 00:29:35,255
This theory has to be wrong,

599
00:29:35,395 --> 00:29:39,695
and we just grasp at the
first straw to say it's wrong,

600
00:29:40,515 --> 00:29:42,735
um, and then never think about it again.

601
00:29:43,675 --> 00:29:47,815
Um, so Inverne is not one of those people.

602
00:29:48,195 --> 00:29:51,415
Um, he took it very seriously on very

603
00:29:51,415 --> 00:29:52,655
seriously from the beginning.

604
00:29:52,715 --> 00:29:57,655
And he constructed a, a test,
which should be, um, decisive,

605
00:29:57,715 --> 00:29:59,855
and that's to do with wide binaries.

606
00:29:59,965 --> 00:30:04,535
Basically hunt through the
Gaia database, identify pairs

607
00:30:04,535 --> 00:30:07,175
of stars that are, are
wide binary candidates,

608
00:30:07,175 --> 00:30:09,855
measure their motions also with Gaia,

609
00:30:10,315 --> 00:30:12,455
and see if you can see
a statistical signal.

610
00:30:12,965 --> 00:30:14,855
Basically you should see an enhancement

611
00:30:14,855 --> 00:30:18,135
of orbital velocities relative
to the Newtonian case.

612
00:30:18,955 --> 00:30:21,575
Um, and Indra Mill saw nothing.

613
00:30:22,075 --> 00:30:24,055
So he, you know, and,

614
00:30:24,115 --> 00:30:27,375
and I think he went into
it expecting to see it, um,

615
00:30:27,875 --> 00:30:29,455
and this would prove mon

616
00:30:29,555 --> 00:30:31,495
and in fact, he, he found the opposite.

617
00:30:31,595 --> 00:30:34,855
So he, he correctly said,
no, that doesn't work.

618
00:30:35,685 --> 00:30:39,335
Whether or not that amounts
to a falsification, uh,

619
00:30:39,605 --> 00:30:41,335
depends on what I said before.

620
00:30:41,335 --> 00:30:43,055
It depends on how you weigh all the

621
00:30:43,055 --> 00:30:44,175
different lines of evidence.

622
00:30:44,955 --> 00:30:48,015
If you put a hundred percent
of the weight onto ev, uh,

623
00:30:48,355 --> 00:30:51,335
in Nils experiment, then
yeah, it's a falsification.

624
00:30:51,795 --> 00:30:53,175
If you put a hundred percent

625
00:30:53,195 --> 00:30:56,535
of the weight on the experiment
I did long ago on low,

626
00:30:56,635 --> 00:30:59,095
low surface brightness
galaxies, it's as close

627
00:30:59,115 --> 00:31:00,935
to a confirmation as you'll ever get

628
00:31:01,185 --> 00:31:02,855
- Under re reputation of dark matter.

629
00:31:03,315 --> 00:31:05,015
- So Malin, I said is binary.

630
00:31:05,155 --> 00:31:06,455
It either works or it doesn't,

631
00:31:06,455 --> 00:31:10,335
and it works way more often
than it should if it's wrong.

632
00:31:10,795 --> 00:31:13,935
Um, dark matter isn't like that.

633
00:31:14,275 --> 00:31:18,335
We often do not have a
well defined prediction

634
00:31:18,365 --> 00:31:19,415
that comes out of it.

635
00:31:19,845 --> 00:31:20,895
It's more of an inference.

636
00:31:20,955 --> 00:31:22,895
So we see things going wrong there.

637
00:31:22,995 --> 00:31:25,655
So there's some dark matter, okay, well

638
00:31:25,655 --> 00:31:27,135
how much, how much should there be?

639
00:31:27,205 --> 00:31:28,695
What do you actually expect?

640
00:31:29,275 --> 00:31:33,135
Um, and if you're only talking
about it at the level of, oh,

641
00:31:33,135 --> 00:31:36,215
there is a discrepancy from
what we see, so there's,

642
00:31:36,355 --> 00:31:39,295
we infer there's some dark
matter, it always works.

643
00:31:40,115 --> 00:31:43,775
Um, if you actually try
to predict something,

644
00:31:44,245 --> 00:31:46,415
then it goes badly
wrong in a lot of cases.

645
00:31:46,795 --> 00:31:50,495
And one thing that you
really do not predict is

646
00:31:50,495 --> 00:31:52,295
that galaxy should look like mon.

647
00:31:52,835 --> 00:31:56,335
Um, basically if you tried
to build dark matter models,

648
00:31:56,485 --> 00:32:00,775
then you have a Newtonian,
um, collection of stars

649
00:32:01,715 --> 00:32:04,335
and a Newtonian dark matter halo,

650
00:32:04,335 --> 00:32:06,775
and you don't know what the mass

651
00:32:07,135 --> 00:32:08,335
distribution of that halo is.

652
00:32:08,515 --> 00:32:11,255
So you have to make some
assumptions in order to try

653
00:32:11,255 --> 00:32:12,775
to predict something and build a model.

654
00:32:12,835 --> 00:32:14,455
And you can make a whole
bunch of assumptions.

655
00:32:14,455 --> 00:32:16,135
And what you find is that there is this

656
00:32:16,855 --> 00:32:20,375
enormous parameter space
of what galaxies and,

657
00:32:20,435 --> 00:32:23,255
and other systems might plausibly do.

658
00:32:23,365 --> 00:32:25,335
When you have both luminous stuff

659
00:32:25,335 --> 00:32:28,195
and dark matter mixed together in mon,

660
00:32:28,195 --> 00:32:29,635
there's only one thing it can do.

661
00:32:29,695 --> 00:32:32,355
It has to follow this force
law that was written down.

662
00:32:32,895 --> 00:32:36,395
And for some reason, nature
always seems to be plucking

663
00:32:37,025 --> 00:32:40,965
this mandian, uh, appearance out of, uh,

664
00:32:41,235 --> 00:32:43,845
dark matter universe if
that's how the universe works.

665
00:32:44,665 --> 00:32:47,525
And that's, uh, you know, in a sort

666
00:32:47,525 --> 00:32:49,085
of a basian statistical sense,

667
00:32:49,225 --> 00:32:51,845
that's just completely improbable.

668
00:32:51,945 --> 00:32:53,605
It should never happen.
'cause there are all

669
00:32:53,605 --> 00:32:54,645
these other possibilities.

670
00:32:55,545 --> 00:32:58,885
Um, and the only way it happens in

671
00:32:58,885 --> 00:33:01,125
that conventional dark
matter context is if

672
00:33:01,125 --> 00:33:02,885
you make it so right.

673
00:33:03,265 --> 00:33:05,645
And so there are lots of
models out there where

674
00:33:06,055 --> 00:33:08,765
after the fact I've told
them, okay, the data do this,

675
00:33:08,825 --> 00:33:11,005
and then the modelers are
like, oh, yeah, I can do that.

676
00:33:11,745 --> 00:33:13,365
But they never did it in advance,

677
00:33:13,585 --> 00:33:16,885
and they can't actually use
that to predict anything.

678
00:33:17,275 --> 00:33:20,765
Whereas mon, I can take
and look at a galaxy

679
00:33:20,765 --> 00:33:22,725
and say, okay, I measured
the mass distribution,

680
00:33:22,805 --> 00:33:24,365
I can predict what the motions will be,

681
00:33:24,505 --> 00:33:27,405
and you know, nine times
outta 10 I'm correct.

682
00:33:28,145 --> 00:33:31,045
Um, and I'm more interested in

683
00:33:31,045 --> 00:33:33,725
that nine times outta 10
than I am out of the one.

684
00:33:33,825 --> 00:33:36,205
You know, they're
astronomical data are goofy,

685
00:33:36,205 --> 00:33:37,485
they're always some weird cases.

686
00:33:38,265 --> 00:33:42,125
Now, Indra no founding
opposite with wide binaries,

687
00:33:42,185 --> 00:33:43,845
and I take that very seriously.

688
00:33:44,145 --> 00:33:47,965
Um, so maybe that is informing
us about the deeper theory,

689
00:33:48,225 --> 00:33:50,125
not necessarily that mon is wrong,

690
00:33:50,145 --> 00:33:53,245
but we know it's not complete as a theory,

691
00:33:53,425 --> 00:33:54,845
and so maybe there's some theory

692
00:33:54,845 --> 00:33:56,165
development to be done there.

693
00:33:57,025 --> 00:34:01,205
Um, but it's, it's a little
worse than that in that there is

694
00:34:01,865 --> 00:34:05,165
as yet no consensus on the wide binaries.

695
00:34:05,545 --> 00:34:08,405
So, um, both Xavier Hernandez and,

696
00:34:08,465 --> 00:34:12,565
and independently, uh,
Kahu Kai have done the same

697
00:34:13,435 --> 00:34:17,285
experiments with Gaia,
basically the same data looking

698
00:34:17,305 --> 00:34:18,365
for wide bearing areas.

699
00:34:19,265 --> 00:34:21,605
And they both claim to
see a mon like effect.

700
00:34:22,065 --> 00:34:24,605
So where Indra nil doesn't see it

701
00:34:24,605 --> 00:34:27,845
and rules it out, they say they
do see it and must have it.

702
00:34:28,825 --> 00:34:30,565
And I don't know who to believe.

703
00:34:31,545 --> 00:34:33,605
- If you don't, can't sort it,

704
00:34:33,705 --> 00:34:35,725
how can anybody else know
what the answer is here?

705
00:34:35,725 --> 00:34:37,165
How, how can anybody look at this

706
00:34:37,165 --> 00:34:39,245
and go, oh, well, that's what's going on?

707
00:34:39,715 --> 00:34:42,815
- Well, I think it's like I say

708
00:34:43,055 --> 00:34:45,175
I, let me step back.

709
00:34:45,175 --> 00:34:46,895
There have been controversies like this in

710
00:34:47,415 --> 00:34:48,895
astronomy since its inception.

711
00:34:49,435 --> 00:34:53,695
Um, in modern times we now
have the Hubble tension, right?

712
00:34:54,115 --> 00:34:56,495
Is it 67 or 73?

713
00:34:57,155 --> 00:35:01,735
Um, when I was young, that was,
is it 50 or is it a hundred?

714
00:35:02,635 --> 00:35:06,455
And, um, it's really hard to
sort through that sort of thing

715
00:35:07,045 --> 00:35:09,575
took decades to solve the first one.

716
00:35:09,925 --> 00:35:12,895
It's may take as long
to solve the new one.

717
00:35:13,755 --> 00:35:18,335
Um, and the ideal way to do
this is for all the principles

718
00:35:18,435 --> 00:35:21,025
to get together, set

719
00:35:21,025 --> 00:35:24,865
and agreed rules that
they're all going to play by

720
00:35:25,205 --> 00:35:27,865
and then compare data, take notes,

721
00:35:28,005 --> 00:35:30,825
and agree that they've all
come to the same answer,

722
00:35:31,485 --> 00:35:32,825
uh, in the proper way.

723
00:35:33,085 --> 00:35:35,705
And, and then somebody has
to admit they're wrong.

724
00:35:36,485 --> 00:35:39,625
Um, that is the sticking point.

725
00:35:39,735 --> 00:35:42,145
Very few people are willing to do that.

726
00:35:42,845 --> 00:35:45,825
Um, and, and you know, I
would say I would do that.

727
00:35:45,945 --> 00:35:46,945
I had a prediction.

728
00:35:47,385 --> 00:35:49,305
I tried hard to fudge it,

729
00:35:49,565 --> 00:35:51,545
and I had to admit that it was just wrong.

730
00:35:51,825 --> 00:35:54,745
I what I predicted for low
surface brightness galaxies

731
00:35:55,585 --> 00:35:57,105
specifically, that they would shift off

732
00:35:57,105 --> 00:36:00,505
of the Tulley Fisher
relation that didn't happen.

733
00:36:00,925 --> 00:36:05,385
Um, and so, you know, I would prefer

734
00:36:05,385 --> 00:36:07,185
that they sort it out among themselves.

735
00:36:07,645 --> 00:36:08,825
Um, now,

736
00:36:10,085 --> 00:36:11,145
- But, but hang on.

737
00:36:11,145 --> 00:36:12,985
Isn't that what peer review does?

738
00:36:13,105 --> 00:36:14,585
I mean, isn't that essentially

739
00:36:15,425 --> 00:36:19,305
- <laugh> Oh, oh my,

740
00:36:20,365 --> 00:36:23,945
um, in principle, yes, in practice, um,

741
00:36:25,045 --> 00:36:26,985
we are all people doing these things

742
00:36:27,085 --> 00:36:29,505
and we bring our own baggage
to the reviewing process.

743
00:36:29,845 --> 00:36:33,625
And, um, I've been on both
sides of that many, many times,

744
00:36:33,925 --> 00:36:35,745
and I've seen all sorts of strange going.

745
00:36:35,805 --> 00:36:37,465
And so it, it's a, it's a bit like,

746
00:36:37,665 --> 00:36:38,785
I think it was Churchill, right?

747
00:36:38,885 --> 00:36:43,065
The peer review is, is the
worst system, uh, except

748
00:36:43,065 --> 00:36:44,225
for every other, right?

749
00:36:44,465 --> 00:36:49,305
I mean, you need some method, um, to, to,

750
00:36:49,725 --> 00:36:51,945
to review what goes into a journals

751
00:36:51,945 --> 00:36:53,585
and what counts and what qualifies.

752
00:36:54,085 --> 00:36:56,385
Uh, and that is the best
method that we have.

753
00:36:56,565 --> 00:36:57,905
But it's certainly not perfect.

754
00:36:58,645 --> 00:37:01,425
Um, and you have these controversies

755
00:37:01,425 --> 00:37:05,985
because people, um, you know, are willing

756
00:37:06,005 --> 00:37:08,265
to accept publication.

757
00:37:08,485 --> 00:37:12,865
In fact, you know, for astronomy, the,

758
00:37:13,005 --> 00:37:15,705
the acceptance rates of
most astronomy journals,

759
00:37:15,705 --> 00:37:18,025
the good ones are pretty high.

760
00:37:18,725 --> 00:37:20,425
Um, and part of that is

761
00:37:20,425 --> 00:37:24,425
because we have a long
history that is informed by

762
00:37:25,175 --> 00:37:27,585
exactly these kinds of controversies.

763
00:37:28,845 --> 00:37:33,025
So, you know, I have many
times gotten a manuscript,

764
00:37:33,065 --> 00:37:36,185
a review where I'm like,
I don't believe this, but,

765
00:37:36,405 --> 00:37:37,425
but I could be wrong.

766
00:37:38,405 --> 00:37:42,105
And so if, um, you know, the,

767
00:37:42,325 --> 00:37:44,225
the authors make a good case

768
00:37:44,405 --> 00:37:47,305
and they maybe have a kind
of data that I haven't seen

769
00:37:47,305 --> 00:37:50,265
before, then I will usually
recommend that for publication,

770
00:37:50,295 --> 00:37:52,665
even if I seriously doubt it.

771
00:37:52,665 --> 00:37:55,625
And of course, I will
explain that in my report,

772
00:37:55,725 --> 00:37:57,465
and there is some back and forth,

773
00:37:57,685 --> 00:38:00,665
and sometimes you can
get people to moderate

774
00:38:00,735 --> 00:38:02,345
what they say and sometimes not.

775
00:38:03,405 --> 00:38:06,505
Um, and it's pretty rare though.

776
00:38:06,505 --> 00:38:09,545
It does happen when you can,
when you get a paper that is,

777
00:38:09,545 --> 00:38:10,545
oh, this is just wrong.

778
00:38:11,245 --> 00:38:15,265
Um, and, and even then
sometimes they get published

779
00:38:15,265 --> 00:38:19,065
because of this long history
of getting things wrong.

780
00:38:19,805 --> 00:38:22,805
Um, I can think of cases

781
00:38:22,855 --> 00:38:25,125
where papers I think should not have been

782
00:38:25,125 --> 00:38:26,445
published, did get published.

783
00:38:27,165 --> 00:38:29,165
I cannot think of any case.

784
00:38:30,465 --> 00:38:33,085
Um, and I've done hundreds
of these at this point.

785
00:38:33,285 --> 00:38:35,205
I can't think of any case where a paper

786
00:38:35,275 --> 00:38:39,245
that was really good did not
eventually get published.

787
00:38:40,005 --> 00:38:44,165
I can think of cases where,
uh, it had to be shopped around

788
00:38:44,185 --> 00:38:47,445
to different journals, um,
before it got accepted.

789
00:38:48,225 --> 00:38:50,165
- Uh, that's interesting.
Has it always been like that?

790
00:38:50,865 --> 00:38:52,885
- You know, 20 years ago, 30 years ago,

791
00:38:53,305 --> 00:38:54,885
the only people submitting papers

792
00:38:54,985 --> 00:38:57,005
to astronomy journals were astronomers.

793
00:38:57,065 --> 00:38:59,525
It was a modest sized community.

794
00:39:00,305 --> 00:39:02,725
If you didn't know
people, you knew of them.

795
00:39:03,145 --> 00:39:05,365
And so there was a basic presumption

796
00:39:05,365 --> 00:39:08,565
that papers were being
submitted in good faith.

797
00:39:09,465 --> 00:39:12,765
Um, they at least tried right <laugh>,

798
00:39:12,765 --> 00:39:13,765
even if they got it wrong.

799
00:39:14,305 --> 00:39:16,685
Um, that's not really true today.

800
00:39:16,795 --> 00:39:19,805
There's a, a whole bunch
of predatory journals.

801
00:39:20,105 --> 00:39:24,965
Um, there are people
usually physicists, uh,

802
00:39:24,965 --> 00:39:27,245
people trained mostly
as particle physicists

803
00:39:27,265 --> 00:39:29,885
who suddenly think they're
qualified to do astronomy

804
00:39:30,875 --> 00:39:34,685
writing papers that make
some of the basic mistakes

805
00:39:34,835 --> 00:39:37,845
that the astronomical
community made 50 years ago.

806
00:39:38,105 --> 00:39:40,085
And you point these out as a reviewer

807
00:39:40,085 --> 00:39:41,965
and they're like, oh,
I never heard of that,

808
00:39:42,065 --> 00:39:43,645
so it can't possibly be right.

809
00:39:43,795 --> 00:39:46,045
It's like, no, no, really,
we've been through this before.

810
00:39:46,045 --> 00:39:47,965
You're, you're making an obvious mistake.

811
00:39:48,705 --> 00:39:51,645
Um, but the editors are also
physicists who never heard

812
00:39:51,645 --> 00:39:52,925
of whatever that issue is.

813
00:39:52,925 --> 00:39:54,405
And so it gets published anyway.

814
00:39:55,145 --> 00:39:57,005
Um, and, uh, some

815
00:39:57,005 --> 00:39:59,845
of these papers are not
even offered in good faith.

816
00:40:00,305 --> 00:40:03,245
Um, and there's a range of
ways in which that happens.

817
00:40:03,665 --> 00:40:06,565
One is just ignorance of
the history of the field.

818
00:40:06,745 --> 00:40:08,205
And so it's like, oh, you,

819
00:40:08,385 --> 00:40:11,205
you really missed a huge
section of the literature.

820
00:40:11,785 --> 00:40:13,885
And if you're trained as a
physicist, you don't even know

821
00:40:13,885 --> 00:40:15,245
what journals to look those up in.

822
00:40:15,825 --> 00:40:19,605
So it can be an honest mistake.
Um, but it is a mistake.

823
00:40:20,065 --> 00:40:23,965
And, um, there are also people,
especially on this subject

824
00:40:24,065 --> 00:40:26,845
of, of the modified
dynamics, um, you know,

825
00:40:26,845 --> 00:40:28,205
if you're a particle physicist

826
00:40:28,225 --> 00:40:29,885
who think you're gonna get a Nobel Prize

827
00:40:30,105 --> 00:40:33,365
for discovering a dark
matter particle, you know,

828
00:40:34,105 --> 00:40:37,325
you do not want to hear that
there's some other solution.

829
00:40:37,665 --> 00:40:38,965
Uh, you just don't. Uh,

830
00:40:39,385 --> 00:40:41,925
- But isn't that true of if
you think you're gonna get a

831
00:40:41,925 --> 00:40:44,285
Nobel Prize for proving
mon that you wouldn't wanna

832
00:40:44,285 --> 00:40:46,165
- Hear, I don't think
anybody's gonna get a

833
00:40:46,175 --> 00:40:47,205
Nobel Prize for that.

834
00:40:47,625 --> 00:40:49,365
Um, not anytime soon anyway.

835
00:40:49,905 --> 00:40:52,965
Um, and and I, I, I laugh at that

836
00:40:52,965 --> 00:40:57,765
because I very consciously chose to report

837
00:40:57,875 --> 00:41:00,965
what I thought was true in
the data, knowing full well

838
00:41:01,075 --> 00:41:04,965
that I would suffer a
social penalty for doing so.

839
00:41:05,625 --> 00:41:10,125
Uh, and had I realized how
steep that social cost would be,

840
00:41:10,605 --> 00:41:11,605
I might not have done it.

841
00:41:12,225 --> 00:41:15,085
And a lot of people choose not to.

842
00:41:15,825 --> 00:41:19,525
Um, so it's, it's funny, I
have conversations with people

843
00:41:20,745 --> 00:41:23,405
and they will say different
things sometimes in private than

844
00:41:23,405 --> 00:41:26,965
they do publicly, um, because
it's a controversial issue,

845
00:41:26,985 --> 00:41:28,245
and they don't want to be seen

846
00:41:28,245 --> 00:41:29,765
to be on the wrong side of that.

847
00:41:30,685 --> 00:41:32,425
Um, so I may be wrong,

848
00:41:32,685 --> 00:41:35,405
but I'm, I'm certainly
being honest about it,

849
00:41:35,505 --> 00:41:37,085
and that's why I say I don't know

850
00:41:38,075 --> 00:41:39,965
what the Y binaries are teaching us.

851
00:41:40,205 --> 00:41:44,725
I know that Inverne is convinced
that he's disproved bond,

852
00:41:45,425 --> 00:41:48,445
and I know he has made an
honest attempt at doing that.

853
00:41:48,845 --> 00:41:50,685
I just don't know if it's right

854
00:41:51,205 --> 00:41:52,205
- <laugh>, I asked Dr.

855
00:41:52,205 --> 00:41:54,005
Adrian Banick if he was surprised

856
00:41:54,005 --> 00:41:55,525
that people were still looking at mon

857
00:41:55,545 --> 00:41:56,845
as a possibility. Well,

858
00:41:56,945 --> 00:42:01,925
- Uh, the thing is, um, you,
you can try to circumvent the

859
00:42:03,335 --> 00:42:07,265
falsification by changing the
how, how the theory works.

860
00:42:07,805 --> 00:42:08,825
I'm not surprised that there'll

861
00:42:08,825 --> 00:42:09,865
be some people working on it.

862
00:42:09,915 --> 00:42:11,985
First of all, like when I
start understand people who've

863
00:42:11,985 --> 00:42:13,785
worked right for many
decades would, in any case,

864
00:42:13,805 --> 00:42:14,945
not easily give it up.

865
00:42:15,445 --> 00:42:17,785
Um, but more importantly, um,

866
00:42:19,065 --> 00:42:23,985
I would say it does work well
in the rotation curve, uh,

867
00:42:24,045 --> 00:42:26,145
was to to predict galaxy rotation curves.

868
00:42:26,685 --> 00:42:31,475
Um, and, uh, in our case, for example, uh,

869
00:42:31,985 --> 00:42:35,795
when we do cosmology,
um, we often rely on sort

870
00:42:35,795 --> 00:42:38,075
of calculations that use more,

871
00:42:38,175 --> 00:42:40,115
but as a, a proxy for

872
00:42:40,115 --> 00:42:43,035
what could happen if gravity
was enhanced in some way, uh,

873
00:42:43,035 --> 00:42:44,715
just to see what that kind, how

874
00:42:44,715 --> 00:42:45,955
that kind of simulation might differ.

875
00:42:46,345 --> 00:42:48,315
Even though by now it's
clear that the extent

876
00:42:48,375 --> 00:42:49,835
of any possible modification

877
00:42:49,835 --> 00:42:51,995
to gravity is much
smaller than Bond gives.

878
00:42:52,535 --> 00:42:54,555
Uh, but it, it's, uh, helpful as a sort

879
00:42:54,555 --> 00:42:56,275
of an extreme sort of case.

880
00:42:56,855 --> 00:43:00,235
Um, but in terms of people
working on bond, uh,

881
00:43:00,235 --> 00:43:02,635
there's actually much fewer
people working on one now, in,

882
00:43:02,635 --> 00:43:06,115
in terms of doing like numerical
bond simulations, uh, a lot

883
00:43:06,115 --> 00:43:08,995
of the people working on
this in v uh, have left.

884
00:43:09,495 --> 00:43:12,195
Uh, that's just because
of the PhD's finishing.

885
00:43:12,195 --> 00:43:14,035
But the thing is, like, it's not, they,

886
00:43:14,035 --> 00:43:16,475
they hire new PhD
students to work on bond.

887
00:43:16,935 --> 00:43:20,355
Um, so, uh, that, that's,
uh, sort of thing.

888
00:43:20,455 --> 00:43:22,195
And, uh, certainly there aren't very many

889
00:43:22,275 --> 00:43:23,715
postdocs working on bond.

890
00:43:24,215 --> 00:43:26,875
Um, and the postdoc stage
especially, you'd have

891
00:43:26,875 --> 00:43:29,275
to write like specific grant proposals.

892
00:43:29,335 --> 00:43:30,795
And this can't really,

893
00:43:31,025 --> 00:43:33,235
it's not really investible,
uh, at the moment.

894
00:43:33,935 --> 00:43:36,315
Uh, obviously I'm not entirely sure if it,

895
00:43:36,315 --> 00:43:37,995
if it will be in the future,

896
00:43:38,135 --> 00:43:39,715
but, um, that seems very unlikely.

897
00:43:39,975 --> 00:43:41,675
But certainly right now it's, it's not.

898
00:43:42,295 --> 00:43:45,715
Um, so yeah, there's
also much fewer in terms

899
00:43:45,715 --> 00:43:47,555
of early care researchers working on one.

900
00:43:47,555 --> 00:43:49,235
There's very few, there's, there's people

901
00:43:49,235 --> 00:43:51,315
who already have tenure,
a lot of free time

902
00:43:51,335 --> 00:43:54,075
and can afford to work
on one regardless of

903
00:43:54,105 --> 00:43:56,675
what other people think in terms
of people who actually have

904
00:43:56,675 --> 00:43:58,315
to write a grant to work on wand.

905
00:43:58,775 --> 00:44:00,835
Uh, you had that in the past,

906
00:44:01,695 --> 00:44:04,075
but, uh, you don't really have that now.

907
00:44:04,435 --> 00:44:07,795
A apart from, um, obviously,
you know, a handful of people

908
00:44:07,795 --> 00:44:09,715
who got grants before it was falsified

909
00:44:09,735 --> 00:44:10,955
and then they're still working.

910
00:44:11,135 --> 00:44:13,075
That's, uh, one of the exceptions

911
00:44:13,385 --> 00:44:14,635
- More from midrail soon.

912
00:44:14,695 --> 00:44:16,435
But let's go back to my conversation

913
00:44:16,665 --> 00:44:18,275
with Professor Stacey McGill.

914
00:44:18,415 --> 00:44:22,195
But if it is, and he is disproven bond

915
00:44:23,175 --> 00:44:26,435
for the wide binaries,
does that, does that mean

916
00:44:27,215 --> 00:44:29,515
you abandon it and you
look at something else?

917
00:44:29,575 --> 00:44:30,795
Or, or what does that mean for you?

918
00:44:31,675 --> 00:44:35,125
- That is a great question and
I wish I had a great answer.

919
00:44:35,505 --> 00:44:40,165
Um, because I have spent a
lot of time trying to find

920
00:44:40,165 --> 00:44:42,085
that intermediate case, right?

921
00:44:42,345 --> 00:44:45,605
So, um, and there are
hybrid models out there

922
00:44:45,705 --> 00:44:48,845
and they all sort of feel wrong to me.

923
00:44:48,985 --> 00:44:52,205
And, and I don't wanna go
into a great length about each

924
00:44:52,265 --> 00:44:54,645
one, but I've tried to do
that and I have failed.

925
00:44:55,465 --> 00:45:00,045
Um, but ultimately, like I say, one needs

926
00:45:00,065 --> 00:45:03,365
to be able to explain the phenomena

927
00:45:03,365 --> 00:45:05,725
that ma does predict correctly.

928
00:45:06,465 --> 00:45:07,645
And there is a lot of that.

929
00:45:08,305 --> 00:45:09,885
And it does not sit well

930
00:45:09,885 --> 00:45:11,485
with the normal dark matter picture.

931
00:45:11,845 --> 00:45:14,325
I mean, uh, you can find
people who say, oh, yeah, I,

932
00:45:14,445 --> 00:45:17,165
I can do that, but no,
I've been through that.

933
00:45:17,225 --> 00:45:18,965
If I thought I could explain it easily

934
00:45:18,995 --> 00:45:21,045
with dark matter, I would do so.

935
00:45:21,505 --> 00:45:24,525
Um, I am still personally way
more comfortable with that.

936
00:45:24,765 --> 00:45:26,605
'cause basically that's
what I grew up with.

937
00:45:27,385 --> 00:45:28,765
Um, and I would also love

938
00:45:28,785 --> 00:45:30,645
to stop having this argument with people.

939
00:45:30,785 --> 00:45:35,205
It gets old. Um, but
it's, it's just not true.

940
00:45:35,745 --> 00:45:40,415
Um, it is very hard to
explain, uh, the phenomenology

941
00:45:40,475 --> 00:45:41,975
of galaxies and a lot of other things

942
00:45:42,125 --> 00:45:46,415
with our conventional
notions of non-BAR cold,

943
00:45:46,535 --> 00:45:49,935
dark matter, just some new
particle that's not good enough.

944
00:45:50,135 --> 00:45:52,295
'cause what we see in the
data is a clear connection

945
00:45:52,295 --> 00:45:54,415
between the distribution
of the stuff we see

946
00:45:54,795 --> 00:45:56,815
and the dynamics that we get.

947
00:45:57,555 --> 00:46:00,335
And so the dark matter knows, uh,

948
00:46:00,335 --> 00:46:01,855
what the normal matter is doing.

949
00:46:01,855 --> 00:46:04,455
There needs to be some
direct link between them

950
00:46:04,565 --> 00:46:06,495
that is way stronger

951
00:46:06,555 --> 00:46:08,615
and more compelling than just gravity,

952
00:46:08,745 --> 00:46:11,695
which is a really weak, um, force.

953
00:46:11,965 --> 00:46:13,575
It's, it doesn't organize things.

954
00:46:13,635 --> 00:46:16,615
And so, so to give you an example, a lot

955
00:46:16,615 --> 00:46:18,775
of times I will make this point, oh, the,

956
00:46:18,875 --> 00:46:22,415
the barian tail is lagging
the dark matter dog.

957
00:46:22,415 --> 00:46:23,495
That doesn't make sense.

958
00:46:23,755 --> 00:46:24,815
Uh, 'cause the,

959
00:46:25,045 --> 00:46:28,135
basically you can have a dark
matter distribution that does

960
00:46:29,045 --> 00:46:30,055
what you need it to do,

961
00:46:31,215 --> 00:46:33,155
but you can only do that
'cause you don't know.

962
00:46:33,215 --> 00:46:34,635
You can't see it. So you just say, oh,

963
00:46:34,635 --> 00:46:35,915
it is whatever I need it to be.

964
00:46:36,015 --> 00:46:37,075
You can't predict it.

965
00:46:37,695 --> 00:46:40,075
And so the, basically the
luminous matter is telling

966
00:46:40,075 --> 00:46:41,115
the dark matter what to do.

967
00:46:41,545 --> 00:46:42,635
That doesn't make sense.

968
00:46:42,935 --> 00:46:44,715
Um, 'cause there's a lot more dark matter.

969
00:46:45,095 --> 00:46:47,275
So people say, oh, well dark matter tells

970
00:46:47,275 --> 00:46:48,475
the luminous matter what to do.

971
00:46:49,305 --> 00:46:52,915
It's like, okay, that sounds
wise, but actually it's stupid

972
00:46:53,225 --> 00:46:57,035
because you cannot use that
statement to construct a model

973
00:46:57,035 --> 00:46:58,755
that predicts anything successfully.

974
00:46:59,555 --> 00:47:02,755
I know I've tried, I've tried really hard.

975
00:47:03,295 --> 00:47:06,475
Um, and so it's really the
difference between, um,

976
00:47:06,495 --> 00:47:09,075
taking some data and
fitting it, that's easy.

977
00:47:09,225 --> 00:47:12,395
I've also done that you can
always find a dark matter model

978
00:47:12,425 --> 00:47:15,315
that fits once you're
told what the data is.

979
00:47:15,855 --> 00:47:19,315
The challenging thing is to
make a model that predicts

980
00:47:19,505 --> 00:47:21,955
what we see in advance, uh,

981
00:47:22,015 --> 00:47:24,475
and that nobody has demonstrated so far

982
00:47:24,575 --> 00:47:25,575
- Mm-Hmm.

983
00:47:25,585 --> 00:47:27,635
Does the fact that we can't use something

984
00:47:27,635 --> 00:47:28,755
to predict it mean it's not true?

985
00:47:28,970 --> 00:47:30,590
Or does it just mean we just can't predict

986
00:47:30,590 --> 00:47:31,590
- It?

987
00:47:31,590 --> 00:47:33,885
Well, so no, and that's one
of the frustrating things.

988
00:47:33,905 --> 00:47:37,085
So at one point, oh geez,
almost a decade now ago now,

989
00:47:37,125 --> 00:47:38,765
I wrote a review in which I said

990
00:47:38,765 --> 00:47:41,365
that the two things were in commiserate

991
00:47:41,545 --> 00:47:42,965
and they really are in commiserate.

992
00:47:43,665 --> 00:47:46,725
Um, so yeah, just

993
00:47:46,845 --> 00:47:49,565
'cause something can't predict
it doesn't mean it's wrong.

994
00:47:50,425 --> 00:47:54,535
Um, on the other hand that
something does predict it,

995
00:47:54,595 --> 00:47:57,935
we usually take to be an
indication it might be right.

996
00:47:58,675 --> 00:48:02,495
Um, and that is basically the answer

997
00:48:02,595 --> 00:48:05,135
to the question you posed
is what would I do next?

998
00:48:05,135 --> 00:48:06,695
Well, that's what I've been trying to do.

999
00:48:06,695 --> 00:48:09,175
And what I've been trying to
get other people to do is like,

1000
00:48:09,245 --> 00:48:12,775
okay, I am open to an a
dark matter interpretation,

1001
00:48:12,835 --> 00:48:14,455
but you actually have to demonstrate

1002
00:48:15,115 --> 00:48:18,135
how this mon like force
law follows from that.

1003
00:48:18,935 --> 00:48:21,975
I have not been able to do
that in a satisfactory model.

1004
00:48:22,715 --> 00:48:24,255
Um, in fact, I thought

1005
00:48:24,875 --> 00:48:27,015
at several points in
my career I had done it

1006
00:48:27,715 --> 00:48:31,175
and I realized I had assumed
something along the way

1007
00:48:31,205 --> 00:48:33,575
that made it so it was
basically a tautology.

1008
00:48:34,435 --> 00:48:38,295
Um, and I see lots of
models being published

1009
00:48:38,295 --> 00:48:39,415
that say, oh yeah, we do this.

1010
00:48:39,515 --> 00:48:41,175
And I look at them, it's
like, oh yeah, I made

1011
00:48:41,175 --> 00:48:43,055
that tautology 20 years ago.

1012
00:48:43,195 --> 00:48:44,935
You're just making the same mistake.

1013
00:48:45,715 --> 00:48:50,095
Um, and you know, so one has

1014
00:48:50,095 --> 00:48:52,535
to actually demonstrate that
with a satisfactory model,

1015
00:48:52,635 --> 00:48:55,255
and that's a much higher
standard than its sounds.

1016
00:48:55,755 --> 00:49:00,035
Um, and people are not
doing that in large part

1017
00:49:00,035 --> 00:49:02,835
because they're already convinced
it has to be dark matter.

1018
00:49:02,975 --> 00:49:06,995
And so there's a very low
bar, um, to trip over to say,

1019
00:49:06,995 --> 00:49:08,035
oh yeah, I got that right.

1020
00:49:08,215 --> 00:49:09,475
Can you give me an example of that?

1021
00:49:09,695 --> 00:49:12,675
Uh, so the standard dark matter
halo is this thing called an

1022
00:49:12,715 --> 00:49:16,795
NFW halo that specifies a
particular density profile.

1023
00:49:17,615 --> 00:49:20,755
Um, and it has its problems,
but if you take that

1024
00:49:21,335 --> 00:49:23,435
and the stellar mass halo mass relation

1025
00:49:23,585 --> 00:49:24,835
that people think work

1026
00:49:25,335 --> 00:49:28,355
and put some bunch of
exponential discs in there,

1027
00:49:28,365 --> 00:49:31,195
which is the standard sort
of approximation we use

1028
00:49:31,215 --> 00:49:35,235
for the luminous parts of
galaxies, then it almost adds up

1029
00:49:35,235 --> 00:49:38,595
to something that I call the
radio acceleration relation.

1030
00:49:39,535 --> 00:49:43,965
Um, which is the sort of manifestation

1031
00:49:43,965 --> 00:49:45,645
of mon in a conventional sense.

1032
00:49:45,745 --> 00:49:47,925
If I didn't know about mon

1033
00:49:48,555 --> 00:49:51,685
then I could still say this
relation is there in the data,

1034
00:49:52,105 --> 00:49:53,845
and it happens to look exactly like mon,

1035
00:49:53,905 --> 00:49:55,085
but let's do it some other way.

1036
00:49:55,825 --> 00:49:59,165
And that, that modeling procedure I just

1037
00:49:59,165 --> 00:50:00,645
described almost works.

1038
00:50:00,985 --> 00:50:04,165
Um, and so if you don't look
too closely, then it's like,

1039
00:50:04,165 --> 00:50:06,645
oh, that's fine, and you
go on your merry way.

1040
00:50:07,265 --> 00:50:11,765
Um, but it has some
assumptions built into it like

1041
00:50:11,765 --> 00:50:14,725
that still a mass halo, mass
relation, a a relation between

1042
00:50:15,425 --> 00:50:18,245
how big the dark matter
is, halo is for a galaxy

1043
00:50:18,245 --> 00:50:19,325
of a given, still our mass.

1044
00:50:19,865 --> 00:50:23,925
Um, that's not native. We
already had to fit that to data.

1045
00:50:24,585 --> 00:50:27,845
And in fact, that was one
of the things that gave me

1046
00:50:28,645 --> 00:50:31,645
problems with the dark matter
paradigm in the first place,

1047
00:50:31,705 --> 00:50:35,845
is that the obvious
thing to, uh, assume was

1048
00:50:35,845 --> 00:50:37,485
that there's a one-to-one relation.

1049
00:50:37,825 --> 00:50:41,245
You know, basically there's a
fixed ratio between the amount

1050
00:50:41,245 --> 00:50:43,045
of dark matter and the
amount of luminous matter.

1051
00:50:43,825 --> 00:50:47,895
Uh, and that is such an
obvious thing, uh, to assume

1052
00:50:47,965 --> 00:50:50,415
that we assumed it all through the 1990s

1053
00:50:50,475 --> 00:50:53,775
and we fought really hard
to not do that, right?

1054
00:50:54,075 --> 00:50:55,695
We did not want to abandon that.

1055
00:50:56,435 --> 00:50:59,055
Uh, and by the turn of
the century we realized

1056
00:50:59,085 --> 00:51:00,335
that we had to do so.

1057
00:51:01,475 --> 00:51:03,775
And one of the reasons is the kind of data

1058
00:51:03,935 --> 00:51:05,535
that we've just been talking about,

1059
00:51:05,605 --> 00:51:07,055
that it simply doesn't work.

1060
00:51:07,875 --> 00:51:12,295
And so if you now 20 years
later make a model that assumes,

1061
00:51:12,675 --> 00:51:17,015
um, that there is some
magic stellar mass halo,

1062
00:51:17,015 --> 00:51:20,015
mass relation, well, you're
already assuming a large part

1063
00:51:20,015 --> 00:51:22,895
of the answer that was
established as something

1064
00:51:23,015 --> 00:51:24,575
that didn't work a long time ago.

1065
00:51:25,195 --> 00:51:27,495
Um, it's just been long
enough we've forgotten that,

1066
00:51:27,495 --> 00:51:30,855
that we've granted ourself
this role in fudge factor.

1067
00:51:31,555 --> 00:51:34,375
Um, even after that, it
still doesn't work, right?

1068
00:51:34,515 --> 00:51:36,455
But I, I mentioned this particular case

1069
00:51:36,455 --> 00:51:39,455
because, um, Julio Navarro,

1070
00:51:39,505 --> 00:51:43,375
who's the inn in NFW Halos,
built exactly a model like this,

1071
00:51:44,125 --> 00:51:46,135
it's like seven years
ago now, and it's like,

1072
00:51:46,995 --> 00:51:48,055
and, and said it worked.

1073
00:51:48,075 --> 00:51:49,495
And I'm like, didn't I try that?

1074
00:51:49,635 --> 00:51:51,935
And sure enough, I went
back and looked and,

1075
00:51:52,195 --> 00:51:55,375
and the last time I had
touched the files was in 2000,

1076
00:51:56,195 --> 00:51:58,695
but it was exactly the same kind of model,

1077
00:51:59,275 --> 00:52:01,095
and I had dismissed it as not working.

1078
00:52:01,235 --> 00:52:03,535
And the reason was what I just described,

1079
00:52:03,535 --> 00:52:07,295
because I assumed something
different about the ratio

1080
00:52:07,295 --> 00:52:08,655
between luminous and dark matter.

1081
00:52:09,165 --> 00:52:10,455
Well, I could update that

1082
00:52:10,515 --> 00:52:12,295
and then I could reproduce his result,

1083
00:52:12,555 --> 00:52:15,535
but I was just, it's
another tology, right?

1084
00:52:15,575 --> 00:52:19,335
I was choosing, uh,
relation between the masses,

1085
00:52:19,335 --> 00:52:21,815
the dark matter halo, and the
luminous mass that made it.

1086
00:52:21,835 --> 00:52:23,375
So, um,

1087
00:52:23,795 --> 00:52:25,935
and that kind of thing is now so

1088
00:52:26,515 --> 00:52:28,335
deeply buried in our psyches.

1089
00:52:28,355 --> 00:52:29,655
It is very hard, right?

1090
00:52:29,705 --> 00:52:32,255
We've gotten way, way
deep in this rabbit hole.

1091
00:52:32,355 --> 00:52:34,335
You know, once you're down
a rabbit hole <laugh>,

1092
00:52:34,595 --> 00:52:36,775
you don't wanna change, right? It's,

1093
00:52:36,795 --> 00:52:39,015
- But I've spoken to two people
today who have done exactly

1094
00:52:39,015 --> 00:52:40,015
that, who have changed, right?

1095
00:52:40,035 --> 00:52:42,975
But in different directions.
So, so people do change.

1096
00:52:43,045 --> 00:52:44,575
They do look at the evidence and change,

1097
00:52:44,595 --> 00:52:46,095
but you've gone different ways.

1098
00:52:47,095 --> 00:52:51,615
- <laugh>, fair, fair,
you know, some of us do,

1099
00:52:51,635 --> 00:52:54,255
but it's actually in
minority in my experience.

1100
00:52:54,795 --> 00:52:57,855
Um, and it's, it's even
more complicated than that.

1101
00:52:58,135 --> 00:53:01,975
'cause for the most part in,
in the community, I think,

1102
00:53:03,085 --> 00:53:05,255
like for me, dark matter was something,

1103
00:53:05,275 --> 00:53:06,335
oh yeah, we need that.

1104
00:53:06,595 --> 00:53:08,015
Uh, when we make galaxies,

1105
00:53:08,175 --> 00:53:09,575
I wasn't really concerned about that.

1106
00:53:09,855 --> 00:53:12,935
I knew it was an element,
but I was specifically trying

1107
00:53:12,935 --> 00:53:15,535
to understand these low
surface brightness galaxies.

1108
00:53:16,555 --> 00:53:20,905
Um, and I did not care one way

1109
00:53:20,925 --> 00:53:23,105
or another about there being dark matter.

1110
00:53:23,205 --> 00:53:24,905
It was just one of the ingredients

1111
00:53:25,005 --> 00:53:26,325
that goes into these models.

1112
00:53:27,105 --> 00:53:30,725
Um, and so the data made
me think carefully about

1113
00:53:30,725 --> 00:53:33,965
that in a way that I
simply hadn't been obliged

1114
00:53:34,185 --> 00:53:35,445
to do before that.

1115
00:53:36,105 --> 00:53:37,885
Uh, and I think that's
where most people are.

1116
00:53:37,955 --> 00:53:42,045
It's not that they, uh,
there's simply not challenge

1117
00:53:42,425 --> 00:53:43,605
to change their minds.

1118
00:53:43,635 --> 00:53:45,685
It's not that important
to what they're doing,

1119
00:53:45,985 --> 00:53:47,045
uh, day by day.

1120
00:53:47,445 --> 00:53:48,965
I mean, same thing for cosmology.

1121
00:53:49,345 --> 00:53:52,085
Um, you know, if mon is correct,

1122
00:53:52,385 --> 00:53:55,325
and we do not understand
a lot of the things

1123
00:53:55,325 --> 00:53:58,525
that we think we
understand in terms of, uh,

1124
00:53:58,545 --> 00:54:00,645
our modern Lambda CDM cosmology

1125
00:54:01,705 --> 00:54:05,405
and, you know, putting
on a cosmologist hat, I,

1126
00:54:05,845 --> 00:54:09,085
I get why we arrived
at the model we are at.

1127
00:54:09,105 --> 00:54:11,245
And there are a lot of
compelling reasons for that.

1128
00:54:12,185 --> 00:54:15,085
Um, you know, putting on a
mon hat, I'm like, well, yeah,

1129
00:54:15,265 --> 00:54:18,605
you got this invisible mass
plus now this dark energy

1130
00:54:18,825 --> 00:54:21,725
and, you know, <laugh>, these are the sort

1131
00:54:21,725 --> 00:54:23,765
of ancillary hypotheses or,

1132
00:54:23,785 --> 00:54:26,365
or tooth fairies if
you want, that you have

1133
00:54:26,365 --> 00:54:29,485
to invoke when a theory
is on its last legs.

1134
00:54:30,265 --> 00:54:34,175
And it's conceivable that
we're doing that in order

1135
00:54:34,275 --> 00:54:38,375
to use the theory to approximate
some deeper unknown theory

1136
00:54:38,445 --> 00:54:40,935
that hopefully would
encompass both general

1137
00:54:40,935 --> 00:54:42,135
relativity and mind.

1138
00:54:42,915 --> 00:54:44,575
But we don't really have that theory

1139
00:54:44,835 --> 00:54:47,335
and there aren't really
any people working on it.

1140
00:54:47,435 --> 00:54:50,335
And so who knows, you know,
maybe it's impossible,

1141
00:54:50,395 --> 00:54:52,975
but, um, we haven't
really tried that hard.

1142
00:54:53,495 --> 00:54:54,575
- I wondered if IL thought

1143
00:54:54,575 --> 00:54:57,615
that we do still need
something else, something

1144
00:54:57,695 --> 00:55:01,255
that isn't dark matter to
explain the way that things are.

1145
00:55:01,725 --> 00:55:03,695
- Well, if you look at
scales smaller than a,

1146
00:55:03,695 --> 00:55:05,415
than a MegaPath and, uh, leave

1147
00:55:05,415 --> 00:55:08,535
beside the cosmological
tensions for a moment, then, um,

1148
00:55:08,595 --> 00:55:12,115
for the galaxy scales and, um, and,

1149
00:55:12,135 --> 00:55:15,675
and larger, uh, cluster
scales, then, uh, I think you

1150
00:55:16,635 --> 00:55:18,995
probably do need something else,

1151
00:55:19,175 --> 00:55:21,195
as in you need some
adjustments to the properties

1152
00:55:21,195 --> 00:55:23,475
for dark matter, so it doesn't
cluster so efficiently.

1153
00:55:24,015 --> 00:55:27,035
And in terms of the, uh, tightness

1154
00:55:27,035 --> 00:55:30,355
of the radial acceleration
relation, um, yeah, I'm,

1155
00:55:30,355 --> 00:55:32,915
I'm still not entirely
sure how that would arise.

1156
00:55:33,685 --> 00:55:35,675
There may be, for example, a hidden

1157
00:55:36,135 --> 00:55:38,915
or an unknown, maybe
an unknown interaction

1158
00:55:38,915 --> 00:55:41,635
between the dark matter and the barons.

1159
00:55:41,775 --> 00:55:46,435
Uh, maybe, uh, that helps to
keep the two in sort of line

1160
00:55:47,215 --> 00:55:49,315
and following the RAR maybe.

1161
00:55:49,815 --> 00:55:52,075
Um, so yeah, there, there
is some chance that you,

1162
00:55:52,095 --> 00:55:53,875
you need some additional ingredients.

1163
00:55:54,095 --> 00:55:57,995
In fact, it's very likely
because, um, for example,

1164
00:55:58,095 --> 00:56:00,675
if dark matter reached the
very high central densities

1165
00:56:00,675 --> 00:56:03,795
that are predicted, um,
many problems would arise

1166
00:56:03,795 --> 00:56:07,395
observationally, uh,
including the rotation speeds

1167
00:56:07,395 --> 00:56:09,955
of galaxy bars in the
centrals of galaxies becoming

1168
00:56:10,615 --> 00:56:11,835
slowed down by sort

1169
00:56:11,995 --> 00:56:14,195
of gravitational friction
against the dark matter.

1170
00:56:14,855 --> 00:56:16,235
Um, which doesn't really happen.

1171
00:56:16,775 --> 00:56:21,445
Um, but, uh, I I, I do
think that, uh, yeah, there,

1172
00:56:21,445 --> 00:56:23,185
there's a decent chance, um,

1173
00:56:23,285 --> 00:56:25,465
you almost actually do
need some additional thing.

1174
00:56:25,465 --> 00:56:27,905
It can't be purely the Lambda CDM model,

1175
00:56:28,255 --> 00:56:29,905
even on the galaxy scales.

1176
00:56:30,565 --> 00:56:31,945
Um, yeah,

1177
00:56:32,445 --> 00:56:36,185
but the basic picture of the
dark matter halos plus the an

1178
00:56:36,185 --> 00:56:40,705
inverse square gravity law,
uh, being the, the main sort

1179
00:56:40,705 --> 00:56:44,185
of things that main, main
thing that's going on that

1180
00:56:44,745 --> 00:56:46,385
I think is probably correct.

1181
00:56:47,165 --> 00:56:51,345
Um, it just, it might need to
be, uh, tweaked in some way.

1182
00:56:52,135 --> 00:56:55,905
- What could possibly bring
mon back into your kind

1183
00:56:55,905 --> 00:56:56,905
of like research area.

1184
00:56:56,905 --> 00:56:58,505
You thought, oh, yeah, no,
I will look at it again.

1185
00:56:59,085 --> 00:57:03,305
- So, uh, the original mon
field equations have been

1186
00:57:03,305 --> 00:57:06,985
falsified in high significance
on, on the galaxy scales.

1187
00:57:07,125 --> 00:57:11,145
Uh, if, if additional tests of the

1188
00:57:11,875 --> 00:57:16,245
so-called, uh, dynamical friction may help

1189
00:57:16,705 --> 00:57:19,805
to clarify if, if there is dark matter.

1190
00:57:20,425 --> 00:57:24,445
So there have been some studies
recently which show that,

1191
00:57:24,625 --> 00:57:26,165
um, essentially

1192
00:57:26,185 --> 00:57:28,965
as the large magnetic cloud
is mo orbiting the Milky Way,

1193
00:57:29,225 --> 00:57:31,485
it, it seems to have
experienced dynamical friction.

1194
00:57:32,105 --> 00:57:34,815
Um, but, uh, studies to try

1195
00:57:34,815 --> 00:57:38,535
and clarify like this issue further, uh,

1196
00:57:38,555 --> 00:57:41,255
and also sort of how much the
milk curate disc has recoiled

1197
00:57:41,315 --> 00:57:46,215
due to the large mag cloud,
which places a limit like it,

1198
00:57:46,215 --> 00:57:48,455
it measures the mass ratio
between the two, right?

1199
00:57:49,115 --> 00:57:51,175
Um, and that's actually very different

1200
00:57:51,175 --> 00:57:52,535
to the ratio visible mass.

1201
00:57:53,035 --> 00:57:55,095
Uh, it's, it's more in line with, uh,

1202
00:57:55,095 --> 00:57:57,855
the ratio it's expect in
the dark matter picture.

1203
00:57:58,395 --> 00:58:00,895
Um, but, uh, measurements
like this, uh, in, in theory,

1204
00:58:00,915 --> 00:58:03,015
if someone were to, uh, if,

1205
00:58:03,015 --> 00:58:04,695
if these measurements
would somehow to turn out

1206
00:58:04,695 --> 00:58:07,575
to be not correct, and
actually the mass ratio

1207
00:58:07,575 --> 00:58:11,175
between the milky and the
LMC is about one to 20 ish,

1208
00:58:11,385 --> 00:58:15,055
which is the ratio of the
visible mass instead of the one

1209
00:58:15,055 --> 00:58:17,335
to five ratio that's
observed and also more

1210
00:58:17,335 --> 00:58:21,285
or less expected in the
standard model, um, then, uh,

1211
00:58:21,315 --> 00:58:23,365
that would obviously
provide compelling evidence.

1212
00:58:23,365 --> 00:58:28,125
The galaxies are purely
bar, uh, in theory, uh,

1213
00:58:28,155 --> 00:58:29,205
that that could happen.

1214
00:58:29,585 --> 00:58:32,085
Um, and, uh, things like
if you managed to prove

1215
00:58:32,085 --> 00:58:34,445
that even such a massive galaxy as LMC

1216
00:58:34,785 --> 00:58:35,965
or something that should be

1217
00:58:35,965 --> 00:58:38,285
so massive in the standard
model, given it's stellar mass

1218
00:58:38,785 --> 00:58:43,165
and typical sort of stellar
to dark halo mappings, um, if

1219
00:58:43,165 --> 00:58:45,685
that experience like no
dynamical friction, uh,

1220
00:58:45,745 --> 00:58:47,445
or new place, really
tight upper limit on it.

1221
00:58:47,625 --> 00:58:51,765
So there's some ways in,
in theory that code, um,

1222
00:58:53,275 --> 00:58:57,265
maybe, uh, show that you
don't have much dark matter

1223
00:58:57,365 --> 00:59:01,505
around galaxies, um, which in turn would,

1224
00:59:02,515 --> 00:59:05,695
um, show that, well,
if you have to make do

1225
00:59:05,695 --> 00:59:07,815
with the visible mass, you,
you'd have to modify the,

1226
00:59:08,195 --> 00:59:10,015
the law of, of gravity

1227
00:59:10,155 --> 00:59:12,815
or invent additional
forces in in some way.

1228
00:59:13,025 --> 00:59:16,455
There is a very high likelihood
of additional problems

1229
00:59:16,525 --> 00:59:20,695
with the Lambda CDM on even
larger scales with, with regards

1230
00:59:20,695 --> 00:59:21,805
to the Hubble tension.

1231
00:59:22,425 --> 00:59:25,485
Uh, and, uh, this is what I'm
working on now, the idea that

1232
00:59:26,285 --> 00:59:27,525
structure formation, uh,

1233
00:59:27,545 --> 00:59:30,205
and perhaps the law of
gravity most likely needs

1234
00:59:30,205 --> 00:59:33,125
to be modified in much larger
scales of, uh, several dozen,

1235
00:59:33,195 --> 00:59:35,365
like up hundreds of MegaPath.

1236
00:59:36,345 --> 00:59:38,725
Uh, and, uh, so hundreds
of millions of light years.

1237
00:59:38,785 --> 00:59:40,005
And what, uh,

1238
00:59:40,135 --> 00:59:44,005
might happen there is if you
form a significant local under

1239
00:59:44,005 --> 00:59:47,405
density, uh, well, you'd
form densities as well,

1240
00:59:47,405 --> 00:59:49,085
but if we happen to be
living in an under density,

1241
00:59:49,555 --> 00:59:51,285
then locally the universe would appear

1242
00:59:51,285 --> 00:59:53,925
to be expanding faster
than it kinda actually is.

1243
00:59:54,525 --> 00:59:56,885
'cause there's additional
outward motion due to the void.

1244
00:59:57,545 --> 01:00:00,125
Um, and that may solve the Hubble tension.

1245
01:00:00,665 --> 01:00:04,405
Um, we're actually able to
recently use a model along those

1246
01:00:04,405 --> 01:00:05,845
lines that we published in 2020.

1247
01:00:06,865 --> 01:00:10,325
Um, it, it sort of had, uh, parameters

1248
01:00:10,345 --> 01:00:12,085
for like how the voy should work.

1249
01:00:12,545 --> 01:00:14,805
Um, but using that model, we are able

1250
01:00:14,805 --> 01:00:18,445
to correctly predict
the, uh, a, a key feature

1251
01:00:18,445 --> 01:00:20,525
of the velocity field
in the local universe

1252
01:00:20,525 --> 01:00:22,205
that was subsequently measured last year.

1253
01:00:22,425 --> 01:00:24,325
And that's a so-called bulk flow curve.

1254
01:00:24,985 --> 01:00:28,845
Um, so there, there's,
uh, definitely, and,

1255
01:00:28,845 --> 01:00:31,125
and I should say the bulk
flows are also much faster than

1256
01:00:31,325 --> 01:00:33,125
expected in the standard
cosmological model.

1257
01:00:33,545 --> 01:00:35,685
So, uh, there's definitely a high chance

1258
01:00:35,705 --> 01:00:38,005
of some modifications to Lambda CDM.

1259
01:00:38,105 --> 01:00:40,605
Um, I, I don't want people to
think that it's sort of going

1260
01:00:40,825 --> 01:00:42,245
to, to work, uh,

1261
01:00:42,335 --> 01:00:45,405
completely without any
further modifications.

1262
01:00:46,025 --> 01:00:47,045
Um, that's,

1263
01:00:47,045 --> 01:00:49,925
that's not really possible
given the current evidence.

1264
01:00:50,425 --> 01:00:55,205
Um, but um, that doesn't
mean uh, that the, um,

1265
01:00:55,945 --> 01:00:59,045
modern field equations
provide a viable alternative.

1266
01:00:59,745 --> 01:01:01,655
- Let's have one final thought from Stacy.

1267
01:01:02,195 --> 01:01:04,655
- We do not understand
how the universe works.

1268
01:01:05,195 --> 01:01:06,375
We think we do,

1269
01:01:07,235 --> 01:01:09,975
but neither we, we don't
know what the dark matter is.

1270
01:01:10,035 --> 01:01:11,135
We just know we need it.

1271
01:01:11,915 --> 01:01:15,815
Um, and we don't really
understand how mon can be true

1272
01:01:15,875 --> 01:01:19,615
as a theory, and I think that's
a wonderful thing, right?

1273
01:01:19,645 --> 01:01:23,775
There's still fundamental
physics to be learned about

1274
01:01:23,795 --> 01:01:24,895
how the universe works,

1275
01:01:25,355 --> 01:01:28,535
and so, um, it's not like science is over.

1276
01:01:28,645 --> 01:01:31,575
It's not like we're filling
in the last few decimal points

1277
01:01:31,755 --> 01:01:32,855
of, of everything.

1278
01:01:33,245 --> 01:01:36,015
There's fundamental issues
here still to be addressed,

1279
01:01:36,115 --> 01:01:38,815
and so that's a good thing.
We're, we're not done

1280
01:01:38,815 --> 01:01:39,815
- Here.

1281
01:01:39,815 --> 01:01:41,855
I'd like to thank Stacy and
Idra nil for talking to me

1282
01:01:41,855 --> 01:01:43,815
for this episode of the
Physics World Stories Podcast.

1283
01:01:44,155 --> 01:01:45,255
And if you'd like to know more,

1284
01:01:45,375 --> 01:01:48,095
I can highly recommend
Keith Cooper's feature on

1285
01:01:48,095 --> 01:01:49,215
the physics world website.

1286
01:01:49,355 --> 01:01:51,975
It is, of course, the first of three,

1287
01:01:52,365 --> 01:01:54,215
this one entitled Cosmic Combat,

1288
01:01:54,605 --> 01:01:56,815
delving into the Battle
Between Dark Matter

1289
01:01:56,995 --> 01:01:58,055
and Modified Gravity.

1290
01:01:58,435 --> 01:01:59,495
The Second Coming.

1291
01:01:59,565 --> 01:02:03,055
Soon we'll explore some of
Dark Matter's, recent successes

1292
01:02:03,235 --> 01:02:06,175
and the serious challenges
that it's also facing.

1293
01:02:06,705 --> 01:02:08,135
Thank you very much for listening,

1294
01:02:08,155 --> 01:02:09,255
and we'll be back next month

1295
01:02:09,325 --> 01:02:12,175
with something else from this
wonderful world of physics,

1296
01:02:16,605 --> 01:02:17,735
physics world.