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Speed of Light Is Not Constant, Solving 100 Year Old Problem, Physicist Claims | Sabine Hossenfelder | YouTubeToText
YouTube Transcript: Speed of Light Is Not Constant, Solving 100 Year Old Problem, Physicist Claims
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A recent paper proposes that dark matter is an illusion due to time-varying fundamental constants, but the author critically analyzes this claim, suggesting it doesn't present new physics and highlights the difficulty of advancing beyond established theories like General Relativity.
Today I have a physicist who solved a
100 years old problem. Dark matter is an
illusion, a mirage. It doesn't exist.
Physicists have gotten it wrong for 100
years. But now we have a solution. Well,
well, how did he do it? Let's have a
look at the paper. The idea of the new
paper is that the constants of nature
change in time, notably the speed of
light. The idea that some of the things
we call constant are not actually
constant has a long history. Paul Durac
already toyed with the idea in the
1930s, though his idea later turned out
to be incompatible with observations.
It's not just the speed of light that
might change with time. Physicists have
also considered the possibility that the
strength of the electromagnetic force
changes with time, but the strength of
gravity changes with time. and recent
observations seem to support that the
cosmological constant is actually not
constant. The problem is to make the
maths work out or rather to make it work
out in such a way that it doesn't amount
to just postulating a new type of matter
that happens to be dark. You see suppose
you change the strength of gravity or
the speed of light. In Einstein's
theory, both appear as factors in front
of the source term which contains all
masses and energies. So if you change
those constants, how's that any
different from just postulating that
masses and energies behave in a weird
way? The author of the new paper now
develops a new model for the entire
universe that takes into account time
dependence of fundamental constants.
Mathematically, he formulates the new
cosmology this way, which is the first
equation in his paper. I've spent so
much time staring at equations of
general relativity, I can tell you at
one glance that this is not a new
cosmology. It's exactly the same that we
use already, just written in a weird
way. The more things change, the more
they stay the same. In fact, the author
notices that himself somewhere in the
depth of his paper and then tries to
explain why he's doing something new
after all. But this is just words. You
can reshuffle some terms from one side
of an equation to another. Okay, but
that doesn't give you any new physics.
This is either the same cosmological
model we already use or it's wrong. This
paper gets a solid 10 out of 10 on my
meter. By the way, some people
have asked how the meter works.
I calibrate it with a slice of emar. If
the holes line up with the logic, it's
bad. Okay, so why am I telling you about
this? Because this paper is a great
illustration of the most
underappreciated property of Einstein's
general relativity. It's how incredibly
difficult it's to improve. In most
cases, when you try to change anything
about it, you just get back the same
theory. It's similar for the standard
model of particle physics. You can add
some new particles, but the mathematical
framework, which is quantum field
theory, is incredibly difficult to
change without breaking it entirely.
This is why I believe that these two
theories are local maxima in some sort
of scientific fitness landscape. And I
don't think that there is any small
variation around them that will result
in an improvement. Physicists have
basically tried these small variations
for 50 years. But the only way we'll
make progress from here on, I'm
convinced, is that we start over a new
from something else entirely. This is
why I think that people like Steven
Wolfrram and Eric Verinde, and yes, also
Eric Weinstein, people who try something
entirely new need more support and less
cynicism. Another thing to say about
this recent paper is that it has some
obvious red flags that you can learn to
recognize. It's a single authored paper
in an MDPI journal. The MDPI journals
are infamous for sloppy peer review. You
can basically get any junk published
there. and the articles written about it
all go back to a press release from the
University of Ottawa which was informed
by one person namely the author of the
paper. Why do popular science news
outlets write about this stuff because
people read it and I don't blame them
for it neither those who write about it
nor those who read it. I understand that
it makes for a good story that some guys
solved a big physics problem on their
own with nothing but mathematics.
But as the recent Nobel Prize shows,
real progress often comes from
developments that look incremental when
they happen and yet 40 years later
entire research disciplines build on
them. And those are the stories we miss
out on. So yeah, dark matter is an
illusion until next week when it's made
of black holes or cubits or the weight
of awful German jokes. But don't worry,
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