Sean Carroll on the Biggest Ideas in the Universe | Closer To Truth Chats
Anybody who says "energy not conserved" opens a can of worms (bad pun intended), so most cosmologists hide this from public view.
For those who want to hear it from Sabine ;-) "... if the wavelength of light increases with the expansion of the universe, then the energy decreases."
Sabine Hossenfelder: Backreaction: What is Energy? Is Energy Conserved?
Carl Friedrich Gauss , Russell's paradox , "There is no Universe" .
The arrow of time
Let's have a closer look / better listening at the video.
Right from the start, Sean Carroll says:
For example, the early universe has low entropy. That's where the arrow of time comes from.
At 40:30 minutes, Sean Carroll and companion start talking about time reversibility.
At 41:30 minutes:
[ Space and time ] are different, obviously, because, unlike space, time has a direction.
And I wrote a whole book on this [ .. ] : From Eternity to Here .
The fact that entropy is increasing from the past to the future.
That statement is false, because in a universe with sustainable life forms order is increasing.
The above is typically a proposition that comes from a science whose only concern is dead matter.
It's actually a matter of life and death. Without enough life in existence, entropy is indeed increasing.
But increasing order due to the activity of living beings means: decreasing entropy of the universe.
And it's not where the arrow of time comes from.
The laws of physics seem to be in support of time reversibility.
But that is only the case if these laws can be considered apart from initial and boundary conditions.
Now let us only agree upon the fact that, in the end, all classical calculus boils down to Numerical Analysis,
for the simple reason that you must get numbers out. But Numerical Analysis is not continuous: it is discrete.
Within a discrete substrate, it's not at all obvious that the laws are independent of the boundary conditions:
Upwind differencing scheme in Finite Volume Method (FVM)
, From Patankar's book .
It's impossible to have a shortcut to the truth without the details. I'm sorry.
1- The galactic inclination angle doesn't affect the angular size for a disk galaxy. However, if galaxies have any other shape [a large bar e.g. SBc on Hubble's classification scheme, elliptical, irregular] the assumption of a circular galaxy makes them appear smaller than they really are.
A bias appears if galactic evolution is assumed, e.g. "in ΛCDM most galaxies of the high-z universe are irregular". Since this assumption is currently being falsified by the Webb Telescope, astronomers panic because they will have to re-analyse all raw data to correct for a majority of spirals.
2- The cores of high-z galaxies are at the detection limit of telescopes, so we only discover the brightest ones = Malmquist bias. Corrections to compensate for the Malmquist bias are based on star-formation-rates in galaxies observed in the near universe, extrapolated to the high-z universe using ΛCDM evolutionary models of galaxies and space expansion.
3- The large redshift of high-z galaxies means that their spectra line up differently with the telescope's filters, and often most of the spectrum falls outside the detected wavelengths. (See e.g. Crawford's description of what happens with supernovae templates.) Corrections are made that are instrument and redshift dependent, and which assume galactic evolution based on ΛCDM to estimate the colour of the galaxy. As a result a ΛCDM-dependent reddening-bias on the angular size is introduced.
4- High-z galaxies images are at the detection limit of telescopes, therefore the outer edge of galaxies are not seen and galaxies appear smaller. There are methods which compensate for that problem (e.g. the Petrosian radius), but those wavelength dependent corrections depend on the cosmology model.
5- Absolute luminosity is calculated assuming a function based on ΛCDM (which is different to that in a non-expanding cosmology). The ΛCDM biased galactic luminosity is then used with the "fundamental plane" relation to compensate for its correlation with galactic size, so the end result is that the galactic size is also biased with the ΛCDM model.
6- Absorption by intergalactic dust, which depends on a distance calculated from z in a model-dependent way, also changes the 'observed' luminosity of galaxies. This can also change the average angular size via the fundamental plane relation.
A real astronomer could certainly list more biases. One thing is for sure, one needs an experienced team to generate "observations" from raw data, but most people who have such an experience are trained in the Big Bang paradigm. Raw data is available from many redshift surveys, some with good spectroscopic redshifts.
Sahil, you graph your "observables" as a function of time, which is a model-dependant variable. Instead, always plot "observables" as a function of redshift, the only model-independent observable. This will make it easier to compare observations with other models. Unfortunately there is no 'clean observed angular size', these "observations" are biased with corrections that are model dependent.
It is difficult to convince cosmologists that ΛCDM is wrong - what they call "observations" are all model dependent!
A Confession
One of the books that changed my life is Karl Marx (1867):
Het Kapitaal, boek 1 (The Capital, book 1)
At that time (around 1970) it was politically correct among students in the Netherlands to have communist literature at their apartment.
I was such a student, the book was not quite expensive and I decided to take it with me during my vacation on the beach.
It was not my purpose to actually read those few hundred pages, just in case the weather was too bad for doing more pleasant things.
Now guess what happened. There was only one rain shower, but it lasted for three weeks! So I had plenty of time to read the book.
If the weather had been different, then definitely the rest of my life would have been .. a bit different.
In 1973 I was going to finish my study at the Eindhoven University of Technology, Mathematical Physics department.
As a naive student, I still had a firm belief in the honesty of science and wrote
this proposal for my graduate thesis.
To be translated in English as:
Foundations for a Materialist Mathematics, a mathematics based upon material reality.
Guess what happened next. I would have been the first student in the history of the university who failed his exam!
However, they became reluctant to let the conflict escalate and, at last, everybody agreed to settle for less.
Needless to say that the above experience has had a deep impact on my attitude towards science, mathematics in particular.
After all those years, much to my disappointment, Marxist science has not become much different from Capitalist science.
I hear a lot of clucking in marxist.com .
And they keep quoting from their bibles all over the place. But where are the eggs?
Length Contraction is observationally equivalent with the Expansion of Empty Space
