Does this explain what generates gravity?

Not a terrible good video tainted with miss information. Factual

‘Light left these galaxies when the Universe was extremely young, and light has been travelling for most of the age of the universe (13.7 billion years) to reach us,’ he explains. ‘All the galaxies are seen within half a billion years of the Big Bang, and the furthest is seen when the Universe was less than a quarter of a billion years old. By discovering galaxies at early times and comparing with more nearby galaxies when the Universe was older, we can study the formation and evolution of galaxies – the astronomical equivalent of archaeology.’

The four galaxies are forming stars, and have a low abundance of heavy elements. This is expected for young galaxies, since all elements heavier than lithium are not born in the Big Bang but instead form in nuclear processes in stars, and are slowly enriched over time.

https://www.physics.ox.ac.uk/news/astronomers-discover-most-distant-galaxies-yet

This page shows the details available in an image at 13.1b light years also it's spectra.
https://www.esa.int/Science_Explora...b/Webb_delivers_deepest_image_of_Universe_yet

This page explains why the red shifts directly measured are much lager than they actually are and need a correction applied
https://en.wikipedia.org/wiki/Observable_universe#Misconceptions_on_its_size
There are also effects on apparent size.
I didn't look at first because I thought the quotes were taken from the video as evidence of miss inormations. However, I just looked at it and I quote for my part - first sentence already:
"... when the Universe was extremely young" (Not: "younger"-)

This is a clear reference to the "big bang". The "big bang" is THESIS and conveyed here as FACT! That already is UNscientific, and all following theses, assumptions, theories, whatever, are again only circular reasoning! Here already the "scientist" in you should scream: "Alarm"-)
Are there any "scientists" here;-?!?
 
Are there any "scientists" here;-?!?
You could say, I will, that this video presents the current astrophysics problems rather clearly. A serious whoopsie has turned up in recent years. Things don't fit as expected.
It also explains what Euclid is about - more precise info especially in the spectrum area. That allows a more accurate 3D map based on red shift.
Dark matter - well the issue is gravity and we do know matter figures in that.

Euclid can do the job a lot quicker than other space telescopes but it will probably still take years to produce results. What those results will show?? Have to wait and see.
 
Who made Einstein cross? 😉

A prediction that Einstein made back in 1915 is being used to study distant galaxies.

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Shown above is a Hubble image of an Einstein Cross, an example of gravitational lensing.

In the centre is a forground galaxy that has warped and quadrisected a bright beam of light from a more distant background galaxy, forming the four smudges of blue light haloed around the orange of the foreground galaxy. The background galaxy is most likely to be a quasar.

Spectroscopic studies and lens modeling have now been undertaken and the system's lensing nature was confirmed earlier this year.

https://www.livescience.com/physics...rses-brightest-objects-in-this-stunning-image
 
I wrote earlier (post #930) about type 1a supernovae which have been used as the 'standard candles' for the measurement of cosmic distances.

The accuracy of the distance measurements hinges on the assumption that all T1a supernovae are of a standard brightness.

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However, it may be that the brightnesses of T1a supernovae depend on how young they are, i.e., how far back in time we can observe them.

This would mess up our previous measurements of cosmic distances and put into doubt the accelerating expansion of the universe and hence the existence of the Dark Energy hypothesised to explain it.

rayma supplied the relevant link around three years ago in another thread: https://phys.org/news/2020-01-evidence-key-assumption-discovery-dark.html

The team involved said that "the luminosity evolution of [type 1a supernovae] is significant enough to question the very existence of dark energy."

So you see, hypotheses are not fixed and immutable. The hypothesis that the Universe's expansion is accelerating is certainly one which is not carved in stone, but is subject to change as our data base expands.

I wonder what the latest thinking is? 🤔
 
I have just skimmed Jim Baggott's book. He has a good old rant about SUSY, Supersymmetry and String Theory, Hidden Dimensions, M-Theory, Multiverses and the Holographic Principle.

"Not even wrong" according to Peter Woit.

When interviewed, Brian Greene, purveyor of popular and money-earning books about String Theory said: "NO", he didn't believe in it! 😳

I grudgingly accept Big Bang Theory as the best idea we have, but clearly something has to be done on Quantum Gravity.

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I am rereading Marcus Du Sautoy's book on symmetry in mathematics. I have improved on this subject over the years. Much surer ground. This is number and group theory.

Euler Zeta(2) Function.png


My favourite things. 😎
 
I've mentioned it before, but I'll do so again as the naming of the SUSY particles makes me giggle! 😊

The superpartner of a fermion begins with an “s” so lepton is partnered with slepton.

The superpartner of a boson ends in “ino” so Higgs is partnered with Higgsino and the W boson with Wino!

And this time round, Steve, you didn't mention the F-theory (or as some would call it the "what the F-theory").

https://en.wikipedia.org/wiki/F-theory
 
However, it may be that the brightnesses of T1a supernovae depend on how young they are, i.e., how far back in time we can observe them.
I came across an older NASA page that said that the sun's brightness was 70% of ???? that at the time I put down to the constituents it was formed from ie various elements being around and in it causing a reduction in brightness. However searches now but it down to evolution - 30% dimmer than it is now over billions of years. ~4.5
Nugent says that the serendipitous discovery of the more than 11-billion year old supernova is important for several reasons.
Add some billions to that - how long did it take to form?
On sigma, posted before
https://www.ox.ac.uk/news/science-blog/universe-expanding-accelerating-rate-–-or-it
 
sun's brightness ... 30% dimmer than it is now over billions of years. ~4.5

The Sun was dimmer than it is now for the first 4.5 billion years of its life, but from now on it gets brighter.

The evolution of the Sun's luminosity is shown in the attached diagram (originally supplied by Bonsai).

3.5 billion years from now the Sun will be around 1.4 times its current luminosity, and that’s enough to evaporate the Earth's oceans!
 

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A new toy model ... suggests that both dark matter and dark energy can be unified into a single phenomenon - a fluid that has negative mass.

This hypothesis would require that negative mass particles actually exist (general relativity says no!) and that they are constantly being created.

This continupus creation is required to ensure that the assumed dark fluid doesn't thin out over time and lose its influence.

I would describe this as an "out-of-the-box" idea! 👎
 
The Russian Spacecraft has crashed!

The Roscosmos Luna-25 mission to find frozen water at the Moon's south pole has failed.

It's now down to India's Chandrayaan-3 to make the soft landing: https://www.bbc.co.uk/news/world-asia-india-66541956

Why are these missions regarded as important? Lookie here: https://www.digitaltrends.com/cool-...ld be,stay on the moon for an extended period.

The worry is that the country that takes control of the Moon and cislunar space will take control of the world, and tensions are already surfacing surrounding the creation of Moon bases.

https://eandt.theiet.org/content/ar...view-the-future-of-geography-by-tim-marshall/