It is important to realise that there is a possibility that these huge structures may not actually exist!
The statistical tests of the Giant Arc results reached a confidence level of 4.5 sigma which falls short of the gold standard for statistical significance known as 5 sigma.
So, there is still the possibility that the structure is a chance arrangement of stars!
The statistical tests of the Giant Arc results reached a confidence level of 4.5 sigma which falls short of the gold standard for statistical significance known as 5 sigma.
So, there is still the possibility that the structure is a chance arrangement of stars!
"Jelly beans cause acne!" But that's not anywhere near 4.5 or 5 sigma. I'm not much of a gambling man but if the Giant Arc is really calculated to exist with a confidence of 4.5 sigma, I'll bet money on it.
There seems to be no consensus regarding the existence of the Hercules-Corona Borealis Great Wall (HCB).
The clustering of gamma-ray bursts that point toward the existence of the HCB are assumed to be emitted by a young, massive stellar population, but our current models of stellar formation could be wrong.
Some scientists have challenged the existence of the HCB, saying that the clustering can be attributed to the sky-exposure biases of gamma-ray telescopes - whatever that means!
The clustering of gamma-ray bursts that point toward the existence of the HCB are assumed to be emitted by a young, massive stellar population, but our current models of stellar formation could be wrong.
Some scientists have challenged the existence of the HCB, saying that the clustering can be attributed to the sky-exposure biases of gamma-ray telescopes - whatever that means!
Too long ago to remember numbers other than the space around the local group is significant. However there is a new kid on the block
https://en.wikipedia.org/wiki/Laniakea_Supercluster
Also earlier
https://en.wikipedia.org/wiki/Virgo_Supercluster
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Yet they still indicate clustering - may be a feature of the pesky effect called gravity.
Or just time (Galu, look away now if you don’t want to hear this. I’ll understand 😉 ).
If time itself had a lumpy characteristic at cosmological scales because of the way energy was dissipating in the early universe, matter would subsequently accrete in those areas of the cosmos where time was passing more slowly due to dilation. So it becomes almost self-reinforcing: energy dissipation causes time dilation which in turn causes matter to accrete which in turn causes more time dilation.
I’ve postulated on this thread a few times, much to the chagrin of my more learned friends, that time is a consequence of energy being dissipated, not some ephemeral quantity or blank canvas upon which events transpire (Newtons view; Einstein thought it was an illusion, despite the existence of space time) and it is this that is causing cosmic expansion (time and space are interchangeable if we use c as a cosmic ruler), gives rise to galactic clumping and perhaps is an explanation (I have not fully got my thought process around this) for dark energy. And at its most fundamental level, it’s time that allows EM radiation to propagate through a vacuum rather than Leonard Susskind’s ephemeral fermions. Physicists talk about the arrow of time flowing in one direction, and that’s a result of the fact that it is being created. If it is being created like this, then is it in fact quantized?
There is no accepted notion or agreement within the physics community on what time is.
As with all things like this, one may postulate on causes, and if proven correct at some point, have to accept that the problem is simply shifted elsewhere, in my case, why does energy even dissipate and how does that a a very fundamental level link to entropy
If time itself had a lumpy characteristic at cosmological scales because of the way energy was dissipating in the early universe, matter would subsequently accrete in those areas of the cosmos where time was passing more slowly due to dilation. So it becomes almost self-reinforcing: energy dissipation causes time dilation which in turn causes matter to accrete which in turn causes more time dilation.
I’ve postulated on this thread a few times, much to the chagrin of my more learned friends, that time is a consequence of energy being dissipated, not some ephemeral quantity or blank canvas upon which events transpire (Newtons view; Einstein thought it was an illusion, despite the existence of space time) and it is this that is causing cosmic expansion (time and space are interchangeable if we use c as a cosmic ruler), gives rise to galactic clumping and perhaps is an explanation (I have not fully got my thought process around this) for dark energy. And at its most fundamental level, it’s time that allows EM radiation to propagate through a vacuum rather than Leonard Susskind’s ephemeral fermions. Physicists talk about the arrow of time flowing in one direction, and that’s a result of the fact that it is being created. If it is being created like this, then is it in fact quantized?
There is no accepted notion or agreement within the physics community on what time is.
As with all things like this, one may postulate on causes, and if proven correct at some point, have to accept that the problem is simply shifted elsewhere, in my case, why does energy even dissipate and how does that a a very fundamental level link to entropy
It is in a sense as gravity effects it, Gravititational "force" from an object falls as distance increases 😉 reach zero though? Interesting question.
When did gravity form? All "Matter" is said to have appeared in an incredibly short period of time. Gravity? Pass but taking typical info such as
A few minutes into the expansion, the period known as Big Bang nucleosynthesis also began. Thanks to temperatures dropping to 1 billion kelvin and the energy densities dropping to about the equivalent of air, neutrons and protons began to combine to form the universe's first deuterium (a stable isotope of Hydrogen) and helium atoms. However, most of the Universe's protons remained uncombined as hydrogen nuclei.
After about 379,000 years, electrons combined with these nuclei to form atoms (again, mostly hydrogen), while the radiation decoupled from matter and continued to expand through space, largely unimpeded. This radiation is now known to be what constitutes the Cosmic Microwave Background (CMB), which today is the oldest light in the Universe.
As the CMB expanded, it gradually lost density and energy, and is currently estimated to have a temperature of 2.7260 ± 0.0013 K (-270.424 °C/ -454.763 °F ) and an energy density of 0.25 eV/cm3 (or 4.005×10-14 J/m3; 400–500 photons/cm3). The CMB can be seen in all directions at a distance of roughly 13.8 billion light years, but estimates of its actual distance place it at about 46 billion light years from the center of the Universe.
Well is definitely did when atoms formed. Clearly gravity still ruled over expansion as stars etc formed but inflation continued. What effect does that have on what might be called local time in various places in the entire universe? Time doesn't appear to be constant over the entire universe. It can't be.
Enter sort fo 3D cobwebs of dark matter that for some reason doesn't attract itself but does attract hydrogen. Suppose that fits if it's denser. 😉 Maybe it forms black holes. The other question is how was it formed?
You must not have noticed the significance of my statement in post #3,321.
I said, "...the Laniakea supercluster which is 520 million light years across (note million, not billion)."
The HCB, if it exists, is on a much larger scale at 10 billion light-years across.
An extremely unlikely proposition, @AjohnL. Dark matter (Whatever it is...) and, indeed, familiar Neutrinos are uncharged. Therefore have no significant radiative energy mechanism whereby they can fall into a Black Hole.
Something I found interesting about Supernova 1987A was that 99% of it's collapsing energy was radiated as Neutrinos:
https://en.wikipedia.org/wiki/SN_1987A
In this ring thing picture, my observation was drawn to the Star Mizar:
This is what you would see through a modest telescope:
But there is more...
https://www.skyatnightmagazine.com/space-science/mizar-alcor-plough-double-star
Apologies for the spelling mistake. It wasn't my fault. But I know @Galu shares my fascination with sextuplet stars.
The restricted 3 body problem also exhibited by Alpha Geminorium aka Castor.
https://en.wikipedia.org/wiki/Castor_(star)
One of my finer posts, one feels. Ignore me at your peril. Best, Steve. 🙂
Why did we adopt the symbol c to represent the speed of massless particles?
Could it be because c is the initial letter of "celeritas", the Latin word meaning speed?
Or, since the special theory of relativity is based on the principle that the speed of massless particles is constant, did c stand for "constant".
Thereby hangs a lengthy tale: https://math.ucr.edu/home/baez/physics/Relativity/SpeedOfLight/c.html
Gigantic structures such as the Big Ring and the Giant Arc are of much interest to astrophysicists who have made observations which appear to suggest that the universe is moving away from us faster in some directions than others.
Some cosmologists have long believed there must be large unseen and unknown structures in the universe that are responsible for causing deviations from the Hubble flow, the expansion that increases the distances between galactic clusters steadily with time.
Some cosmologists have long believed there must be large unseen and unknown structures in the universe that are responsible for causing deviations from the Hubble flow, the expansion that increases the distances between galactic clusters steadily with time.
There is mounting evidence that filaments of dark matter connect galaxies and galactic clusters together like a vast, cosmic web.
It is conjectured that hydrogen flows along these strands, feeding into the galaxies
In 2021 astronomers finally imaged the faint emission from diffuse hydrogen in intergalactic space, providing the strongest indirect evidence yet for the existence of dark matter filaments.
The hydrogen pathways are shown in blue in the above image.
Just though that reminds me of the quasar observer - a video was posted earlier. Why do they seem to have trailing blobs which show red shift. That fact preventing him from getting his reports published by Nature.
Sextuple systems are simply smashing!
We just have to "Castor" minds back to past discussions.
Forgive the degenerate ellipses, which have been used in the illustration for the sake of clarity! 😉
https://mathworld.wolfram.com/Degen...f an ellipse as the eccentricity approaches 0.
;-)
😉
Great picture, but: the driver does see the same!
a) images only! b) mirrored images: cancel each other out!
No special and general relativity of Einstein!
No "spacetime", that does expand, or is curvable, bendable, stretchable...-)
Doppler effect only;-)
Now you finally got it;-)
😉
Great picture, but: the driver does see the same!
a) images only! b) mirrored images: cancel each other out!
No special and general relativity of Einstein!
No "spacetime", that does expand, or is curvable, bendable, stretchable...-)
Doppler effect only;-)
Now you finally got it;-)
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