There's lots in that article that has been discussed in this thread.
What is interesting is that the uncertainty in the evidence for Dark Energy is currently +/- 7%, and that future observatories such as the Vera Rubin Observatory will improve that uncertainty.
What is Dark Energy? What is Dark Matter and Dark Energy? - YouTube
“What we know is a drop, what we don't know is an ocean.” ― Isaac Newton
What is interesting is that the uncertainty in the evidence for Dark Energy is currently +/- 7%, and that future observatories such as the Vera Rubin Observatory will improve that uncertainty.
What is Dark Energy? What is Dark Matter and Dark Energy? - YouTube
“What we know is a drop, what we don't know is an ocean.” ― Isaac Newton
Interestingly, DE only became the major force ‘pushing’ everything apart between 7 and 9 billion yrs ago - it was not present straight after the Big Bang, or if it was present prior to 7-9 billion yrs ago, it was swamped by other forces.
The other point is it appears to be uniform throughout the cosmos - so not clumpy like ordinary matter at ~ 7 × 10−30 g/cm3 (cf the wiki article).
The other point is it appears to be uniform throughout the cosmos - so not clumpy like ordinary matter at ~ 7 × 10−30 g/cm3 (cf the wiki article).
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Ah! Terry Pratchett OBE - sadly missed.
Perhaps photons of light are not their own antiparticles after all, and the darkness in the universe is due to the presence of hitherto undetected 'dark' anti-photons.
P.S. I do not offer that as a viable hypothesis - it is just plain silly.
Unless, of course, it turns out to be true - in which case I will claim all the credit! 😉
Perhaps photons of light are not their own antiparticles after all, and the darkness in the universe is due to the presence of hitherto undetected 'dark' anti-photons.
P.S. I do not offer that as a viable hypothesis - it is just plain silly.
Unless, of course, it turns out to be true - in which case I will claim all the credit! 😉
You need dust or smoke in the air to make a laser beam visible as the light scatters off the tiny particles.
This is why the universe will be completely dark when all matter has turned into photons. Efter this, all photons start to collapse into one single point... hence, the big crunch.
And it all happens again - around and around, forever and ever...
//
And it all happens again - around and around, forever and ever...
//
Photons have no mass TNT. Unlikely they would collapse in a Big Crunch. Brian Cox gave the time for all matter to evaporate into photons as ‘10 billion trillion trillion years’.
I think we are safe 🙂
I think we are safe 🙂
The opposite of matter being converted into photons would be photons being converted into matter.
According to a theory first devised by scientists Breit and Wheeler in 1934, if you smash two photons together hard enough, you can generate matter - an electron-positron pair.
Up till now, it has not been possible to generate sufficiently energetic photons to prove the theory correct. The photons would have to be gamma ray photons, and we don't have a gamma ray laser.
However, and hot off the press, physicists have detected the strongest evidence yet that matter can be generated by collisions of light.
The process is complicated, but can be examined here: Physicists Detect Strongest Evidence Yet of Matter Generated by Collisions of Light
According to a theory first devised by scientists Breit and Wheeler in 1934, if you smash two photons together hard enough, you can generate matter - an electron-positron pair.
Up till now, it has not been possible to generate sufficiently energetic photons to prove the theory correct. The photons would have to be gamma ray photons, and we don't have a gamma ray laser.
However, and hot off the press, physicists have detected the strongest evidence yet that matter can be generated by collisions of light.
The process is complicated, but can be examined here: Physicists Detect Strongest Evidence Yet of Matter Generated by Collisions of Light
But the process you are talking about took place during and just subsequent to the BB (see Steven Weinberg ‘The First Three Minutes’). Surely when all matter eventually decays into photons at the end of the universes life, it will be trillions of LY in diameter, photons will be very diffuse and the temperature will be at circa absolute zero. How will matter form spontaneously in that situation?
I didn't intend to link the new experimental results to what would happen in a cooling universe. It was a stand alone piece of information.
Yes, but what I was pointing out is that physicists now seem able to reproduce this process in the laboratory.
Just been reading about the 2nd law of thermodynamics and how biological processes move from disorder to highly ordered systems through ‘work done’.
How do highly ordered systems arise out of disorder? And why would evolution (life as we know it) move in the opposite direction to that of entropy?
How do highly ordered systems arise out of disorder? And why would evolution (life as we know it) move in the opposite direction to that of entropy?
Back in post #6581 I mentioned the project "Life on the Edge: quantum thermodynamics, quantum biology and the arrow of time" which will be led by Professor Jim Al-Khalili and Dr Andrea Rocco of the University of Surrey.
The idea is to explore the distinct ways in which the thermodynamic arrow of time manifests in living organisms compared to inanimate objects.
The hypothesis is that biological systems may have evolved to harness quantum processes, such as quantum thermodynamics.
Quanta Magazine
Perhaps the Surrey team may come up with the answers you seek. 😎
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