Page 1 of 1
HETDEX survey for dark energy effects
Posted: Mon May 03, 2021 7:59 pm
by notFritzArgelander
Re: HETDEX survey for dark energy effects
Posted: Mon May 03, 2021 10:05 pm
by helicon
While other studies measure the universe's expansion using distant supernovae or a phenomenon known as gravitational lensing, where light is bent by the gravity of massive objects such as galaxies and black holes, HETDEX is focused on sound waves from the big bang, called baryonic acoustic oscillations. Although we can't actually hear sounds in the vacuum of space, astronomers can see the effect of these primordial sound waves in the distribution of matter throughout the universe.
Hope this sheds more light on the dark energy enigma, so to speak.
Re: HETDEX survey for dark energy effects
Posted: Tue May 04, 2021 10:28 pm
by turboscrew
Funny, that I haven't thought it before, but when they say that the universe is expanding, does it mean "the whole" universe, the observable universe, or both?
Re: HETDEX survey for dark energy effects
Posted: Tue May 04, 2021 10:32 pm
by notFritzArgelander
turboscrew wrote: ↑Tue May 04, 2021 10:28 pm
Funny, that I haven't thought it before, but when they say that the universe is expanding, does it mean "the whole" universe, the observable universe, or both?
Both actually. If it’s not both it runs afoul of Noether’s Theorem.