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Accelerating universe and Big Bang are illusions
Reason why Big Bang and expanding universe are wrong.

Dark energy,
Physics  Astrophysics  Astronomy 
16 days ago by LordSnow
Backreaction: Evidence for modified gravity is now evidence against it.
Indeed, it would be an interesting exercise to quantify how well modified gravity does in this set of galaxies compared to particle dark matter with the same number of parameters. Chances are, you’d find that particle dark matter too is ruled out at 5 σ. It’s just that no one is dumb enough to make such a claim. When it comes to particle dark matter, astrophysicists will be quick to tell you galaxy dynamics involves loads of complicated astrophysics and it’s rather unrealistic that one parameter will account for the variety in any sample.

Without the comparison to particle dark matter, therefore, the only thing I learn from the Rodrigues et al paper is that a non-universal acceleration scale fits the data better than a universal one. And that I could have told you without even looking at the data.

Summary: I’m not impressed.

It’s day 12,805 in the war between modified gravity and dark matter and dark matter enthusiasts still haven’t found the battle field.
physics  science  argument  astrophysics  methodology  reference 
22 days ago by kmt
Gravitational Lensing by Spinning Black Holes in Astrophysics, and in the Movie Interstellar
Создателям Interstellar пришлось провести целое исследование для визуализации чёрных дыр. Тот пример когда кинематограф лёг в основу научных открытий
black  holes  astrophysics  white  paper  research  visualization  graphics  interstellar  movie 
25 days ago by gregoryvit
APOD: 2018 July 22 - Planck Maps the Cosmic Microwave Background CMB
Explanation: What is our universe made of? To help find out, ESA launched the Planck satellite from 2009 to 2013 to map, in unprecedented detail, slight temperature differences on the oldest optical surface known -- the background sky when our universe first became transparent to light. Visible in all directions, this cosmic microwave background is a complex tapestry that could only show the hot and cold patterns observed were the universe to be composed of specific types of energy that evolved in specific ways. The final results, reported last week, confirm again that most of our universe is mostly composed of mysterious and unfamiliar dark energy, and that even most of the remaining matter energy is strangely dark. Additionally, the "final" 2018 Planck data impressively peg the age of the universe at about 13.8 billion years and the local expansion rate -- called the Hubble constant -- at 67.4 (+/- 0.5) km/sec/Mpc. Oddly, this early-universe determined Hubble constant is slightly lower than that determined by other methods in the late-universe, creating a tension that is causing much discussion and speculation.
space  History_of_now  writing  ideas  astronomy  astrophysics  grade_A 
26 days ago by Marcellus
Stellar Disks Reveal How Planets Get Made | Quanta Magazine
Detailed images of disks swirling around young stars show the details of how solar systems come to be.
articles  astrophysics 
28 days ago by gmisra
The Young Milky Way Collided With a Dwarf Galaxy | Quanta Magazine
Astronomers have found stars dating from a long-ago collision between the Milky Way and another galaxy. The crash helps to explain why the Milky Way looks the way it does.
articles  astrophysics  cosmology 
28 days ago by gmisra

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