Yesterday 10:34 PM
SABINE HOSSENFELDER
https://youtu.be/0xt5-FTpASM
VIDEO EXCERPT: So this idea solves several problems at once: it explains how the universe started, it explains how our universe came to be that big from what should be a tiny quantum fluctuation, it explains why the universe stopped growing that rapidly, and where matter came from.
And it does all that without running into the problem with quantum gravity! They even make some predictions for how this idea could become measurable in the
future from the gravitational waves that would be produced in the early universe.
Sounds too good to be true. And yes, there is a caveat. It’s that this particular way that they connect Einstein’s gravity in the low energy low curvature range that we observe to the quadratic gravity at high energy and strong curvature is well-motivated but not strictly speaking derived. This means that basically they have some artistic freedom in designing just how the transition happens.
So there is somewhat of a gap in the logic, but maybe it can then be fixed with further work. I give this paper a 2 out of 10 on the bullshit meter.
There are a lot of theories for the origin of the universe, but few are as minimalistic as that. The idea that quadratic gravity can solve the problem with quantum gravity is not entirely new, it is also behind an approach called asymptotically safe gravity that goes back to Steven Weinberg. But this is the first time that I have seen the idea applied to the Big Bang.
In summary, they solved quantum gravity, explained the Big Bang, and avoided all known problems. The only remaining issue is whether it’s actually true.
PAPER: https://journals.aps.org/prl/abstract/10.1103/6gtx-j455
New Theory Explains How Time Began ... https://youtu.be/0xt5-FTpASM
https://www.youtube-nocookie.com/embed/0xt5-FTpASM
https://youtu.be/0xt5-FTpASM
VIDEO EXCERPT: So this idea solves several problems at once: it explains how the universe started, it explains how our universe came to be that big from what should be a tiny quantum fluctuation, it explains why the universe stopped growing that rapidly, and where matter came from.
And it does all that without running into the problem with quantum gravity! They even make some predictions for how this idea could become measurable in the
future from the gravitational waves that would be produced in the early universe.
Sounds too good to be true. And yes, there is a caveat. It’s that this particular way that they connect Einstein’s gravity in the low energy low curvature range that we observe to the quadratic gravity at high energy and strong curvature is well-motivated but not strictly speaking derived. This means that basically they have some artistic freedom in designing just how the transition happens.
So there is somewhat of a gap in the logic, but maybe it can then be fixed with further work. I give this paper a 2 out of 10 on the bullshit meter.
There are a lot of theories for the origin of the universe, but few are as minimalistic as that. The idea that quadratic gravity can solve the problem with quantum gravity is not entirely new, it is also behind an approach called asymptotically safe gravity that goes back to Steven Weinberg. But this is the first time that I have seen the idea applied to the Big Bang.
In summary, they solved quantum gravity, explained the Big Bang, and avoided all known problems. The only remaining issue is whether it’s actually true.
PAPER: https://journals.aps.org/prl/abstract/10.1103/6gtx-j455
New Theory Explains How Time Began ... https://youtu.be/0xt5-FTpASM
