by _aleph2c_ on 7/15/23, 1:43 PM with 78 comments
by pbhjpbhj on 7/17/23, 10:10 AM
When I was in uni, I did a brief informal undergrad-level paper on modelling cosmological inflation using superfluid He-4. What I hadn't realised, and perhaps was supposed to discover, was that one of the unis [past] professors, Prof JF Allen, had worked in that field. As I read now I find that he actually was a co-discoverer of superfluid He-4.
The journal Nature describes him as "the last of a generation of independent-minded classical physicists". We knew him as "god" for his mystical presence on campus and his cartoon-God appearance, whispers followed him around the physics lounge. He also taught me QFT, or tried. It wasn't until after I graduated that I learnt the building really was named after him. I do wish that I had known to interview him about this field of modelling [cosmology] using superfluids.
by fastneutron on 7/17/23, 10:24 AM
by uoaei on 7/17/23, 9:54 AM
> But physicists seek the more fundamental, quantum theory of gravity that underlies Einstein’s picture; it’s this quantum gravity theory that governs extremes like the Big Bang and black holes. And one way to inch toward this complete theory is to study quantum fluctuations in the space-time fabric.
I'm uncomfortable with the implicit framing that quantum gravity is The One True Theory and we just need to figure out how to formalize it. I'm sure this comes from the author and not the researcher, maybe something was lost in translation from the technical to the colloquial, but nonetheless it is still inaccurate to say that there is any kind of certainty that this is the right path forward. (Ditto for dark matter and dark energy, though those could more accurately be described as lacks of models than models per se.)
by quickthrower2 on 7/17/23, 9:30 AM
by peter_d_sherman on 7/17/23, 12:24 PM
[...]
"If the wave isn’t too tall, then this wave doesn’t interact with other waves of different frequencies — you can try this in the bathtub.
But if the amplitude gets high, then the different frequencies interact."
Fascinating!
by OldGuyInTheClub on 7/18/23, 1:58 AM
https://www.youtube.com/watch?v=kOnoYQchHFw
"The Black Hole Machine"
by sparrowInHand on 7/17/23, 12:13 PM
by amelius on 7/17/23, 12:19 PM
by trhr on 7/17/23, 11:04 AM
I thought he was insulting me, but apparently I would have made a decent physicist.
by acqbu on 7/17/23, 10:10 AM
cosmic wonders that leave me askew
they gobble up matter with voracious delight
sucking everything in, day or night