Neil Turok
speaker
2,693 appearances
2 recordings
1 series
first heard Apr 2025
last heard 22 Jun
Neil Turok’s voice in public audio — every appearance, attributed to the second.
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recordings per month · last 12 monthsRecordings per month over the last 12 months — 1 in all, peaking in Jun 2026 with 1.
Appearances
So he associated an entropy with a black hole.
And what we did a few years ago is generalize his arguments to cosmologies.
You can associate an entropy with a different cosmology.
And what we find using Hawking's definition of entropy, which is tremendously elegant mathematically, is that the most probable or the universe with the greatest number of microstates is smooth, is homogeneous and isotropic.
and spatially flat, just like ours, and has to have a small positive cosmological constant.
This is a consequence of Hawking's formulation of entropy.
So why is the universe so simple on large scales?
Same reason that a room full of air is almost uniform.
It's just a typical state.
Now, it's very interesting because in cosmology, people traditionally took the point of view that the problem was to understand the initial conditions.
You know, for some reason we don't understand, somebody injected or somebody set off a universe.
And then the big puzzle is, why did they start a universe in such a smooth state that when it got big, it would be as smooth as we see it?
That was very paradoxical.
They would have to start the universe out in this incredibly special state for it to end up so smooth.
I mean, if it was lumpy initially, it would have just collapsed early on or fragmented or made black holes.
It doesn't do that.
On large scales, it's incredibly simple.
So that was a big puzzle.
So they said, we've got to start it.
So they imagined somebody started the universe in a random state, and then they wanted a dynamics inflation to smooth it out and make it big and smooth.
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