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
if you do it directly.
So you have to do some trick to control those oscillations.
And going to imaginary time is a beautiful mathematical trick, which converts an oscillatory integral into a perfectly damped convergence integral.
There's this mathematical trick which people have used forever in quantum field theory and in QCD, but not much in gravity.
It doesn't work with Einstein's theory of gravity.
People have studied that.
But if you include these squared curvature terms, they suppress the curvature on short distances.
It looks like this theory is sensible in Euclidean time.
Now, that's all very well.
What I'm saying is that it looks like there's a sensible theory in imaginary time, but we don't live in imaginary time.
We live in real time.
We have to do this procedure called the wick rotation or analytic continuation from this imaginary time to real time.
When you do that, there are two disasters strike, and this is why people abandon this approach, although they keep coming back to it.
What we've done recently is half understand how to deal with that.
The two problems, one of them is probably the oldest no-go theorem in physics.
It's called the Ostrogradsky theorem.
In 1850, Ostrogradsky, I think he was in St.
Petersburg, decided to generalize what Hamilton had done with Hamiltonian treatment of classical mechanics.
And so Ostrogradsky asked, what if instead of F equals ma, instead of a second derivative equation, what if we had three derivatives in the equation of motion or four or five or any number of derivatives, what goes, does anything go wrong?
And he found something very interesting, which is the Hamiltonian or the energy of the system.
Showing 61–80 of 2,693 · page 4 of 135
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