Mindscape 236 | Thomas Hertog on Quantum Cosmology and Hawking's Final Theory

Patreon: / seanmcarroll
Blog post with audio player, show notes, and transcript: www.preposterousuniverse.com/...
Is there a multiverse, and if so, how should we think of ourselves within it? In many modern cosmological models, the universe includes more than one realm, with possibly different laws of physics, and these realms may or may not include intelligent observers. There is a longstanding puzzle about how, in such a scenario, we should calculate what we, as presumably intelligent observers ourselves, should expect to see. Today's guest, Thomas Hertog, is a physicist and longstanding collaborator of Stephen Hawking. They worked together (often with James Hartle) to address these questions, and the work is still ongoing.
Thomas Hertog received his Ph.D. in physics from Cambridge University. He is currently a professor of theoretical physics at KU Leuven. His new book is On the Origin of Time: Stephen Hawking's Final Theory.
Mindscape Podcast playlist: • Mindscape Podcast
Sean Carroll channel: / seancarroll
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[@ddavidjeremy]

A bit over my head but I would've happily listened to this conversation for 3 hours.

[@tyhggb]

I love Sean Carroll. I also love that when the conversation goes way over my head that it is just like a mothers lullaby and puts me right to sleep.

[@magnushorus5670]

This was by far the best thing I’ve heard on KZbin. Thank you for sharing this

[@akumar7366]

Really excited to listen to this guest .

[@neostar1479]

Good to hear that Thomas is attempting to resolve the origin issue. I agree with him that in a universe that is causally connected, it must undergo branching together with prunning thus removing the need for a parallel universe. Further, I agree with both Sean and Thomas that there is the possibilty of a causally disconnected multiverse.

[@bryandraughn9830]

I'm do pleased to hear you talking about the state of what is observed in the immediate area as opposed to things that are far away. If they are indeed "uncertain" that makes sense to me. The whole idea about what is going on "out there" is separated from our reality more and more the further out you go.

[@lovefeelsbest]

Absolutely loved this episode. Thanks dudes.

[@carrieorsel1340]

I like to watch your videos (I've ordered your latest book as well) and then have them on in the background as I drift in and out of sleep. Helps the information to sink in to my hungry brain.

[@gravecac9522]

I believe the measurement problem is resolved by retro causality. Quantum mechanics allows the future to affect the past. Not only do you have (as Einstein would say) Spooky action a distance, but also Spooky action in time. I know that is hard to wrap one’s head around, since our experience is time moving forward, but quantum mechanics does not care about that. Retro causality is the simplest solution (even simpler than the Everett interpretation).

[@hopperpeace]

thanks for the good questions explanations and the discussion

[@savage22bolt32]

I love it when two people of differing beliefs can gtg and have a great conversation! I seem to remember when this was an every day occurrence.

[@spaceinyourface]

That was brilliant,,,We've just been listening to a book about Feynman & some of all histories & were wondering if many worlds was similar. Was probably going to be a question for Joye to ask you but you allready answered it. Puka

[@Amethyst_Friend]

SEAN- Please consider making longer episodes! I’ve stopped listening regularly because I often wish the conversations would continue for much longer. Thank you for your work, regardless.

[@lucianmihail584]

Excellent episode

[@evcoproductions]

My favourite topic discussed on my fav podcast, just leaving a comment for the algorithm. Also human driven climate change is real Climate change climate change climate change

[@origins7298]

Anyway the measurement problem is just one of scale, even classically things don't have exact values, but this just gets magnified when you get down to the subatomic world

[@NessieJapan]

You can tell that Sean is buddies with Hertog, because you rarely hear Sean tease a guest this much.

[@michaelvandijk6490]

I liked the last few minutes

[@ZootaAndrewMahera]

One physics channel says Hawkings was overhyped!! I kinda agree

[@jafo8501]

Amazing talk! I have a question but I am not a phicisist so bare with me. During The stage before and during inflation seems to me a place where there are no observers so, wouldn't that mean that there we no possible way to collapse the wave function? How the wave field collapsed then?

[@jeremiahmilazzo1446]

Hi Sean I appreciate everything and actually listen to you more than michio Kaku, because you seem to have substance, question being , the unknown force it's not dark perhaps not necessarily or even black energy it's an unknown maneuver in how it behaves

[@Storyy2296]

as density reach to infinite at singlarity of a blackhole,dimension of time should be gone or approximate to zero,due to time dilation should we count only three dimension inside blackhole?

[@jeremiahmilazzo1446]

Fuxking love you Sean carol your fucking incredible

[@lukemurray-smith5454]

If a singularity has infinite density, but not infinite gravity should the orbit of whatever is stuck on its surface be zero and infinite? Can it form trajectories based on being spun up or down into higher energy states of themselves with no where to go other then itself? If these states can be variable (via some external or greater gravity) can we have them active simultaniously and would that allow for a black hole to have potential frames of reference, of energy states, which seperate into infinite density of them selves through pilot wave of theory of infinitely dense states. Essentially preventing them from returning to back into each other so have to treat each other as a fluid or vacuum with elasticity? If enough of these occur and the potential for relative reference frames along the "branes" allows for anywhere between 0 and Infinity chance to be on a slightly similar trajectory? Chould we use this to simulate gravity, and cohension of permenant particles with local orbits, also virtual particles with non local orbits? Still it leads to thinking that black holes exist within black holes. I'm probably confusing things but if possible can that make our cosmic horizon or the temporal horizon (arrow of time) be a black hole with a size in excess of the black holes contained within it? The result causing it to return to absolute density but happens faster then the local frame rate of the universe? For a non local frame rate they never experience this collapse and instead we do, as both events are causally disconnected?

[@igor.t8086]

Sean, I did like your lecture given during the first Maryland Quantum-Thermodynamics Symposium on March 14, 2023 (minus that joke about “The New York Times”; yeah, you had to be you, I know; likewise, I have to be me, always). BTW (or therefore) I’ll set with Seth Lloyd et al. I also had an idea why the laws of physics are local, but then I remembered you physicists (authoritatively) assert these laws of nature might be changing across endless spacetime of our Universe (not to mention the vast landscape of eternal inflation’s many universes - so I was discouraged to do so (finding myself lost in a multiverse of claims))… | However, in another “parallel instance” (i.e. many-worlds branch of “me” function) I did just that; so, it’s win-win… 👍😉🙃

[@origins7298]

I think our scientific theories and models will always be approximations! Anyone else with me? I mean reality is reality or the universe is the universe, and any way to try to make sense of it can only be an approximation, it's like you're looking at it through a certain lens... and that lens itself is going to be unable to give the complete picture... and therefore will be an approximation?

[@WizardSkyth]

...absolutely correct and in addition the approximation is the result of interpretation a la the Rorschach Test of Reality filtered through/with/by hardwired brainmath-psychointerface.

[@jeremiahmilazzo1446]

What center are we trying to reach

[@DavidGrimes63]

Anyone else look at the thumbnail and think "Hertog cubed"?

[@ddavidjeremy]

Absofrickinlutely😂

[@CognizantApe]

Woop Woop 😎

[@brasileiroloko5375]

So when i die there will be no observers so the universe will cease to exist

[@origins7298]

Sean tried to say that classically things have values for position of momentum but in the quantum world they don't... But that's not true! Even classically things only have approximate values! Even something mundane as measuring a book is only an approximation... If you want to know the exact length and width of a book you cannot, all you can know is an approximate value within a certain measuring bar of errors...

[@benjaminkennedy6260]

What he means in principle its possible...things do have definite locations and momentum, if you were Laplace's demon with infinite calculating power you could find out

[@origins7298]

@@benjaminkennedy6260 no they don't That's the point! It might be the common way of thinking about it but it is wrong! The only thing we can say is things have a value within a certain margin of error...

[@benjaminkennedy6260]

@@origins7298 classically things do in principle have definite position and momenta...we may not be able to resolve those values to an arbitrary amount but in principle nature knows where the particles are and what their momentum is.

[@origins7298]

@@benjaminkennedy6260 Yeah and classical physics is inaccurate!

[@benjaminkennedy6260]

@@origins7298 our measuring capability is inaccurate

[@jeremiahmilazzo1446]

My question being , funny enough , is gravitation , what is the nature of gravitation , like white and black bad and wrong , why do they attract each other ,,,,,,,,,buttttttt !!!! What center are they trying to grasp best of luck love you guys many blessings 🙌

[@c.f.3503]

First

[@origins7298]

Yeah I was first, I just know how to watch videos without making the counter register

[@bytefu]

Next time try to be the first to leave a meaningful comment.

[@bookdmb]

Is Carroll typically so combative on personal levels, apart from the material discussed? The content was very engaging, but he didn’t seem to embrace the role of an interviewer in aiding and facilitating dialogue, much to the detriment of the episode.

[@davebewshey1549]

The closer we get to the Big Bang time seems like it would have to slow infinitely. If time slows in the presence of gravitational fields and at relativistic speeds and the theory of inflation is correct how can we precisely estimate time with such immense concentrations of gravitic field energy and acceleration of energy/mass if our theories break down at the singularity levels? Would that not cause inconceivable variables and immeasurable differences in our understanding of distant time structure in the past such as the closer to the Big bang you get the worse the distortion may be? Also implying time has to be infinite in the future? Penrose cyclic sounding to an idiot with no inflation. Seems like we intuit alot from things too small to measure with mathematics as we understand them? Forgive if this question is elementary to you guys, I'm just an old Construction worker that fell in the deep end of the pool dog paddling.