Physics at the limits of reality | Sabine Hossenfelder in conversation with Hilary Lawson | In full

Sabine Hossenfelder speaks to Hilary Lawson about physics, reality, and what really motivates her.

What makes a theory 'ascientific'?

Join physicist @SabineHossenfelder and non-realist philosopher Hilary Lawson in riveting conversation. With Hilary interviewing, Sabine outlines her attitude to the problems of modern physics and the importance of philosophy.

#physics #reality #multiverse

Sabine Hossenfelder is a theoretical physicist, author, musician, and science communicator who researches quantum gravity. Hilary is a non-realist philosopher known for his theory of closure.

00:00 Introduction
00:45 Can science answer the big philosophical questions?
03:45 What does ‘ascientific’ mean?
07:04 Can maths mask a lack of evidence?
08:08 Are you a realist?
14:30 What really motivates you?
16:30 Where should we be looking for an underlying theory in quantum mechanics?

[SB-ieen]

I like the fact that Sabine always allows the other person to finish no matter how absurd or provocative they sound.

[laszlosandor]

Some of her answered are “I don’t know”. How often do you hear that statement? She is humble and I like that.

[pdxyadayada]

Sabine is a giant! She is so refreshing…seeking answers to ‘how things work’ without an agenda, for our knowledge alone. She is a rare individual, indeed!

[patrickgravel]

Truly enjoy Sabines outlook and common sense. I also take issue with the theoretical and mathematical views that are unprovable or unobservable. Anything goes with such illogical accepted rhetoric. Thanks Sabine for saying it out loud.

[giovannironchi]

I am a simple wave function. I see Sabine Hossenfelder and I press like with probability 1

[WilliamLHart]

Sabine is so unusual and refreshing in the world of science. She has the rare and unusual ability to continually review the basic reality of the problem as she works through it without getting entangled solely in the numbers or data. Just because the math works doesn't mean it's real

[kylebeatty]

They managed to find chairs that are clearly not comfortable for someone who is not tall as well as someone who is not short

[sylvainbougie]

They could have provided more comfortable chairs.

[michaeltrower]

Sabine, you are wonderful. I love your no-nonsense approach to these questions and ideas.

[shubus]

Sabine is great in disentangling Hilayr's questions--many of which I have a hard time grasping. When talking with Sabine, one can get a word in edge-wise and get a well-considered response. This interview is a great example of clarity of expression. And why we subscribe to Sabine's channel.

[davewood]

"The only stupid question is the question you do not ask", I am not so sure. The fact that Sabine can produce coherent answers from a so called non-realist, Philosofer's questions speaks volumes to the nature of Sabine. I love the fact that Sabine sticks to the facts and has an uncanny ability to cut through (insert whatever you want here) and speak intelectually and inteligently in an understandable manner.
Sabine is excellent.

[wulphstein]

Mathematics absolutely can mask the unreality of a theory.

[mysticmikeable]

I feel the issue is that the difference between Maths and physics is that Physics is an application of Math, but Math is NOT physics... Hence Mathematical speculations are abstract logical theory which may or may not relate to observable events whereas Physics is observation and explanation of those 'events' - one can fit many mathematical formulae / solution to an event described by a set of data however the event described by the data is a singular event so all the varied mathematical possibilities would likely get more and more constrained with better data till ideally there is only one mathematical solution. Hence math is not reality but can become our best description of reality

An example is Newtons gravity which varies with 1/R^2... If R=0 then there is a mathematical singularity... but we accept that because most observations show that mass is not a point mass, it has volume, so below a certain radius eg Earths surface... the formula fails/requires more sophisticated interpretation because the mass is no longer 100% below that R value so gravity in fact reduces from the earths surface to Zero at the centre NOT infinity as the simplistic interpretation of Newtons formula would give... Perhaps Einstein's gravity has some similar limiting case where extension of the simplistic interpretation again 'assuming a point mass' is no longer valid hence again singularities though simplistic mathematical extension into the unknown are 'not real' and there is some other physical concept required that prevents the mathematical singularity - ie. the physical reality will not be a simple extension of the math into an area we have no data.... And hence GR perhaps does NOT fail it just has ranges of applicability (like with Newton) after which there have to be modifications due to currently unknown physics in GR's case (as in Newtons case where a new physical regime takes over - gravity 'inside' the mass). An aside is that one should not forget that GR describes what we see as an observer NOT what is as the object being observed... eg if a particle accelerates continuously at 1g towards alpha centauri it would arrive there "before" a light beam would... yet we have never exceeded the speed of light to the observer at take off. So we could theoretically get to alpha centauri faster than light... The particle would find it arrives there after only months... yet never "BE OBSERVED" going faster than light... The paradox of light speed or time would not apply to either the observer nor the particle.

So the problem is NOT that Einstein's GR is wrong - it's that we have no data - and so we only have a myriad of mathematical extensions which, though 'logical', lead to apparently crazy speculations - they explain nothing physically/in reality, until we have more data ;) I personally might suspect the black hole is just a region of pure energy supporting the event horizon, with no singularity and with Gravity dropping to Zero in the centre - but I have no data.

[ruurtbos]

Dear Sabine,
I do like your almost impeccable english and coherent stories
in fysics. And as an old guy I do take joy in your dry humoristic remarks.
And I try to understand your great outlines.
So thank you❤.

[davidkent]

Sabine is patient with this interviewer

[Patriarchtech]

I love Sabine. She is down to earth and patient. I find Hilary rather frustrating in the way he tries to put far fetched ideas of his own in to her mouth. You can tell he has read a lot of books but his style is not really that of being investigative it is rather to show of he has read a lot of books. Thomas Kuhn's(The Structure of Scientific Revolutions) perspectives written in the 1960's very much outlines the way Sabine is thinking, and if Hilary had read it and understood it this interview would have been so much better.

[jcortese]

11:05 -- SHE'S RIGHT. I'm sick of the whole "unreasonable effectiveness" argument in favor of math somehow being the blueprint for reality. I can imagine the ancient Greeks arguing in favor of epicycles by using the same argument -- but its math is so unreasonably effective that it must be true, which is exactly what today's physicists say about their latest crop of super-symmetric stringy whatnots. Math is just as unreasonably effective at describing bunk as useful stuff!

[aleksandarzivkovic]

Philosophy muddies the water of clear thinking.

[dougtsax]

Well done Sabine, for avoiding all the traps.

[ginebro]

Why science works? you observe, generate a model, test your model and if the experiment is succesful it's a valid model with certain criteria.
Of course later some observation compromises the model but that's to be expected, it's a model, not the real thing, whe're always generating more accurate and compatible models but they are still abstractions of reality, i don't understand the question, why woldn't it work?