Max Tegmark - Events and the Nature of Time

max we're here in Banff says the fqx I conference and you've called it if it tree falls the physics of what happens what what is happening lots of trees here few of them have fallen why is the concept of events so important and how does it relate to our sense of time we had we had a conference on time we didn't talk so much about events we talked about time people said it was illusion or not now we're talking about events so wow did they articulate I'm fascinated by events because I feel like we're at the heart the toughest mystery we face in physics and we have two diametrically opposite views of thinking of thinking of reality we can either start with this abstract timeless mathematical description of all of reality where nothing happens there's just a bunch of coordinates a bunch of quantum field numbers and relations and then there's the opposite point of view the inside view of us observers where we feel that things happen time is changing and how do we connect these two things together the event is the fundamental fundamental building block that Einstein used and his theory to define the thing happening in a certain place right but if someone comes and asks me you know at what time what time is this event happening or what time is it that's kind of a sense of question to me because what is the time it's as ridiculous to me as asking what is the place there are lots of places the person is asking something about what the place is that we're having this conversation and this particular time and this is what we wanted to bring all these people together to discuss how can we take this timeless reality we're nothing with or no events labeled or and we can Seiler with what we actually expand or are there are two opposite views that says that events are a sequences of things happenings that occur within time or that time is defined by the sequence of events now that sounds like it's a tautology but those two radically different ontologies in terms of meaning that make sense absolutely so back in the days of when I when Einstein theory of relativity was born the first picture made a lot of sense that there was this thing face time within it events happened but now we know that isn't quite right because of quantum mechanics making everything a little bit fuzzy so at best an event might happen kind of sort of here kind of sort of now and we've been discussing a lot here and all the quantum gravity talks is that the opposite might be the case if you start with something which a priori has neither space nor time and that both of those ideas are somehow emergent much like if I have a continuous water liquid that I'm swimming in it feels like this nice continuous substance but really it's just a bunch of atoms bouncing around which make me feel that it's all sort of smooth maybe space itself is made up of some sort of building blocks and maybe in the distant past this these building blocks were so discombobulated that time lost its meaning and maybe in the distant future again time is going to stop to make sense maybe time and space are just an approximation that holds now for a while but in both past in the future just turns into some sort of quantum size how would that happen in the future I can understand it how it happened to pass when you run everything back together and then there's so much we don't understand so not you understand we don't understand but in the future things are going to continue to expand and so how can you go back to the the fuzz of time it could happen in the future if we wait long enough and we might have an infinite amount of time if the dark energy stays constant that everything we know that I linked it away and ultimately you get a sort of heat death situation we just have a uniform super things and nothing is changing anymore and when you have no more change then you don't have any clocks because they're by definition things have changed you have no way of talking about measuring time talking about I and it's not clear that even makes sense to say that anything is happening anymore so time really would lose its meaning if change came to a halt there's a difference though between not being able to measure anything that's right and not being able to end to say that time does it exist anymore or or do they begin to merge together you you can't measure it and you can't measure change does that mean that time isn't there it doesn't imply it logically but I think it's quite likely that it is that way notwithstanding and since there is no change any way built-in fundamentally and I think theory where time is just the fourth dimension of something that is right space-time itself doesn't exist in time but something's in it so the only way we know how to get the feeling of something happening out of that is to put to ask how does an observer in here feel if there are no observers feeling anything you can't get any experience of time out then I think time loses meaning but let me ask you the sociology of the group we're here at the conference about 125 physicist cosmologist some other scientists what's the percentage do you think who think that time is is derivative or an illusion or something other than the traditional understanding we had a debate about that today and it's really fascinating to hear that although there was some support for the idea that there is a fundamental time most people in the base actually guess that no time does not exist fundamentally it's something that emerges only in a certain approximation so it might very well be then that even right now this approximation is great and tomorrow is going to happen and so on if you go really far back or really far forward in the future time will dissolve and totally lose its meaning what a funny way for reality to be yeah at them but I think in a way it's a beautiful answer to the question of what happened before the beginning with nature telling us actually the paradox see me but you seem to have right that they would have to always be something new thought isn't the paradox because whole premise that there always was a well-defined time that breaks down you go really far back and things just kind of go all fuzzy and timeless and and same thing in the future so I'm you're happy with that world I would love to understand it in more detail of course what happened but I feel that one of the most important lessons we've learned is physicist is that the ground that we thought we were standing on the things before were holding onto is very shaky this is dissolving under s not only are things like solid matter much more approximate than we thought but even the very fabric of space and time are probably just emergent approximations

Channel: Closer To Truth

Views: 33,281

Keywords: Max Tegmark, Closer To Truth, Time, Space, Events, Universe, Physics, Cosmology, General Relativity, Einstein

Id: rXJBbreLspA

Length: 7min 29sec (449 seconds)

Published: Mon Jul 10 2017