Physics: Are we forever trapped in the arrow of time? | Sabine Hossenfelder
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- Опубліковано 30 чер 2024
- Why does time move forward but not backward? Physicist Sabine Hossenfelder explains.
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Up next, The mind-bending physics of time ► • The mind-bending physi...
Why does time move in only one direction? This still-unsolved question was posed in 1927 by the British astrophysicist Arthur Eddington, and the concept came to be known as the arrow of time.
As theoretical physicist @SabineHossenfelder explains, there's a longstanding mystery in the foundations of physics: If we look at the laws for microscopic constituents, like elementary particles, they work the same way forward in time as they do backward in time. But the same does not hold true on macroscopic scales.
In this Big Think video, Hossenfelder dives into this mystery and explores how it has captivated the minds of so many scientists and science fiction writers.
0:00 The arrow of time
1:14 Why doesn’t anyone get younger?
2:39 Can we stop human aging with entropy control?
4:01 Is ‘maximum entropy’ how the universe will end?
Read the video transcript ► bigthink.com/series/explain-i...
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About Sabine Hossenfelder:
Sabine Hossenfelder is a physicist, author, and creator of "Science Without the Gobbledygook". She currently works at the Munich Center for Mathematical Philosophy in Germany.
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Read more of our stories on time:
Does time really exist?
► bigthink.com/starts-with-a-ba...
Will time run backward if the Universe collapses?
► bigthink.com/starts-with-a-ba...
What are wormholes?
► bigthink.com/hard-science/wor...
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I really love that Sabine is here. She is amazing and deserves more recognition.
I think she already has a too good life to just doing random talking, doing morals and never doing some tough math to fill with some meat the bag.
Completely agree!
(With the original comment, not the hater with the previous comment)
@@mahnamahna3252 recommend her new book to read, hopefully human and easy to understand
@@leojack1225 sure she did more math than you are writing lame comments
@@Thomas-gk42 Amazing , she can make videos on UA-cam all day and doing great Math everyday. Neither Gauss could have done better .
It's easy to comprehend entropy as things moving from orderly to disorderly, but this is coming from beings who can't truly understand the full meaning of why things operate the way they do. It really is our best guess at a comforting explanation, but continuing to analyze it is part of our battle to make sense of the unknown (best part of being a living being!)
Jesus is the way.
Yes I have problems with the word as well. It just means we haven't mapped the microvectors that underlie the causes of what seems as "disorder". Disorder inherently is a subjective term, viewed from the perspective of those who try to establish order with imperfect frameworks of understanding.
I would say nature is the way, but we’re sooo far gone that maybe Jesus is the way😅😂
I've been thinking for some years, since my father gave me that famous book of Hawking, A brief history of time, that life could be the only thing that challenges entropy in the universe. That thought had me hooked ever since.
What a beautiful question! I think entropy is the reason why we see things the way we do. Let's suppose we saw things going backwards or in a different direction; maybe the meaning we previously gave to them would be completely different. We would have a different context or even other ways to explain our reality. Entropy is a law that points out our direction and our sense. Perhaps entropy is the law that makes us give value to our lives.
you said "I think entropy ... why we things the way we do. ..."
No matter what direction natural laws obey, and whatever constants that created a universe that birthed life, we would be biased towards the universe that birthed us. We will see it as the best and most natural way it is supposed to be. Not backwards or sideways. So for a "backward" universe, if they observe our current universe, they will think we are the backward universe and their's is the correct direction.
@@pulsar22this is true but we cannot blame ourselves for thinking that. id rather appreciate our universe for what it is even if maybe there aremore beautiful universes out there that i still dont appreciate and are aware of today. if we dont appreciate the universe we live in ourselves, no one else will do that.
Entropy is the word we have given to describe the sensation of life we feel. I love the fact this beautiful person says 'i am only a physicist'
That’s not what entropy is at all. She even explained it in the video
Honest: "we don't really know"
Sabine is true scientist not peddling religious opinions or complete fantasies
Never knew until THIS video of the source material that was used to formulate HitchHiker's Guide to the galaxy had come from Issac Asimov. HitchHiker's guide answer was 42 whereas it was "let their be light" but the EXACT same question was posed to a computer in both stories. I see now that was simply a play on the original story so it now makes even more sense
Philosophically - for me this lecture has been quite interesting and helpful 🤔🙂
Sabine, I love your presentation style and the way you step back from the fine detail to get a broad overview. Have you read the book by Unger and Smolin? I believe it is the answer to so many big questions.
You're just a physicist and a beautiful singer and musician and whatever it takes to make this stuff happen for me. Thank you!
Entropy is our understanding of universe in entirity,but entropy is complex because we have memory of past but not future 👍 that's why we feel that way, memory of humans was devised a survival mechanism,it has nothing to do with universe itself.
If we had memory of the future we would not consider it as "future", mainly because that scenario implies zero entropy and predictable way things will unravel.
Not to start a religious debate, but religion in its basic form proposes low entropy or being satisfied with not knowing aka "believing", whether in higher plan or self. On the other hand, science proposes probing and questioning, but it also claims reducing entropy to its lower state will preserve the universal order ?
So basically, they are proposing the same thing but with different methodology. Yikes, this is some Star Wars shit right here.
Amazing knowledge incapsulated in 5 minutes video.
I believe we are currently way short of reaching a point in our understanding of the universe and how it works at a fundamental level ( Though our current advancement in physics is awesome). It would be easier to understand simple interactions such as a free falling object , light from a torch, water boiling off, etc.and question them from entropy's perspective. Can gravity be reversed ? Can a photon traverse a reverse path and get back inside the torch ? Can water vapour condense back into the pot at right condition? To reverse entropy at a grand scale , it is important to understand if we need the ability to reverse the direction of fundamental forces' direction and if it becomes an essential condition.
Some species can not only slow down entropy, but can actually get younger.
Like the immortal jellyfish (Turritopsis dohrnii), there are crocodiles that don't age (just grow bigger & hungrier and eventually die of starvation or stupidity like the russian previously oldest crocodile that ate some nylon ropes at the zoo and died from it).
But humans (as practically all life forms) can do it too. Not in the scope of a single individ. Our bodies are still aging, but some processes ensure that the genetic material that makes the next generation doesn't degrade with time.
So aging doesn't have to do with Entropy. Aging is specific to Biology.
But those animals are still affected by our 'version' of physics. They dont move backwards and their interaction with the environment is linear.
Yeah so, I don't believe she was saying that aging is caused by entropy. Like she mentioned, there are species which in theory could live forever, except that eventually the total amount of entropy in the universe (via the heat death of the universe/atomic decay) will eventually destroy on a subatomic level everything that has any mass at all. Entropy in the form of the universe itself moving to the lowest energy state possible until the very fields that produce particles can't anymore.
more great information by Professor Hossenfelder! thanks for putting the things together!
Something I find confusing about entropy is why do they say things go from order to disorder. If the end point of entropy is when there are no more interactions between particles and the universe is in complete equilibrium, surely that would mean entropy has taken things from disorderly to orderly.
Can anyone explain.
Connor Wilkinson - "surely that would mean entropy has taken things from disorderly to orderly." Yes. In fact the 3rd law states that a perfectly ordered crystal at zero Kelvin will have zero entropy. Order and disorder is a non-issue with respect to entropy. Entropy only deals with going from a high potential energy to a lower potential energy. Or high energy gradient (low entropy) to a low energy gradient (high entropy).
Exactly. Strangely enough few people comprehend this 👍
I thought entropy was just like dispersion but I really don't care about any of this stuff so I learned a lot from this and now have been inspired to read more books besides the Bible.
True entropy is watching a toddler take everything organized and thoroughly disorganize it. It's up to the adults to stave off entropy
Huh? What u smoking?
The “adult” being complexity?
@JohnnyCalifornia don't understand me? Try watching the video again maybe you'll understand it better the second time around
I think he meant it as humorous analogy. I give it a 5/10. Kinda reminds me of a joke a youth pastor or teacher might make. Wasn’t particularly funny but damn don’t act like the man’s a raving lunatic jeez. We all make dumb jokes now and then
@@michaelmilson7538 Kinda sucks when he tries to shove it in your face after the fact instead of admitting it was a bad joke yk? look at that reply! Fiesty!
Yes if you break a glass cup it doesn’t un-break. But also if you glue a broken cup together and put it on a shelf it doesn’t spontaneously break. You broke and and you fixed it. If we just look at moments where something moved toward less order than we get a confused idea that things always move toward less order. We could just as easily only consider moments where things became more orderly, where energy concentrated. Then we’d think the universe only moves towards more order. The obvious view to me is that it does both and it isn’t obvious if it does one more than the other. I would assume it is in perfect balance.
Well done, Madam ... you make me think (not an easy task for anybody~!). Thank you.
I read that Asimov short story in junior high and it blew my mind! 🤯
Coming from a genomic background, to me aging seems like the inevitable failure to maintain the integrity of information in time. What is striking is that some cells (germline) are in a way protected by this loss, allowing for reproduction, generating "new youth"
GianMa you said "to me aging seems like the inevitable failure to maintain the integrity of information in time ..."
This is a fallacy. Any plant or animal can create a system where they can perfectly make copies of their cells in perpetuity and correct the errors. The reason we age and die is so that a new generation takes our place. Without this generational turnover, evolution will almost completely stop. We all know that evolution is what has driven the progression of living things to progress. Aging and death are essential to this process and is programmed in our genes.
You are right, my perspective was definitely too human centric. I agree that such system can exist, but I can only think about either very simple organisms or the germline - but I guess you argue that such system in a full complex organism had no reason to evolve, or could even be detrimental, while I would argue that such conservation for a full organism (especially in functional tissues) is impossible. To be honest both seem plausible to me, but your explanation makes more sense!
@@pulsar22 It is funny to see the things that people come up with. the real truth is in Jesus.
Sabine is one of my favorite people.
the most interesting thing about this whole theme is the awareness that due to the continuous increase of entropy things will change but we are smart enough to slow them down
We're smart enough to try. And when we succeed, it is at the expense of additional enthropy in some other system.
So, beware.
Our smartness only helps in driving entropy away, not decreasing it.
@3_Pancakes i think i said we are smart enough to slow down entropy. Obviously, the examples are many like Old age natural disasters, etc although according to Boltzmann we can have a state with maximum entropy and no apparent change.
Great video!
Psychedelics are just an amazing discovery, it's quite fascinating how effective they're for depression and stress disorders. Saved my life
Psychedelics definitely have potential to deal with health issues like anxiety and depression,I would like to try them but it's hard to source them here
My first shroom trip was really awesome, it felt like I was deep into the sea
Tripping is not a bad idea but having a
Mycologist who will recommend you the dosage is the best option
/JAI_HEALS/
Got psych's**
Reach him on insta…
Wow, well put 👍🏻👏🏻
"There is as yet insufficient data for a meaningful answer."
--Isaac Asimov
One of the greatest lines in science fiction history.
"Entropy, little sweet, is just a word which means the amount of running-down of the
universe. Everything runs down, you know, like your little walkie-talkie robot,
remember?"
Everything mean to be cycle and changes. Rock do reduce into dust. Unbreak egg in fridge turn bad, turn back into dust, minerals into soils.
It’s what we define as Forward. Technically just because something is deteriorating doesn’t mean it’s dying or aging. It’s what WEve defined as forward in time. Open your mind to things you’ve never even considered and you’ll move closer to answers
poop
@@cadcncengineeringfabricati3497 yes poop
@@fishcheeks971 If you open your mind too much, your brain will fall out. See Tim Minchin's animated movie: "Storm".
@@cadcncengineeringfabricati3497 No, poop.
"Ordo ab Chao" means that "work" is required to reverse the flow of entropy to achieve "order". Such work requires life, which requires the sun's energy. Life itself is thus an attempt by the universe to finally solve the endless cycle of entropy increasing to a maximum, and all stars burning out, and then collapsing to a minimum once again.
"There are certain creatures, like types of lobsters or maybe trees that can keep entropy increase very low for a certain amount of time on the expense of increasing entropy elsewhere."
How do creatures increase entropy elsewhere when they keep their entropy increase low? In other words, if I decrease my entropy then somewhere else entropy is increased, right?
The CO2 you breath out has higher entropy than the food you eat. It's that simple. We are constantly increasing the entropy in our bodies, but we dispose of most of it.
Excellent...❤ thanks 🙏.
There can a sharp rise in specific entropy when an alpha particle hits two or more molecules of nitrogen tri-iodide, as compared to when it hits nitrogen trifluoride. I would suggest that a tachyonic Wiener process is the culprit. We need something to destroy unitarity, and I am advocating the tripartite interaction of the wave function, the electromagnetic field and this TWP. Without the electromagnetic field, TWP is still present but ineffective, so the system is a superfluid.
"In this one of many possible worlds. All for the best or some bizarre test? It is what it is and whatever. Time is still the infinite jest. The arrow flies when you dream. The hours tick away. The cells tick away." Neil Peart.
I just discovered Sabine Hossenfelder today, twice accidentally in two different videos. I'm in love with her... I love Germans
Entropy may can be repeated again on different things with same state of patterns in different time and we know them as cycles.
Considering that time itself is the construct of consciousness and does not really exist or matter or apply to the universe, is entropy then also a mere psychological construct?
Quantum measurement (*) is not time reversible, so there is another possible cause for the psychological arrow of time. Some think that our brain functions can be explained classically, but we really do not know, and others (like Penrose) do not think so. (*) "Quantum measurements" or in general any quantum phenomena that causes a "macroscopic" consequence in a classical system.
The interesting question is why the arrow of time related to "measurements" (when going from the superposition of alternatives to a single alternative) coincide with the arrow of time of increasing entropy.
I like her videos about limited physics questions much better, because here nothing gets explained or answered at all.
And this „Let there be light“ fits perfectly to the Conformal Cyclic Cosmology / CCC theory from Roger Penrose
¡Alguien que le diga a Sabine que la amo!, gracias ❤
Thats asimov story is very good , i think in that time , many people wants to beleve in a ciclical Universe that began with a big bang and contract again ..i think some kind of Budist Idieas , i think this Asimiv Story is somehow similar to Dr Penrose Ciclical Cosmology ,maybe Penrose read it and have some inspiration 😅
I wonder if you can decrease the entropy within yourself, you may be able to live longer, slowing down the aging process. But this is just a virtual reality. I imagine there’s more to do outside of this reality frame.
You can defeat entropy if you can tap into sources outside of this physical universe
if we view it from a highly abstract level, we think of the body as any other system. maybe one that reaches its peak equilibrium and has a finite though dynamic set of processes for staving off its rate of destabilization and decay, so to guarantee it's cyclical nature in some ways. increased life expectancy and the constrast of birth rates haa already highly disrupted many of the patterns created by our complex human systems.
@@penderyn8794 pics or it didnt happen
Your body is a wonderful organic process of decreasing entropy within it. Every time your body creates a new cell it has less entropy than the ones that will be replaced. The problem is that the process isn’t perfect and multiplication of errors over time increases entropy in the overall process. The idea decreasing entropy in this process would depend on being able to manipulate every aspect of your body at a molecular level, which means understanding and mapping every molecular process in perfect detail. In other words, a pipe dream. What do you mean-what can you even mean-by ‘this reality frame’? I believe you’ve used an excess of words to mean what Penderyn below said: ‘outside this physical universe.’ This is of course, at best, a guess, and at worst, a fantasy. As far as anyone can prove, there isn’t anything outside this physical universe. Of course, it’s possible that this physical universe contains everything (that’s possible given physical principles, laws, and constants) somewhere within it. That doesn’t help much because you can’t get there. My view is that, philosophically speaking, there can’t be anything outside physical reality because when we discover it it will just become part of our newly described reality. Before about 400 years ago, ‘up above the sky’ was outside people’s reality; now we know it’s just the part of reality that is a long way away.
You defeat entropy by giving children a new life
Entropy - I understand why increasing entropy is described as lowering of useful energy. However I don't understand why increasing entropy is also defined as increasing disorder. For example at some smallish period after the big bang the universe is composed of lot of particles and waves moving with high energy but I would have thought of as a fair degree of disorder. Then the particles clumped together forming galaxies, solar systems and planet - which may well be a lower energy state. But I would have also thought that this arrangement is more ordered than separate particles moving with high energy.
Similarly consider dust particles blown by wind (on Earth), suspended in air. Disordered in three dimensions. The dust then gets into a house, the wind stops and the dust settles on the floor. Less energy yes. But I would have thought still particles in a two dimensional plain was more ordered than dust particles moving in three dimensions.
Perhaps order and disorder means something different in the world of physics compared to every day use?
And when the energy and matter will be dissipated at the end of the universe (thermal death) everything will be so separated and dissipated that there will be no energy useful but also a very ordered state because everything would be ideally at the same distance from each other
Thus to decrease the entropy in our bodies and slow down aging we need to somehow restrain the metabolic activities in us. Probably long fasts and detaching ourselves from every thing and everyone in a cyclic manner can do it
I can think of few reasons this just wouldn’t help, so it’s wishful thinking .
I was telling someone the other day, that if we could live up to 400 years; how would we store our memories, our brains would have to grow substantially larger or just forget everything that happened the previous 300 years, this would also have to be true for learning and experiences; there are probably many reasons we have evolved to die - including biological entropy.
Have u read the case of James Leininger? If u haven't, u should. There r also several cases like his.
your brain already does this for past memories and forgets them to make room for more relevant tasks
I wonder what opinion you have about Aguirre & Gratton's 2002 model of "Steady-State Eternal Inflation", which has twin universes passing thru time in opposite directions, on opposite sides of a Cauchy surface. Too simple?
She talks about in her book
Isnt that the point of life to fight entropy and sure one organism will die but only so as it can continue decrease entropy by repackaging its antientropic code in its progeny... only leaving the comment cause sabina's content is well thought out and i enjoy it so hope it helps her get more views 👍
I have question! Is this entropy only applies to big particles or systems? How do explain entropy for virtual particles?
The answer is yes, elementary particles, virtual or not aren't aging, and entropy doesn't exist in quantum mechanics
If I watched this clip back in school, I would've been a physicist
Not sure that we can say entropy is the sole reason for our aging. Organisms are able to combat entropy, but they don't necessarily have to do so after they have reproduced.
Organisms can self-repair and decrease entropy until they cease. This process is called senescence. Is there any evolutionary advantage to keeping an old organism alive long after it was able to reproduce itself?
So, entropy is probably a physical constraint that makes the cost of fighting senescence much harder as time passes. But if there were any evolutionary advantages to doing so, we should be able to live much longer.
Since Earth's resources are limited, the worst thing for future generations is a discovery that allows us to stop aging.
nobody knows until somebody knows. But knowing just is a addiction sometimes
What about if in the end, universe gets increased instead of decreased? What if we are on a loop?
What gets increased? Be specific. If you mean entropy you should have said decreased instead of increased. Entropy increases over time. Do you think that there is any reason to think that it would change. Science is specifically about ruling these things out (or in) based on evidence, and, barring that, rational arguments about the likelihood of something being true.
@@YourFurnace I mean what if the size of the universe is getting increased due to the bing bang but it goes 'till stopping and reverts to decreasing mode till re-bing-banging in an ongoing loop?
Has anyone investigated the entropy lowering anomaly that apparently goes on inside a chicken:
🍳➡️🐔➡️🥚
They can even unscramble an egg. It's amazing.
I really beggining to see Entropy (low entropy) as a kind of a fuel/credit to run the simulation (what we call life). If that is the case, we might not be able run from it but we can see if we can find new sources of it either at the edges of space/time or higher/lower dimensions to create maybe an infinite(oxymoron term since we wouldn't know if the source is finite or infinite forever (oxymoron term as well since forever is a relative term) existing bubble that is constantly introduced with fresh 'low' entropy. Nonetheless, so long as we cannot foresee the potential depletion of it and if it has been providing the bubble for trillions of trillions of eons then it is fine by me.
Maybe I’m looking at it completely wrong but I’ve got a question and can’t seem to find an answer anywhere… Hopefully someone here can tell me how silly I am..
Does life not go against Entropy? And I don’t mean evolution or life itself or anything broad.. I mean a human growing from a nothing to an adult, an elephant to behemoth.. I understand we eventually grow old, shrivel up and go back to dust and the older we get the more chance of issues occurring, we degrade AFTER a certain point.. But from cell to a 27 year old peak human, what’s happening there? And I mean how we grow in size, not physical prowess or anything like that, just BIGGER.. Surely we don’t really “eat” enough for that to happen all while being active and burning the fuel we consume?
I think I’m either looking at entropy wrong or I massively understate how much energy we actually take in from food?..
I understand that as a “closed stystem” the Earth actually gets a lot of energy from an outside source, the sun, obviously.. But on a smaller scale living, physical things growing from seemingly very little to whatever seems odd to me.. I’ve never been comfortable with applying the “laws” of inanimate objects to life, especially when we still have no idea what the hell life actually is on any level.
If you're on a magnet to the future, - and you are - and space, time, and gravity are supposedly intrinsic - why can we choose any direction in space, free (unbound) from time and entropy to do so... maybe entropy and time is more intrinsic in a specific way to gravity, than it is to space..
Like also what am saying, what if the 'magnet' to the future was a straight line one direction of SPACE but we could go any direction in time/entropy and gravity ??? Would it be the same reality were in just perceiving it weird ?? Or different ??
Somehow it's just not all connected right.. lol
It seems to me though that the magnet is gravity and entropy is intrinsic to what gravity is doing and time is a measurement frame of those, which space itself might be free of entropy, but not gravity. It would also imply independent gravities perform independent entropies and create independent time frameworks of space.
It also proves the Earth is a hill in a hole surrounded by independent gravities and therefore entropies - and those on it get to chose not just of independent spaces and directions but independent entropies and gravities.
And call it a 'time'
I like how you think dimensionally. For a moment forget about everything you said and just think this:
Time is an axis just like the x and y axis, but is distinct in that:
For 3D distances, which I assume you are used to, you can find the absolute distance with pythagoreans theorem given coordinates like sqrt(x^2+y^2+z^2)
For 4D distances, which no will ever have the privilege of getting an intuition for, it goes something like this:sqrt(x^2+y^2+z^2-ct^2), c being some constant related to the speed of light. Anyway just imagine time as like another axis just like the interchangeable xy&z except t violates your standard Pythagorean distances rule. Sabine actually has a video about it, which I can't quite remember the name of.
The minus is NOT a typo btw.
If the egg did "unbreak" how would you know? Because your memory of the egg having been broken would also be gone (assuming you go back in time with the egg). That does not seem as weird to me as "time going backwards for the egg" but continuing to go forwards for you. THAT would be weird.
Entotropy exists and the universe in a constant state of ever growing entropy. Entropy shows us time moves in one direction and time only exists while there is change. When the universe finally goes into a state of complete entropy where there is no change of state, time will then too cease to exist. Without change there can be no time.
I get that aging and mortality is something we can feel more intuitively, but I don't think it's a good example for entropy, because it's not so universal.
There are actually animals that are immortal - jellyfish that cycles thru its baby-adult phases, crocodiles whose telomers don't shorten and their cells & organs don't degenerate ... Sabine mentioned these possibilities briefly.
It's really the environment that ultimately kills these animals.
Yes we're not close yet, so the analogy works for us. But it's more accurate to say that we can't live outside an environment that we've evolved to (even if we adapt fast to changes) and the Entropy is eventually going to destroy our environment. However there are plenty of other things to destroy our environment before Entropy gets to us - like our Sun swelling to a red giant for example.
Although the red-giant phase of stars is actually a direct product of Entropy - by losing their fuel, their fusion energy runs out...
In any case I don't think that Entropy is that universal. I would say that all the heavy elements are points of higher order, and many of them are quite stable.
For example if you put a piece of iron in the vacuum of space it'll first lose its heat until it reaches the temp of surrounding vacuum (which isn't exactly 0°K, but very close) and then it'll still stay together indefinitely. It won't suddenly decay back to the elements that formed the Iron (as far as we know).
In my opinion - uneducated guess if you'd like :) - entropy is the effect we see of a cause we still have to properly describe (but is apparently strongly linked with the flow of time).
And a thought I had some time ago is that most quantum particles aren't actually subject to entropy themselves.
Unlike a wave in a pond which slowly dies when its energy is transferred to the environment, the waves of quantum particles are usually stable and would persist if not forever at least for billion of years. Actually a photon travelling thru expanding space loses its energy, but not to Entropy, but to the result of being stretched by the expansion of space (stretching its wavelength).
But I wonder does that happen with massive particles? From our observations it seems expansion of space actually happens between galaxies, as the gravity inside galaxies is strong enough to overcome it. So does that scale down to lets say a hydrogen atom (or a piece of iron?) flying thru expanding space?
Time is just an increase in entropy. Lunchtime doubly so.
Make a vídeo about entropic forces
Better is to read her new book, she explains very well there
If we don't really know, let's make up the coolest fitting ideas that all work and then everyone can have their own belief system that works the same, in parallel if you like so we don't step on each other and hurt each other. That way we can look each other at detail. And not offend each other. This way I think we can be equal and individual simultaneously. If we do it as a planet. Wow! Maybe that would be a singularity. I would like to have a singularity to music. We are the world. Sounds like a good one. I think it needs an edit though. I've been listening to it a few times and I'm not sure what it is yet. I'll get it though.
Wow !
Doesn't it look as if entropy can be lowered in one part of a system at the expense of increasing it somewhere else, for example, in sorting?
Yes, "Let there be Light!"
How do we actually know that time exists? and how do we know that entropy is not proving the exact opposite (time going backwards)?
Time exists like a dimension , perpendicular to the 3 spatial dimensions and sometimes in physics is said that antimatter is going backwards
We may never be able to know, it's like trying to measure the amount of water in the sea with a cup.
Existential physics is a great book!
you have 8 subscribers now, and you're profile picture is familiar 🤔
I just wonder who is going to be the one out there when entropy has brought the universe to a standstill to utter: "Let there be light."
The lost dream of every physicist is to provide answers to the eternal philosophical questions. If that's not why you went into physics you're just a clerk doing some fancy book keeping.
Where do we observe particles going backwards in time?!?! Is it only a mathematical model? Or have we actually observed this from particles?
All it means is that the current laws are time invariant. In that there is no cost to moving through time, so it could be processed forward or backwards.
• *Everyone disillusioned*
• Me, who has already watched Tenet & DÀRK : *Hold my beer* 🍺
🤣💯
@@the_candid_mechanic 🫂❤️
The question posed presumes that the Universe will, in fact, "end." Seems like circular logic to me?
we don't really know is a correct answer. because it is opening the possibility of knowing.
There is no entropy in our youth when we're still growing. Instead of decay, there's only growth in our first 20 + years of our existence. How do physicists explain that?
Sabine says that everything is cause - effect in our universe. Now she was talking about time going backwards. Then we would get an effect - cause chain. How could that work?
"Time flies like an arrow, but fruit flies like a banana" - Groucho Marx
Omg it's Sabine!
Very good video and I have loved Asimov since his first book and I will continue loving him until I die. 5:24
There's a hilarious meme out there where one man says "i love science" and someone else says no you don't ... loving science means doing painstaking research and analysis .... you like to stare at Science's butt as it walks away.
That meme is me, I like to look at Science's butt as it walks away as I am not a scientist but this video made me consider a very fascinating thought.
And if Hossenfelder read it, it would tickle me to no end as I'm a huge fan, she's both brilliant and hilarious (I follow her YT channel).
The premise of time moving forward and not backward fascinates me because if it did move backward, wouldn't that also include the neuron's firing in our brain. If time moved backward for 10 seconds and then forward, would we really know ?
I also ponder on the law of thermodynamics and that entropy only increases. We often hear about 'black holes' but I've heard about a 'white hole', as in, a spherical body where nothing can enter but can only leave. I often ponder that we have a very small data set from which to make and test our theories and I wonder if our universe is a bit like a lava lamp, a combination of forces that drive massive amount of energy and mass around to form beautiful forms that will disappear but reappear in a different form.
I had another thought regarding the "forward/backward" movement of time.
For Christmas, I got a cup that automatically spins the tea/coffee when I press a button. But I can take a straw and spin it the opposite direction, over powering the mechanism forcing it to spin the other way but once I stop, it will quickly go back to spinning the direction the mechanism in the cup dictates.
If we explore the concept that time might move backward as well as forward, maybe there is a force moving time one direction but that is occasionally interrupted (like me forcing it to spin the other direction with my straw) but it eventually goes back when the temporary force stops. And if time truly went backward, I wouldn't remember it because even the neurons in my brain would go back as well.
Again, I'm not really a scientist, just a nerd who ponders on whatever interesting thought that enters my head.
the movie tenet: reversing entropy and turning the silly concept of time on its head.
entropy is a good concept
Entropy is a matter of perspective and somewhat illusion
LET THERE BE LIGHT!
Entropy is a partial mathematical modelisation of time
The wheels on the bus go round and round, and so does time?
Is entropy a finite "thing" (I wanted to say "substance", but I won't). 😉
Scarcity and abundance... And the dogma inbetween. Things accumulate and surprise dogma.
Entropy keeps increasing just the same way as gravity does on the other direction… it is just a matter of Density.
Let's assume we live for infinity. But our goals are just to evolve as fast as we can to become the things that we are as the spark. Maybe that sounds like a good way to play.
We only ever live in the infinite present...... Living for infinity would not bother me...... Because we already do it perceptively
@@penderyn8794 everybody has their own infinity of course. You have a beginning and an end, you wouldn't know anybody else's beginning or end or if it diverged. I'm working on writing the definitions down for a simpler concept of life. Something that everybody can use to communicate with in simplicity. To stay away from arguing about a word and it's definition as opposed to the idea. Or just bitching and complaining that your thing is bigger or better or worse than the others. Instead of creating a goal to achieve and then repeating it.
Big think, not giving me the answers to the questions I didn't ask but now want to know
Underrated comment.
Probably vaguely remembering the gist of the Asimov story, I once flabbergasted my religious brother and a few dinner guests when I said, ‘God doesn’t exist now, but he will…’
The "dark energy" could be a force that comes outside our universe; such as other universe's gravity flowing into ours and "bulging" our spacetime and making it stretch. It has increased and slowed in the past, and we don't know the explanation for it. We have just given the name "dark energy" to this phenomenon. And since spacetime seems to be able to do whatever it wants, it could at some point shrink and restart the universe.
I am not convinced that time does move forward. We perceive it that way because that’s the only way we could perceive it. Even if time moved backwards, we would still perceive it as moving forwards. Only an outside observer could perceive anything different because they are free from its constraints.
"keep entropy increase low by making entropy increase outside higher ..."
No, many species that are long lived do not try to make entropy increase outside high to keep internal entropy low. They just keep their metabolism low making both internal and external entropy increase low. In other words, they make time (or change) slow down by choosing to relax and not run the rat race.
Causality is only apparent
Love Sabine's logical explanations of deep topics.
Kind of a joke but i'm happy for you to find this logical 😅
@@paatrick90 How so?
@@nicksdinosforkids6001 I'm guessing he wants to insult you for some reason but just can't, possibly due to his disagreement with Sabine's interpretations of physics and the universe in general.
@@3_pancakes767 Thanks, just thought I was missing something.
If you take a piss you can’t unpiss😂
I am not a physicist but how does everything go from less entropy to more entropy? A glass might break but if you melt the pieces down and make a new glass it has decreased in entropy. So it would seem that matter could go through many different states of entropy.
Entropy increase is simply the transition from a less likely state of a system to a more likely one. When you decrease entropy locally, it has to increase somewhere else - the net entropy always increases. Read about statistical mechanics if you want to dive deeper into the physics!
It takes energy for heat, and energy will be spent at a greater rate to re animate the object. Technically, this is no longer the same object structure arrangement but a new arrangement.
Thank both of you for answering.
In her new book she explains it very well.
Time has speed limits that goes from zero to approaching the speed of light. That means that TIME AND THE SPEED OF LIGHT ARE TWO DIFFERENT AND SEPARATE ENTITIES, which in turn opens up a modern door into physics. TWO UNIVERSES!
But that's just the first step. The above suggests TWO UNIVERSES. The one of time , matter, etc. And the other a universe of speed of light photons.
Next the eternal photon universe was the first singularity that created all, through photons create electron positron pairs... next ...