The Arrow of Time and How to Reverse It

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PBS Space Time

8 päivää sitten

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Ever wish you could travel backward in time and do things differently? Good news: the laws of physics seem to say traveling backward in time is the same as traveling forwards. So why do we seem to be stuck in this inexorable flow towards the future? It's time to begin our journey towards really understanding time.
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Hosted by Matt O'Dowd
Written by Matt O'Dowd
Graphics by Leonardo Scholzer, Yago Ballarini, & Pedro Osinski
Directed by: Andrew Kornhaber
Assistant Producer: Setare Gholipour
Executive Producers: Eric Brown & Andrew Kornhaber
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IAM HE Tunti sitten
Isaiah 14
Patricia Brown
Patricia Brown 3 tuntia sitten
I was looking for cat massage videos, not sure how I ended up in this weird part of FIpost.
Olivier ANDRIEU 4 tuntia sitten
Hello Dr Matt and the team, a few question, for an episode ? Why are galaxies spinning ? Where does this energy come from and what choses the direction of rotation ? Does a Black home spins (from the inside) or just the matter around it twirls ? Why do particules spin ? Mass vs spin ? Spin vs information ? Does inflation spin ? If our universe would spin, could we see it ? Sorry my head is spinning upside down...
incog burrito
incog burrito 5 tuntia sitten
Nope, I call b.s. We are all plunging to the center of a gravity well that is located somewhere . It cannot be reversed. There, that's all I know. Things are the way they are, it is what it is, and it shall be what it used to be in the past ,in the future. Even if we escape our galaxy it will take longer to get to another galaxy than the universe has left to exist. Unless of course the inky vast nothing in-between galaxies is actually a vast natural worm hole that causes instant travel between galaxies. But if it worked that way everything would instantly fall in on itself and become a singularity again. It doesn't ,so it must not actually work that way.
dalek vader
dalek vader 7 tuntia sitten
In the Alchemy of Neutron Stars video you mentioned that it is is possible that everything we are made of was forged in a neutron star collision. If this is true where is the resulting neutron star or black hole from that now?
Madasu Revanth
Madasu Revanth 8 tuntia sitten
Egg can reassemble when time go back
Jr M
Jr M 8 tuntia sitten
Ok I am confused by an apparent contradiction, or did I miss this - Why would we presume running time backwards, between any two points of time, means that all events and particles will do exactly what they did in reverse? To reverse reality in this way, means a knowability of all states and elimination of uncertainty - the complications of life and consciousness aside, arent we well passed the question of whether reality is probablistic at the quantumn level? How does changing the arrow of time circumvent that reality?
Shrikant Chidgopkar
Shrikant Chidgopkar 9 tuntia sitten
So how does Infinitely dense singularity (Big bang) aligns with the laws of Physics and how does it is differ from the mythology of some God flying across the sky in a chariot ? Does it differ coz we call it scientific hypothesis? How come density be infinite ? Even if we consider that the universe was infinitely dense, how is it possible that it didn't have a volume, given that theory states that spacetime itself started after the big bang. If it had any volume then the spacetime existed even before the big bang. The creator theory also fails, because if god created everything then who created god and this chain goes on infinitely.
Changwe Kunda
Changwe Kunda 12 tuntia sitten
Liked the video, thanks
mikea hiooi
mikea hiooi 14 tuntia sitten
God bless this channel. I've been searching for a video about the arrow of time for a while and you're the only one yet.
JP Dingle
JP Dingle 16 tuntia sitten
could someone (with a strong enough computer) plug the laws of physics into a simulator and when you eventually find earth you know you have all the right laws (along with the ability to see the past present and future in full viewable detail) like is it theoretically posible?
Umit 19 tuntia sitten
Watched it multiple times but still don’t understand how time is reversible at quantum level. If all particles at QL carry a high degree of uncertainty which disappears with ‘observation’, how would ‘unobserving’ look like when the time is reversed? To me it sounds like information had to be destroyed to make something uncertain :/
mikea hiooi
mikea hiooi 14 tuntia sitten
Seriously may be my favorite ever.
Undie Cover
Undie Cover 20 tuntia sitten
Could you talk about relativistic thermodynamics?
Rafael Soares Torres
Rafael Soares Torres Päivä sitten
So, okay, say there's an explosion, right? A big one, particles fly in all directions away from the epicenter for a very large distance. Say in a tiny fraction of a tiny debris of this explosion, a group of sentient monkeys develop consciousness. To these monkeys, their movement away from the blast is fixed - a(n apparently) constant velocity in a(n apparently) constant direction. Is that what time is, to us? If so, then the "mirror reversed" universe isn't actually moving "backwards" in time, it's just moving forward in their direction, in relationship with the explosion. Is that it? Am I tripping too much?
Iridium Päivä sitten
I have a bit of a question. So if we flip directions of all particles, in theory, time flows backwards. But does it actually flow backwards, or is it flowing forwards but it's particles are returning to their initial positions? Is time an actual thing, or do we just define time as where entropy is increasing? Also, on the off note, if we could perfectly reverse every particle, would time flow backwards forever, or would fundamental randomness of particles and waves stop it after some time and make it flow forwards again, but from some position in the past?
boo Jay
boo Jay Päivä sitten
So glad you guys are spending more time on Time, my favorite subject.
Dan Yxng
Dan Yxng Päivä sitten
Quantum Electrodynamics - qed. LOL
bouligab Päivä sitten
What about the other side of the big bang would have got most of antimatter? Can't the latter be described as matter coming backwards in time? ... And... coming from where, ehr
Radu Marian
Radu Marian Päivä sitten
I watch this guy only to feel academic in terms of language expression...
Evan Nibbe
Evan Nibbe Päivä sitten
There was an experiment about this that scientists running a simulation of three rotating black holes orbiting each other in a simulation and found that, after a point, when they tried to reverse the effective passage of time, they ended up getting different paths from how they moved up to that point.
Raccoon Grrrl
Raccoon Grrrl Päivä sitten
9:37 is when my brain begin to (reverse) big bang before and after the point
EricMichaelManuel Päivä sitten
So quick question, if time & space are actually spacetime...then isn't it self evident that you can't move backward in time? How do you have negative movement? I'm not talking about moving 'forward' in the opposite direction, I'm talking negative movement. It makes me wonder if the space distortion of a singularity is in fact the reason time seems to reverse, if the maximum speed is exceeded by the compression of space itself.
Thulyblu Päivä sitten
Hypothesis that time is just the fourth dimension of space (spot the pattern): +0 dimensions: point +1 dimension: continuous arrangement of points in a "line" with two 0-dimensional boundaries (left, right) +2 dimensions: continuous arrangement of lines in a "square" with four 1-dimensional boundaries (left line, right line, upper line, down/lower line) +3 dimensions: continuous arrangement of squares in a "cube" with six 2-dimensional boundaries (left square, right square, upper square, down/lower s., forward s., backward s.) +4 dimensions: continuous arrangement of cubes in a "moving cube" with eight 3-dimensional boundaries (cube moved to the left, right, up, down, forward, backward, cube at the first moment, at the last moment) (+5 dimensions: continuous arrangement of moving cubes/universes-with-objects-like-cubes-in-it in a "multiverse" with ten 4-dimensional boundaries (universe on the left, right, up, down, forward, backward, universe at the first moment, at the last moment, unnamed multiverse boundary one, unnamed multiverse boundary two) Any objections, thoughts, errors ? Thanks for considering.
Prateek Chand
Prateek Chand Päivä sitten
Will entropy be calculated as a whole for our universe for all particles together or it will be seen for a group of object or group of molecules,atoms...??
Wendy Odesky
Wendy Odesky Päivä sitten
There's a different world out there, Just past our universe. Life's the same as anywhere, But there time runs reverse. They know about the future, Have glimpses to the past. The present is a suture, Where first can become last. Born knowing how stories end, They read them to forget. While erasing ink with pen, They do not feel regret. We think of them with pity, While they unsettle Mars. They'll dismantle their cities, But we'll abandon ours.
Jan Segal
Jan Segal Päivä sitten
i think arrow of causality and arrow of time are one and the same propagation, a property of space
doire aintu
doire aintu Päivä sitten
Hiccup Haddock
Hiccup Haddock Päivä sitten
Ah yes,understanding time requires understanding of space time And space and time,why did I never think of that But legit,this was also an amazing episode Looking forward to next one
Likas Pokas
Likas Pokas Päivä sitten
Are weak force and entropy related ? both break time symmetry
Avinash DH
Avinash DH Päivä sitten
If there is no entropy, does time stop to flow...?
doire aintu
doire aintu Päivä sitten
This is actually brilliant
Justin Solms
Justin Solms Päivä sitten
Haahaha. The endings are pure genius :)
johnsonmaje Päivä sitten
What does fusion look like in reverse? Does physics says that would be the same, or even possible?
quertbarbie62 Päivä sitten
Maybe time goes reverse. We just don't know it, as we have forgotten it. All memories of the future has gotten erased as time travels backwards. If all vectors are reversed then our brain will be affected as well. Maybe past present and future happens simultaneously, and time is omnidirectional, but we can only observe and make sense of it in one direction, which leads us to think that time only moves forwards. You could have travelled nth time to your 10 year old birthday, but each time you do, you would think that you are just turning 10 for the first time. any memories beyond that haven't existed as far as the 10year old you is concerned. If that is the case, we would not even know if we kept doing the same thing over and over again or if we are able to change something.
UpAndOut Päivä sitten
If time was going backwards, how could we even notice?
R.A. Dragon
R.A. Dragon Päivä sitten
Why does no one think about the probability that we are riding a wave through time that "started" (for lack of a better term) at the "Big Bang" and resulting in "time" expanding in all temporal "directions"? The physical (uni)multiverse being "predetermined" along with time as every and anything that could be is, and the conciousness creating the ability to "choose" which path we experience. This theory would seem to indicate that as the velocity of time as we know it "slows down", we may (at some point in the distant future) be able to move through time in the same way we currently move through space. (As well as a whole slew of other concepts that could break the mind! lol)
Nothing Is real!
Nothing Is real! Päivä sitten
How do you get a lower zero than zero? Zero is zero, zero means nothing how do you get more nothing when you already have nothing 🤷‍♂️
Roddy Rich
Roddy Rich 2 päivää sitten
How many dimensions does Imaginary time have?
Roddy Rich
Roddy Rich 2 päivää sitten
If someone actually found away to travel back in time. There are might be two or more options; 1. They are thrown back to the beginning of the universe. 2. The Quantum Multiverse interferes and puts them into another universe. Could anyone or Matt care to explain?
Johnwill Keating
Johnwill Keating 2 päivää sitten
At 7:20 - Comparing a low entropy particle cluster to the compressed state of our early universe isn't a good analogy, is it? As I understand, space was uniformly dense everywhere in our early universe. It was just more dense than it is today. There was never a super dense volume of matter contained within a larger empty space. Correct me if I'm wrong.
noaholtas 2 päivää sitten
I have a question. Do the anti particles use the same force carrier particles as regular particles? If not, are there anti photons carrying anti electromagnetic force?
Mike Brown
Mike Brown 2 päivää sitten
What do you think of this new paper published only a few days ago? Physicists discover the 'Kings and Queens of Quantumness' | Space
Mister Nobody
Mister Nobody 2 päivää sitten
Would the universe exist if there was no one there to see it? :D
Mad Mental Hibby
Mad Mental Hibby 2 päivää sitten
Time is not an arrow. It's now how we think of it or perceive it. It doesn't move "forward". Life isn't some video tape that can be rewound or fast forward. Life isn't linear, it's chaotic. The atoms around us are wiggling around randomly, it's our minds that create the illusion of order and structure. We're experiencing a randomness that we are simply accustomed to.
Guénaël Soum
Guénaël Soum 2 päivää sitten
What if the universe bounces from big bang to big crunch and at each time a coin is flipped and the result is who win in the amount of matter vs antimatter, creating a symmetry between a matter universe and an antimatter universe?
doliio volay
doliio volay 2 päivää sitten
"Time flies like an arrow, Fruit flies like a banana." --Unknown author
Callum Bush
Callum Bush 2 päivää sitten
Aliens 👽 are just humans travelling back in time!
Mark Shiman
Mark Shiman 2 päivää sitten
Aren't there particles that break time symmetry, and are actually different going backwards than forwards? Veritasium did a video on this in 2017 called "This Particle Breaks Time Symmetry." I know I'm late, but I'd like it to be addressed.
Multiversal Explorers
Multiversal Explorers 2 päivää sitten
If charge is an intrinsic property of matter , Why electron and proton have same amount of charge although their mass is different????
doliio volay
doliio volay 2 päivää sitten
This is a great channel, that's why it would be very interesting to watch a video on this.
Chucky Dickens
Chucky Dickens 2 päivää sitten
So, this video talks a lot about perfectly reversing the motion of particles. But similar to the Egg mentioned at the start, if time ran backwards, would we expect to see stars instantaneously turn Iron into Carbon, and then over a few weeks, turn the Carbon into oxygen, then lighter elements, all the way back to a hydrogen nebula? Would entropy increase by way of everything becoming a homogeneous hydrogen sea with stars being the great doomsday machines of that universe, and black (white?) holes spewing out new and complex matter?
Additional Pylon
Additional Pylon 2 päivää sitten
🎵If you made a scrambled egg tonight, there'd be no return to yolk white. And when it's fried you can't turn it back to raw food that is the arrow of ENTROPIC TIME🎵
Compelling Satanist
Compelling Satanist 2 päivää sitten
I have a question. Is there any reason to believe that the fundamental forces of physocs could be anything other than what they are? There's a lot of talk of fine tuning and the anthropic principle, but I've never heard anyone explain why or how we think the "dials" could be set to anything else.
Kai M.F.S.
Kai M.F.S. 2 päivää sitten
I LOVED what you said about creating an illusion of understanding. I've seen so many people use words they don't understand to create a total BS argument....
jimmypalavi 2 päivää sitten
Could gravity simply be a manifestation of a physical deformity of 3-dimensional space into a fourth physical dimension, much as we could create a dimple of Flatland into a "downward" 3-D direction which is outside of the Flatlanders' field of view? Flatlanders would experience acceleration towards a dimple as we experience acceleration due to gravity. As one could move more quickly than otherwise possible between two points on Flatland via a 3-dimensional warp, could a 4-D warp of 3-D space possibly help explain the linkage between entangled particles? Would then a linkage between time and gravity (time slows down near a black hole's event horizon) - or is it rather a linkage between time and velocity (such as the lifetime of a muon in our frame of reference) - preclude or support such a notion of gravity simply being a 4-D curvature of our space, and time being something completely different and independent?
steven kyle
steven kyle 2 päivää sitten
One of famous argument The author of general relativity, Puts a white glove in a wooden Box But I think specifically the middle One on the right is one empty box On the left is one empty box Solve This argument, when few could understand Einstein's explanation Is not as difficult to understand as some may consider But as a man of good will with good intentions would I want to share the mathematical assumption of this scientific thought experiment? I can't say I knew Einstein But I do comprehend how science could have really bad out comes. The problem is put simply Einstein withheld some comprehension for fear of its usage If a dimond of significant worth, that is not cubic zirconia, the density of matter that could be created could lead to compressed matter to the extent warping of gravity is accomplished Long distance space flights could require gravity the closest form of artificially generated gravity minded for our intentions is many many light years away. Electron is faster than light. © Steven Peter James Kyle ISBN: 14/03/1989
steven kyle
steven kyle 2 päivää sitten
Matt O'Dowd, I disagree, if an instant occurrence of all matter reverseing, in the arrow of time, so including a clock that has wound backwards 5 minutes approximately as part of this anoamly in physics, but the clock ticks for 5 minutes into a new future, the 5 minutes wound backwards is lost forever untill time moves forward in an instant exactly to the time arrow where time went bacwards the arrow needs to be resset, as each tick forward is 1 tick lost over time for the purpose of moving backwards or fowards in time. Light equal 576 why? © Steven Peter James Kyle ISBN: 14/03/1989.
Vincent Proxy
Vincent Proxy 2 päivää sitten
Nice Shirt
Iam-Hanss Acosta
Iam-Hanss Acosta 2 päivää sitten
Love all your videos 🤩🤩
Iam-Hanss Acosta
Iam-Hanss Acosta 2 päivää sitten
U look fit on that video lad!!!🥸
Ryan Christopherson
Ryan Christopherson 2 päivää sitten
Why use entropy as the big hurdle? If I accept some part of “quantum“ uses the concept of “randomness”... reverse the arrow means roll the negative dice? What is “negative random”? How do you reverse a quantum random event? A+random=B... B-Random=A? The act of choosing a“random” value breaks this doesn’t it? If you can run the equation the same backwards or forward, what equals “negative dead/alive cat”?
agar32 2 päivää sitten
I've been thinking about this (5:11) these past few days. Life, in a way, is a region of space with low entropy fighting against the thermodynamic-compliant rest of the universe trying to disperse it's energy and increase it's entropy. Since that is a basic requirement for life, then in a time-reversed universe wouldn't life operate in the "opposite" way, being a region of space fighting to increase it's entropy against the rest of the time-reversed universe? We know our consciousness emerges in our universe of increasing entropy, so maybe consciousness is emergent specifically in this direction. That would mean that a consciousness should perceive time as going "forward" regardless of the type of arrow of time of their universe. Better yet, time wouldn't need to flow at all. Maybe it is just another static dimension, and consciousness only emerges when moving through time in a direction of increasing entropy, so it would always perceive as if time itself was flowing, and it was being carried along with it.
ccvcharger 2 päivää sitten
Is it possible that imagining the future is equivalent to remembering the past in a time reversed universe?
Brent Bay
Brent Bay 2 päivää sitten
How do you separate or distinguish time from light/energy? Or for our current understanding are they inseparable ?
Flamma2512 3 päivää sitten
What do you think of scientists like Eric Lerner and many others, who keep pointing out that the Big Bang theory itself is unfounded, it keeps failing with its numerous predictions and leads to an always increasing number of further assumptions and exotic hypothetical entities, e.g. inflation, dark energy and dark matter? Apparently, Hubble himself did not believe in an expanding universe and in the Big Bang theory. Eric Lerner explains that all observations can be explained without the expanded universe, except for the redshift, which can be explained in other way as well, without requiring such an extreme amount of additional assumptions. If this is true, then this cannot be ignored. A lot of these scientists advocate the plasma universe theory, as an alternative to Big Bang, although whether plasma cosmology is true or not, seems rather another question. They also affirm a huge bias of the scientific community towards the established paradigm and lack of proper questioning of numerous observations. It's also hard to argue that the world is plenty of biases, manipulations and mainstream lobbies. I am no expert, but reading a few articles about it and watching a few scientific videos, made me more aware and question a bit the validity and an almost unanimous acceptance of the Big Bang theory, despite indeed its leading to many incomprehensible assumptions, such as inflation. This is a great channel, that's why it would be very interesting to watch a video on this.
Benjamin Shropshire
Benjamin Shropshire 3 päivää sitten
I'm sad that the Conway's game of life cameo isn't getting more attention. :-(
Alex Chong
Alex Chong 3 päivää sitten
Does the release of the new World of Warcraft expansion have anything to do with the timing of your release break? :P
Ham 3 päivää sitten
because there is no time, "arrow of time" is simply entropy in action. you can't reverse time because you can't reverse entropy.
Albert Jackinson
Albert Jackinson 3 päivää sitten
1:08 to 1:10 Can we just appreciate how realistic that aging effect looked?
Cosmic 3 päivää sitten
The clock is always ticking
Jhause 9
Jhause 9 3 päivää sitten
Great video 👍🛸
Jais Mathews
Jais Mathews 3 päivää sitten
This one is a Super Sleeper. This is 5th time I'm trying to watch this video.
Ben Rudolph
Ben Rudolph 3 päivää sitten
"since entropy can occasionally decrease locally, i.e. particle trajectories converging, then entropy could conceivably drop on such a large scale so as to assemble an entire universe." Ok, we are talking about not only a gross violation of the second LAW of thermodynamics, but arguably the most improbable thing conceivable - far more inconceivable than witnessing a reversal of time itself. To make things more relatable, the probably of such a thing happening is infinitely more improbable than such miraculous events as 1) a river suddenly reversing course 2) a broken vase spontaneously reassembling and jumping back up to the shelf from which it fell 3) a sand castle destroyed by pounding surf suddenly being reformed by waves 4) a decaying corpse suddenly getting better, etc. We need to take a moment to consider the mind-numbingly-stupidly low probability of such an event. Scientists are fond of invoking such entropy fluctuations to explain the supposed origin or evolution of the universe. We observe the arrow of time because no entropic fluctuation large enough to amount to anything significant has ever been observed. And any suggestion that such an event will ever occur is as outrageous as suggesting that time will spontaneously reverse. Such things may be possible but the faith required to believe them rivals any religious explanation for science.
Svend Korsgaard
Svend Korsgaard 3 päivää sitten
Think about it from a quantum mechanical point of view, if we reverse the arrow of time, we will just play the schrödinger equation backwards, But the results of our observations will still be probabilistic and not be the same events played in reverse order. In short, there is no "reversal of time", Only evolution of probabilities.
John K
John K 3 päivää sitten
Hey Matt, would you consider touching the question about if the time dimension, t, even exists in the first place? No I don't mean the passage of time or how we experience it by our brain and senses nor that the universe is a 4th dimension static block. I actually mean, the time as the fourth dimension. Does that fourth dimension actually exists and is a part of the universe and reality? In other words, what is it about time, the t variable, that makes it absolutely necessary to be included in to the equations of modern theories? Is there perhaps, a possibility that those equations be written instead without the t variable at all and still work? If a theory can be written down, without using the t variable, and still work, wouldn't that prove that t is redundant and imaginary? Also the fact that quantum physics work entirely without the DIRECTION of t (the arrow of time) and on top of that it is actually impossible to define that directionality in QM (as QM stands now), isn't that a good enough indication for t being just a useful concept and not really representative of any physical part of reality? First and foremost, there is no satisfying definition of what t is. None that I know of. some claim, that in order for 2 parties to meet at a point in our universe, it requires 4 different coordinates, the three x, y, z and a fourth one the t. Well, I can easily demonstrate, that this is not the case. Actually, only the first 3 coordinates are needed. The fourth one is not needed, at all. All it requires, is an agreement for both parties, to start moving, upon a third party event or signal, or even better yet, the random decay of an atom! And they indeed, will eventually meet at that 3 dimensional point. Therefore, no fourth coordinate was required for this and therefore it is not needed, at all. The agreement between the parties, about the signal, is not a coordinate, and cannot be considered as such. In fact I just used a completely random event instead, which is the exact opposite of a coordinate! Most go by the definition that Einstein haves it, in order to move forward with his theories and just defined it as "what the clocks measure". This "definition", is a circucal logical fallacy that just begs the question. It is far from satisfying, it is actually a fallacy. How can we base our entire physics and science, on a... Logical fallacy? What is really the undoubtable reason, for the absolute necessity of the t dimension? I can't give any answer to that. There seems to be none, but the insistence on using it feverously on GR theories by all scientists, blows my mind. I struggle thinking, because there must be a reason that all those scientists take t as granted and real. So, what is this reason?
E Z 3 päivää sitten
you getting older
Niels Pedersen
Niels Pedersen 3 päivää sitten
But does this not mean that entropy does not always ends up in higher states but rather fluctuate or is a sort of a wave function going between high and low? If low entropy in “current” state both in “past” and “future” ends up high, a high entropy should equally end up as a low.
Alliance News Network
Alliance News Network 3 päivää sitten
If there were supersymmetry; there's not. Reversing particles is not time reversal either. You cant reverse the change of particles.
Don Cloud
Don Cloud 3 päivää sitten
I have a question (full disclosure, I'm not a mathematician nor a physicist ... not even close). Is there a proof or theory or experiment that shows the Heisenberg uncertainty principle is symmetric for time? Asked another way, what are the effects of the Heisenberg uncertainty principle (which generates chaotic effects in the "forward direction of time") when those equations are "run backwards in time"? That is, we know there are challenges predicting the future position/momentum of the atoms running forwards in time ... and the longer you run the computations the more the predictions become chaotic. So how do we know that running the same equations backwards will result in "particles retracing their footsteps" given the same quantum effects/fluctuations/uncertainty?
Jezza Mobile
Jezza Mobile 3 päivää sitten
Cannot reverse quantum interactions because they're probabilistic, momentum & location together being uncertain --> time's arrow
Patrik Wihlke
Patrik Wihlke 3 päivää sitten
Q.E.D... Good one!
Sugar Rush Times 2030
Sugar Rush Times 2030 3 päivää sitten
Obviously this vid isn’t directly talking about Blackholes but your general expertise - you would make a great consultant on the Disney remake of ‘The Blackhole.’
Sugar Rush Times 2030
Sugar Rush Times 2030 3 päivää sitten
Excuse me ‘The Black Hole.’
Untitled Document
Untitled Document 3 päivää sitten
I'm going to try and ask this question to the best of my ability: In space-time, we always talk about the arrow of time either pointing forwards or backwards. If we were to introduce a black hole, and enough energy to magically pass through the event horizon unharmed we could enter a place where time and space is flipped... My question is, in Time-Space, what would the arrow of time look like where we would now *not only* be able to travel back and forth through time - but left and right, and up and down as well?
Devalish 3 päivää sitten
How would a universe "before" the big bang that is time reversed be distinguishable from our universe? If physics don't care about the arrow of time, shouldn't it be indistinguishable? Just flip the diagram a random couple of times and you're lost.
Big Bang Theology Is A Fallacy
Big Bang Theology Is A Fallacy 3 päivää sitten
Have they found fart matter yet before you talk about "arrow of time"? Metaphysics and pseudoscience garbage mix; too much fancy terms and nonsensical math does not mean science.
Tom Walter
Tom Walter Päivä sitten
Your name suggests you don't like physics. What's your best idea of the beginning if not the big bang? Why are you smarter than all the cosmologists that agree it makes good sense and agrees with evidence? And the good evidence for dark matter suggests something is there..
pittsburghjoe 3 päivää sitten
Interference fringes require all possible paths at the same time. Time is all possible paths of causality. Entanglement is when we cause two particles to share the same spot in spacetime ..they shared all possible paths for a split second. Tunneling can happen because the wave is coherent and has access to all possible paths.
Bexley75 3 päivää sitten
Would travelling back in time not also require travelling forward for it to be meaningful? If in one moment we were in the present and in the next we were in the past then our travel is still forward in time, as opposed to time just playing out backwards and we get younger...?
Guilherme Sanches
Guilherme Sanches 3 päivää sitten
I have a curiosity. If space and time are components of the same structure (the space time) and the space is expanding, shouldn't the time also be expanding? I heard about time dilatation due to relativity, but never heard about time expanding in a whole like the space.
Davide Allegrucci
Davide Allegrucci 3 päivää sitten
So, the spacetime could have a Pendulum behaviour with the Big Bang at the center of time dimension. Could the "backward" direction be the thing we call "an antimatter universe"? The temperature should be the "force" (or it's manifestation) that choose the direction, under the 0 kelvin degrees matter become antimatter. But the other question is: how could a so cold universe exist? The temperature should increase again going backward. Like having 2 big bangs at the 2 poles instead of one in the center. But, again, if we suppose this, the concept of time travel or antimatter world are wrong again. Or are just... Relative to our direction?
Chinese Virus
Chinese Virus 3 päivää sitten
How can time stop at event horizon, cause force and movement can only occur if time is moving and in black holes gravitational waves are at work and also at outside layers hawking radiation is being emitted which is proven than how can time stop please answer
Mediocre Media
Mediocre Media 3 päivää sitten
So does this mean living beings all possess free will? They don’t have to obey the entropy of particles, just homeostasis, do they become “particles” in a system that can be traced just as easily forwards and backwards through time?
Diwitdhar Tripathi
Diwitdhar Tripathi 3 päivää sitten
U know. Anant anantum ishwar narayan.
Diwitdhar Tripathi
Diwitdhar Tripathi 3 päivää sitten
God's realms.
Diwitdhar Tripathi
Diwitdhar Tripathi 3 päivää sitten
The God's power.
Diwitdhar Tripathi
Diwitdhar Tripathi 3 päivää sitten
TheDamian58C 3 päivää sitten
I'm wondering how does friction play into this. Because friction is highly dependent on the direction of motion, if we reverse time, the motion of an object affected by friction will vary greatly from its motion when the time is going forwards.
kind kender
kind kender 3 päivää sitten
Cool t shirt!
Cainz Juss
Cainz Juss 3 päivää sitten
Since gravity and time are so heavily entwined. Wouldn't the reversal of time also reverse the effect of gravity? As in blast the planet apart.
Burton Pierre
Burton Pierre 3 päivää sitten
Everytime i wish i could travel back!
Paul the Audacious Bradford
Paul the Audacious Bradford 3 päivää sitten
Perhaps, as I’ve been told relentlessly since high school, the Big Bang was immediately preceded by an absolute entropy minimum throughout the multiverse... ...or... ...perhaps it was preceded by an immensely improbable LOCALIZED entropy minimum within that minuscule slice of the universe knowable to us. Don’t forget, friends, immensely improbable multiplied by a mind-bogglingly expansive duration of time equals completely inevitable! Just sayin’ You’re going to give me an argument. You’re going to say I’m crazy. You’re going to ask, “How many PhD’s in Physics did you argue past MIT thesis juries while you were driving a taxicab out in the suburbs for thirty five years?” Alright. Alright. Have to admit you’ve got a point there ... but, as the eminent George W. Bush once remarked about the Theory of Natural Selection one day while he was exiting the Little Boy’s Room: “The jury is still out on that one. A theory’s just a hunch. Darwin had a hunch, you have a hunch, I have a hunch - but God’s gonna get the last laugh on all of us, just you mark my words.” Answer that, smart guy! We’re talking about the President of the United States, here. Not just some rando FIpostr. After all, how many electoral votes has Roger Penrose ever won? Think about that, huh. So, maybe those “scientists” in their “universities” are clever enough to have a better hunch than God... ...or... ...just maybe you might one day find yourself on the OTHER side of the Big Bang, heading backwards in time. Don’t be surprised if you’re on hand to see Marty McFly teach Chuck Berry how to play “Johnny B Goode”. Mark my words!
onehit pick
onehit pick 3 päivää sitten
A key realization is that fundamental particle interactions are reversible, and should be, intuitively, "as if viewed on film". Once you proceed to bulk particles, however, you no longer get perfectly elastic collisions or reversible interactions zoomed out to that bulk scale. I guess this is another way of saying that, in no sequence or reality would the egg ever "un-smash" itself. A thought on some of the comments -- if all forces are eventually hoped to be unified, and gravity truly turns out to be a pseudo-force as it really appears to be in many cases, would it be possible that all forces are actually pseudo- forces. To me, it has always seemed that electrons in orbitals are merely following geodesics of their own kind -- in their own, curved spacetime.
Paul the Audacious Bradford
Paul the Audacious Bradford 3 päivää sitten
Matt O’Dowd ... you be schmaaaahht!
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