Brian Cox explains why time travels in one direction - BBC 

Very relatable! It made almost too much sense back then,. of such a fundamental thing as time that, to speak with Neil de Grass Tyson it "made me want to grab people on the street and say: ‘Have you HEARD THIS?

How old is this show? It looked pretty new to me... I must be stuck in a time warp...

@@Freikinator It came out 10 years ago, so if this person's just starting a PhD, they're probably 22ish, so they could have seen the show when they were 12, which I'd consider a kid.

Congrats!

@@licl4708 As far as our current understanding of things are: entropy can only increase from a lower state to a higher state of entropy, but not vice versa. You live, alive is a state of low entropy, and one day you die, death is a state of high entropy. This suggests that it can't be reversed and therefore you can only move in one direction in time. It's why you experience aging as a linear thing. But that is what we know of it so far, it's what currently seems most likely and what yields the right results in our models. However, we might be completely wrong. Just as our models can be great tools to predict a lot of things, they are not reality. What you try to describe is never exactly the described: e.g. if I pick up the map of England and tell you I have been everywhere in England just by literally standing on the map, you would rightfully call me foolish; the map is only a model. Take Newtonian mechanics, great for most of our current day applications, we even put people on the moon with it, yet it is rubbish once we try to study the quanta (the tiniest particles we know of, such as atoms and their parts). The more we think to know, the less we seem to know. _“We live on an island surrounded by a sea of ignorance. As our island of knowledge grows, so does the shore of our ignorance.”_ - John Archibald Wheeler If you like to think of a new perspective on time, check out dr. Julian Barbour, you can find documentaries where he speaks of time on RU-vid.

He already brought a flag. Doing a proper job.

@@janpeternelj2309 Which is upside down...

@@Climpus no, it's showing the reverse side.

@@davebox588 No, it's upside down. It doesn't matter which way it's being blown by the wind, the top corner on the flag pole should display the thicker white diagonal stripe above the thinner red.

O

I want to see him playing keyboard in his failed band "Dare"

@@TonyEnglandUKhow did they fail?>

@@jonbateman3245 His band released two albums _"Out of the Dream"_ and _"Blood from Stone"_ - they both flopped. He then went on to join D:Ream _("Things Can Only Get Better")_

@@jonbateman3245 Apparently, Brian is a good keyboard player, though.

@@TonyEnglandUK he’s not done too bad then, I wouldn’t call him a failure, but we all have different views which is cool.

Excuse me sir but Carl Sagan is and will always be the daddy of space and time. If you haven't watched his series 'Cosmos' then do yourself a favour (this was remade by one of his students Neil deGrasse Tyson many decades later)

Can't stand him. I heard he added "Ucker" to his surname.

@@analogpixel We know dude lol. And literally everyone knows about the famed Cosmos series. They were just comparing Brian Cox to another individual. He wasn't designating the GOATs of cosmology or something.

​@@Ryan88881 Haha I know, it's just that, nobody who's seen Cosmos would ever utter the phrase "Brian Cox is the David Attenborough of Space and Time".

@@analogpixelCarl Sagan is a yank. David and Brian are fine english gentlemen, don’t compare them to a yank please.

So nice to see a gamer who also loves physics! Keep making excellent gta vids

@@ctboy1989 those two interests are way more common than you think man

Talks like Roger Waters.

This is what you get when you become a true expert in your subject, it's called competence and gives rise to confidence. I wonder how many youngsters have been inspired by Professor Brian Cox to study Science.

@Yao Jie Wong 0

Thank you👍🏻

So it's not really explaining why it travels in one direction, it's proving that it does? But I feel like perception is intertwined with time so maybe we just perceive it in one direction? Still totally confused haha. Thanks anyway.

Yea but how would we know for sure ?😐after all the universe had very low entropy in the first place now it’s having high so when the death of the universe happens from heat death entropy ( could ) decreases 😐and in time you could get a new universe 😐I also think the universe may have some determinism after all how can our lives really be that random ?😐if the universe were to end forever you might as well kick out earth and the universe all to together😑 if our universe is an isolated system witch means nothing goes in and nothing goes out that means out universe is infinite and if it’s finite and it expirences a heat death entropy will decrease 😐leading to a reverse Big Bang or creating another one 😐and if earth formed from evolution why can’t it not form again?😐

@@jettmthebluedragon All process strive for minium free nergy. In the development of thermodynamics, entropy was developed as a parameter needed to increase, when free energy goes down, in any spontaenous process.

@@dropdtune9199 hmm interesting 🤔but why should humans like you and me only formed from the so called Big Bang only 14 billion years ago? When the earth is 4.6 billion years?😐it does not make since 😓the universe could all ready be infinite and we are just living in mot just planet but a patch of it 😐also you say entropy ALWAYS increases so why do scientists say the universe had very low entropy ? 😐you say it always increases so explain why and how entropy was low 😐?

You heard the infinite monkey cage?

@@n0body550 it's great.

totally agree with you

Yes time only runs in one direction, from past to future. You cant go into the past unless you have a camera and you can record moments of past and see them in future. That's the closest we have come to time travel. Otherwise tangibly its impossible to go from past to future or future to past because you will disrupt the very laws of universe. Thus time travel is impossible and time runs in only one direction. Time travel is only a myth and fictional.

I honestly don't think it's impossible. I'm more of an optimist in this. I believe everything is possible. Anything you can think of: monsters, time travel, lightsabers and what not is creatable.. the only thing standing in the way of those things being created are the laws of physics, which can certainly be defied or surpassed but only with enough knowledge of course.. I basically believe that our thoughts are all realisable, some are just held back by the laws of physics since we don't know enough to surpass them

Pretty sure he was in a rock band in his youth!

@@avocajoe1916 D-Ream were not a rock band, pop...and he played keyboard!

@@Gavinlovesfishing haha thats even better tbh!

Truth is his students think he's a shit lecturer at uni

Try telling him aliens don't exist

hahahhahahah

Yes time only runs in one direction, from past to future. You cant go into the past unless you have a camera and you can record moments of past and see them in future. That's the closest we have come to time travel. Otherwise tangibly its impossible to go from past to future or future to past because you will disrupt the very laws of universe. Thus time travel is impossible and time runs in only one direction. Time travel is only a myth and fictional.

I like he said " in the 19th century ". Like, i know i was born when the first ever nintendo came out, but its not that long ago lol.

@@asahmosskmf4639 but you were not born in the 19th century ;)

He also has a painting in his attic that ages so he doesn't have to. True story.

He's grade A , moron !

@@MrHoldemace 1. He evidently isn't. He literally has credentials that stand up to accreditation and published works to prove so. 2. He's far more accomplished in his life than you'll ever be in yours so why you'd make such an idiotic statement I do not know.

@@Nine-Signs Accomplished because he was a singer firstly . Memories of education means jack , real physics disagrees with dogma .

@@MrHoldemace 2:05 I'm surprised he didn't build a pyramid 😉

Yes, but entopy has nothing to do with ''time''. Non sentient entropy is not ''time''.

@@user-ky5dy5hl4dI think the past has a lower entropic state which is why it’s always going forward, although it may have nothing to do with entropy as time is a dimension

@@Why_did_RU-vid_add_handles How do you know that from the lower entropic state the past is always going forward and not backwards?

@@user-ky5dy5hl4dTime is a human concept - at least the way we perceive it. Our brain is hardwired to detect the vector from a lower state of entropy towards a higher state, and represent it in our minds as a "feeling of motion from the past towards the future". Just like we perceive electromagnetic radiation within certain wavelengths as "colors". It is all immensely practical for survival, but not necessarily physically correct.

@@thomaskolb8785 Entropy does not go from a higher state to a lower state. It goes from low entropy state to higher entropy state. If it ran like you described then time would run backwards. But anyway, entropy has nothing to do with ''time''

I started reading a Stephen Hawking book once. A book whers he had, he believed, dumbed down so normal people could understand it. I think i managed about 25 pages. I dont ger this guy either. Surely when he made the sand castle he contradicted himself. Its not extremely unlikely that castles will be made in the sand or they wouldn't sell bucket and spades in the beach shops. The sandcastles get washed away by the sea. Not by wind. Its a good job this guy isnt in Dr. Who or he wouldnt wanna go anywhere "Nah. It'll just be sand by now". I spose at least the daleks would struggle to move about in it.

​@@themanfromvolantis Yeah, you really don't get it 🙂

There isn't really a place for pedants like you; especially in 5 minute video summaring entropy using no maths, aswell as avoiding jargon that would confuse the layman's. He's trying to make physics accessible, and your best rebuttle is to be quibble 😂

@@themanfromvolantis You managed to fundamentally misunderstand absolutely everything Brian said to a point where I don't think there is any explanation of physics possible that you would understand. It's really quite impressive how you utterly missed the point so well it could just as well not have even been said.

@Repent to Jesus Christ Repent to Jesus Christ IDIOT.

Yeah actually he does

There is a problem with Brian's claim. If increasing disorder creates the arrow of time then that means that time must reverse, every time entropy decreases and things get more complex. That include biological systems, evolution, human development and technology and that is clearly not true. Another issue about entropy is that it was formulated by studying gases which are fairly unstable. Not by studying solids like diamonds that can maintain structure for huge periods of time.

@@Andrew4HandelAre you also a physicist?

Yes@@kfalla1

@@Andrew4Handel Impressive. I so admire the way your mind works.

@@Andrew4Handel Yes, if it is 'highly unlikely' that entropy will decrease, that means that it CAN decrease, and therefore that would mean that (very rarely) time would run backwards. Entropy is a measure (perhaps a symptom) of the arrow time, not its cause.

The way i understood it is, time moves in one direction to the future because the future will have high entropy because if time would move all over the place or even a circular way, if you could go back in time freely paradoxes would appear such as going back in time and preventing your parents from meeting, etc. That would have low entropy because it would be very complex. Time being Linear would have high entropy, any other way will have low entropy. That's how i got it anyway. Sorry for my broken english.

The past is set so therefore has a low entropy, it is the sand castle. From that castle (time period), forces work against it like the wind in this video and allow for many possible futures, high entropy. The Arrow of Time is entropy. As time passes changes occur and once they occur they can never be undone.

CorsetGrace Agree with all but the last sentence. They can be undone and they do get undone like the sand castle. They get undone in what is essentially the present. However there are many ways that the future can be like, so it's high entropy, so that's why we're moving toward it, as you said. That's what I got out of it but I could be wrong. Just learned about it five minutes ago.

You are not stupid. Instead, the statement that "time moves" is nonsensical. Time is a mental concept. It has no physical reality. It's not even a true dimension: there is no freedom to move on it (in contrast to moving in space). It is always now. Don't take my word for it. Just check your experience.

CorsetGrace thanks for that... after reading it out loud a few times its kinda clicked

He got plenty of sand in his knickers.

Hairstyle is for a reason

Well, he didn't take a p*ss.

Who says he didn’t? ;)

Thank you! I was wondering.

@@tastyanagram there's always someone who knows the obscure.

Yessss

Strange that he's also talking about time, something the album does a lot of as well

haha i was wondering if anyone noticed that

OMG YEAH

Holy moly

since entropy always increases as time passes, time will not run backwards. If it were to run backwards, entropy will have to decrease which then breaks the law of thermodynamics.

+Kai Wen Lum _"since entropy always increases as time passes, time will not run backwards. If it were to run backwards, entropy will have to decrease which then breaks the law of thermodynamics."_ Unfortunately, there is a fatal flaw in this statement. Specifically, the _"as time passes"_ part. Or, to put it in synonymous terms: _"as time moves forward"_. That's the crux: the Second Law of Thermodynamics only tells us something about the case in which time *already* runs forward. Time running forward is the *premise* that is required for the Second Law to hold. Therefore, the Law can, by definition, never be used to explain why said premise *must* always hold. It's like trying to prove the existence of a God _[which I don't believe in, for the record]_ by means of an established truth that starts with _"If (a) God exists, then [...]"_. You can't prove a statement by means of another statement if the second statement relies on the first statement being true.

Yes. This is what they call circular reasoning. I think somewhere in the editing or production process the logical structure of the argument must have been lost. Now we're left with some super flimsy albeit intriguing nonsense.

Ahsim - As in with Maths, there exists Axioms. Without such preconditions, then the whole science cannot hold. Let's take cooking for e.g. baked 220 degrees celcius for 10mins and it's cooked. Granted varying atmospheric pressure it will change but generally speaking it will be cooked as designed. Let's take your presumption, that we cannot assume the thermodynamics to hold. However one would have to ask with all the observation and experiment that we know of to date, is there an existence that this holds, whereby time is not a factor? Hence physics theorem is as far as we acknowledge of the observable paradigm.

That's not what Ahsim is saying, dude.

Interesting. I found that for chemistry (since what was happening at a molecular level was rather abstractly related only to any experiments we could perform), but not for physics. We did little experiments regularly, practically modelling and testing whatever it was we were learning about at the time (well, except for a few things like radiation), and it was the hands-on link between theory and prac that I most enjoyed.

Unfortunately the physics you learn in school isnt all fun and games, rather it helps us solve earthly problems and make money. Thatd be amazing if it had even a little philosophy and pop science though, just to inspire kids even if they have to get down to the nitty gritty stuff first.

Yeah my physics class was trash too actually. Although it is entirely possible you as an adult now are well more rounded say Vs.. your highschool self :p So maybe finding these concepts finally tangible is a result of that.

Someone said to me "if you can't explain something simply, you most probably don't understand the subject enough". That's why Brian Cox and Neil de Grasse are definitely one of the best scientists.

All a load of tripe , next they will be saying we are descended from apes.and the only life in the universe 😂

speak for yourself I don't understand shit!

@@domantlen6231 Neil and Hawking have a way of explain science that makes it easier to understand. I love reading their books

@@brucedunn6845 both of those things are true as far as all empirical evidence would suggest.

I mean he was a rock star

@@meetaverma8372 in more ways than one 😉🤤🤪

HipFire_HeadShot agreed, but the flag is upside down, or is that entropy in action :-)

i spotted that immediately! well done

Yep quality work indeed.

That is why we must fight to protect its artistic integrity from the interference of petty fogging politicians who try and do it down at every turn - it is only one small step to Trumpism and one small stride from North Korean crack downs.

I admire the British for their artistic and intellectual integrity. (Aussie here.) Hopefully it always remains.

his appearance has low entropy

This was uploaded 10 years ago...

Except it’s not a theory and it’s not his either.

I think its his big head, we all know time runs slower closer to the centre of a dense black hole.

This was 10 years ago lmao

Level 0 you mean

ya stoned

@@markroper6644 …

but enthropy contradicts evolution

@@cloud42269 if entropy is the involvement of things becoming more chaotic and random over a period of time and evolution is a structured order of all things over a period of time; could we not see this not as one over the other but both, merely separated by phases or portions of time?

No. The castle of sand was assembled by a human being who thought about it using pictures, models of castles, and direct of real castles that were engineered by at least one engineer and/or architect, all of whom had brains with minds that directed their able hands! Those brains and hands were in turn designed by a SUPER ENGINNER, AN ARCHITECT AND the BUILDER of the UNIVERSE! The wind destroys the castle, and the body of sand does NOT "reassemble into some other order! The sand just comes back to the original state of disorder.

Bud, this is edutainment don't get it confused. This does not enrich you in any tangible, usable way.

@@jayocaine2946Anything that causes curiosity is enriching in every way possible. I am sorry that you cannot see that.

@@jayocaine2946 what a dumb comment

Lol

😁😂🤣🤣

United Kingdom flag. British flag is different.

@Tonald Drump aaahhh an idiot.....

@@deanmoncaster That flag is called the Union Flag and, by the way, it is upside down.

Tim Marchant BS

It demonstrates why time appears to travel in one direction for us, not that from every perspective or under ALL circumstances that it does.

I travel in one direction. Sometimes forwards, backwards even sideways! Never all three at once.

More like justin bieber

😂

Needs more likes

He had that hairstyle when the one direction guys were still swimming in daddys' ball soup.

One direction what? Your sentence makes no sense.

Same here. For some reason I struggled with the concept of entropy at school. This taught me more in 5 minutes than hours of classes did.

Well , according to Brian , it was inevitably going to become cool , sooner or later. 😉

Ur dad is stupid and so are u

The quote you are looking for is "If you can't explain something to a six-year-old, you really don't understand it yourself." - Richard Feynmann

@@gpr1016 Thank you xD

​@@gpr1016have you read his work it a little bit beyond a six year old.. I believe he was actually referring to his diagrams

Kicking around on a piece of ground in your home town, waiting for someone or something to show you the way

So you run and you run to catch up with the sun but it's sinking

I don't need more Cox in me.

You might want to look up the concept of arrow of time.

Time can be expressed by measuring a difference in entropy. The big bang had low entropy, yet now we have much higher entropy and it will continue to increase... Or something like that

Time doesn't exist, if it does, then it's merely a scale we use to measure the process of low entropy ==> high entropy

Almost had a stroke reading this small thread but I think I get it

en.wikipedia.org/wiki/Arrow_of_time Its the same thing.

It's almost perfect. Can i ask why do you think it's Namibia ?

@@skevakler There's an abandoned town in Namibia that looks a lot like this scene- empty houses filled with sand... it was the first thing I thought when I saw it too :)

thank the algorithm of recommended videos.

it is kolmanskop! the buildings match up, and i actually lived in namibia!

Adam Ryan agreed, although channel 4 do a lot of great docs too.

It could also be be with the death of the universe entropy falls back in time 😐or if it does not 😐time always goes forward then eventually leading to a new universe if you think about it the universe had very low entropy😐after all I have realized the universe could have some determinism to it as well after all we could have Ben anything or anyone so why are we human 🤔in specific points if this planets history 🤔it seems off 🤔

the bending of light in the presence of colossal gravitational fields leading to wormholes.

Yeah some more time on that would have been good. Presumably it's along the lines of, when you age & die your body might decay & be dispersed in many ways but the probability that it will reform as you with the spark of life is not equal to all other options, therefore it goes forward but not backwards? I'm guessing that's the inference, but it seems separate to why we wouldn't walk backwards & talk & think backwards - if we did we'd be unremembering so we wouldn't know we were - but we use gravity to walk (fall forward) so there's that, but it still feels only half answered.

He lectures physics at Uni of Manchester

@@MD-ji2ct oh great, I'll sign up for a course then !

Ask him to bild that castle for you 100.000 times... Then ask him if he is part of nature and why it would be rare if nature would have found it importand to show that sand castle many times to you. ;)

same

Same

same

I see the sand playing with a man.

In slow motion at times

Or the complexities of the sandcastle!

Yea but it could be that time is just an illusion 😑after all what do you remember before you were born ? That’s right nothing 😑nothing but darkness if you can’t even remember events before the day you were born what makes you think time had a beginning? 😐you were all ready dead for who knows how dam long 😑your mind can’t accept it beacuse your alive 😐the truth is the universe could be indefinitely old it’s just or brains can’t handle it 😑you have to think before you were born before earth before the soylar system before the milkeyway before if our milkey way is part of a merger or not and you have to think about the previous galaxies and galaxies That came before those all Those planets stars etc you would have no idea and before those galaxies ever came to be before who knows what else and even if the universe is finite you would have idea what caused everything to begin with and what happens before the moment of creation 😑this may be to much to your brain to handle 😐it’s just that you don’t realize it

Big bang and black holes can be understood by younger still. Head-to-head with Disney.

Agree. Bless Professor Cox, for he is a Meritorious person whose deeds will being many great things to Humanity, for the people he inspires, including your son, my son, and all the other kids who will grow up to become scientists