I pay for RU-vid premium and will always do so just to listen to his talks over and over. A big part of the reason I want to be a physicist is because of him.
Al-Khalili is a good orator and an intelligent man, some of his previous ('Horizon' etc.) appearances have been marred by directors trying to overdramatise what would be interesting in it's own right (e.g.'Shock and Awe') - which has incorrectly made him seem somewhat shallow. Kudos.
A classic paradox is the plot of Robert Heinlein's short story, "All You Zombies." Isaac Asimov also dealt with some of this stuff in his novel, "The End of Eternity."
It would be useful to try and develop an updated definition of TIME. We are so conditioned, (unsurprisingly), to the usual definitions, ie seconds, minutes etc. I am trying to imagine an alternative concept...This is so interesting!
Towards the end he made a faulty mistake. Says Alison would see the earth slowed down??? Wait. Hold up. Let's say our time reference be: 1 day on Earth. -Bob(on Earth) sees Alison in space. Alison travels around the Earth in ONE(1) day.(what he sees) -Alison(spaceship) sees Bob on Earth. Traveling around the Earth, it takes her 12 minutes to go around. Comparing Alison's time and Bob's time, Alison reached the destination in 12mins, but to Bob he saw it took Alison 1 day to travel around it. Alison's clock had to slow down, therefor she slowed down. It makes sense, have a speed(mph) on the y axis and distance on the x axis. You mark how far your gonna go, let's say 5 miles. You draw a line leading to the point(line represents time reference). The more speed you put, the longer it takes to get to the distance(u don't draw the line going, but a linear line plotted already[also describes that "time" and "space" is "framed", plotted out). Therefore, the more speed Alison put, or the higher it goes, the longer it would take to get to the distance. That doesn't make sense! I though you go faster from point A to point B the more speed you put in! Well, that's where I got confused..... But it's said that the speed of light cannot be crossed over, because if the ship really is going toward the speed of light, and Alison moves with it(her speed + speed of light) she is crossing over. The rules says that speed of light cannot be crossed over, therefore the effects leads to that Alison will slow down. Concludes that the rule is being applied to us right now. We are constantly within the speed of light, our molecules are moving because of it. The nature of movement is because speed of light/acceleration is already on us. Once we move, we slow down! The faster someone goes, the slower they get. However, each relativity of time differ within each moving particle. Considering the line graph we created true, we induce that whatever is moving the line is actually our time of reference. At the stable point of moving the line at the stable reference of time that moves the line in the line graph, must be the true time originality. 0.o someone who read this and isn't confused at all, please try to prove me wrong T-T this is what I think why time slows people in a more, sensible way!
At the start of this momentum, a special episode of Black Adder showed our two characters travel in a time machine to Leonardos design. All this time I thought it was not true. Long live king Black Adder.
They say there is more than a million atoms in the smallest dot the human eye can see with no glass amplyfi so if there are 1679007542114^5th power of atoms in the human body you could get a 3 d one dimension sender printer that is big enough to take in your 1679007542114^5th number of atoms in your body and the 3 d one dimension sender printer instead of using the right click "copy" it would use the right click "cut" and cut your atoms out of place and line the cross hairs up on a different planet that is livable and one dimension send 3 d print your atoms to that planet. But that technology would need to be able to calculate all the stupid little curves that each part of each atom has and one dimension I think is even smaller than one atom so that would be a lot of phazin from troom troom the happy unicorn have you ever heard of uniporn? Uniporn made by the RU-vidr unicole unicron cuz she is really hot and she has an awesome personality and she is interested in how China is making sex bots yeahyeahyeahyeahyeah yeahyeahyeahyeahyeah yeahyeahyeahyeahyeah yeahyeahyeahyeahyeah
Sorry about that! Too many characters, this is a continuation of my question!... How would you watch 10 years of video in 1 year of what's happening at home from the space craft and vice versa. How would you watch 1 year of video in 10 years from home? Would the video being taken on Earth and sent to the spacecraft live be played almost like in 10x the speed or something, and at home would the live video from the spacecraft seem 10x slower or so? I'm very confused by this, please explain! :)
How would time travel to the past be possible in the face of the second law of thermodynamics? Would it be permissible to have someone move from a higher entropy system to a lower entropy system? If the second law of thermodynamics holds that the entropy of our universe is always increasing, does this suggest the concept of parallel universes even more so, so that one can move from a higher entropy universe to one with lower entropy without violating the law of entropy in ones own universe?
On the Theory of Everything Laplace famously suggested that a sufficiently powerful intellect could, if it knew the position and velocity of every particle at a given time, along with the laws of nature, calculate the position of any particle at any other time: An intellect, which at a certain moment would know all forces that set nature in motion, and all positions of all items of which nature is composed, if this intellect were also vast enough to submit these data to analysis, it would embrace in a single formula the movements of the greatest bodies of the universe and those of the tiniest atom; for such an intellect nothing would be uncertain and the future just like the past would be present before its eyes. Laplace - Essai philosophique sur les probabilités, Introduction. 1814 Although modern quantum mechanics suggests that uncertainty is inescapable, a unifying theory governing probabilistic assignments may nevertheless exist. But, man can affect changes in the universe in an undetermanistic fashion (Laplace's theory is only valid if man didn't exist). The Bogey of Determinism Let's suppose that determinism is true, that there is some set of human conditions C that are jointly sufficient to bring about an event a, in this case an action, which changes the movement of atoms in the universe. For anyone who knows the theory "C causes a," a is predictable from C. But now let's suppose I find out about this theory, and it is my action a that is in question. The set of conditions C is no longer complete, for there is now an additional condition - my knowledge of the theory "C causes a" - and so we need a new theory, according to which we can predict action a1, from the new set of conditions, C1 (C plus the fact that I know C causes a and the complications that brings about). Now let's suppose that one of the conditions included in C1 is the fact that I am a dishonest person, Accordingly we can be sure that in our new theory, a1 will be a different act from a, precisely its opposite where it is possible. But now we have a new theory, C1 causes a1," which takes into account this dishonesty and includes it as a variable in the theory. But suppose I come to know this new theory, thus adding a new condition to the set of condictions C1(C2), Out of dishonesty, I will now act in such a way as to falsify that theory, too. But, of course, a new theory would would predict that also, (as long as I don't find out about it.) Even if determinism is true, no one can know in advance what they are going to choose, not even a sufficiently "powerfull intellect." Determinism, then, is not an intelligble thesis. In other words, we can accept determinism without concern if we exclude humanity from the universe. Einstein's discovery that time and space are illusions does not mean that determinism is valid, that the future has already happened. It means that time and space are relative.
is a headech to try to get this thing in order,but what i can think of that if we know that time is relative to speed or gravity we could count back untill we start counting with a minus in front of the number so may be thinking , it mean that we have to travel at the spped of light where time is zero
Time and space are two different things.....you can have time without space bcoz time does not take up any space and you can have space Frozen in time while time continues on....like a picture of yourself Frozen in time while you age on
I like to imagine that a person going into the past creates another timeline that does away with all the paradoxes, effectively creating another universe where he lands at the specific time that he chose to be in in that other newly created universe. "Parallel universes" does not have to be only two or three or so universes. It could mean an infinite number of universes, each one coming into being by any of the infinite number of ways there can ever be. There are those who muse that at the other end of a black hole could be another big bang, another universe. Perhaps the energy released by a supernova and its resultant black hole is the key. Harnessing it might just enable one to "go back into the past" creating another universe.
Why bother ? You can do that right now. We do time travel all the time. Our minds are our time machines. Following quantum physics, our physical world is just an illusion. The metaphysical world that is not observable and not knowable by humans is the real reality, and we navigates in there with our minds, through memories, dreams, imaginations, beliefs, conviction, faith, ….. and we create new illusions , or new physical worlds like landing on the moon, blacks and whites live like brothers, and money. It's that simple. May the love and the peace of Jesus be with us.
44:46 answer to this question should have been that our math shows that time travel is possible, so ruling out time travel is not the simplest solution. Explained at 25:04
Einstein said = If your are moving with respect to me, we shall not agree upon the rate of flow of time, your clock runs slower than mine when you move, and all processes that change with time change at a slower rate when observed in motion, one clock does not beat out time for the whole universe, a separate clock is needed for each state of motion , ,
IF any changes travelling in the past would only take effect in a separate universe what would be the point? when you return to "normal" time nothing you attempted to change would have happened in the universe you are in
Was that last question not answered correctly or at the least incomplete? If the clocks change then it's more than perspective no? I believe that's what she was aiming for.
35:36 "At a certain time Leonardo da Vinci had in his possession the Mona Lot painting. But at no point did he ever _paint_ it". The same actually applies to Skynet's original CPU, which was extracted from Arnie in the first Terminator film. That CPU, without which Skynet couldn't exist, is also caught in a time loop and it was never developed, designed and manufactured. It is just highly advanced technology taken from the future. This is called a predestination paradox, or "bootstrap paradox", named after Robert Heinlein's novella "By his Bootstraps". By extension Skynet itself and all of its terminators and other robots are a huge predestination paradox and thus couldn't exist, assuming the Terminator films reside in a single timeline. There's no problem with parallel timelines, which is how Avengers Endgame handled time travel.
if Alice travels at the speed of light in front of Bob within his view, back and forth for 1 year, from point a to point b, do they still age differently? what's the deal here?
Yes. Thats basically what girl asked at the end. With our brain developing in everyday physics we cant comprehend mechanics beyond rules we are hardwired to obey. Here's another brainteaser: if Alice travels away from Bob at exactly the speed of light - can he see her at all?
i think we have all missed the bigger pic here, if time is relative to the point of view if the position of the viewer, and gravity and time are woven but may suffer from "dents" in places, im going to assume that both light and protons may be influenced by the fields of time and gravity are we ie earth in a "dent of time and gravity"? are we able to see in to the "past with" telescopes??? and is our universe the age we estimate it to be?? if we take the theory of relativity seriously we have no idea what happens when outside our solar system. just a thought.
To answer some comments below. A time gate and time machine are 2 different things, you wouldn't be able to kill ur gran dad using a time gate because it will only send you back to when it first started. A time machine can move thru time and take u back to kill ur gran dad. Also u can't observe in real time using video camera someone moving at speed of light when on earth as the signals don't move infinitely fast and their would be a delay in the transmission for either party simple.
I was informed, whilst there in reality, that time moves more slowly when standing as close as possible, at base level, to th great pyramid of Gina. Of course it's by an infinitesimal amount but indeed calculable as a steady rate, just slower than it would be if you stood 250 Metres away. I don't know if this had something to do with th pyramids structure, shape or whatever or th fact that th closer you are to a vast solid structure, it has th properties of some mathematical physics anomaly? It was difficult for me to judge as th air was shimmering due to th incredibly heat, making it difficult to see if th view ahead of me, of moving vehicles & people were indeed moving more slowly. It appeared to be a reality as I concentrated on th scene, like watching a slowed down film. Th effect was very strange. I"be not heard anyone mention this before (My experience was 27yrs ago)
It's as easy as cake. If you travel in time independent of your timeline you will end up floating in space, or in a star or anywhere except the place (on earth) where you started your journey. If on the other hand you travel back over your own timeline, everything that happened must un-happen, so you will not know that you have traveled in time. Third option: travel both in time and space, but you will need to steal a TARDIS to do that.
Question about light: Astronomists say that we can look at stars (quasar, galaxy) 13 bilions years from us, Brcause light tooks 13 bilions years of travel to rech us on earth, My question is: how light of stars reched us after 13 bilions years if we (the earth) was there (not yet formed) with that stars (or gas) at that same time when the universe was formerd ? I give you a sample in order to clarifying my tougth: If am sitting in the same place of an event (let's say a car crash) how can the ligth of the car crash arrive to me after 13 bilions years if I was there in the same place were that event (car crash) took place ?
There are many ways to travel faster than the speed of light. Entanglement, memories, dreams, imaginations, or beliefs all can travel at speeds faster than light. When we travel at a speed faster than light, we don't travel to the past but we can observe the past in reverse order. We can travel to the future even though the future has not occurred yet. We can visualize, or predict the future. All these can occur in the same universe, we don't need parallel universes to do that. Parallel universes assumed that one universe cannot cross to the other. When we observe the past or imagine the future, can we interact or change the past or the future ? The answer is not the past but yes the future. We have lots of time machines. For example, drawings, photographs, motion pictures, our memories, are all time machines which captured the moments in time and we can play back at will. When we observe the past like watching a motion picture or like observing the past in reverse while travelling at a speed faster than light, we can only observe but we cannot participate, interact, or alter the past. But the past can affect us, our emotions, which may in turn cause our actions one way or the other. So, because of the fact that the past can interact with the present, and in turn the future, the past,the present, and the future are all in the same universe, not parallel universes. Our dreams, our imaginations, our beliefs, are time machines too. With these we travel and observe the future. Like we are now living the dreams of MLK, we and MLK are in the same universe, not parallel universes. There is no guarantee that the future will occur in the same way we dreamed, imagined, or believed it will though. However, if we have faith, or a strong conviction in our beliefs, the future's future will eventually play out what we believed. May the love and the peace of Jesus be with us.
shooting a photon at a slit of any measurable size would be like shooting a tennis ball at the earth...the only way it could go through either slit would be if you aimed to either side, so we should never see interference patern
As a programmer I have made programs that accidently have an infinite loop. They cause the program to crash or lock up. If the universe is just a big program then perhaps this can happen? Who's to say that it couldn't? Why does there have to be an explanation around it?
+B L i have an even silly theory, the universe has already collapsed in to a black hole, we cant travel back in time due to gravity, we can travel forward as we are "facing forward" in to the black hole, and the universe we see is in fact just a photon "in print" on the side of a black hole, witch would explain the lack of a defined view of the universe, as gravity from the black hole will only allow a view to the past and an enlarging universe, with is in a reverse image, as its actually our universe slowly being sucked in to the black hole.
+nomad nimoi you have a conjecture, maybe hypothesis ... but not a theory ... also, it's wrong ... universes can't exist in black holes, white holes have been shown to be mathematically wrong ... and the thing about gravity not allowing to go back in time is even more preposterous ... But it's good that you have ideas and imagination, don't give up, you just have to learn a little more about astrophysics.
The twin paradox explantion is not correct. Acceleration plays a small part in the time delay. The real delay however comes from velocity. The paradox remains unexplained.
I believe time travel into the past because, any object would defy the law that no mass or energy in the universe is created or destroyed (they just are converted).
Point of view is a good point as he keeps saying time ,but that is just our point of view is it not? The universes equivalent is entropy...Think thats the right word anyway...The steady rate of decay. But if this is so we need to re-think how we track time like the point raised at the end we still track it in a very primitive way
Time travels at the speed of light, when I see you move relative to me, I see you catch up with time, i see your clock run slower than mine, , , S=D\T, all processes that change with time change at a slower rate when observed in motion. , ., , so, If you move at 99.9 % C, I see you move at just 4.5 % C, , , Zero mass particles move at V C, because they are moving along with the ACTUAL expantion of the universe ?
Except that you don't come back to "normal". By going back you have created and you live in a new branch. If you go in the future again, it would be in the future of that branch, not the one you departed.
Time travel to the past does not make sense because it's not possible. The events between the present and the past you want to revisit only exist in mind. it’s not possible to have those events be in 'actual' existence for your manipulation'. The paradox of parallel universe is just a creation and imagination that is being used as an end to the earlier paradox of time travel to the past. Let's talk about the future!
Exactly. Our minds are time machines. Following quantum physics, the past, the resent, and the future are not the physical illusion we observe, but the metaphysical, quantum reality we cannot observe as humans. We do time travel all the time, with our memories, our dreams, our imagination, our predictions, our beliefs, our convictions, our faith, …… We are currently living the dreams of MLK, and the predictions of Isaac Newton. See ? It's that simple. May the love and the peace of Jesus be with us.
If it will be, then by definition, it was. Or, more accurately: it will was be too. But everyone's missing the *real* question. The world is spacetime, not time. If you travel back to the past, what's to prevent you from landing out in the middle of Outer Space where the Earth "used to be at"? What even is "used to be at" when motion is relative?! So, in reality people who talk about time travel, while taking so much for granted to not even mention it that they will somehow land in the "same place" (meaning on Earth) are what we call *You* *Got* *Busted* for being closet Absolute Motionists! (They're tacitly assuming the Earth is like some kind of absolute frame). You can't have time travel without space travel and teleportation. It implies the other two, because the world is not time, it's spacetime. And you *still* have to answer the question: how are you controlling spatial location for the trip's destination?! There won't be any paradoxes. You're be too busy suffocating out in the middle of Outer Space where the Earth used to be, to spend any time getting to your grandparents to kill them.
+Nautilus1972 But The Pig and Whistle doesn't exist in my dimension dude. What do I do? I am enthused by the idea of being in the club. What's my next step?
We are made up of cells that age and die off. What about the biological clock of cells in our body if the twins - Alice travels into space and Bob stays on Earth. Will Bob's cells age more than Alice's?
'Time' is the 'Shadow' of Motion, movement. Where We are, is no time. Time do Only exsist in Our Consciousness. We cannot 'travel in time', time is the result of the travel. The Ablity of Sensing in Time, mostly happends in glimses, de'ja vue, past, more often than future, these experiences happends spotaniously, not controlled by the Will. The Ability of Sensing in Space, refer to syncrone experiences, here and now, somewhere else, in space, less often than Sensing in Time, and also these experiences happends spontaniously in glimses, not controlled by the Will. But in the future these Abilities is going to be permanent abilities under the control of the Will. So according to the indiviual Ability, and purpose, We can 'Thought-travel', the only limit is the potential of Our own Abilities, desire, interest and purpose. We are 'Stillness', our thoughts and the Stuff-side, is motion, (Motion-Ocean) it is the 'shadow' of motion, that We call time. Amount of time, is compare to other amount of time. We All make Our very Own time. The motion become time, and time become time-spaces in our Memory, periods of living pictures, memories, experiences in our memory- and destiny-archive, in Our Memory-Body corresponding with the memory in our Day-consciousness. So, timetravel, artificial Intelligence, racism, are in the same helpless science fiction-superstition imagination, drived by pure whish-thinking, with no relation to reality. Over weight of emotion on the cost of the intelligence.
traveling info past is not possible because for us massage of time is related to forward emoticon of earth. to travel in past, one has to travel against the motion of earth, with the velocity few times that of earth. this velocity and travel in the direction against that of earth would be diceded by the time frame in past you want to reach. but in doing so the velocity has to be few times that of velocity of time or earth that exists on earth. To eXecute this plan, you first have to travel in future for fee moments then turn to past by increasing opposite acceleration.
Its interesting the point where he says if you can build a time machine the earliest you can ever go back in time is when the machine was built.. that contradicts his earlier willingness to entertain the grandfather paradox outcomes.. If you cant go back beyond when the time machine is built then how could you assume a person could go back before their birth and try and shoot their mother or grandfather ? under that logic the question of a paradox becomes moot because you couldn't pass the point of your birth.. Also how do you define the moment of inception for a time machine ? Is it when the last screw is drilled into the chassis ? the universe then official recognises anybody trying to time travel beyond this point will fail now because the technicians have placed the final screw in the machine ??
If the time machine was switched on today and left running for hundreds of years, then someone could travel back in time in and try to kill his grandfather. I couldn't, since the time machine didn't exist before I was born but for someone born a hundred years from the day the time machine was switched on could try it. There's no contradiction.
I understand the concept.. ie: the precise moment we are able to access time travel is the line in the sand the universe draws on where we can travel back to.. except..... its contradictory to think a human could travel before their own genesis when the machine cant travel beyond its own creation.. also the idea that we could break free of time but still be hamstrung to a secondary timeline on when things are discovered makes it nonsensical I think.
maybe john connor is not fully in the past? maybe he's in a dimension outside of the dimension that the past existed? so he cannot interacted with the past only observe it
