This Time Paradox Is Terrifying Scientists! No Solution! 

"Science and science fiction are the same thing" William Shatner.

That's crazy it comes back faster then it went. It's just like being on a long car ride it always seems to take longer going but on the way back it seems almost 2x faster. So I guess if you want a long life always move forward don't waste your time trying to go back!

That was awesome. Love the different explanations. ♥

We just need the next visionary to be born. Seems like over a certain period of time a person is born to solve a huge problem that pushes the human race forward. We had those who proved the world is round, those who imagined the laws of the universe, the crazy old man who thought of relativity, and so one. It’s like certain people are born to solve a problem so the next person can move forward. Not saying it’s just part of the plan, but it’s interesting to think about.

The Grandfather Paradox might have a solution...if one theory is correct,when you go back in time you go into another dimension,so you kill that dimension's grandfather not YOUR grandfather,thus no paradox.

The solution is quite simple: travelling back in time to our past is not possible, the laws of physics does not allow it.

Oh good, another terrifying thing that isn't terrifying. Entertainment at it's best.

"What's really gonna bake your noodle later is would you have still broken it if I hadn't said anything." -The Oracle, The Matrix

I love the thumbnail. The astronaut has a young look and then 10 minutes later he's an old man with a neatly trimmed mustache and beard. How did he get neatly trimmed facial hair just like that? LOL

There is a way to avoid the “mirror bounce” method for measuring the speed of Light. It has been shown that, at a certain distance from a black hole, light entering a special zone on one side of a black hole will travel in a curved path (around the backside of a black hole) and will re-emerge on the other side of a black hole.

this is why old people drive slow

Damn, this video makes my head spin. Too much mind-blowing information, but it was damn interesting. Talking about time travel is a really damn interesting thing that you can listen to endlessly. And I love that I can do it for you. 🤗

Finding something I don't understand interesting for 17mins should be studied as well 😂

I think Avengers: Endgame did a good explanation of backwards time travel, where your past is your past, and if you travel back there, any changes made become an alternate, separate timeline, and when you return to your timeline, nothing has changed (multiverse theory). Other option is traveling back in time and you take a particular action, even though you think you're trying to change something, it ends up you were always meant to take that action (think first few seasons of Red Vs Blue, Harry Potter: ATPOA, or Interstellar) but that begs the question, as mentioned in this video, of where did the event start as it's seemingly stuck in an infinite loop. Time travel, although interesting, is probably a good way to fry one's brain permanently trying to figure out the how, why, and and all its nuances. Also consider, as mentioned in the video, we're on Earth moving. So how much slower is our time dilation compared to someone who is truly still in space, as we're roughly moving at 2.1 million KM per hour?

People who have taken psychedelics have more experience on this topic than scientists do 😂

Numbers, language and time: these are examples of mental constructs that help us to understand reality and each other. Much as we like to think that reality will bend itself around our mental constructs, it remains unyielding.

Thanks! This video really boggled my mind but I understood everything that was described. Thank you so much! 😊

time is gonna take a lot more from us before revealing its self.

Well done!

The narrator called the loops "casualty", but shouldn't it be "causality" loops?

With the theoretical device that he mentions, where flying a ship around a long tube that has essentially the density of a black hole in it, wouldn’t that only work up to the point of it’s own creation, because once you reach that point in time, you will no longer have the device to go around

“Time is a flat circle.” -True Detective, Season 1. Seriously, though, what boggles my mind is if it really is true that time is another dimension like space. So imagine every spacetime event with a “location” pin somewhere out there. So even if it hadn’t happened yet, it’s out there just like a tree in a distant forest. Crazy.

We have known for more than a century that space and time are inseparably linked. While this is a fun gedankenexperiment, round trip time might be the only way to properly define distance, so it's not that surprising that one-way time is undefined.

I was easily able to go back in time AND make time flow backwards.... after eating some "special" mushrooms.

At this time, I'm a hardcore "no" on the whole time travel thing. But I still enjoy watching films that involve time travel. So long as I ignore the 'how' and focus on the storyline, I'm good. I never studied quantum mechanics or string theory or anything advanced. Straight forward here and now physics involving potential and kinetic energies is my thing. I see time as a man-made construct, a method for recording instances in history in order of happening. For an instance to happen, all a certain type of molecules have to be in a certain place at a certain moment. The universe is how it is at that moment. The snapshot of that moment is labelled as happening at a moment 'in time". That's not to say that that same instance could never happen again (the monkey type-writing a Shakespearean piece likely has the same level of probability of occurring). But that's it; all the atoms and molecules are where they're at at that moment in time. So, how can it be possible to rewind time? I can get my head around travelling faster than light from A to B to see what is happening at B a little before people at A see it, but that's it for me. I've never been able to imagine a ginormous, cosmic camera that records everything that ever happened everywhere in which we can rewind the film to a historical moment, ie time-travel.

Excellent! Thank you!

If we take a moment and realize we can be both the measurer and observationist of ourselves we become participants and thus superposition our lives accordingly. As with Schrodinger's cat some look inward to themselves, others are the cat looking to get out of the box and some don't look to change anything at all. If you were to be confined in the box your the type to keep having yourself build a time machine (determined). If you're the type to look inward to yourself you'd realize the time machine blueprints aren't what defines you (super positioning). If you're the type to just get out of the box and not repeat the same fate than your the many worlds type (double slit experiments randomness)

Time is an illusion and so is our life

Grandfather paradox is only a paradox if you think in linear time where its always cause, then effect. In non linear time, this need not hold. It's not something we normally encounter but that doesn't make it invalid, just confusing. Of course you couldn't go back in time in the first place as going back just one nano second would cause there to be two of you in the same space at the same time violating both the Pauli exclusion principle and the conservation of matter energy.

I think that time is an illusion because time is only present and witnessed in the context of Thermodynamics and more notably entropy. Even then we witness it as humans in our own reality, it doesn’t mean that it can be witnessed outside of our reality. That is my two cents.

The two way light/mirror measurement is perfectly valid. The flaw lies in assuming measurement one way could be different from another. But since the earth, sun, and galaxy are constantly moving, rotating and revolving, directions are always changing. If light-speed depended on direction, it would constantly vary through the motions of the earth, sun, and galaxy. But we don’t see even a hint of that. If so, light from flowers to the left would appear to be a different color than the same type of flower to the right. But we don’t see that either. This may be and interesting thought exercise, but it’s totally flawed in reality.

Or traveling to the past could be like watching old home movies, You may be able to observe the past but may not be able to inter-react to it in any way shape or form. So no paradoxes would be possible.

There are no paradoxes of time only paradoxes of thought.

*Employer ....* "Why are you late?!!" *Employee.....* "sorry boss, got caught in a time dilation!!"

Time is just another way we use "something" to explain the unexplainable.

My question is... How does anyone really know that time is different in space? Has anyone actually experienced this time difference before?

Paradoxes are only an issue in linear models of time. It is far more probable that there Are three intertwined forms of time That exist in nature. In one of the forms, each particle wave is on its own partly separate Timeline. Another form Has 3 dimensions that match Each point in space. And the third form has an Infinite number of dimensions.

Time, in this definition doesn't exist. As time is only a measurement, like an inch, it doesn't exist outside of some activities to measure. For us, time is based upon the rotation of the sphere on which we live. We have, over time, found ways to more finitely measure these events, but we are still simply labeling the series of events / observations we make. There is only now. There is the hope of future events (tomorrow / future) and the remembrance of prior events (yesterday / past); but there is no scale to move forward and back upon.

Outstanding video. Very well done Destiny! 👏

0:25: 🌌 Understanding the speed of light is crucial to unlocking the enigmatic nature of time. 4:15: ⏳ Time dilation occurs as objects approach the speed of light, causing changes in perception of time, length, and motion. 7:58: ⏰ The concept of time travel and its potential methods are explored, including the Tipler cylinder and the block universe theory. 11:30: 🕰 The paradoxes and possibilities of time travel. 14:58: 🌌 The many worlds interpretation suggests that the universe exists in a superposition of multiple states, and each event creates a new parallel universe. Recap by Tammy AI

I think the best part would be that the person moving at speed light (like in Star Wars or Star Treks, you might not be able to record it as well on a video camera.

If you travel through space , the faster you go the less time you will have to react, steer. Doesn't that mean that traveling reqires time, mostly as control. If you have more time you have better control, and you have more time if you move slower.

The so-called paradox of twins is probably reversible - similar to distant figures that "appear" smaller to us, but when they get closer they "grow" to their original size.

Could we ever comprehend.....who created these rules & who set all the creation/existance bound to follow these rules ie the laws of nature.

I really like your channel they make learning fun

The multi universe is a fun concept but the universe does not have endless resources to fulfill everyone's time travel fancies. It's still a finite, physical place.

Consider this! Like you said towards your end of your video! "Consider this" , What kind of plant growth have you been smoking??? LOL 😛😃🤣😂🤪😜😎

time travel could be actully quite simple when your consciousness is creating spacetime, in that case it would create the future looking like your past while you travel, but its not your real parents that you meet since you are not back to the same spacetime coordinates thus anything you do like killing your parents or even the copy of your younger self has no consquences on you

I'm fairly convinced, multiple world is not only a theory, I had several occasions when some of my belongings were traveled between dimensions, disappearing in our dimension, and reappearing some days later on a completely unrelated place. Even my family was puzzled sometimes when like my wedding ring was disappeared, when we were at my mum. We know it was there, because I have showed them to family. That evening the wedding ring was diasppeared while we were in a pub. We looked for it everywhere, but couldn't find it. A few days later when I travelled back home from my parents, it was on my bed. It was the same ring, with the same markings on it. Just travelled through time and space.

Nice video

I bet you can't find _one_ scientist who's "terrified" by whatever you're going to talk about.

if you want to not be affected by paradoxes in sci fi just say that you quantum entangled yourself to an indestructable\unaffected object, like a black hole and as long that exists you exist in any timeline, it's like being watched by a 3rd person camera in a video game, as long as the camera films you, you exist whatever you do to your grandparents.

Time doesn't exist, it's just a measuring tool invented by people.

In the case that past, present and future exist all at the same time, it is not that you don’t have free will but instead it is that you already used your free will and made you decision and can not change what you have already decided and done! That’s exactly how I feel all the time, like I know that I have already decided just don’t know the decision yet !😊

The science fiction concept of time travel predicates on the notion that the traveler will retain his future properties as he goes into the past, which will mean he *could* affect changes in the past. Picture, on the other hand, that with past travel, you revert to your past state, and even past position. Not as exciting, but would certainly prevent any paradoxes.

Someone already built a backwards time travel device that allows for information to be sent back in time. He switched it on and no messages came through. This suggests that there may be a law within physics that prevents backwards time travel. It also implies that time has a linear flow, even if all of time is in existence.

I met 4 scientists who are so terrified about this just yesterday.

I argued with my teacher while in school that the speed of light couldn't be a constant if time wasn't bendable... while at the same time it couldn't be a constant if time was a variable... I used the rotation of a planet that a star shone upon for reference. on one side the viewer is moving away from the light meaning it's relative speed is reduced, while on the other side the viewer is moving towards it meaning the relative speed was increased. I also argued that the universe was proof that either energy could be created from nothing or cause and effect didn't have to be linear... we tried proving/disproving it by making som calculations with a timetraveler that went back to before the big bang to see what started it and entering a 0D space meaning that space went from nothing to something in pretty much no time since time is a effect of the physcial laws reacting

this may be unfitting, but the legacy of kain series (a game treasure) has wonderfully included the self consistency theory in their storyline although with an interesting twist

Time travel paradoxes always make me roll my eyes. If you could theoretically travel to any point in time, the act of travelling, as well as your mere presence at that point, would cause ripple effects that could not be predicted. The Multiverse is about Balance. Imbalances are ALWAYS corrected.

In my opinion on the subject, time always moves forward, no matter how fast you go. I don't think there ever will be a way to travel backwards in time, but I do believe at some stage in our existence, we will develop methods of travelling forwards in time.

One of the best videos on time dilation... Life is surreal but we take it as real until the last day when we truly realise that it was just a passage of time.....

HELEN: Is that the time? MIKE: No, time is an abstract concept. This is a wristwatch. The Young Ones - Time Written by Ben Elton, Rik Mayall and Lise Mayer.

If you shine a torch in the direction of travel while traveling at the speed of light you will never see the light because it would never leave the torch because it is already traveling at max velocity! If you turned the torch to face 180 from the travel direction and move the torch in the direction of travel, then the light would start at the start position on the torch and extend to where the torch stops moving and just stay there, never to go away, even when the torch is switched off!

I feel like the grandfather paradox is when you kill your own grandfather then go back to the current time but seeing yourself isn't disappear yet and it's probably because the time machine doesn't go to your previous parallel universe because your parallel universe doesn't exist so it bring you to where you exist with different answer to why you still exist

grandparent paradox: if you travel back in time and prevent your branch of the family tree to progress to where you were born, a new timeline might be created, or an alternate reality in the multiverse. If that is the case, then there's no longer a paradox.

Human imagination isn't enough for the reality.😅 Man! i wish God let me sit in front seat with him and watch everything😊

The best read on a topic adjacent to this one is *Dean Buonomo book from 2019 "Your Brain is a Time Machine: The Neurosciences and Physics of Time".* The reason why time itself and the way it is experienced by humans is a paradox, is because the rate at which our central nervous system is moving in relation to our acceleration, our efforts and gravitational position in relation to objects, is always changing to accommodate sympathetic and parasympathetic feedback loops.

Anybody wondering how a species that can only get a person about 400 miles from the surface of the planet can make such bold declarations about the nature of the universe???

If you go back in time, your past becomes your future. It is counterintuitive, but think of it as a sort of insertion of yourself into the past and the timeline. You exist, go back, insert yourself and still exist. You need to understand time more in a space-time correlation. For instant if you have an apple in the room next to you and you don't see it, the apple is still there (most likely at least. It is not, if we live in a simulation.) Think of time as the two rooms and of the apple as yourself. If you take the apple from one room to the other, the apple still exists. The apple exists unconditionally to time, because he once started to exist and wasn't deleted. Both rooms exist simultaneously, it doesn't matter what you change in them. I think i explained it poorly, but that is my theory.

"Time is an illusion, lunchtime doubly so." Douglas Adams

Hearing that just brought tears to me because I may have been 4 or 5 but quite possible i seen this take place thinking it was the north star i was looking at but when it got tiny gradually then go red and still gradually got smaller i knew at that moment that was someone leaving us, it did terrify my thoughts but was calmed down from noticing it leaving and not coming

Want to hear something truly terrifying? Several years ago I got to the realization that time dilation proves we're each the only conscious observer of our own universe. By this I don't mean we're the only ones perceiving our own thoughts from a certain experience: I mean literal physical reality and the entire universe must be unique for each person. Here's why: Two people, X and Y, walk to a space ship. Only one of them, let's say Y, boards this ship... X stays behind on the ground and waits: The ship will travel at 99% the speed of light for an hour with Y in it, then land at the exact location where it started. Once the ship returns, we know that Y will find a slightly aged up version of X and the entire Earth; Even if time passed at the same rate for each person relative to their own body, there's a desync between their perception of time from each other. Now here's where it gets scary: Both X and Y are consciously perceiving different points in time now, meaning different versions of reality and each other. They both chat after the ride is over, but the person staring back at them is no longer the same observer: Each consciousness is in a different reality perceiving a different version of the other person, one in the past the other in the future. From here on they may each make their own choices and go on to live in different physical realities from the other observer: To X it's possible Y died an year later, to Y he might still be hanging out with X from his perspective... or X experiences a version of Y who had an accident and was left with an impediment, while to Y he never had that accident and is just fine. I've thought about it many times and it's the only option that makes sense: Physical reality can only be the same for all observers if everything is synced up. As long as time dilation exist which it clearly does, we each end up in the past or future compared to others; Merely getting on a train or plane makes you desync from someone who is staying at home, heck even walking past someone sitting on a chair does it to a miniscule amount... at that moment you're automatically no longer perceiving the same physical world as the other person. So who is really staring back at me whenever I talk to another person? Is everyone else just a representation customized to our own reality, like a character that can do different things based on what you do during that particular run of the game? Someone will read and may even reply to this message, but in their own conscious world I might already be dead or never been born... so will any consciousness but my own actually read this exact message I typed here? How creepy but also cool it is to ponder this stuff!

The universe is not causal…it operates on retro-causal principals. That’s why particles know before hand, what you will do and adjust…and explains why some people can see exact futures and then change them.

I saw someone say, "this is why old people drive slow" on here but, I accidentally refreshed the page and now the comment disappeared. 😢

Love your videos.

Fascinating video. Will have to watch it a few times!

Casualty loops? No! Causality, please! What a calamitous catastrophe! (... that's cat...as...troph...eee!) Phew!

Noether-Theorem: Every symmetry is equivalent to a conserved quantity. Esp. translational symmetry has conservation of momentum as a censequence. We have tested a million time the conservation of momentum, so we know that physics is independent of the place. Same with rotation symmetry and conservation of angular momentum (and energy conservation and time symmetry). This contradicts the idea of different speeds of light depending on the direction of the path.

10:08 He really says "casualty loops." Twice. Unforgivable.

I think this notion is wrong. Perhaps with speed, time slows down, and if you were travelling with such speed, after slowing back down, the time would realign with it's normal timeline ie. it would speed up to catch up. So in essence you wouldn't be X years younger when coming back, you would instantly age to catch up to the timeline you "landed" in.

The grandfather paradox is impossible. Traveling backwards in time is an impossibilty wnd of discussion, the atoms that made up that past point of time have decayed and cannot be reclaimed. You can travel into the future, but only by slowing your own relative time in comparison to others' relative time, but it isnt the future to you, its still YOUR own perceived present. But even if you COULD go back onto time, the atoms that create you are in existence, they cant just "vanish', and now your atoms exist in that past time, so therefore there is no reason why you shouldnt exist in the future. Either way, the genetic material that makes you, you, exists. Whether not yet combined, or already combined.

God who is outside of time created time to give us a period to accept or reject. No time is not fluid and will one day run out. Choose wisely

'....casualty loops' (sic) sound painful. Causality loops - now they're a different matter :-)

Going back in time violates energy conservation and thus is not possible. Anything that goes back in time and meets itself in the past means duplicating matter, the atoms going back in time are the same atoms that will be met, this means creating matter out of nothing. Traveling back in time not possible.

Big difference between "casualty loops", what you said, and "causality loops", what you meant to say.

It's not to solve . . . It's to be accepted, and likely never understood.

Great Scott!

Clocks don't measure time. They measure motion in space expressed in units of time. Just as rulers don't measure inches but length express in units of inches. The value of the second doesn't change, just like the value of an inch doesn't change just because the ruler expands and contracts with changes in temperature.

Time is configurational change -- in its most comprehensive sense, the word time refers to the evolution of our universe. Time dilation is the purely symmetrical artifact of the clock synchronization convention. Differential aging, e.g. clock slowing, is a result acceleration, which affects the frequencies of oscillators. The past only exists as records, recollections, etc. The future only exists as projections, imaginings, etc. In reality, there are no time travel paradoxes.

instructions unclear, have monkeyed with a clock until it became a typewriter

Issue with constant being one of the paradoxical group of terms known as absolutes. It doesn’t necessarily mean the terms in it are useless because as it relates to comparative observability, they do have their uses, as long as they are treated for what they are, including a resolving of the statement that it cannot even be absolutely stated legitimately that there are no absolutes. Regardless, it used to be regarded that light travelling only in a straight line until they hit something with blocking, reflecting or refracting capabilities was also a constant regardless of any other mechanic out there, but now it is understood that it can also be redirected by the extreme gravitational force of a black hole. I know I’m no professional, and it’s rare that, on this stuff, I can say stuff with any sense of conclusiveness, unless it’s to call out people confirmably with a certain addiction induced complex, but I will admit I can be happy to share that bit, at least. Also, mostly hyperbole, I know, but going on what I’ve picked up on relevant stuff with a hope that it could maybe incentivise an exploration of the concept, but… if there might possibly be a mechanic called temporal diversity, facilitated by there being more than one temporal dimension, too, maybe even a temporal equivalent of x, y, z, etc, etc, as well as the nature of how matter interacts with other matter in its path, maybe with a cost to it being, to quote a phrase loosely, “You can never go home”, might it be possible that temporal diversity resolves the grandfather paradox? Like I said, nothing more than hyperbole and I’d rather hope it doesn’t get picked up by these people I prefer to call out, but… I do like to consider it’s worth exploring at least.

The block universe theory is supported by special relativity. It describes space-time as an unchanging four-dimensional "block".

I said "wow" at least 3 times during this video. Cheers ❤

i've watched so many videos etc on this topic and still cannot wrap my head around the concept of time slowing down

What we call time is just what is, a word. What probably isn’t mentioned in this video for good reason, is that what we call time sometimes speeds up for 1 observer and slows down for another. It bends. Don’t we say multiple times: times passed so quickly. Another at the same “time” sais the opposit. Time travel will only be able if we could liquify our bodies and the the paradoxes come at play of which we could potentially never observe a different result because we can’t change our 3 dimensional perspectives. So many laws prohibit us from moving through time as if we were meant to live in the moment and observe.

This reminds of pi (yeah the thing that starts of as 3.14159), it never ends and never repeats. Within it, you will find your birthday, death date, social security number... any of them out of sequence or all of them in any sequence. It’ll include every single number or series of numbers you can fathom. If you assign the letter A =1, B = 2, etc you’ll find somewhere every book ever written, every word known, and probably every thought you’ve ever had.

7:37 "Time is a UNIdirectional flow..." 10:07 "Such a world would be full of CAUSality loops." Proofreader/listener for hire, reasonable rates. 🙂

Philip J Fry became his own Grandfather.

I'm sure there's a god answer/response to the following but I've never seen either point being addressed. 1) The twin paradox always deals with one twin staying at home and one speeding away in a spaceship and then returning. The direction of acceleration and movement for the space-twin is what causes the end result of the earth-bound twin bein older, even though they each saw the other aging slower. It's also said that if they never rejoin in the same inertial frame, they never had to resolve the difference. But what about two twins that leave Earth in opposite directions and then return? They should both still be the same age, right? But they saw each other staying young. 2) Gravity and acceleration are stated to be indistinguishable and people talk about how you can't tell if you're in a room on Earth or in a room in a spaceship accelerating at 1G. But there's very EASY ways to tell the difference. Drop two objects. On Earth, they get closer together and on the spaceship, they remain exactly the same distance apart (well, actually, they WOULD move close together due to the gravity between them but that can be factored out.) So at the very least, saying "gravity and acceleration are indistinguishable" isn't quite accurate, even if it does help illustrate an idea.