Is Time Travel Possible? | The Science of Doctor Who | Doctor Who

Would Jim age BIOLOGICALLY slower if he traveled at nearly the speed of light?

For everyone commenting that time travel is possible, you should probably watch Brian’s debate on how he knows it’s impossible to go back in time 😂

If Jim's clock ticked faster than our clock then surely also our clock ticked faster than his (from symmetry)? This would suggest that no time travel occurred. Have I missed something?

If someone travels to space there time moves slower thereby travelling to the past

No, time is a constant , it’s irrelevant at what speed something is traveling at in relation to time . The only respective in this experiment is the perception from different locations , however the movement of light is still the same even when two people see it differently from perspective . The actual movement and time it takes is not different it’s only perceived to be different . Time travel is not possible and only exists in complicated hypotheses .

this is the only reason why i want to become an astronaut to outlive my parents 😂

Yes time/space travel is possible. And you don't necessarily need a so-called 'time machine'.

So it’s possible to travel into the future, but not the past?

If we had teachers with as much enthusiasm as the Prof, British kids would have a much better chance of success. The man is a genius.

Concept

What if Doctor Who had Hotel Oblivion from the Umbrella Academy of his own?

I don’t get it. If we reversed the experiment and the person moving was looking at a “stationary” bouncing light the same triangle would occur because of relative movement.

Before watching the video i must say, that in my opinion, people, who believe in time travel, don't actually understand the concept of time.

i dont belive this is actualy how it works... time and space are connected, jim might be 29 years into the future someplace else, but when he wuld return to point of origin he would simply return to the same timeline, he would return 10 years later, becouse as jim was leaving earth he was also traveling back into the past (relative to earth observer) with light itself. jim just lost 5 years traveling away from earth to the past relative to earth observer, now jim is turning ship around, and traveling 5 years back to earth, and he is returned back to the same time space that he left. 10 years later jim returned as we observed from earth and thats the time that passed for him exeactly. He would not return into any future.

off topic. blackholes might be formed out of particles that are not atom, let it be quartz etc one theory. Second one is this. Blackhole is endoergic nuclear reaction, instead of releasing energy it is consuming it. That would explain all the behavior we noticed so far. Unfortenatly we do not know much about endoergic nuclear reactions. idea of infinity gravity seems redicolous to me, if gravity would be infinite in the blackhole than it would consume entire universe, redicolous idea.

just like a star is releasing energy for milions of kilometers around, blackhole is doing the oposite. If somebody finds a solution to an equation with nuclear reaction that does not release energy, but consumes it... that guy will discover the true nature of the blackhole, it all comes down to breaking the atom.

light is a frequency, if you observe the frequency as moving along with it, then the observation will be different, so the only thing that will happen is, that you will see the whole color spectrum until you hear sound until you see and hear nothing. 1 year means 1 rotation around the sun. if you are gone for 1 rotation then you are gone for one rotation. no matter where you are. if the outer planet or light is far away and needs many earth rotations to have one with planets that are further away from the sun. You won't experience anything faster or slower. Some people's IQ is so low they can't keep these 2 apart and will never understand. Also light travels in several directions, so this is where that theory falls apart. no

what an absolute load of crap... his grasp of physics is worse than a child's and his assumptions are based on theoretical postulations from a guy who couldn't do algebra. Time is the constant and the speed of light is what changed based on the amount of energy put in to the photons. Visible light has a set speed and wavelength of which we can perceive and measure but photons with enough energy can travel faster than we can see.

The light bouncing between the lasers is only traveling between the mirrors at the set speed and when the platform moves more energy is being introduced to the equation thus to the stationary observer the light trail traces a longer path and travels more distance in the same time frame. The moving observer who is relatively stationary to the light mirrors will see the light only bouncing up and down in the same time frame.

Time is the constant here with energy and velocity/speed being the variables. Stating that time slows down based on how fast you are moving is ridiculous. I also can't believe he also thinks that nothing can travel faster than the speed of light like its the maximum speed achievable in the universe. It is only not possible for our current level of technology and fuel but given enough fuel and time then even with our current technology we could technically achieve and go faster than the speed of light.

So all we need to speed up our technologies to achieve "near light speed"

nothing is good anymore

The ten year trip didn't take into account the time necessary to accelerate and decelerate. You can't accelerate from 0 to 99.4% the speed of light instantaneously.

Wouldn't the path be curved like a sine wave?

Theoretically possible but in reality it is not possible as the energy required to accelerate a given mass to near the speed of light is so enormous it can't be done.

What a wonderful demonstration of time by two of my most favourite scientists .

As the movie Interstellar demonstrated to time travel into the future would be devastating for a human being to suffer as you would return to see that everyone and everything you loved was now much older and lived full lives even though for you it would have felt like only a small amount of time.

Hi anyone please help me time travel it's real how is possible i want to go back and change my past please help me 🙏🙏🙏

Time travel into the future is possible… Knew that already that’s why we have calendars.

Dr Cox underappreciated by QE2

A fantastic explanation. All that's left now is to explain time travel to the past.

This moving mirror explanation doesn't explain gravitation time dilation when both objects/people are not moving and both record different times dur to being either near or far from a large mass.
What I think is really happening is that the mirrors are moving closer or further apart due to distortions in gravity/space.
In high speeds or high gravity mass, space is somewhat contracted causing time to run slower.
In low speeds and far from gravity mass, space is expanded and time runs faster.

A way to think about it is that you are kind of stretching time frames.
Imagine space distortion is represented by a cone with one end a small radius (contracted space) and the other a really large radius (expanded space).
A ball on each end rotates at the same revolutions.
The ball on the larger end has to move much faster (i.e. time is sped up) compared to the smaller end which runs slower.
This all makes visual sense in our 3D space but is strange when you cannot see the distortions in space and you think the cone is actually a cylinder for example with same diameter ends.
When that happens you see one ball moving quicker than the other and so you record different time.

In conclusion we think both the clocks mirrors are equal distant because we cannot see the curvature of space beyond our 3 dimensional world but it could be that there are 2 different clocks, distorted by the different space that are in and so have 2 different times.
Remember, everything is affected by the fabric of space including the clocks as you move higher speeds.

Time travel is a thing of the past, like the glove earth.
Only with a REAL science in a REAL and OVERALL TRUE world, things like that are true.
In the MASS LIES world we live, this things are impossible.
Research FLAT EARTH

Would Jim have to travel at 99.4% the speed of light in a straight line away from us, and then make a bee-line straight back to us for this to happen? Or could he travel at that same speed, only instead of traveling in linear directions for 10 years, circling the earth for 10 years?

I would ask the Professor to implement this "experiment" in an environment that is MORE REAL compared to the prescription....if the speed of the cart is synonymous with 99% C, then the period of "oscillation" should be PROPORTIONATE.... so if the "cart" moves with 99% C, what is the Fc-centrifugal force acting on the "oscillator",..and...

Easiest answer: yes. We already do it every day


Now going backwards is more complicated

Given that all the matter in the universe is constant but shifting, a time machine is impossible because if I stepped out of a time machine the atoms in my fingernail may by that time be on a beach in Bermuda or at the county dump. Matter cant be in two places at once ergo I cant exist in a time different than when I stepped into my time machine.

we cant put a person on Mars and get giddy talking about time travel

That guy looks like Professor Jim Al-Khalili.

Daca ar fi posibila calatoria in timp, ea... a fost (sic!) deja inventata, mii sau zeci de mii de ani in viitor. Iar daca omenirea din viitor ar fi vrut sa repare "greselile trecutului", prezentul si trecutul nostru ar fi fost pline de "agenti justitiari temporali care i-ar fi omorat pe Nero, Caligula, Atilla, Genghis Khan, Hitler, Stalin, Mao, Putin, ar fi impiedicat coliziunea Titanicului cu icebergul etc. Cand colo, ce sa vezi: miliarde de oameni care ar fi putut fi salvati, au murit in chinuri inainte de vreme, zeci de mii de specii de animale superbe si utile au fost exterminate de specia noastra cretina, care, mai mult,, acum distrige insasi planeta. Din copilarie am iubit science-fiction-ul, dar nu am fost si idiot...

Have gun will travel

I partially agree . According to the theory of relativity ,time travel
is possble , but it takes a lot of enagy to travel through time at
very high speeds. This could also create a "time paradox" problem if time travelers changed history.

Not secessarily
For the reason is the speed of light is
constant for all observors, if we only consider the simplest case that the interaction between normal materials we have found, it is possible to make time traveling real!
Hoverer, there are lats of materials and their properties we still don’t know.
for example, the dark material, which don’t t have electromagnetic interaction, but mess interaction, is a kind of unknown materials.
The evidence is that base on the relativity theory, the mass would cause the light wave be bend
As the result, if we travel in the rate of hght, We might get interaction with the dark materials and Fail?

That’s so true! According to special relativity, time will dilate by the velocity of the object. For instance, time in high speed rocket is slower relative to Earth, which means when a year passes by on Earth, only a month passes on a rocket.

😂

Maybe all of us are time travelers😅😅

I agree with Einstein's theory of relativity that time is not an absolute concept, but rather depends on the observer's relative motion and position. However, I also believe that there are still certain situations where time can be considered absolute, such as in everyday life when we measure time using clocks or calendars.

I just realised you can calculate time dilation with Pythagoras and it makes so much sense!

Does the period of the light track change as the direction of motion changes?
In this way, the time flow rate of the experimenter and the listener is also the same

So if you ever get complained at for being late to anything. Your response can be. Time is relative and personal, not absolute!!! 😂😂😂👍🏻👌🏻

thinking that a theory of time traveling to the future is feasible, can this theory be applied to traveling the past?

According to the video, we understood the way traveling to the future. But I would like to know, what premise can travel to the past?

I have a question that’s how would time go if our speed exceeded the speed of light?

What do you think if humans find the second timeline?