# Time: impossible to stop?

#### LockeJ

ok from what I've heard and seen so far of many videos on time travel and space, i came to conclusion that we have the capabilities or the right idea of time travel, many other people will obviously say how we can stop time. i thought about it for a minute, i think that we can stop time but we won't wont know that we stopped time. if we are to stop time we are only stopping the time continuum of one of the many times of many universes, there for being an observer of stopped time, the observer will still have time passed on their own realm. so in result stopping time is impossible, but the possibilities of moving through it is allowed.

what do you guys think, i think i might be wrong but i might be on the right track as well.

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#### Crazy Tosser

I believe that if you freeze something to absolute zero, you can rightfully (and proudly) say that you stopped time in a given system - because as we see it, no change of state occurs... The other thing is, it's impossible to freeze something to absolute zero. Anyway, time is defined as change in state. I personally don't think it's possible to stop a system from changing state, or at least, referring back to QM, it's sure impossible to observe a system that doesn't change state without making it change state...

#### LockeJ

no no you didn't understand my question. lets say you have the ability to "stop" time in your universe. you stand in the middle of time square, you see everything stop moving, the clock on the tower, the movie screen, the car on the road. but while your looking at it, doesn't time is still moving for you? so another question would be does time stopping only consist of stopping object which are moving in the universe or is there something else? i don't think time can be stopped you can only move fast enough to see time slowing down as almost to a stop.

#### jreigel

someone got high and watched the universe again, amirite?

#### ZapperZ

Staff Emeritus
2018 Award
no no you didn't understand my question. lets say you have the ability to "stop" time in your universe. you stand in the middle of time square, you see everything stop moving, the clock on the tower, the movie screen, the car on the road. but while your looking at it, doesn't time is still moving for you? so another question would be does time stopping only consist of stopping object which are moving in the universe or is there something else? i don't think time can be stopped you can only move fast enough to see time slowing down as almost to a stop.
This question/scenario makes no sense. By saying "you see everything stop moving", you ARE seeing something moving - LIGHT! Did you think the light from all parts of the "stopped" universe got to you all at the same time? If not, then they each reach your eye during different times.

And think a bit how you are able to perceive depth. You have two eyes, and it requires both eyes for proper depth perception, meaning you are able to slightly distinguish not only angular differences, but also path differences, something that you need the concept of "time".

So no, it is not as simple as things "stop moving". You have to KNOW that things have stopped moving, and to know that, you inherently invoke "time".

This, really, has nothing to do with "Quantum Physics", so it is being moved to the General Physics section.

Zz.

#### Anticitizen

no no you didn't understand my question. lets say you have the ability to "stop" time in your universe. you stand in the middle of time square, you see everything stop moving, the clock on the tower, the movie screen, the car on the road. but while your looking at it, doesn't time is still moving for you? so another question would be does time stopping only consist of stopping object which are moving in the universe or is there something else? i don't think time can be stopped you can only move fast enough to see time slowing down as almost to a stop.
Before you go down that road, describe first the difference between time and motion.

#### ZapperZ

Staff Emeritus
2018 Award
I believe that if you freeze something to absolute zero, you can rightfully (and proudly) say that you stopped time in a given system - because as we see it, no change of state occurs... The other thing is, it's impossible to freeze something to absolute zero. Anyway, time is defined as change in state. I personally don't think it's possible to stop a system from changing state, or at least, referring back to QM, it's sure impossible to observe a system that doesn't change state without making it change state...
No, it is more than that. Quantum phase transition also occurs, in principle at T=0 K. So it is a fallacy to assume that at absolute zero, nothing moves and nothing will occur. Quantum critical points can drive a system from one state to another, all at 0K.

Zz.

#### LockeJ

Before you go down that road, describe first the difference between time and motion.
the way i see it. human cant see time, we can only see the effect of time, therefor motion, we know that it takes time for one object to go from one point to another, so when i see every single moving object around me stop, it doesn't mean i stopped time does it?

#### ThomasT

Anyway, time is defined as change in state.
I used to think of it that way (change of state is time, change of state is motion, hence time is motion) but now I don't think that's the correct abstraction wrt our use of the word, time. Physics defines the time of an event as the readout on a clock in the same frame of reference as the event.

More generally, the word time seems to refer to indexes of snapshots of our world or some part thereof. You might think of our various time indexes as different 'videos' of the world of our sensory experience. The index variables are frame rate and frame of reference.

This can get a little complicated sorting out the details (eg., wrt the difference between subjective, or psycholgical, time indexes and objective time indexes), but imho the correct definition of the word time is that it is a certain sort of index.

Using this definition, the actual meanings of phrases like the passage of time or travelling through time are clarified and we can see that time isn't so mysterious as discussions of it might lead one to believe. It's just that the meaning (the actual physical referents) of the word, time, has been obfuscated by the desire to have it refer to more, or something other, than it actually does -- much as some interpretations of the mathematical formalism of quantum theory are obfuscations of its physical meaning.

#### Naty1

No time..no bodily processes..you die instantly..

if you hypothesize that you live on, as zapper says, everything else STOPs..no sun, no light, (basolute black, zero degrees kelvin) no electromagnetic radiation, atoms cease to exist, etc,etc..without time there is NOTHING...

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