Is Time Travel Possible with a Device That Slows Down Time?

In summary, time dilation occurs when an object is moving at high speeds relative to another object. In this scenario, both objects would experience time passing at different rates, but neither would be "slower" or "faster" than the other. It is all relative to their own frame of reference. The scenario you described does not involve time dilation, but rather a manipulation of time perception.
  • #1
39ster
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If we have two balls, a red and blue ball, and the red ball passes the blue ball at 99.9% the speed of light, would "time" for the red ball pass slower than it does for the blue ball? If it does, and if speed is just relative, couldn't we say the blue ball is passing the red ball at 99.9% the speed of light, but just in the opposite direction? Wouldn't this cause the blue ball and red ball to age at exactly the same speed and make "time travel" impossible?
 
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  • #2
39ster said:
If we have two balls, a red and blue ball, and the red ball passes the blue ball at 99.9% the speed of light, would "time" for the red ball pass slower than it does for the blue ball? If it does, and if speed is just relative, couldn't we say the blue ball is passing the red ball at 99.9% the speed of light, but just in the opposite direction? Wouldn't this cause the blue ball and red ball to age at exactly the same speed and make "time travel" impossible?
Yes, yes and no. I assume that what you have in mind when you say "time travel" is just the lame kind where you travel very fast for a while, and when you stop, a lot more time has passed on Earth.

The red and blue balls are both correct when they think "right now, the other ball is aging at 60% of my aging rate". This is not a contradiction. The reason has to do with the fact that "now" refers to a different set of events in different coordinate systems, and these balls aren't using the same coordinate system.

The attempt to prove that this is a contradiction is called the "twin paradox", but it really is nothing more than a mistake in a calculation. If you're interested, check out e.g. #3 and #142 in this thread.
 
  • #3
Hmmm, I'm not sure if i get it or not. Can you verify? Is the time only different for an object that is accelerating, rather than just having a higher velocity? (as in, does the object only experience this slow down of time during the period that it's speed increases from 60Km/h to 100Km/h, and once it's speed has reached 100Km/h, and it doesn't increase any further, would their time rate be the same?). Because that's the only difference i can see. Once the velocity of the red ball stops increasing, they would be identical..?
 
  • #4
If both are moving at constant velocity relative to one another, both measure the other one to be aging more slowly, in their own coordinate system (their own rest frame). Each one's own coordinate system is defined in terms of measurements on rulers and synchronized clocks at rest relative to themselves (note that in relativity the meaning of 'synchronized' is relative to one's coordinate system too, clocks that are synchronized in their own rest frame will be out-of-sync in a different frame--see here and here). For an illustration of how each system can measure clocks in the other system to be slowed down without this leading to any disagreements about what any pair of clocks read at the moment they pass next to one another, take a look at the example I wrote up on this thread.
 
  • #5
I was wondering about a certain situation and I'm not sure if it has anything to do with time dilation. Let's say that i have a device that could slow down the time for everything around me, but time for me passes at normal speed. If i were to walk from one point to another, everyone around me would see me walk much faster than i actually am, and from their view, i would get to my destination much faster. To them it would look like i was in fast forward. Would that effect be time dilation?
 
  • #6
39ster said:
I was wondering about a certain situation and I'm not sure if it has anything to do with time dilation. Let's say that i have a device that could slow down the time for everything around me, but time for me passes at normal speed.

You have to pin down the science underlying the scenario. Stating "I have a device" does not do this. I could state "I have a device that makes miniaturizes objects." This might make for a good movie or novel (Fantastic Voyage), but that doesn't mean that there is real science behind the statement.

This forum discusses real science.
 

1. What is time travel?

Time travel is a concept that refers to the ability to move between different points in time, either forward or backward. It is often depicted in science fiction stories, but there is currently no scientific evidence that time travel is possible.

2. Is time travel possible?

According to our current understanding of physics, time travel is not possible. The laws of physics, such as the theory of relativity, make it extremely difficult, if not impossible, for an object to travel through time. However, some scientists are actively researching and exploring the concept of time travel.

3. Can we go back in time?

As mentioned before, time travel is currently not possible. However, there are some theories that suggest that under certain conditions, traveling back in time may be feasible. These theories involve concepts such as wormholes and parallel universes, but they are still highly speculative and have not been proven.

4. What are the potential consequences of time travel?

The consequences of time travel are purely speculative, as it is currently not possible. However, some theories suggest that it could lead to paradoxes, altering the course of history, and even causing the collapse of the universe. These are all hypothetical scenarios and have not been scientifically proven.

5. How would time travel affect our current timeline?

Again, since time travel is not currently possible, it is impossible to know how it would affect our timeline. Some theories suggest that it could create alternate timelines or cause changes to our current timeline, but these are all purely speculative and have not been proven.

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