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

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Discussion Overview

The discussion revolves around the concept of time travel and time dilation, particularly in the context of objects moving at relativistic speeds. Participants explore the implications of relative motion on the perception of time and the conditions under which time may appear to slow down for different observers.

Discussion Character

  • Exploratory
  • Technical explanation
  • Debate/contested
  • Conceptual clarification

Main Points Raised

  • Some participants propose that if a red ball moves at 99.9% the speed of light relative to a blue ball, then time for the red ball passes slower compared to the blue ball, raising questions about the nature of time and aging.
  • Others argue that both balls perceive each other as aging more slowly due to their relative velocities, which is consistent with the principles of relativity and does not lead to contradictions.
  • A participant questions whether time dilation only occurs during acceleration rather than at constant high velocities, suggesting that once a constant speed is reached, time rates might equalize.
  • Another participant discusses a hypothetical device that slows down time for everything around the user while allowing the user to experience time normally, questioning whether this scenario relates to time dilation.
  • Concerns are raised about the scientific validity of hypothetical devices, emphasizing the need for a basis in real science when discussing such scenarios.

Areas of Agreement / Disagreement

Participants express differing views on the nature of time dilation and the conditions under which it occurs. There is no consensus on whether time dilation is solely a result of acceleration or if it applies at constant velocities as well. The discussion remains unresolved regarding the implications of hypothetical devices on time perception.

Contextual Notes

Participants highlight the importance of defining terms and conditions clearly, as well as the relativity of synchronized clocks in different reference frames. There are unresolved assumptions regarding the scientific feasibility of proposed devices.

Who May Find This Useful

This discussion may be of interest to those exploring concepts in relativity, time perception, and theoretical physics, as well as individuals curious about the implications of high-speed travel on time.

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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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.
 
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..?
 
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.
 
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?
 
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.
 

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