Relative Time in Space: What Speed for 1 Day Equals 1 Day on Earth?

In summary: However, for practical purposes, the difference is negligible and usually not worth worrying about.In summary, the ship and people on the ship would observe that the other person's clock is running slow, but the time difference is negligible and usually not worth worrying about.
  • #1
mileymo
6
0
What speed does a ship traveling through deep space need to travel at for 1 day on the ship to equal 1 day on earth?
 
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  • #2
Any speed will do. But both will observe the other guy's clock is running slow !
 
  • #3
I think it's 11km/s in the nearby Solar system, up to some 500km/s outside the Solar system, and even bit faster outside the Milky Way.
 
  • #4
mileymo said:
What speed does a ship traveling through deep space need to travel at for 1 day on the ship to equal 1 day on earth?
If by 1 day you mean 24 hours measured by a clock on Earth and 24 hours measured by a clock on the ship, then they represent the same amount of time regardless of the speed of the ship relative to Earth. During the 24h measured by a clock on Earth a person on Earth would have aged 1 day, during the 24h measured by a clock on the ship a person on the ship would also have aged 1 day.
 
  • #5
mileymo said:
What speed does a ship traveling through deep space need to travel at for 1 day on the ship to equal 1 day on earth?

If the ship and the Earth are moving relative to each other, then there is no invariant way of matching up their "rates of time flow". So this question doesn't have a well-defined answer.
 
  • #6
SlowThinker said:
I think it's 11km/s in the nearby Solar system, up to some 500km/s outside the Solar system, and even bit faster outside the Milky Way.

How are you coming up with these numbers?
 
  • #7
What I mean is, if you travel at 87% the speed of light, then 1 day on that ship is equal to 2 days on earth. So, is there a lesser percentage of the speed of light at which time would be equal for both the ship and the people on earth?
 
  • #8
mileymo said:
What I mean is, if you travel at 87% the speed of light, then 1 day on that ship is equal to 2 days on earth.
That's only for an observer on Earth ! The guy in the ship thinks it's the other way around !

So, is there a lesser percentage of the speed of light at which time would be equal for both the ship and the people on earth?
In your line of reasoning: zero. Stay put on earth.
 
  • #9
Thanks. Much appreciated!
 
  • #10
So, is there a lesser percentage of the speed of light at which time would be equal for both the ship and the people on earth?
There is - relative speed zero, meaning that the ship is not moving relative to the earth.
You can calculate this from the time dilation formula, which google will find pretty quickly - try "relativity time dilation".
 

1. How is relative time in space measured?

Relative time in space is measured by comparing the elapsed time on a moving spacecraft with the elapsed time on Earth. This is done by using a clock on the spacecraft and a synchronized clock on Earth.

2. What is the concept of time dilation in space?

Time dilation refers to the fact that time passes differently for objects in motion compared to objects at rest. In space, the high speeds and gravitational forces can cause time to pass slower for a moving object, leading to a difference in elapsed time compared to a stationary object on Earth.

3. Can the speed of light be used to measure relative time in space?

Yes, the speed of light is a constant and can be used to measure relative time in space. The closer an object gets to the speed of light, the more time dilation occurs, resulting in a slower passage of time compared to Earth.

4. How do space missions account for the effects of time dilation?

Scientists and engineers take the effects of time dilation into account when planning and executing space missions. This may involve adjusting the timing of spacecraft maneuvers or using specialized clocks that can account for the effects of time dilation.

5. Can we travel through space at a speed that would result in 1 day equaling 1 day on Earth?

Currently, it is not possible to travel through space at a speed that would result in 1 day equaling 1 day on Earth. However, some theoretical concepts, such as wormholes or faster-than-light travel, could potentially allow for this in the future.

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