Objects near the speed of light

In summary, the time interval between two bounces on the ship would be different than on Earth. The time interval would be measured as \Delta t, where \Delta t = \gamma \Delta t_{0} = \frac{\Delta t_{0}}{\sqrt{1-\beta^2}}\hspace{1cm}\beta = \frac{v}{c}<1.
  • #1
really?
5
0
Hi,

i'm new to this and maybe this has been covered but-

Imagine an object moving at almost the speed of light, is on a collision course with earth. To observers on Earth the ship seems to be motionless, due to it's speed being extremely close to c.

Eventually the ship is going to be very close to earth, let's say, that to an Earth observer it seems to be hovering about 1m from the Earth's surface.

What would happen to someone or something which touched this ship?
Would they be instantly propelled into the ships frame of reference or would they be able come and go as they please?

I hope that made some sort of sense... any thoughts would be much appreciated...

Thanks
 
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  • #2
really? said:
To observers on Earth the ship seems to be motionless, due to it's speed being extremely close to c.
That is incorrect.
 
  • #3
cesiumfrog said:
That is incorrect.

incorrect how? could you please direct me to something which will explain how an observer on Earth would see the ship.

i came to believe that it was a consequence of time dialation
 
  • #4
Imagine a stopped clock being thrown at you: they won't see the occupants moving very quickly inside the ship, but they will see the entire ship (and everything inside) approaching at nearly the speed of light. It will hit the Earth very quickly (with little notice).
 
  • #5
cesiumfrog said:
Imagine a stopped clock being thrown at you: they won't see the occupants moving very quickly inside the ship, but they will see the entire ship (and everything inside) approaching at nearly the speed of light. It will hit the Earth very quickly (with little notice).

i don't understand what your trying to say...
are you saying that the observers on Earth would see the ship approaching at nearly the speed of light and not time dialted to a point where it appears motionless?

i forgot to mention that the ship is moving at nearly the speed of light relative to the observers of the earth
 
  • #6
really? said:
i don't understand what your trying to say...
are you saying that the observers on Earth would see the ship approaching at nearly the speed of light and not time dialted to a point where it appears motionless?
That is correct, it won't. As Cesium frog said, time will 'slow down' for the people inside the ship, but will be running at 'normal' time for you. Time will appear dilated for the crew but not for you.
 
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  • #7
Hootenanny said:
That is correct, it won't. As Cesium frog said, time will 'slow down' for the people inside the ship, but will be running at 'normal' time for you. Time will appear dilated for the crew but no for you.

okay, so what would be the relationship between my time and the time in the ship? in other words if i could see a clock in the ship at what speed is it running and vice versa?

i'm trying to make sense of the time dialtion formula in special relativity that i found on wikipedia, maybethat was my first mistake?
 
  • #8
Okay, say someone on this ship (travelling towards you at v m/s) was bouncing a ball. Another crew member timed the interval between two bounces. This would be the proper time interval ([itex]\Delta t_{0}[/itex]). Now, if you timed the same interval on Earth you would measure the time interval as [itex]\Delta t[/itex], such that;

[tex]\Delta t = \gamma \Delta t_{0} = \frac{\Delta t_{0}}{\sqrt{1-\beta^2}}\hspace{1cm}\beta = \frac{v}{c}<1[/tex]
 
  • #9
running very slowly, but nonetheless moving towards you very quickly.
 
  • #10
cesiumfrog said:
running very slowly, but nonetheless moving towards you very quickly.

i think that is where i was getting confused... i thought that since the clock was running slowly then the whole ship would seem to be moving slowly...

thank you both for clearing that up...

cheers
 

1. What is the speed of light?

The speed of light in a vacuum is approximately 299,792,458 meters per second (m/s). This is the maximum speed at which all objects in the universe can travel.

2. Can anything travel faster than the speed of light?

According to Einstein's theory of relativity, nothing can travel faster than the speed of light. As an object approaches the speed of light, its mass increases infinitely, making it impossible to reach or exceed this speed.

3. How does an object's speed affect its mass?

As an object's speed approaches the speed of light, its mass increases exponentially. This phenomenon is known as mass-energy equivalence and is described by Einstein's famous equation, E=mc^2. This means that the energy of an object increases as its mass increases.

4. What are the effects of time dilation on objects near the speed of light?

According to the theory of relativity, time appears to pass more slowly for an object moving at high speeds. This is known as time dilation and is a result of the object's increased energy and mass. As a result, time appears to slow down for the object, while it remains constant for an observer at rest.

5. Can we observe objects near the speed of light from Earth?

While we cannot directly observe objects near the speed of light from Earth, we can indirectly observe the effects of their high speeds through phenomena such as time dilation and redshift. These effects can be measured and studied using advanced technology and mathematical equations.

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