Does time dilation only affect matter that has mass?

[Milfeulle]

Does time dilation only affect matter that has mass?

For example, A spaceship is 1 light year away from Earth at rest. It sent out a radio wave to Earth then travels at 99.99% of the speed of light. On Earth, from our perspective, we will receive that radio wave 1 year later but the spaceship arrives 70 years later. If that spaceship speed up to 99.999999% of the speed of light, it will take 7000 years from our perspective to see that spaceship.
As a result, from our perspective, the faster that ship travels, the later it arrives, how does that makes sense?

 

[DrGreg]

A spaceship is 1 light year away from Earth at rest. It sent out a radio wave to Earth then travels at 99.99% of the speed of light. On Earth, from our perspective, we will receive that radio wave 1 year later but the spaceship arrives 70 years later.

You have the dilation the wrong way round. The spaceship arrives just over 1 year later by Earth's clocks, but ¹/₇₀ year later by the ship's own clocks.

 

[Milfeulle]

Ahh I see, I got the wrong way around all this time! Thanks for the reply!

 

[Milfeulle]

You have the dilation the wrong way round. The spaceship arrives just over 1 year later by Earth's clocks, but ¹/₇₀ year later by the ship's own clocks.

So that means it only took the ship 5.21 days to arrive on Earth (from the spaceship's perspective) ? If so, that means if the spaceship can travel at 99.9999999999999% of the speed of light, it will only takes 1.41 second to arrive on Earth from the spaceship's perspective. It would be almost like... instantaneous travel...?
In another word, From the light's perspective, all that light from the Big Bang 14 billion years ago was already spread out everywhere in the Universe since the beginning and what we're seeing are just the trails it left behind:grumpy:?

 

[sardar]

This is a very interesting and complex question that touches on the concept of time dilation in relativity. Time dilation is a phenomenon that occurs when an object or body moves at high speeds, causing time to pass slower for that object compared to an observer at rest. This effect is predicted by Einstein's theory of relativity and has been proven through various experiments and observations.

To answer your question, time dilation does not only affect matter that has mass. In fact, it is a fundamental principle of relativity that applies to all objects, regardless of their mass. This includes light, which has no mass but still experiences time dilation when traveling at high speeds.

In the example you provided, the spaceship's speed causes time to pass slower for the spaceship itself, which is why it takes longer for the radio wave to reach Earth from the spaceship's perspective. This is because the faster an object moves, the more it warps the fabric of space-time, which affects the passage of time.

From our perspective on Earth, we would also observe the spaceship arriving later because time has passed slower for the spaceship. This may seem counterintuitive, but it is a consequence of the relativity of time and space.

It is important to note that the amount of time dilation experienced by an object is dependent on its speed relative to the observer. In your example, the spaceship traveling at 99.99% of the speed of light experiences a smaller amount of time dilation compared to when it travels at 99.999999% of the speed of light. This is because the faster an object moves, the more significant the effects of time dilation become.

In conclusion, time dilation is a fundamental principle of relativity that affects all objects, regardless of their mass. It is a complex phenomenon that can be observed in various situations, such as the example you provided. It is a fascinating concept that continues to be studied and explored by scientists.