Originally Posted by Adraco

Everything is realtive

Time is relative. Time is also a human concept, where the ground unit, one second is defined as 9192631770 periods of the radiation which equals the transition between the two natural states of the Cesium 133 atom.

These transitions can be almost halted, by bringing the cesium 133 atom to or very close to the Absolute zero, which is 0K on the Kelvin scale and as −273.15°C on the Celsius scale. Then we can reach an interesting state, agreed on an academic level, where 1 second, by its definition becomes longer, because the periods of radiation will decrease and thus take longer to accumulate to 9192631770 periods. So if one could totally stop the downfall of the Cesium 133, you would, by definition, also stop time as humans know it. Natural time would still go on, the earth would still spin and day would become night somwhere on the globe. At least everyone expects life to go on as usual, but in theory, since the definition is stopped, the whole world could also potentially come to a scretching halt.

It is, to this date, still very uncertain if the downfall of the highly radioactive Cesium 133 atom actually can be completely stopped or only slowed down.


On the other hand, we have light. Natural light travels at a speed of 299792.458 km/s (186000 miles a second, from Earth to the Moon it's roughly 239000 miles). If you could somehow transport yourself at the same speed, it would look like the rest of the world stood completely still. The light emanicipated would travel with you all the time, kind of following you and it would be like if you never moved but remained in the same spot. To everyone else, you would be moving incredibly fast, but from your own view, the world would be like frozen.

Now, if you could transport yourself FASTER than light, you would be able to be in Position A and watch the touchdown there, then get into your time capsule and travel for one minutes, at twice the speed of light, get out in Position B and in one minute you would be able to see the images, such as the world happened back in Position A three minutes ago.

It is today unclear where Position B exists, if it even does exist. It could be an empty future, just waiting for our light in this very moment to come in and fill it, there are also theories of a parallell universe and so on. This is what is usually referred to as time travel, to actually travel faster than the speed of light and thus already be there, when the light reaches that exact spot and then see what happened "back there". However, this creates other problems.

It is likely, that nothing created by humans has ever been able to supercede the speed of light and remain a stable mass. Some claim this is proof against time travel, others say "give it a few more years".

Remember, everything is realtive. The only thing that matters is whose perspective we use.