- Sep 28, 2001
- 8,464
- 155
- 106
This is sort-of in addition to
https://forums.anandtech.com/threads/interstellar-travel-no-matter-where-to-is-theoretically-possible-and-doesn’t-even-take-long.2489499/
but I think it might warrant an extra thread.
When we're talking about space travel like in the above thread, we use expressions like "when the ship reaches light speeds", FTL, the effects of relativistic speeds etc.
But what does this "speed" actually refer to?
I am always having this picture in mind:
We are on a planet which turns at speed X, while we orbit the sun at speed X, on the outskirts of a galaxy which revolves around its center, part of a cluster of galaxies which may move towards a point at whatever speed.
You get the idea, WHAT "speed" is actually meant when we say, for example, "when the ship reaches 0.9999999993 of c"?
The only logical answer here of course is that this term "speed" only applies in reference to an observer, or say in reference to a point, say the travel destination. ("Flying at light speed to star system X")
But how does "the ship" or whatever even "know" that it is at light speed or at relativistic speed? (Relativistic speed meaning that the effects of time dilation come into play which will shorten travels SIGNIFICANTLY). But also things like that the ship, although its mass will increase almost to infinity AND at the same time it will "shrink" in the direction of travel down to a plank length.
How can the ship gain mass or the travelers on the shop experience time dilation when there is no reference for the ship's speed? The observation that a ship "has reached light speed" can only be valid for ONE observer, but it could be entirely different for an observer somewhere else, say, someone who watches the ship from another galaxy which itself is moving about relative to the ship etc..
https://forums.anandtech.com/threads/interstellar-travel-no-matter-where-to-is-theoretically-possible-and-doesn’t-even-take-long.2489499/
but I think it might warrant an extra thread.
When we're talking about space travel like in the above thread, we use expressions like "when the ship reaches light speeds", FTL, the effects of relativistic speeds etc.
But what does this "speed" actually refer to?
I am always having this picture in mind:
We are on a planet which turns at speed X, while we orbit the sun at speed X, on the outskirts of a galaxy which revolves around its center, part of a cluster of galaxies which may move towards a point at whatever speed.
You get the idea, WHAT "speed" is actually meant when we say, for example, "when the ship reaches 0.9999999993 of c"?
The only logical answer here of course is that this term "speed" only applies in reference to an observer, or say in reference to a point, say the travel destination. ("Flying at light speed to star system X")
But how does "the ship" or whatever even "know" that it is at light speed or at relativistic speed? (Relativistic speed meaning that the effects of time dilation come into play which will shorten travels SIGNIFICANTLY). But also things like that the ship, although its mass will increase almost to infinity AND at the same time it will "shrink" in the direction of travel down to a plank length.
How can the ship gain mass or the travelers on the shop experience time dilation when there is no reference for the ship's speed? The observation that a ship "has reached light speed" can only be valid for ONE observer, but it could be entirely different for an observer somewhere else, say, someone who watches the ship from another galaxy which itself is moving about relative to the ship etc..
Facebook
Twitter