3 ms·

The way you'd phrased it confused the matter further, though. I'd consider rewording some of it.

by diziet 16y ago

ars 16y ago
So it's necessary that it's impossible to exceed the speed of light. For example if you had two objects each traveling at 51% of the speed of light (relative to third placed in between them). You only gave them a certain amount of energy, but if speeds were additive and you compared them then it would appear that their comparative speed was greater than the speed of light! And that would imply an infinite amount of energy, which would be a problem. Even if they were each traveling at 49% of the speed of light, so there are no issues of infinity, it takes a lot less energy to accelerate two object to 49% of the speed of light than it does to accelerate one to 98% of the speed of light (because it's a lot heavier when it's going that fast, so it contains far more energy), so you would have issues with conservation of energy. Because of all that, speeds are not additive, and they get adjusted in a way that keeps conservation of energy exactly correct. Therefor relativity is necessary if you want mass to be interchangeable with energy.
- diziet 16y ago
  I understand that you say that they're not additive, but I have a feeling you aren't really understanding what the actual math behind it is. Two objects traveling at 51% the speed of light relative to a third object placed between them (or anywhere else) would STILL travel at 81% the speed of light relative to each other. Please take a look at a very simple relativity homework solution to see if you misunderstand the math or the concepts of relativity (that happens to be the top result for "two spaceships approach each-other" on google)http://www.phy.duke.edu/courses/143/homework/hmwk3_solutions.pdf http://www.phy.duke.edu/courses/143/homework/hmwk3_solutions... [It's problem #2]
  - ars 16y ago
    You are utterly missing my point. I'm trying to show why relativity is necessary, I'm not trying to explain relativity. I'm giving an alternate universe where relativity does not exist and showing why that universe could not work. And because it does not work, relativity is necessary. Please go back to the original question I am answering: Someone wanted to know why the world is Einsteinian not Newtonian.

The way you'd phrased it confused the matter further, though. I'd consider rewording some of it.

by diziet 16y ago

The way you'd phrased it confused the matter further, though. I'd consider rewording some of it.

ars 16y ago

So it's necessary that it's impossible to exceed the speed of light. For example if you had two objects each traveling at 51% of the speed of light (relative to third placed in between them). You only gave them a certain amount of energy, but if speeds were additive and you compared them then it would appear that their comparative speed was greater than the speed of light! And that would imply an infinite amount of energy, which would be a problem. Even if they were each traveling at 49% of the speed of light, so there are no issues of infinity, it takes a lot less energy to accelerate two object to 49% of the speed of light than it does to accelerate one to 98% of the speed of light (because it's a lot heavier when it's going that fast, so it contains far more energy), so you would have issues with conservation of energy. Because of all that, speeds are not additive, and they get adjusted in a way that keeps conservation of energy exactly correct. Therefor relativity is necessary if you want mass to be interchangeable with energy.

diziet 16y ago
I understand that you say that they're not additive, but I have a feeling you aren't really understanding what the actual math behind it is. Two objects traveling at 51% the speed of light relative to a third object placed between them (or anywhere else) would STILL travel at 81% the speed of light relative to each other. Please take a look at a very simple relativity homework solution to see if you misunderstand the math or the concepts of relativity (that happens to be the top result for "two spaceships approach each-other" on google)http://www.phy.duke.edu/courses/143/homework/hmwk3_solutions.pdf http://www.phy.duke.edu/courses/143/homework/hmwk3_solutions... [It's problem #2]
- ars 16y ago
  You are utterly missing my point. I'm trying to show why relativity is necessary, I'm not trying to explain relativity. I'm giving an alternate universe where relativity does not exist and showing why that universe could not work. And because it does not work, relativity is necessary. Please go back to the original question I am answering: Someone wanted to know why the world is Einsteinian not Newtonian.