Recent content by Kynnath

Fictitious forces are already indistinguishable from real forces. They are as 'real' as genuine forces. They're fictitious because they don't have a reaction pair. In an inertial system, every force is balanced by an opposing reaction. Te fictitious force is the remainder from the acceleration...

Not really. The stage can be considered another 'actor' in the play. The actors have to be at certain places on the stage at given time, but you can make the same considerations for other actors. You could describe the play in terms of how the stage and the other characters flow around a given...

I'll have to disagree. Imagine you want to plot the trajectory of a ball you launch inside a space shuttle. If you used any inertial reference system, you'd have to account for the force of gravity, and the ball you launched would follow a curved trajectory. It'd be a pain to do it that way...

As I see it, it is not a matter of whether a coordinate system is right or wrong. They are all right, in that they all describe what they each see. A way to see it is, imagine that the universe is a play. And each coordinate system is a seat. It doesn't matter what seat you are in, you are...

There is no 'photon of a specific wavelength'. The wavelength of a photon depends on the reference frame from where you're observing it. But yes, it won't change until it interacts with something.

Photons don't decay, far as I know and was able to search. Relativity kind of requires that they don't, though not explicitly. There's some experimental evidence to suggest, in any case, that if they do their half-life is well over the age of the universe. From relativity, for them to decay...

There isn't an absolute reference frame, but the idea is close. There are inertial reference frames, and non-inertial reference frame. Inertial reference frames are the ones we care about, because they have the handy property of all inertial reference systems being in a sense equivalent. In...

We don't need to be sure, and proving is not possible. So long as the model we have is internally consistent and agrees with observations, it's good enough. I'm don't know myself, but astronomers have figured out ways to measure the distance of the farthest emissions we can see (observable...

It's limited by both, in a sense. Light travels at a fixed speed. So you can describe the observable universe in terms of the distance the light we can see travelled, or the time it took it to travel that distance. The result is the same either way.

Actually, there are fictitious forces in both cases, but the effects are different. In the first case, the fictitious force is what is keeping the other body aloft. Now, let's say the bodies are not rotating, but falling towards each other. The real forces in play are one force from a to b...

Photons don't have rest mass, because there is no valid inertial reference frame where they are at rest, which is required to calculate the rest mass. Their energy is not 0 because the equation is not applicable to them. You can't use the photon itself as a reference frame because you can't...

I think the problem you're having is wth forces that are perpendicular to your movement. Acceleration is a vector. Vectors have a magnitude and a direction. A change in either magnitude or direction means a change in acceleration. When you are rotating, acceleration is perpendicular to your...

The first thing to understand is that your reference frame does not alter the system itself. It merely alters how you perceive it. If two particles do not collide in one reference frame, they will not collide in any reference frame. Think of it as watching a play (while you are not one of the...

Not sure if this is what you mean, and it's been a while since my last physics course so you'll have to excuse if I'm sloppy with the language, but I'll give it a shot. So your reference frame is one of the particles, with the y-axis looking 'up' at the other particle. According to this...

Right. Energy of the system doesn't change, not energy of each individual particle. As I said, was just an idea, didn't think it through.