Homework Section

[Kitsune]

a/i=-ia. Now from the right side take that i to the left side and you get a/(i*i)=-a. We know that i^2= -1 therefore we get a/(-1)=-a => -a=-a. Everything matches don't know any better way to proof it.

 :ps: I am waiting for Ghost to come and say I'm wrong

Nothing wrong here. :P

[Trobby888]

Ok. I got a question which I'm having a lot of trouble finding answers to :

Rocket A travels at 4c/5 in a certain direction (c = sped of light). Rocket B travels in the opposite direction of rocket A, at 4c/5. What is the velocity of rocket B relative to A?

[Kitsune]

If you can explain to me why you can't travel faster then the speed of light, I may be able to find an answer. I think it may have to to with the relativity.

[Trobby888]

If you can explain to me why you can't travel faster then the speed of light, I may be able to find an answer. I think it may have to to with the relativity.

Because as you travel towards the speed of light, the factor gamma (gamma = (1-v^2 / c^2)^(1/2)) tends towards 0, so when you have m = m0 / gamma, a divide by 0+ would tend towards infinity, and to make an infinite mass go faster, you need infinite force, which is obviously impossible to archieve. Also,  when you apply more force, a percentage of that force would tend to increase your mass rather than to make you go faster. When your speed tends towards the speed of light, the percentage of the force which increases your mass would tend towards 100%, while the percentage of the force which makes you go faster would tend towards 0%, hence, you don't go faster.

[Kitsune]

It's all about relativity, which is what I thought initially. Let me put it this way...

I sitting on my chair right now, travelling with basically no speed.  Relative to a fixed point in space I am travelling with no speed, with the speed of the earth's or also with the universe's rotation (if you consider a fixed point in space to be absolutely fixed) and I do not know if anyway has calculated the rotation of the universe relative to a fixed point in further space, but if it existed, I doubt it would be anywhere close to the speed of light. Now, if I then consider my speed relative to the light bouncing off the walls around me, I am travelling at the speed of light and I have this incredible mass. So, relative to light, anyone ravelling faster then no speed, is travelling faster then the speed of light. This shows that these laws in physics, cannot apply to such relative speed, but only to a fixed point.

If a that's a mouthful, then here's a simpler example...

You want relative speed? Why not compare the speed of light in one direction against the speed of light in another direction (because light travels in all directions)? That makes their relative speed twice the speed of light. Think about this and you will realise that you must compare speed to an absolutely fixed point in space when using such concepts in physics.

Now I am cannot say for certain where such places exist (though I would assume it is in the regions, which are not occupied by universes, assuming universes do not move, otherwise it would just be some point in our universe's space), but it seems obvious to me that there exist these constraints with regard to what you consider as travelling faster then the speed of light and defying physics.

I could be completely wrong but this seems like the most logical, so if someone can explain more correctly, please do! ^^

* Kitsune wonders when Jubin will check the topic...

[Kitsune]

Another point is that if you were to argue that relatively, an object being compared to the speed of light is not travelling faster then it, you may not be defying some laws of physics, but you are defying others with regard to calculations involving relative speed. I have never heard of any such exceptions for these calculations, so if you really think it is so, I would be glad to hear how you can explain this.

You're explanation to why you can't travel faster than the speed of light is not detailed enough to help me. You need to explain the why of your why if it is to be of any help, but that's not needed atm as I would rather get something to contradict my theory (unless it involves explaining the why of your why).

why of your why = explain the explanation o_O

I just realised that even if I consider something out of our universe, relative to here if you consider other factors with the earth's speed with the light travelling, maybe that because faster then the speed of light. So my main issue is, what is a fixed point in space?

Someone please explain this before I go mad!!!

[Kitsune]

How did you calculate that?

I read Wikipedia and everything makes sense now. Apparently the conventional speed formula becomes less accurate at speeds approaching the speed of light, which is where another equation (that I didn't know about) comes in.

Why didn't they teach this in my high school physics? >.<

[Jubin]

sry the answer is 292 000 km/s. Equation is u=(v1+v2)/(1+(v1*v2/c^2)) where v1 is speed of the first body, v2 speed of the second body. c- speed of light and u is relative speed.

[Kitsune]

Yeah, that's what I got.

[Trobby888]

It's all about relativity, which is what I thought initially. Let me put it this way...

I sitting on my chair right now, travelling with basically no speed.  Relative to a fixed point in space I am travelling with no speed, with the speed of the earth's or also with the universe's rotation (if you consider a fixed point in space to be absolutely fixed) and I do not know if anyway has calculated the rotation of the universe relative to a fixed point in further space, but if it existed, I doubt it would be anywhere close to the speed of light. Now, if I then consider my speed relative to the light bouncing off the walls around me, I am travelling at the speed of light and I have this incredible mass. So, relative to light, anyone ravelling faster then no speed, is travelling faster then the speed of light. This shows that these laws in physics, cannot apply to such relative speed, but only to a fixed point.

If a that's a mouthful, then here's a simpler example...

You want relative speed? Why not compare the speed of light in one direction against the speed of light in another direction (because light travels in all directions)? That makes their relative speed twice the speed of light. Think about this and you will realise that you must compare speed to an absolutely fixed point in space when using such concepts in physics.

Now I am cannot say for certain where such places exist (though I would assume it is in the regions, which are not occupied by universes, assuming universes do not move, otherwise it would just be some point in our universe's space), but it seems obvious to me that there exist these constraints with regard to what you consider as travelling faster then the speed of light and defying physics.

I could be completely wrong but this seems like the most logical, so if someone can explain more correctly, please do! ^^

* Kitsune wonders when Jubin will check the topic...

Those formula apply for if there was an object stationary relative to the universe, it would observe an object moving at high speeds, and see it with m = m0 / gamma, t = t0 * gamma and so on. But for a person sitting in that fast moving object, it won't detect any of this. It would still see everything on the ship to be the same. That also explains why a person in a ship going at, say c-1 ms-1, could skip generations of life, due to time dialation.

You included the concept of twin paradox there, Ghost. The truth in the twin paradox is that, while both objects may see each other going younger, and all those relativity things, it is the actual moving object relative to the universe which is suffering the relativity consequences.

Also, light is always travelling at c, from anyone's frame of reference, even on someone who's travelling fast. According to your explanation, you are saying that if there was an object going at c/4, if a electromagnetic signal (same concept as light) goes to that object, it should arrive at the ship at (c - c/4) = 3c/4 ms-1. Sorry, but that's the wrong concept. When the light arrives, it should be c, no matter what.

sry the answer is 292 000 km/s. Equation is u=(v1+v2)/(1+(v1*v2/c^2)) where v1 is speed of the first body, v2 speed of the second body. c- speed of light and u is relative speed.

Ok. I got 40c/41, which is the equilivant to 292682926.8ms-1.

[Kitsune]

Yeah, if only the Australian (Western) education system decided to do something more decent, I wouldn't have to think so hard to come up with useless logic. = ="""""""""

[~Legend~]

Remember kids: It's only cheating if you get caught!

 :razz:

 

Better not be a bad influence to younger children!   

[Voodoo]

Better not be a bad influence to younger children!  

Too late.

[~Legend~]

Too late.

Oh well,
At least we tried (:trust:)

[WBlastRose]

Here's my homework: Stay home for 2 weeks, eat donuts, play Wii, play GTA SA:MP, and stay up untill 6 A.M!