Science a GoGo's Home Page Forums General Discussion General Science Discussion Forum i just duno why you can't observe light speed as half c

totally not what i said. i said the speed of light was the same no matter what the speed of the object that sent out the light.

nothing can go the speed of light, so there is no way a galazy can go that speed.

light is the yardstick that other speeds are measured against.

lets say that a galazy is moving at .99 light speed, in the opposite directions. we are moving at .01 light speed in our directions. that means that in relation to each other we see they other moving away at light speed. since we know that it cant be moving at light speed. we would then figure out that we are moving too. due to time dialation they would see us moving several times the speed of light, but knowing that is impossible (assuming they understand relativity) they would conclude that their time was being dialated.

lets us some real numbers here.

light speed is 186000 miles a second. a ship moving at .8 light speed is moving at 148800 miles per second. in relation to it, everything else appears (perception) to be moving at 148800 miles a second in the opposite direction. a beam of light would be moving at a real rate of 37200 miles per second in relation to the ship. due to time dialation someone in the ship would measure the speed of light as still being 186000 miles a second. this is because time dialated to 1/5 that of someone not moving in relation to light.

if this ship was approaching a planet, and they saw a ship comeing from the opposite directions, the light from that ship would still be reaching them at the speed of light. im afraid i dont remember the formula the researcher gave as to how to determine that appearant they would see the other ship approaching, but they would not see it being faster than light either.

that is called time dialation and that is what ive been saying, which ive been jumped on and dumped on for saying. the only thing is i did not have a formula for it.

i was told quote "time and space can not be seperated"

dehammer wrote:
"lets say that a galazy is moving at .99 light speed, in the opposite directions. we are moving at .01 light speed in our directions. that means that in relation to each other we see they other moving away at light speed."

No. No. No. Stop proudly parading your ignorance.

I notice you totally ignored my challenge to your claim that you'd read Einstein's paper so I'm going to shove it in your face a second time.

What is the derivation of this formula?

E^2 - (pc)^2 = m^2*C^4

And if you don't know try demonstrating integrity, ethics, and maturity by admitting that (A) you don't know and that (B) you've never read anything on relativity more serious than nursery school level.

Dan,
Please cool it with the insults or I'll have to edit your content.

Amaranth,
Moderator

i was not ignoring it, i just did not see it. I will admit that i am not that good with equations but that appears to have the dirivitive of e = mc^2. I have read up on it, but im an not that great on it. i can see where armchair scientist parate things they dont fully understand.

since your on the fact that you challanged me, what about my repeated challange to you about how the same photon can move at two different speeds simulataniously. you have done nothing about it, save insult me.


actually that is not quite true. you said in to two different people, light was still seen to be moving at light speed. the way you wrote it, that meant that the light was still moving away from each of them at 186000 miles a second, even when they were moving apart at 93000 miles a second. please explain that. i have stated repeatedly that light only has one speed. according to you, the light would have to be moving away from the one fartherst away at a speed of 279000 miles a second. which is possible only if he was the one that was moving. if he had never accelerated, then either the two of them had been moving at .5 light speed to begin with (which would mean the light beam had been traveling in the opposite direction at a speed of 279000 miles a second relative to them), or the second person was moving at .5 light speed and the light was only traveling .5 light speed faster than him.

the thing is, with time dialation, the light would still appear to be moving at light speed away from the second person.

dehammer wrote:

"i have stated repeatedly that light only has one speed. according to you, the light would have to be moving away from the one fartherst away at a speed of 279000 miles a second. which is possible only if he was the one that was moving."

I can now see what your problem is. The first sentence that I quoted from you above is incomplete. It should read that "lght has only one speed relative to any inertial reference frame". Inertial reference frames move relative to each other with different speeds. Nonetheless, RELATIVE TO ANY ONE OF THEM you will measure the same light speed c. You are making the mistake of adding the light speed relative to an observer moving relative to you as if this light speed can also be measured relative to your reference frame. This is not possible because both of you can only measure light speed to be equal to c within your respective inertial reference frames. I hope this helps.

no, that is what da has been telling me, and i keep repeating that light has only one speed. the thing is that it still appears to the faster traveler to be going away from him at light speed due to time dialation.

here is the thing though. if you can measure light going in any direction and it is close to the same speed, then your not moving much. if we measure the speed of light comeing from stars the difference in the speed is extreamly small (so small they cant be certain its not the measureing equipment). that is because our planet does not move at anywhere near a measureable fraction of light.

on the other hand if you in a space ship you should be able to detect some difference in the speed of light comeing from infront of you and that comeing from behind you, even with the time dialation. that would tell you what your speed is in relationship to light, and therefore to the universe.

dehammer, what you write is only the case if Lorentz invariance is broken. There are some physicists who have proposed similar experiments to test if Lorentz invariance is exactly valid or is broken at very high energy.

never knew its name. only knew what i read about it. If thats it, then i now have a name for what i read, IF i can remember it lol

Dehammer wrote:
"I will admit that i am not that good with equations but that appears to have the dirivitive of e = mc^2."

No: e^2 - (pc)^2 = m^2*C^4
is the formula that Einstein wrote. Had you read Einstein's publication you'd know that. e=mc^2 was not written by Einstein. It is a popularized simplification that is not valid in our universe.

Sorry Rose. I just hate it when people claim to have read things they clearly never read and haven't the integrity to admit it when clearly caught in their prevarication.

dehammer wrote:
"no, that is what da has been telling me, and i keep repeating that light has only one speed."

That is not what I've been telling you. It is what you have been MISUNDERSTANDING over and over and over and over again.

And your statement that "the thing is that it still appears to the faster traveler to be going away from him at light speed due to time dialation." is incorrect.

It was incorrect the first time you wrote it.
It is incorrect this time.
And it will remain incorrect in the future.

Read a book!

how would it not be correct. the time dialation that you are affected by is basically (simplistically) proportional to the percentage of light speed you are traveling.

You are NOT affected by time dilation because from your perspective you are NOT travelling at a percentage of light speed. It is only from another observer's perspective that you are travelling at a percentage of light speed. According to your perspective the other observer is travelling at a percentage of light speed.

from your point of view your not moving, but from the perspective of the speed of light, you are. period. that means that you are affected by time dilation. its not the perspective of speed that causes time to dilated, its your speed in relation to the entire universe, to space, to the photons moving past you. You will not see the time dilation, because its affecting you AND your senses. they dilation will not affect someone that has not accelerated.

I am starting to feel as if I am just wasting my time trying to point out the fallacies in your reasoning. You state: "its your speed in relation to the entire universe". How do you measure "your speed" relative to "the entire universe?". Which reference frame relates to the "entire universe?". You really do not understand the postulates on which Einstein based his special theory of relativity; do you?

simple. there are two ways.


1) stars do not acclerate unless there is some force that is working on them. unless that force is a majorly large one and/or close to it, any acceleration that affects them is going to occur over millions of years before its measureable. therefore any change in your speed relative to them is your speed.

2) light has only one speed. that is why we know that the distance stars are a certain distance from us. it is also why we can know that they are moving towards us, or away from us. if light has different speeds then we cant know the distance of anything, from a star to an aircraft. measureing the difference between the speed of light coming towards you from in front and from in back and you will easily have the speed you are traveling.

a third way for slower speeds is to check the redshift/blueshift of stars in front of you and behind. since relatively speaking, the stars are not moving very fast, nor are they accelerating very fast, then any change is due to you, not them.

any first year high school algerbra student should be able to figure that out.

i will not claim to have a perfect understanding of the equations, but the ones that are easiest to understand are not that hard.

do you really not understand math?

going over the sites i had used to learn about relativity, i can to a sudden realization.

when discussion speed and time dilation WE'RE ALL WRONG . its not speed that is involved, its acceleration that is the key. time dilation occurs during accleration so it does not matter what the other person speed is in relation ship to you.

a positive acceleration causes a negative time dilation (slowing of time, causing things away from you to appear to speed up) while a negative acceleration (commonly called deceleration) causes a positive dilation (the universe appears to slow down). it does not matter that from your point of reference (relative to you) the other person is moving away at .8 light speed), if he did not acclerate one way or the other he is not affected by time dilation. If you did, it will affect you.

Wow! you have come a long way. You are nearly there. Time dilation is an "illusion" when you look at the time within a reference moving at a constant speed relative to you. Similarly the person moving with a constant speed relative to you will "see" a time dilation within your reference frame. Finally you have grasped the fact that "real time dilation" only occurs within a reference frame when it accelerates (or decelerates). However, there is no "positive" and "negative" time dilation. A clock actually ticks slower when it is accelerated or decelerated; which is the same as the clock finding it in a larger gravitational field. Keep up the good work! We have not "all been wrong". You are finally approaching the truth. Congratulations!!!

And now we get back to your question.

Why does your 'moving` observer perceive
no change in C?

Because the length of his 'yardstick` changes.
Google 'Fitzgerald Lorentz contraction`.

My question to you:
How is your observer to perceive light moving away from him?

The "moving observer" perceives no change in light speed because according to him he is stationary relative to his inertial
reference frame. Therefore all observers will measure light speed as c relative to their own inertial reference frames; they are all in effect stationary. Corrections for "contractions" only need to be made when you are observing events occurring relative to an inertial reference frame moving relative to yourself; for example, the clock in a GPS sattellite clicks away at the same speed as it would if it were on earth; but as observed from earth it is not, and therefore a correction has to be made.

As I have said it is a type of an "illusion" but the illusiopn is "real"; for example, kinetic energy is a similar "illusion". When a mass m travels with you it has no kinetic energy within your reference frame; however, within a reference frame relative to which you are moving an observer will conclude that the mass has kinetic energy. Although this observation is an "illusion" as observed relative to the reference frame within which the mass m is stationary; it is a "real" factor within the reference frame relative to which the mass is moving.

Thus to state that: "the length of his 'yardstick` changes.", is not possible within his reference frame; it only seems to you as if it is the case from your reference frame. If you can teleport to his reference frame you will find that the 'yardstick' is not really any shorter, because now you also will be stationary relative to the 'yardstick'.

I hope this helps.