Posers and Puzzles
08 Sep 07
21 Sep 07
Originally posted by FabianFnasyes, you are
May I interpret the answers in this way?
Yes, a wave of sound can move from plane A to plane B, when they move 2 times Mach 0.866 relative to each other, but the frequency will be changed. We don't need any of Einsteins postulate here.
Am I right in this interpretation?
22 Sep 07
Originally posted by AThousandYoungOh, you are missing the point. I try again.
If you ask him, he'd say that turning around took a really, really, really long time.
When you look at your watch, you will always see the hands going in the same speed, no matter in any velocities, in any accellerations, in any gravitation field, you will se the time going at the same speed, no matter what, as long the watch is following you where you are. You cannot ever feel any time other than your own.
22 Sep 07
Originally posted by FabianFnasCorrect.
Oh, you are missing the point. I try again.
When you look at your watch, you will always see the hands going in the same speed, no matter in any velocities, in any accellerations, in any gravitation field, you will se the time going at the same speed, no matter what, as long the watch is following you where you are. You cannot ever feel any time other than your own.
25 Sep 07
1 edit
Originally posted by FabianFnasAlthough there is some sliver of evidence about the invariance of space. There is some data, needing verification for sure and newer detectors are to come on line in a year, the CBR pattern from Cobe and the latest ones, seem to have in it POSSIBLE data indicating that MAYBE the universe as a whole, is spinning. Totally preliminary of course but if independently verified, it would shake physics to the core, AND make a preferred direction in the universe, there would be a 'Center line' around which everything rotates, however slow that is.
Oh, you are missing the point. I try again.
When you look at your watch, you will always see the hands going in the same speed, no matter in any velocities, in any accellerations, in any gravitation field, you will se the time going at the same speed, no matter what, as long the watch is following you where you are. You cannot ever feel any time other than your own.
The idea of what the universe is expanding into is misleading. Space is being INJECTED into our universe, driving everything else apart, more like a balloon blowing up but any such expansion would be in a higher dimensional sense.
26 Sep 07
Originally posted by sonhouseYou quote me, and then you write about something totally different.
Although there is some sliver of evidence about the invariance of space. There is some data, needing verification for sure and newer detectors are to come on line in a year, the CBR pattern from Cobe and the latest ones, seem to have in it POSSIBLE data indicating that MAYBE the universe as a whole, is spinning. Totally preliminary of course but if indepen ...[text shortened]... more like a balloon blowing up but any such expansion would be in a higher dimensional sense.
New, untested, and highly disputed theories us fun, of course, but I usually stick with the well founded theories. The neighbour of fringe physics is often religion and their twisted view of science. And religion is a personal matter.
26 Sep 07
Originally posted by FabianFnasI was just pointing out there may be a chink in your unstinting support of the invariance of space. Of course its tentative, the data is not clear yet. But if shown true, it would blow a big hole in physics! I am not trying to inject some religious view into the discussion, just trying to point out there may be other physics going on yet undiscovered and don't be TOO pedantic about the invariance of space, this data may end up falsifying that idea.
You quote me, and then you write about something totally different.
New, untested, and highly disputed theories us fun, of course, but I usually stick with the well founded theories. The neighbour of fringe physics is often religion and their twisted view of science. And religion is a personal matter.
26 Sep 07
Originally posted by sonhouseWell, the invariance of space is an accepted view of cosmologists, it's not mine. Do you believe in the universal aether too? Which by the way is a space absoluteness, a defined stillness of space.
I was just pointing out there may be a chink in your unstinting support of the invariance of space. Of course its tentative, the data is not clear yet. But if shown true, it would blow a big hole in physics! I am not trying to inject some religious view into the discussion, just trying to point out there may be other physics going on yet undiscovered and don't be TOO pedantic about the invariance of space, this data may end up falsifying that idea.
Actually, a kind of space stillness is a religous point of view. The earth being creatid at the center of everything and all. Theology supports the idea of stillness to 100%.
You don't have to believe of any invariance. Let the future show the answer of this question.
Over and out.
26 Sep 07
Originally posted by FabianFnasAether didn't account for the Earth's rotational movement did it?
Well, the invariance of space is an accepted view of cosmologists, it's not mine. Do you believe in the universal aether too? Which by the way is a space absoluteness, a defined stillness of space.
Actually, a kind of space stillness is a religous point of view. The earth being creatid at the center of everything and all. Theology supports the idea of ...[text shortened]... o believe of any invariance. Let the future show the answer of this question.
Over and out.
14 Nov 07
Originally posted by AThousandYoungis the answer to this 0.0971c ???
In classical Newtonian mechanics, the spaceships would be travelling apart at 1.6c since you simply add the two. However, the real equation is
[i]If [spaceship] B is moving with velocity u relative to [Planet Earth] C and [spaceship] A is moving with velocity w relative to C then the velocity of A relative to B is given by,
v = (w ...[text shortened]... 1 - (-0.64c^2/c^2))
v = (1.6c)/(1.64)
And voila, 0.8c + 0.8c < c due to the Lorenz factor.
sorry but i am trying to fully understand this thread...does this mean the 2 ships appear to hardly be moving relative to each other??
i am a little lost!
15 Nov 07
3 edits
Originally posted by Ulmer FriggNo, it's 0.98 c.
is the answer to this 0.0971c ???
sorry but i am trying to fully understand this thread...does this mean the 2 ships appear to hardly be moving relative to each other??
i am a little lost!
1.6/1.64
The two ships see one another as moving away at almost the speed of light.
15 Nov 07
I'll post what I consider MY simple, intuitive explanation... then read the rest of the posts here if I have time. First, erase Earth or any other point of reference and just consider the two "platforms" or "vehicles" or "frames of reference" so that each moves only in relation to the other. Don't try to relate it to "space" yet. If mass didn't increase and time decrease as ANY platform approaches the speed of light, then the two velocities would be "addative"... their sums would add up to a logical value.
But now if you stick "space/time" into the situation, you must realize that as reference point 1 approaches the speed of light, it's mass and it's "time" change. As does reference point 2's
What is the result if TIME slows down? Speed is distance / time. So speed will alter in a very subtle way. Since NEITHER frames of reference can ever actually attain infinite mass (the speed of light) then their added velocities can never achieve it either.
Now if we introduce the "magic bullet"... a photon traveling from reference 1 to reference 2 or vice versa... it will always be observed as "arriving" at the speed of light. No matter which platform it arrives at. But since "time" on platform 1 and platform 2 has slowed down... How long will it take a photon to travel from 1 to 2 if it is fired off toward 2 after they both have traveled for six months?
Here is the cool part. From the photons point of view... it just arrives. Time is not "meaningful" for it travels at the speed of light.
The punch line is that we live in a pretty weird little box that has all sorts of bells and whistles. Energy really does equal Mass and mass and time are variables as related to time/space. The really neat thing is that there is one place in our universe where Quantum law meets Relativity law... and that is at a Singularity. At this meeting place, space/time becomes undefined. BUT! At this place, Mass and Spin become the ONLY properties in existence! If anyone can figure out WHY this is the case, then HELLO NOBEL! A black hole is the simplest object in the universe. If you know its mass and it's spin, YOU KNOW EVERYTHING THERE IS TO KNOW ABOUT IT. It has no other properties. Not even "Location", which is really counter intuitive.
19 Nov 07
Originally posted by StarValleyWyI'll post what I consider MY simple, intuitive explanation...
I'll post what I consider MY simple, intuitive explanation...
Since NEITHER frames of reference can ever actually attain infinite mass (the speed of light) then their added velocities can never achieve it either.
Now if we introduce the "magic bullet"... a photon traveling from reference 1 to reference 2 or vice versa... it will always be ob ...[text shortened]... It has no other properties. Not even "Location", which is really counter intuitive.
Most beginners in relativity doesn't consised it very intiutive, au contraire very contra-intuitive.
Since NEITHER frames of reference can ever actually attain infinite mass (the speed of light) then their added velocities can never achieve it either.
Like this one. I would say - Why? Why is not 0,75C + 0,75C not 1.5C? An explanation which is not related to any mathematics and intuitive at the same time would be nice.
Time is not "meaningful" for it (photon) travels at the speed of light.
Also contra-intuitive. Why is time not meaingful for light? If it is, why as it a component of time in its speed, 300.000.000 m/s.
The punch line is that we live in a pretty weird little box that has all sorts of bells and whistles.
Again contra-intuitive. An intuitive theory doesn't have any "bells and whistles"
And so on. Relativity theories, like quantum and string and other theories are contra-intuitive in its very nature. At the good old days, in the days of Newton, nature wasn't contra-intuitive. Everything that could be explained in those dys was intuitive and straight forward.
When you start your last posting with "MY simple, intuitive explanation" then I have to object. You have (more or less) right in everything you write, but not the fact that it is intuitive. It's not. It couldn't be. If it was, then it wouldn't be a good theory.
19 Nov 07
Originally posted by FabianFnasDo you assume that scientific explantions have to be straightforward intuitive? If the world doesn't fit our view it isn't the world who is wrong it is our view of it. If one wants straightforward explanations you have aristotelic physics. The only problem with it is that the world doesn't follow it.
[b]I'll post what I consider MY simple, intuitive explanation...
Most beginners in relativity doesn't consised it very intiutive, au contraire very contra-intuitive.
Since NEITHER frames of reference can ever actually attain infinite mass (the speed of light) then their added velocities can never achieve it either.
Like this one. I wou ...[text shortened]... intuitive. It's not. It couldn't be. If it was, then it wouldn't be a good theory.[/b]
0.75c+0.75c is not 1.5c because space and time are not independent of the observer. This equivalent t say that they are not absolute. So when you ask that question what you're really asking is why isn't Nature how I would like it to be.
Intuitive is all about getting used to it. Nowadays is pretty intuitive that to do science you need mathematical laws. Go back 4 centuries and everybody will call you mad for saying such thing out loud. So for a working physicist relativity theory can be said to be intuitive. All you have to do is accept the two postulates than everything follows.
But what people really need to put on their heads is that not all explanations need to be intuitive. The world doesn't have to bend at our will. It is what it is. Being naive won't take us anywere if we truly want to understand what's going on around us.