Said mrjesse: So let's say it's a sunny summer and an Eskimo is standing on the north poll watching the sun through his bone-slit sunglasses. Will he notice that the sun appears to change position as he rotates his head left to right and back? How is that different then the world speeding up or slowing down?It isn't any different from the world rotating left to right and back. If both the earth and the sun where stationary then the sun would be where you see it.
So let's say this Eskimo has his staff stuck in the snow 10 feet in front of him, directly between him and the sun, and he's got a flashlight taped to the top, shining at him.
Are you saying then that as he rotates his head right to left and back, the apparent position of the sun to him will lag its real position due to the 8.5 minutes flight time from sun to earth, causing the sun to first appear on the left of his flashlight then on the right?
Said mrjesse: What's your best evidence that this absurd-sounding idea is true? Why can't I replicate it on the merry go around? What is different between the merry go around rotating 180 degrees per 8.5 minutes and the earth doing the same?
As I patiently tried to explain before, your merry go round experiment is fine except that you have to pulse the water and laser to see what is happening and it would help if you used the outside of the center spinning cup instead of the center.
I've mentioned two different merry go around experiments. The first one was in 472 where I talked only about the sun's apparent lag and merry go around RPMs. I didn't mention a thing about water jets or laser pulses on the first merry go around experiment. Then in 488 you said "Your merry go round experiment conclusion was wrong " but never explained how or why it was wrong!
It wasn't until 490 that I first introduced the second merry go around experiment, which I introduced by saying "Here's another merry go around experiment." I proceeded to describe an experiment with me on a merry go around with a laser and water pulses shooting at me from the same position and timed together. But I never mentioned any cup in the center. Are you thinking of the "Turntable experiment" I described in 469?
Anyway, since you had proclaimed that my merry go around conclusion was wrong before I had even posted the second merry go around experiment, you must have been talking about the first one. In any case, here are my two merry go around experiments again, in order:
Said mrjesse:
Lets say that I'm on a mountaintop park, where there is a merry go around. It's a beautiful bright sunny warm morning, and as I sit on the merry go around, I look out and notice that the sun is exactly horizontal. Now let us further pretend that I get the merry go around rotating at 17 minutes per turn. This way, it'll have turned 180 degrees in the time it takes the light to reach the earth from the sun. So now let's say I have a very sensitive gravity meter which can measure the sun's gravitational pull.Now let me ask you - which way will the sun's gravity appear related to it's light? Will the gravity of the sun be in the east while its gravitational pull will be toward the west?
And here's merry go around number two:
Said mrjesse:So which is it, on these two experiments? They are careful and simple, and a simple "yes" or "no" would be perfectly reasonable and would solve a lot of confusion.
If I am on a merry go around, and it's turning, and there is a pulsing water jet and laser (which pulse in unison) both pointing at the center of the merry go around. The pulse rate and turn rate of the merry go around are such that no water pulse overlaps the life of the previous, and the merry go around turns 1/4 of a turn in the time it takes the leading edge of a water pulse to reach the center of the merry go around. Now it's a warm day and I'm sitting in the middle of the merry go around, with a good water proof compass. The water jet and laser are exactly north, 20 feet, of the center of the merry go around.Will I not find that every time either light or water hits me that it will be coming exactly from the north?
Logical answers would be "Yes, No, or Yes but this doesn't carry over to the situation with the sun and its apparent position."
Thanks,
-Jesse
Hmm, I will give it one last try. Forget everything up till now : ) Break the loop and start fresh. Here is a slightly different topic but it may help you understand the principle.
The first thing to note is that you can’t see something until the light from it reaches you. It isn’t instantaneous. Now lets pretend that light (photons) are moving slowly like snow or rain. You go get in your car and observe the snow falling straight down. Then you slowly start driving the car down the road, gradually accelerating. As you accelerate you start to notice that the snow is not coming from straight above anymore it is coming from somewhere in front and and above you. Now as the car gets going really fast you notice that the snow is coming straight at the car as if the source of the snow is straight in front of you being blown horizontally by the wind. If the snow was photons you would see the sun above you as you got in the car and then as you accelerated to relativistic speeds you would see the sun directly in front of you.
If you watch many science fiction flicks you will occasionally see the effect illustrated when the space craft accelerate to faster than light speed. They bring the whole universe down to a single point of light as they accelerate. Some science fiction flicks are more accurate than others : )
You could also think of it like a strobe light except that the flashes of light tell you where your dancing partner was and that they have moved since you last saw them in the light. It is still pretty much the same effect.