[LeGrande]

Huh? A laser ring gyro works just fine to measure earth's rotation on the equator just like any other absolute reading gryo -- assuming of course you have the gyro oriented in the correct way to measure the rotation of the earth...! Do you really think that a top like this wouldn't work on the equator? Are you smoking varius weeds? [grin]

What can I say? Your ignorance is virtually limitless. Quote "When a Foucault pendulum is suspended on the equator, the plane of oscillation remains fixed relative to Earth... the angular speed, α (measured in clockwise degrees per sidereal day), is proportional to the sine of the latitude." Wiki Foucault pendulum.

Notice that they say that the plane of oscillation is the reference point, not that the plane of reference is fixed.

I don't know if you knew this or not, but if you bury a ring laser gyro (or any good gyro for that matter) in the correct orientation, it will measure the earth's rotation. Now it has no idea where the sun is, or anything else - all it knows is that it's rotating -- and what, I ask you, is it basing its measurement off if not absolute angular velocity of zero?

LOL No I didn't know it because it isn't true : ) It is just as valid to say that Foucault's pendulum is rotating and the Earth is fixed. It is only when you add a third point of reference (like the stars, or sun) that you can say that the an object is moving (rotating or otherwise) with respect to that reference.

Oh I already answered them for myself -- but I came to the opposite conclusion that I expect you will. And I don't know if you know this, but in science, there are times when a measure can be taken of the angle between two things at an instant in time. For example, 2 cars are traveling the same speed down the road. How far apart are they? 20 feet. That 20 feet measurement is a valid measurement and is still valid even though now "frame of reference" was defined - well, actually, the frame of reference was defined - it was the distance of one car in a frame of reference of the other car - in other words, the distance between them, referenced to each other. And this is the same thing with my question, and this is why it is valid of me to ask you about the apparent displacement of the sun from its actual position - at an instant in time because the question is not one of rate but one of angular difference. And I don't know if you knew this, but it is possible for two things to have an angular difference at an instant in time.

Take another look at the Merry Go Round, and visualize the ball as a photon. Notice that both observers are facing each other when the photon is emitted and when the photon is received, the person on the Merry go Round has his back to the receiver.

Which 'point in time' is the correct reference? When the photon is emitted (the observers are facing each other) or when the photon is seen (both observers are facing the same direction,180 degrees difference)? This is exactly the answer to your 12 light hour question.

You're totally missing it! Back to my example of two cars which are both moving at the same rate: If they are moving at the same rate (and direction), then the distance between them will remain constant! so once we know them to be moving at the same rate, it is then valid to ask "What is the difference between them at any instant in time."

No, I understand exactly what you are trying to say. Your problem is that you are implicitly using the Earth as your frame of reference for the two vehicles. If you eliminate the earth as your frame of reference then the vehicles are not moving at all.

[mrjesse]

Oh, this is starting to get fun!

Said LeGrande:What can I say? Your ignorance is virtually limitless.

You think I could sell some one Ebay and have plenty left over, huh? [grin]

Said MrJesse:Huh? A laser ring gyro works just fine to measure earth's rotation on the equator just like any other absolute reading gryo -- assuming of course you have the gyro oriented in the correct way to measure the rotation of the earth...! Do you really think that a top like this wouldn't work on the equator? Are you smoking varius weeds? [grin]

Replied LeGrande: Quote "When a Foucault pendulum is suspended on the equator, the plane of oscillation remains fixed relative to Earth... the angular speed, α (measured in clockwise degrees per sidereal day), is proportional to the sine of the latitude." Wiki Foucault pendulum.

Like I pointed out (See bold above) if you are going to try to measure the absolute rotation of the earth, and you have only a 1 axis gyro, you have to align that axis with the earth's rotation - just like using a tape measure - you can't measure the length of something by having the tape measure crosswise.

I guess you didn't know this, but the Foucault pendulum is a single axis gyro, and due to the construction thereof, its axis of measurement works best on the poles and not at all on the equator. But there are lots of other gyros which can be operated in any orientation (like those in airplanes, flywheel gyros and laser ring gyros) which can detect and measure the earth's rotation even on the equator, simply by starting out the gyro with it's axle pointing either up or down or east or west. (or any direction not north and south.)

So it is most absurd for you to say that since the Foucault pendulum doesn't work on the equator that therefore no type of gyro works on the equator -- because not all gyros are constructed in such a way that their operation is limited to a certain orientation.

So on the poles, you could measure the absolute angular rate/velocity of the earth with a Foucault pendulum. Using a correctly oriented gyro of other types (like spinning flywheel, laser ring gyro) you can measure absolute angular rate of the earth at any point in or on the earth.

And do you notice that they mention "sidereal day?" Do you know what that means? Even the Foucault pendulum measures the absolute angular rate of the earth's rotation - regardless of the sun's position! In other words, the star-referenced direction of the sun changes throughout the year, and yet a good gyro can not only track and measure the earth's rotation each day, but it can also track and measure the earth's rotation of 1 turn per year! And you think there's no such thing as absolute angular rate?

Said MrJesse: I don't know if you knew this or not, but if you bury a ring laser gyro (or any good gyro for that matter) in the correct orientation, it will measure the earth's rotation. Now it has no idea where the sun is, or anything else - all it knows is that it's rotating -- and what, I ask you, is it basing its measurement off if not absolute angular velocity of zero?

Responded LeGrande: LOL No I didn't know it because it isn't true : )

You don't think that a gyro can track the earth's rotation? How about that. Anyway, if you really believe that a correctly oriented gyro of good enough quality cannot track the earth's rotation when placed anywhere on or in the earth, then you should read this or go search google or go to the library yourself. Trust me - absolute reading gyros can be used to measure the absolute angular rate of the earth!(I mean if you are certain that there is no gyro that can be used to measure the absolute rotational rate of the earth by placing it anywhere on the earth, then you go ahead and provide some evidence or articles to that affect - but I'm telling you, you're wrong. I've provided a link that demonstrates that you are wrong.)

And if you did have a Foucault pendulum on the north pole, just why do you suppose it's turning strangely at the rate of the earth? What gets it spinning, anyway? If the Foucault pendulum is not tracking absolute zero angular rate, then what is it doing and why does it pick that speed?

And if it's not tracking absolute zero angular rate, then what is it tracking? It's obviously tracking something -- and it's not the sun!.

It is just as valid to say that Foucault's pendulum is rotating and the Earth is fixed. It is only when you add a third point of reference (like the stars, or sun) that you can say that the an object is moving (rotating or otherwise) with respect to that reference.

Sorry dude, I'm not buying your claim when the evidence is to the contrary. The earth could spin at any speed, but it would take force to change its rotational velocity. The gyro goes at zero angular rate as compared to the stars. If you're going to say that that's not absolute zero angular rate then you'd better provide some nice evidence.

Take another look at the Merry Go Round, ...

Sorry, not now. You refuse to answer my color coded questions. And you have contradicted yourself on whether light is or is not a third body. You contradict science when you say that it's not true that a gyro cannot measure the absolute rotational rate of the earth. I've already seen the merry go around and given you my response.

I also know that you keep trying to move this to a discussion of "frame of reference" when the questions I'm asking don't require any such discussion - but that's just another outworking of your desire to change the subject.

Which 'point in time' is the correct reference? When the photon is emitted (the observers are facing each other) or when the photon is seen (both observers are facing the same direction,180 degrees difference)?

You're not getting it, are you. Remember, we are talking about the constant angular displacement between the suns actual and apparent position. Since the distance to the sun is more or less unchanging (close enough for our discussion) and since the apparent rotational rate of the sun (in other words, the rotational rate of the earth) is also reasonably constant, any apparent displacement of the sun will also be constant. Thus, it doesn't matter which point in time - it doesn't matter whether it's yesterday, or tomorrow, the day you were born, or in 50 years - since all the parameters are the same, the apparent angular displacement will be the same - it doesn't matter which point in time. Your football merry go around demo may only send out one photon, but the sun really sends out a constant flood of light.

This is exactly the answer to your 12 light hour question.

Hey, speaking of your merry go around demo, doesn't that prove that if I was on a merry go around turning at the rate of 180 degrees per 8.3 minutes - that the sun would appear in the exact opposite direction of it's gravitational pull?

Said MrJesse:You're totally missing it! Back to my example of two cars which are both moving at the same rate: If they are moving at the same rate (and direction), then the distance between them will remain constant! so once we know them to be moving at the same rate, it is then valid to ask "What is the difference between them at any instant in time."

Replied LeGrande:
No, I understand exactly what you are trying to say. Your problem is that you are implicitly using the Earth as your frame of reference for the two vehicles. If you eliminate the earth as your frame of reference then the vehicles are not moving at all.

How am I implicitly using the earth as a frame of reference? I never said with reference to what they were going x miles per hour. The only frame of reference I gave in an absolute way was that they were both going the same speed and in the same direction one ahead of the other, and that they were a certain distance apart. In other words, my frame of reference was the other car. Same thing goes for the sun and its apparent position: Since the lag (if any) and rates are all constant, the only question left is "How far apart are they."

By the way, you said "When someone shows me an error that I have been making, I thank them.". And then you said "If you were correct that light can determine absolute angular velocity, Michelson and Morley would have succeeded : )".

Then I pointed out to you that "Michelson did succeed in measuring absolute angular velocity! It was called the Michelson-Gale-Pearson experiment!"

As a matter of fact, I've pointed out quite a few points where you've been in error - and I've used sources so you can go read it for yourself! And yet you provide no supporting sources for your claims. In your opinion, have I ever told you something that you didn't already know? Or do you really see yourself as 100% correct in this discussion and me as 100% wrong?

I simply cannot fathom how you can make such claims, and stick behind them for so long (seven months!) even though we've provided so much scientific material that counters your claims and even though you haven't provided a single scientific material that supports your claims. What's going on? I mean, are you like the brightest person since good old Albert E. ? Are your ideas just such new and amazing that nobody else has ever had them? Unless you are the inventor and pioneer in the field, there has got to be some other scientific writings that support your views. But there sure don't seem to be any!

Is this just a matter of faith for you? You know it must be true so therefore it is? Amazing. How could somebody go on for so long believing something that is scientifically unsupported -- and as a matter of fact, scientifically refuted, unless it is by pure faith? Please help me understand! I mean, just imagine what it'd be like to believe with all your heart in something that you claimed was purely scientific and yet for which you could not present a shred of scientific support or evidence!

Please explain!

Thanks,

-Jesse