.....

Spend $20 on a laser pointer, a torch and some mirrors.
You don't have to think about outer space to demonstrate most of this.
I've got one on my desk, and can test right here, it's really not that hard.

You can see the difference in spread of a laser beam between shining it on your wall, or a house across your street.

Quote from: Art on April 19, 2013, 08:07:44 AM

Spend $20 on a laser pointer, a torch and some mirrors.
You don't have to think about outer space to demonstrate most of this.
I've got one on my desk, and can test right here, it's really not that hard.

Not quite aiming at the moon is it, which is what I'm on about, if you read the topic through.

No, but it can show you how laser beams do spread out somewhat over long distances.

How does a few mile wide beam hit a retro reflector and beam back a few feet beam turning into(once again) a few mile wide beam?

As has already been said, obviously only a tiny portion of the mile wide beam hits the reflector. The thin reflected beam turning back into a mile wide beam has less to do with beam divergence but more to do with the retro-reflector not being perfect. The tiny corner mirrors it has aren't precisely perpendicular to each other, so you end up reflecting back a beam that has scattered into a cone shape somewhat.

How many on this forum believes this sack of horse crap?

Now that you understand it better, does it not seem more feasibly true?

Quote from: Puttah on April 19, 2013, 08:40:33 AM

Quote from: sceptimatic on April 19, 2013, 07:54:38 AM

How does a few mile wide beam hit a retro reflector and beam back a few feet beam turning into(once again) a few mile wide beam?

As has already been said, obviously only a tiny portion of the mile wide beam hits the reflector. The thin reflected beam turning back into a mile wide beam has less to do with beam divergence but more to do with the retro-reflector not being perfect. The tiny corner mirrors it has aren't precisely perpendicular to each other, so you end up reflecting back a beam that has scattered into a cone shape somewhat.

Quote from: sceptimatic on April 19, 2013, 07:54:38 AM

How many on this forum believes this sack of horse crap?

Now that you understand it better, does it not seem more feasibly true?

Truthfully, it seems as pathetic as ever.

Can you elaborate on what part of the explanation quoted in this post confirms the patheticness of the idea and why?  I would respectfully ask you stay away from generalizations such as "bull-crap", "its obviously a lie" and so on.  I am interested in knowing specifically why it seems incredulous.

You do not accept that only a portion of the kms wide beam can hit the reflector and then come back?  Why do you reject that?

Quote from: Rama Set on April 19, 2013, 09:27:48 AM

You do not accept that only a portion of the kms wide beam can hit the reflector and then come back?  Why do you reject that?

I don't accept the kms wide beams, it's a load of ermmm...you asked me not to say it, so It's bunkum.

Why do you think light cannot travel in a cone?  To eliminate any possible defense by ourselves, why won't you conduct the experiment suggested by Art?

That is a nice cartoon Markjo, what about the .25 to .75 miles the earth would have moved the laser while the photons are going to the moon and back. The cartoon shows the laser sitting in the same place.

That is a nice cartoon Markjo, what about the .25 to .75 miles the earth would have moved the laser while the photons are going to the moon and back. The cartoon shows the laser sitting in the same place.

Read all the points on the diagram and you will see that 0.75 miles is a trivial radius for the reflected photons to cover.

Quote from: hoppy on April 19, 2013, 02:58:30 PM

That is a nice cartoon Markjo, what about the .25 to .75 miles the earth would have moved the laser while the photons are going to the moon and back. The cartoon shows the laser sitting in the same place.

Read all the points on the diagram and you will see that 0.75 miles is a trivial radius for the reflected photons to cover.

I was supposing the laser detector was in, or near the laser. So if the beam hits anywhere near, the detector will register it?
 While the laser is moving horizontally it would be moving vertically also, as the earth(sphere) rotates. How can they know within inches how far the moon is away

That is a nice cartoon Markjo, what about the .25 to .75 miles the earth would have moved the laser while the photons are going to the moon and back. The cartoon shows the laser sitting in the same place.

Obviously the cartoon was simplified, but it still seems to gone over your head.  The .25 to .75 miles that the earth would have moved would still be well within the 9 mile or so diameter of the returning beam.

Math Hoppy. They know from other methods, the distance to the moon so they can calculate the path a photon would have had to travel to arrive at the detector.