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Laser Specialist?

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Posted by Alexander on February 16, 2001 12:14:03 UTC

Sorry, Richard but you are incorrect - accounting for General Relativity in weak Earth field will not change much these negligibly small shift of flashlight beam toward the Earth - you will still get about the same very small numbers as I gave you, plus-minus 2 times AT MOST. Near event horizon of a black hole - yes, GR will give you much stronger effect on your light than Newtonian term - after all Newtonian equation is a weak-field limit of GR.

And, I do not invent laws of nature - as I said just a couple posts up, they follow from fundamental symmetries of space-time and a couple of other symmetries. It is strange for a peron working with lasers not to know that fact (it is in many high-school textbooks not to say about colleges). Let me know if you want to learn more about those as you claim "invented by me" fundamental laws like energy conservation and others.

Now, you claim that you made measurements which "refute" the numbers above (plus minus GR corrections)? Let me just ask you, how could you possibly measure such small displacements over large distances?

You claimed to "work with lasers". I am not exactly specialist in lasers, but I can divide and multiply numbers.

So, let me ask you what was the divergence of the laser you used to make measurements that "refute my ideas"? In no way it can be less than diffraction limit, right? And let me ask you what should be the beam size to have a diffraction divergence of laser beam to diverge less than 10^-5 meters on the distance 186 miles away to check my largest number (let's assume that your laser went that far)? I can tell you - it should be 10^-5 m/186 miles= 3.3x10^-11 (!) Did you have a SUPERLASER with that small divergence? Well, congratulations then - even for for the green lased (0.53 micron) your laser beam should have a cross-section about 10 miles! What a good laser! But, may be you used CO2 one (10.6 mkm)? Then the beam of your laser should be about 200 miles in diameter. Cool laser, huh?

Of course, ordinary few m or smaller in diameter laser has diffraction spot which is not even close to measure such small deviations from horizontal.

Also, if you worked in lasers, tell me what is a coherence length, and what is a coherence length for a single photon? What is mode coupling? Q-switching? How does line narrowing work?

If indeed you were "working in lasers", then there is no problem for you to answer those "laser primer" questions.

But if you do not say anything, or if you just say: "Can't tell, this is secret" - then sorry. These is widely known academic knowledge in the field and can not be "secret" unless you have nothing to answer. I can then safely assume that you just lied about testing gravitational bending of light with laser.

Sincerely, Alex.

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