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Catching Photons Coming from the Moon 146

Roland Piquepaille writes "In 'Shooting the moon,' the San Diego Union-Tribune describes how and why physicists from UCSD are using lasers to send light pulses in direction of an array of reflectors installed on our moon in 1969 by Neil Armstrong and Buzz Aldrin. One of the goals of these experiments is to check the validity of Einstein's theory of general relativity. Another one is to measure the distance between the Earth and moon with a precision of one millimeter by catching photons after their round trip to the moon. But it is amazing to realize how difficult it is to capture photons after such a trip. I also have up a summary, which contains additional details and pictures, if you just want to learn how difficult it is to capture photons back from the moon."
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Catching Photons Coming from the Moon

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  • by DumbSwede ( 521261 ) <slashdotbin@hotmail.com> on Saturday July 15, 2006 @12:41AM (#15723478) Homepage Journal
    You can just make out the begin of what looks like the word "chair"
  • title? (Score:3, Funny)

    by binarybum ( 468664 ) on Saturday July 15, 2006 @12:53AM (#15723512) Homepage
    must say that title is a bit vague. I was just outside last night getting bombarded with photons from the moon. I'm betting technology circa 1888 is capable of capturing photons coming from the mooon.
  • by Anonymous Coward on Saturday July 15, 2006 @12:57AM (#15723523)
    It amazes me that so many allegedly "educated" people have fallen so quickly and so hard for a fraudulent fabrication of such laughable proportions. The very idea that a gigantic ball of rock happens to orbit our planet, showing itself in neat, four-week cycles -- with the same side facing us all the time -- is ludicrous. Furthermore, it is an insult to common sense and a damnable affront to intellectual honesty and integrity. That people actually believe it is evidence that the liberals have wrested the last vestiges of control of our public school system from decent, God-fearing Americans (as if any further evidence was needed! Daddy's Roommate? God Almighty!)

    Documentaries such as Enemy of the State have accurately portrayed the elaborate, byzantine network of surveillance satellites that the liberals have sent into space to spy on law-abiding Americans. Equipped with technology developed by Handgun Control, Inc., these satellites have the ability to detect firearms from hundreds of kilometers up. That's right, neighbors .. the next time you're out in the backyard exercising your Second Amendment rights, the liberals will see it! These satellites are sensitive enough to tell the difference between a Colt .45 and a .38 Special! And when they detect you with a firearm, their computers cross-reference the address to figure out your name, and then an enormous database housed at Berkeley is updated with information about you.

    Of course, this all works fine during the day, but what about at night? Even the liberals can't control the rotation of the Earth to prevent nightfall from setting in (only Joshua was able to ask for that particular favor!) That's where the "moon" comes in. Powered by nuclear reactors, the "moon" is nothing more than an enormous balloon, emitting trillions of candlepower of gun-revealing light. Piloted by key members of the liberal community, the "moon" is strategically moved across the country, pointing out those who dare to make use of their God-given rights at night!

    Yes, I know this probably sounds paranoid and preposterous, but consider this. Despite what the revisionist historians tell you, there is no mention of the "moon" anywhere in literature or historical documents -- anywhere -- before 1950. That is when it was initially launched. When President Josef Kennedy, at the State of the Union address, proclaimed "We choose to go to the moon", he may as well have said "We choose to go to the weather balloon." The subsequent faking of a "moon" landing on national TV was the first step in a long history of the erosion of our constitutional rights by leftists in this country. No longer can we hide from our government when the sun goes down.
  • by H3g3m0n ( 642800 ) on Saturday July 15, 2006 @01:06AM (#15723549) Homepage Journal
    Its being further out might have somthing to do with all those pesky scientists bouncing photons off it.
  • Re:question (Score:5, Funny)

    by Anonymous Coward on Saturday July 15, 2006 @01:15AM (#15723572)
    How did Neil Armstrong and Buzz Aldrin install reflectors on the moon from a soundstage in Burbank?

    They didn't. The Burbank soundstage looked fake, so they had to build one on the Moon.

    The Burbank Landing is a hoax. We never went to Burbank. Going to Burbank requires resources and capabilities far exceeding those we possess or will be able to possess in the foreseeable future.
  • by megaditto ( 982598 ) on Saturday July 15, 2006 @02:08AM (#15723702)
    http://science.slashdot.org/science/06/07/13/16542 00.shtml [slashdot.org] Apollo 11 TV Tapes Go Missing

    Let me ask, have YOU seen any of these "thousands of hours" of high-res tapes that you refer to. Have you seen a single original frame? The fact is that Williams and Kranz (top brass in charge of the archives and missions at NASA) conceed that the original data is misplaced, believed wiped.

    All we have now is re-filmed qvga-res shit: tv-grabs, literally.
    But don't despair, for NASA, like the OJ, just might finally find the reel killer.

    What's funny is that one would need post-doctoral training to even understand just the kind of info one could extract from high-quality TV scans; I do not expect you to understand.

    The bottom like is that whether the TV feeds came from the Moon or from a set [wikimedia.org] we will not know until the original tapes can be examined.

  • by Antony-Kyre ( 807195 ) on Saturday July 15, 2006 @03:01AM (#15723808)
    Gravity accelerates all objects at the same rate? What does this mean? My understanding is that two objects of difference masses will fall at different rates. More massive objects will reach their destination quicker than the less massive objects. This has been mathematically proven. I even had a physics teacher help me write out the hypothetical trials.

    (As to whether hotter objects fall faster than colder objects, I don't know yet. That's something else I've been wondering.)
  • Not yours! (Score:2, Funny)

    by badzilla ( 50355 ) <.ultrak3wl. .at. .gmail.com.> on Saturday July 15, 2006 @04:23AM (#15723943)
    ...installed on our moon in 1969...

    Hey! Just cause you Yanks got there first doesn't make it yours, m'kay?

  • by agw ( 6387 ) on Saturday July 15, 2006 @04:48AM (#15723970)
    Fire the "L.A.S.E.R."!
  • by Antony-Kyre ( 807195 ) on Saturday July 15, 2006 @05:38AM (#15724043)
    Below are some of the formulas. I haven't been taught how to derive the bottom one. If you do a couple trials, objects A and C in trial one, and objects B and C in trial two, with A being more massive than B, with center of gravities being dropped from the same distance, the more massive one will reach it's destination "sooner" than the less massive one. This is math. It's provable. I need to go to sleep now, so maybe later I'll be posting the complete example with trials.

    Force of Gravity = 6.67 * 10- mass1 * mass2 / distance

    distance = ½ * acceleration * time
    time = (2 * distance / acceleration) ^ ½

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