# Lunar Ranging experiment on the Big Bang Theory **URL:** \ **Category:** Factual Questions\ **Created:** [January 25, 2011, 11:43pm UTC](https://boards.straightdope.com/t/lunar-ranging-experiment-on-the-big-bang-theory/568984 "2011-01-25T23:43:46Z")\ **Posts on this page:** 14\ **Page:** 2
**Author:** ![Antonius\_Block](https://avatars.discourse-cdn.com/v4/letter/a/51bf81/32.png) [@Antonius\_Block](https://boards.straightdope.com/u/Antonius_Block)\ **Post date:** [January 27, 2011, 4:25am UTC](https://boards.straightdope.com/t/lunar-ranging-experiment-on-the-big-bang-theory/568984/21 "2011-01-27T04:25:56Z")
> [@Chronos](#): > > …detecting the 1-3 photons isn’t all that hard, if you have a way of distinguishing them from the background. That’s one advantage of using a laser: It’s a very narrow frequency line. You also know exactly (to within a few nanoseconds) when to expect them back, which means that you can gate the detection system when needed. ---
**Author:** ![tellyworth](https://avatars.discourse-cdn.com/v4/letter/t/977dab/32.png) [@tellyworth](https://boards.straightdope.com/u/tellyworth)\ **Post date:** [January 27, 2011, 4:40am UTC](https://boards.straightdope.com/t/lunar-ranging-experiment-on-the-big-bang-theory/568984/22 "2011-01-27T04:40:18Z")
> [@Antonius\_Block](#): > > Now, the _ **average** _ power of that ruby laser would only have been around 1W (a 3 Joule pulse every 3 seconds), but it’s the _ **peak** _ power that made the experiment feasible. It just took them a long time to accumulate good data with the laser only firing once every 3 seconds… Ignorance fought, thanks. In the interests of a definitive negative answer to the original question: is it plausible that a knowledgeable amateur might get his hands on a laser with the necessary peak power, say by borrowing a piece of lab or industrial equipment? ---
**Author:** ![Antonius\_Block](https://avatars.discourse-cdn.com/v4/letter/a/51bf81/32.png) [@Antonius\_Block](https://boards.straightdope.com/u/Antonius_Block)\ **Post date:** [January 27, 2011, 12:39pm UTC](https://boards.straightdope.com/t/lunar-ranging-experiment-on-the-big-bang-theory/568984/23 "2011-01-27T12:39:16Z")
“Need answer fast”, **tellyworth**? 😉 My one-word answer **to that question** is “ **yes** ”. A commercially-available, uncustomized, order-from-catalog US-built laser, providing the necessary peak power, could be bought new for probably less than US$200k. Several physics and chemistry labs around the world would have these on hand, although “liberating” one may take some social engineering. The “amateur” team would need someone to align the laser _in situ_, but the [Caltech Physics post-docs](http://en.wikipedia.org/wiki/List_of_The_Big_Bang_Theory_characters) in the OP’s video clip could easily suffice if the script required, even if they hadn’t used that particular model of laser before. Knowledge of general alignment and operation of pulsed solid-state lasers is a prerequisite, but that’s not _ **too** _ esoteric. Dozens of people at Caltech would qualify, and such devices **do** come with printed step-by-step manuals… A putative **S** traight **D** ope **M** oon **B** ounce project team, for instance, would also have the necessary experience for operation of the laser part of the experiment. Further details, ordering info, etc, coming later today. ---
**Author:** ![Xema](https://avatars.discourse-cdn.com/v4/letter/x/9de053/32.png) [@Xema](https://boards.straightdope.com/u/Xema)\ **Post date:** [January 27, 2011, 1:39pm UTC](https://boards.straightdope.com/t/lunar-ranging-experiment-on-the-big-bang-theory/568984/24 "2011-01-27T13:39:34Z")
> [@Whack-a-Mole](#): > > Mythbusters (which was debunking the myth that the moon landings were a hoax) went to an observatory to have them shine a laser on the moon and get the return from the reflector. So how do the hoax believers account for the results of these tests? ---
**Author:** ![Whack-a-Mole](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/whack-a-mole/32/141_2.png) [@Whack-a-Mole](https://boards.straightdope.com/u/Whack-a-Mole)\ **Post date:** [January 27, 2011, 2:18pm UTC](https://boards.straightdope.com/t/lunar-ranging-experiment-on-the-big-bang-theory/568984/25 "2011-01-27T14:18:36Z")
> [@Xema](#): > > So how do the hoax believers account for the results of these tests? I have no idea but my guess would be they’d say the video merely shows a green light flickering on the telescope and the data the computer showed could have merely been a program to display whatever the show wanted it to display. There is no “proof” they actually bounced a laser off a reflector on the moon. Just TV special effects and not even very complicated special effects. To be clear, I am not a moon landing hoax believer. I absolutely believe we put men on the moon. Just guessing what a moon hoaxer might say about the above. Aside from the Mythbuster episode there is plenty of moon hoax debunking stuff out there and these people continue to believe their nonsense. A TV show won’t change it. ---
**Author:** ![The\_Controvert](https://avatars.discourse-cdn.com/v4/letter/t/dec6dc/32.png) [@The\_Controvert](https://boards.straightdope.com/u/The_Controvert)\ **Post date:** [January 27, 2011, 2:59pm UTC](https://boards.straightdope.com/t/lunar-ranging-experiment-on-the-big-bang-theory/568984/26 "2011-01-27T14:59:02Z")
The comments from the YouTube video give other reasons, too. For example, if the belief is that humans never walked on the moon, then the presence of the reflector is explained by postulating that robots put the reflector there. ---
**Author:** ![Stranger\_On\_A\_Train](https://avatars.discourse-cdn.com/v4/letter/s/13edae/32.png) [@Stranger\_On\_A\_Train](https://boards.straightdope.com/u/Stranger_On_A_Train)\ **Post date:** [January 27, 2011, 4:09pm UTC](https://boards.straightdope.com/t/lunar-ranging-experiment-on-the-big-bang-theory/568984/27 "2011-01-27T16:09:06Z")
> [@Xema](#): > > So how do the hoax believers account for the results of these tests? When you have The Truth on your side, you don’t need no stinkin’ facts. Stranger ---
**Author:** ![Xema](https://avatars.discourse-cdn.com/v4/letter/x/9de053/32.png) [@Xema](https://boards.straightdope.com/u/Xema)\ **Post date:** [January 27, 2011, 4:41pm UTC](https://boards.straightdope.com/t/lunar-ranging-experiment-on-the-big-bang-theory/568984/28 "2011-01-27T16:41:28Z")
> [@Stranger\_On\_A\_Train](#): > > When you have The Truth on your side, you don’t need no stinkin’ facts. Right. But a lot of the moon-hoax stuff I’ve seen seems to make an attempt at explaining facts - like how the shadows appear in video, or whether the flag is waving in the breeze. Perhaps the biggest weakness of the hoax theory is the number of people who’d have to be in on it (none of which has ever been tempted to come clean). Lunar ranging experiments add to this problem - every time someone does one, the SCFPLLH (Secret Committee For the Perpetuation of the Lunar Landing Hoax) must find out about it, visit them, and get them to agree to say they are receiving reflections when in fact they aren’t. I guess it’s simpler to claim that the reflectors really are there, placed during several complicated space missions that somehow were undetected and have remained secret. ---
**Author:** ![Lare](https://avatars.discourse-cdn.com/v4/letter/l/53a042/32.png) [@Lare](https://boards.straightdope.com/u/Lare)\ **Post date:** [January 27, 2011, 5:56pm UTC](https://boards.straightdope.com/t/lunar-ranging-experiment-on-the-big-bang-theory/568984/29 "2011-01-27T17:56:15Z")
As a member of SNASA (Secret NASA\*) I have been to the moon and can attest that the reflectors are there. I even brought back one of the golf balls Alan Shepard hit and will sell it for the right amount. In regard all the people commenting on amateurs having access to the equipment, I just wanted to point out that these people all have advanced degrees and are on staff at the physics department at a major institution. I think they would be able to arrange to use the equipment if they wanted to, even if it was just for the hell of doing it. (And I thought it was just the kind of thing they’d do, too.) \*= “Secret NASA” is a reference to “How I Met Your Mother,” my other favorite CBS show. The specifics don’t matter if you don’t watch it. ---
**Author:** ![Chronos](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/chronos/32/134_2.png) [@Chronos](https://boards.straightdope.com/u/Chronos)\ **Post date:** [January 27, 2011, 6:48pm UTC](https://boards.straightdope.com/t/lunar-ranging-experiment-on-the-big-bang-theory/568984/30 "2011-01-27T18:48:57Z")
> [@](#): > > The “amateur” team would need someone to align the laser in situ, but the Caltech Physics post-docs in the OP’s video clip could easily suffice if the script required, even if they hadn’t used that particular model of laser before. Knowledge of general alignment and operation of pulsed solid-state lasers is a prerequisite, but that’s not too esoteric. Dozens of people at Caltech would qualify, and such devices do come with printed step-by-step manuals… Especially since three of those four are, respectively, an experimental physicist who works with high-powered lasers a lot, an observational astronomer, and an aerospace engineer. ---
**Author:** ![Lare](https://avatars.discourse-cdn.com/v4/letter/l/53a042/32.png) [@Lare](https://boards.straightdope.com/u/Lare)\ **Post date:** [January 27, 2011, 7:41pm UTC](https://boards.straightdope.com/t/lunar-ranging-experiment-on-the-big-bang-theory/568984/31 "2011-01-27T19:41:41Z")
Yeah. What he said. ---
**Author:** ![tellyworth](https://avatars.discourse-cdn.com/v4/letter/t/977dab/32.png) [@tellyworth](https://boards.straightdope.com/u/tellyworth)\ **Post date:** [January 27, 2011, 10:02pm UTC](https://boards.straightdope.com/t/lunar-ranging-experiment-on-the-big-bang-theory/568984/32 "2011-01-27T22:02:58Z")
> [@Antonius\_Block](#): > > “Need answer fast”, **tellyworth**? 😉 Sadly no. The powers that be here have outlawed most lasers \> 1 mW, lest we use them to shoot down aircraft. It’d take me a while to catch a photon returning from the moon with that sort of power. I was secretly hoping to hear a story about the time a bunch of physics grads got drunk and hauled a bunch of equipment out into the parking lot in order to settle a bet, or something like that. But the amateur EME experiments linked above are actually pretty cool. ---
**Author:** ![Saint\_Cad](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/saint_cad/32/18907_2.png) [@Saint\_Cad](https://boards.straightdope.com/u/Saint_Cad)\ **Post date:** [January 27, 2011, 11:29pm UTC](https://boards.straightdope.com/t/lunar-ranging-experiment-on-the-big-bang-theory/568984/33 "2011-01-27T23:29:25Z")
> [@Xema](#): > > So how do the hoax believers account for the results of these tests? That we can send probes and whatnot to the Moon, just not PEOPLE. So we sent up a probe that spread out these reflectors. ---
**Author:** ![Sam\_Stone](https://avatars.discourse-cdn.com/v4/letter/s/ecccb3/32.png) [@Sam\_Stone](https://boards.straightdope.com/u/Sam_Stone)\ **Post date:** [January 27, 2011, 11:29pm UTC](https://boards.straightdope.com/t/lunar-ranging-experiment-on-the-big-bang-theory/568984/34 "2011-01-27T23:29:57Z")
You guys are missing the part where the receiving telescope has to be really freaking big. The guys using the 3.5 meter telescope collected a grand total of 2500 photons, and that was an amazing accomplishment. The article says that the McDonald Observatory in Texas collects about that many photons from the reflectors in 3 _years_ of measurements. Let’s say the boys had a 12 inch telescope, which about the limit for the size of a scope you could carry up to a rooftop easily. That scope would have .8% of the light-gathering ability of the 3.5m scope used in the article. Actually less because of other factors that come into play, but in general we’re in the ballpark. It’s not going to work… [Previous page](https://boards.straightdope.com/t/lunar-ranging-experiment-on-the-big-bang-theory/568984.md?page=1)