Hey, this is great! I'm watching this video and I'm sitting there wondering how plausible it is, and it just so happens I know the perfect place to ask. [img]/phpBB/images/smiles/icon_biggrin.gif[/img] It's "The Arrival", with Charlie Sheen, from 1996. Here's its IMDB listing. http://us.imdb.com/Title?0115571

Total non-astronomy person here, so speak slowly and use words of one syllable, please. (Thanking you in advance for not laughing.)

The movie is a pretty straightforward "the aliens are already among us and the government is covering it up" flick. The central premise is that Charlie is a serious professional radioastronomer who is using his telescope time to search the FM bands for SETI signals from the stars. He's presented as a maverick for doing this, as they're supposed to be searching microwave wavelengths. So, questions.

1. Stars emit FM signals? Is it plausible that he'd be the only radioastronomer in the world to think of listening on FM wavelengths? Has anybody actually checked for FM signals from outer space?

2. Stars emit microwaves? Don't laugh, I didn't know that.

3. So, Charlie and his buddy get the signal for 40 seconds and they're frantically trying to call some other observatories to get confirmation. Does it really work like that? "Quick, phone so-and-so and see if they heard it, too"? IRL, aren't there lots of different telescopes all listening, and wouldn't lots of other people have heard it, too, anyway, without needing to get a panicky phone call, "Hey, man, turn on your telescope, there's something really hot on 107 MHz"? Which gets back to whether it's plausible that he'd be listening for FM, and whether other people wouldn't be listening for FM, too.

4. So Ron Silver, in the thankless role of the "You-Know-He's-the-Bad-Guy Executive", tells him, "It's a radio burst from a blah-blah-blah military something", and Charlie says defiantly, "Not at one-oh-seven megahertz, it isn't". So I thought 107 MHz was, like--radio. My Sony boombox out in the kitchen goes up to 108 MHz. So how could Charlie be so certain that he wasn't just picking up the local Dance Party station? He does mention that it was "moving in sidereal time", and I do kinda know what that means. But, the way he said it, it sounded like the number of MHz had something to do with it, was the important thing--he didn't say, "It was moving in sidereal time". Does the military not use wavelengths like 107 MHz? Anyway, can you pick up local radio stations on, say, the Arecibo array? In the movie, they've given him a really huge dish, like the size of the one in that Sam Neill movie that just came out, about the Australian radiotelescope and Apollo 11, "The Dish", that's what it's called.

5. This signal is supposedly coming from a star called Wolf 336, which is 14 light years away. Later on he gets another signal from it, but it gets mixed up in an atmospheric "bounce" from a Mexican radio station. So he says, "Hey, the first signal was definitely from the star because it moved in sidereal time, but this one is definitely from Earth. Hey, what if they're talking?" So I go, "How could they be talking if the star is 14 light years away? How long would an FM signal take to get from here to Wolf 336? Is that plausible?"

6. He finds the second signal because after he gets fired from his radioastronomy job, he gets hired on as a satellite dish installer, and then he goes around to all the folks in his customer service area and rearranges all their TV satellite dishes into a "phased array" and runs the thing out of his attic, with computers and stuff. Can you do that?

7. Up in his attic, he has tubes and things installed hanging out of a big canister-thingie with dry-ice smoke coming out of it, and he tells the handy neighborhood kid (who is there in his role as "audience surrogate") that that's a "cooling jacket for a low noise amp". So there's a big yellow metal tank like an oxygen tank connected to it, so I'm assuming that it's liquid nitrogen? Yes? No? Do they use liquid nitrogen for that? The kid writes his name with his fingertip in the frost on the canister-thingie, which looks like it's made of Pyrex like a beaker. Is that plausible, that a "cooling jacket" with liquid nitrogen would be made out of Pyrex? Also, wouldn't the kid's fingertip freeze?

8. While he's demonstrating his attic equipment for the kid, he supposedly picks up a signal from Voyager 2. You can do that, in your attic, with a backyard satellite dish and a PC? Don't laugh, I didn't know that.





<font size=-1>[ This Message was edited by: Jigsaw on 2002-02-23 23:03 ]</font>