# Is SETI a Waste of Time? **URL:** \ **Category:** Great Debates\ **Created:** [May 4, 2007, 5:59pm UTC](https://boards.straightdope.com/t/is-seti-a-waste-of-time/402775 "2007-05-04T17:59:18Z")\ **Posts on this page:** 20\ **Page:** 4
**Author:** ![DMC](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/dmc/32/18049_2.png) [@DMC](https://boards.straightdope.com/u/DMC)\ **Post date:** [May 5, 2007, 10:57pm UTC](https://boards.straightdope.com/t/is-seti-a-waste-of-time/402775/61 "2007-05-05T22:57:34Z")
[QUOTE=aguirretherathofgod] Exactly. Because 13 in base 5 is the same thing as 8 in base 10. [/QUOTE] Let me know when you strike oil. ---
**Author:** ![the\_PC\_apeman](https://avatars.discourse-cdn.com/v4/letter/t/ac8455/32.png) [@the\_PC\_apeman](https://boards.straightdope.com/u/the_PC_apeman)\ **Post date:** [May 5, 2007, 11:03pm UTC](https://boards.straightdope.com/t/is-seti-a-waste-of-time/402775/62 "2007-05-05T23:03:13Z")
[QUOTE=aguirretherathofgod] Exactly. Because 13 in base 5 is the same thing as 8 in base 10. [/QUOTE] Yes, ““13” in base 5” is the same thing as ““8” in base 10” but since ““8” in base 10” is not a prime you have again failed to make your point. That number you are describing is not prime in either base. ““13” in base 10” is the same thing as ““23” in base 5” and both are prime. You can’t have it both ways. You must do the math. Don’t believe me? Try asking any math teacher. You will fail their course. Try working as a programmer. Your programs will fail: hexadecimal is base 16, octal is base 8, binary is base 2, I’ve seen base 36 used at times too. ---
**Author:** ![the\_PC\_apeman](https://avatars.discourse-cdn.com/v4/letter/t/ac8455/32.png) [@the\_PC\_apeman](https://boards.straightdope.com/u/the_PC_apeman)\ **Post date:** [May 5, 2007, 11:07pm UTC](https://boards.straightdope.com/t/is-seti-a-waste-of-time/402775/63 "2007-05-05T23:07:33Z")
**aguirretherathofgod** , do you realize you are trying to argue that (\* \* \* \* \* \* \* \* \* \* \* \* _) and (_ \* \* \* \* \* \* \*) are the same number? ---
**Author:** ![aguirretherathofgod](https://avatars.discourse-cdn.com/v4/letter/a/71e660/32.png) [@aguirretherathofgod](https://boards.straightdope.com/u/aguirretherathofgod)\ **Post date:** [May 5, 2007, 11:16pm UTC](https://boards.straightdope.com/t/is-seti-a-waste-of-time/402775/64 "2007-05-05T23:16:33Z")
> [@](#): > > Yes, ““13” in base 5” is the same thing as ““8” in base 10” but since ““8” in base 10” is not a prime you have again failed to make your point. My point is that 13 in base 10 is prime, but 13 in base 5 is not. Here’s another example: 21 is prime in base 8. But not in base 10. Because 21 in base 10 equals 7 (in base 10) times 3 (in base 10). 21 in base 8 is the following in unary: 11111111111111111 21 in base 10 is the following in unary: 111111111111111111111 ---
**Author:** ![the\_PC\_apeman](https://avatars.discourse-cdn.com/v4/letter/t/ac8455/32.png) [@the\_PC\_apeman](https://boards.straightdope.com/u/the_PC_apeman)\ **Post date:** [May 5, 2007, 11:30pm UTC](https://boards.straightdope.com/t/is-seti-a-waste-of-time/402775/65 "2007-05-05T23:30:49Z")
[QUOTE=aguirretherathofgod] My point is that 13 in base 10 is prime, but 13 in base 5 is not. [/QUOTE] But your point is off point because ““13” in base 10” and ““13” in base 5” are two different numbers - just as (\* \* \* \* \* \* \* \* \* \* \* \* _) and (_ \* \* \* \* \* \* \*) are two different numbers. To refute **Lemur866** , you must come up with “a number” that is prime in one base but not another. That’s all you have to do. Just find one number. You haven’t done that yet. ---
**Author:** ![Pleonast](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/pleonast/32/1183_2.png) [@Pleonast](https://boards.straightdope.com/u/Pleonast)\ **Post date:** [May 6, 2007, 12:02am UTC](https://boards.straightdope.com/t/is-seti-a-waste-of-time/402775/66 "2007-05-06T00:02:38Z")
[QUOTE=KarlGauss] SETI may not be a waste of time . . . but **BOINC** \* sure as hell is. It sucks. \*the program by which you help SETI by “loaning” it your CPU to help in the search whenever your computer is idle. ☹ [/QUOTE] Why the hate for BOINC? It’s a great framework for asynchronous, heterogeneous, parallel computing. I’ve used it myself for several internal projects in my company. Fairly easy to set up and very scalable. ---
**Author:** ![aguirretherathofgod](https://avatars.discourse-cdn.com/v4/letter/a/71e660/32.png) [@aguirretherathofgod](https://boards.straightdope.com/u/aguirretherathofgod)\ **Post date:** [May 6, 2007, 7:02am UTC](https://boards.straightdope.com/t/is-seti-a-waste-of-time/402775/67 "2007-05-06T07:02:59Z")
[QUOTE=the PC apeman] But your point is off point because ““13” in base 10” and ““13” in base 5” are two different numbers - just as (\* \* \* \* \* \* \* \* \* \* \* \* _) and (_ \* \* \* \* \* \* \*) are two different numbers. To refute **Lemur866** , you must come up with “a number” that is prime in one base but not another. That’s all you have to do. Just find one number. You haven’t done that yet. [/QUOTE] The same numbers I’ve been talking about all along. Obviously two numbers that are different in the same base are not the same. That’s been my point from the beginning. Now cough up the million dollars!! Lol. 🙂 ---
**Author:** ![aguirretherathofgod](https://avatars.discourse-cdn.com/v4/letter/a/71e660/32.png) [@aguirretherathofgod](https://boards.straightdope.com/u/aguirretherathofgod)\ **Post date:** [May 6, 2007, 8:16am UTC](https://boards.straightdope.com/t/is-seti-a-waste-of-time/402775/68 "2007-05-06T08:16:53Z")
Here’s a more dramatic example: In every base where it has meaning, the number “2” is prime. But if you express **the same number** in base 2, you get “10.” The number 10 is prime **if and only if** the base is prime. So in base 10, 10 is “composite” (a fancy word that basically means “not prime”). Will aliens have a prime number of fingers? It seems unlikely, but you never know. ---
**Author:** ![Indistinguishable](https://avatars.discourse-cdn.com/v4/letter/i/90ced4/32.png) [@Indistinguishable](https://boards.straightdope.com/u/Indistinguishable)\ **Post date:** [May 6, 2007, 8:40am UTC](https://boards.straightdope.com/t/is-seti-a-waste-of-time/402775/69 "2007-05-06T08:40:32Z")
Normally, when people say “The number 10”, they mean the referent to be a specific quantity, varying the representation according to the base (or whatever other encoding system you have). They do NOT mean the referent to be a specific representation, varying the quantity according to the writing system. A person saying “10” generally means to refer to "The number represented in decimal by ‘10’ ", to refer to “The number of asterisks in \*\*\*\*\*\*\*\*\*\*”, to refer to "The number represented in base 7 by ‘13’ ". They do not mean to refer to “The string consisting of a 1 followed by a 0, to be interpreted as different quantities depending on the base.” That’s what people are calling you out on. A representation may represent a prime in one base and a non-prime in another base, no one in this thread disagrees. But they wouldn’t call that the same thing as a number being prime in one base and non-prime in another base. So, again, when people say “The same number” across bases, they mean “the same quantity with possibly varying representation”; they don’t mean “the same representation with possibly varying quantity”. ---
**Author:** ![aguirretherathofgod](https://avatars.discourse-cdn.com/v4/letter/a/71e660/32.png) [@aguirretherathofgod](https://boards.straightdope.com/u/aguirretherathofgod)\ **Post date:** [May 6, 2007, 11:17am UTC](https://boards.straightdope.com/t/is-seti-a-waste-of-time/402775/70 "2007-05-06T11:17:27Z")
[QUOTE=Indistinguishable] Normally, when people say “The number 10”, they mean the referent to be a specific quantity, varying the representation according to the base (or whatever other encoding system you have). They do NOT mean the referent to be a specific representation, varying the quantity according to the writing system. A person saying “10” generally means to refer to "The number represented in decimal by ‘10’ ", to refer to “The number of asterisks in \*\*\*\*\*\*\*\*\*\*”, to refer to "The number represented in base 7 by ‘13’ ". They do not mean to refer to “The string consisting of a 1 followed by a 0, to be interpreted as different quantities depending on the base.” That’s what people are calling you out on. A representation may represent a prime in one base and a non-prime in another base, no one in this thread disagrees. But they wouldn’t call that the same thing as a number being prime in one base and non-prime in another base. So, again, when people say “The same number” across bases, they mean “the same quantity with possibly varying representation”; they don’t mean “the same representation with possibly varying quantity”. [/QUOTE] But here’s the thing: In your terminology, the “quantity” signified by a “representation” is different depending on the base you use to interpret it. So in Base 7, for example, the number 10 is prime. But in good old base 10, the number 10 is not prime. ---
**Author:** ![the\_PC\_apeman](https://avatars.discourse-cdn.com/v4/letter/t/ac8455/32.png) [@the\_PC\_apeman](https://boards.straightdope.com/u/the_PC_apeman)\ **Post date:** [May 6, 2007, 1:07pm UTC](https://boards.straightdope.com/t/is-seti-a-waste-of-time/402775/71 "2007-05-06T13:07:20Z")
[QUOTE=aguirretherathofgod] The same numbers I’ve been talking about all along. Obviously two numbers that are different in the same base are not the same. That’s been my point from the beginning. [/QUOTE] Which statement do you disagree with? [list=A] **Lemur866** ’s challenges was to tell him “a number that is prime in base ten, but not prime in binary, or some other base.” [li]You claim that 13[sub]10[/sub] and 13[sub]5[/sub] qualify as “a number that is prime in base ten, but not prime in” base 5.[/li][li]13[sub]10[/sub] and 1111111111111[sub]1[/sub] are the same number.[/li][li]13[sub]5[/sub] and 11111111[sub]1[/sub] are the same number.[/li][li]1111111111111[sub]1[/sub] and 11111111[sub]1[/sub] are not the same number.[/li][li]13[sub]10[/sub] and 13[sub]5[/sub] are not the same number.[/li][li]13[sub]10[/sub] and 13[sub]5[/sub] are not “a number”.[/li][/list] ---
**Author:** ![boygenius](https://avatars.discourse-cdn.com/v4/letter/b/c68b51/32.png) [@boygenius](https://boards.straightdope.com/u/boygenius)\ **Post date:** [May 6, 2007, 1:34pm UTC](https://boards.straightdope.com/t/is-seti-a-waste-of-time/402775/72 "2007-05-06T13:34:33Z")
Yes SETI is a waste of time. For a hypothetical alien race, it would be far easier to send messages to us using Von Neumann probes. Which would make their presence very obvious – as obvious as the aliens chose to be. The fact that we don’t see obvious Von Neumann probes means that any aliens out there have chosen not to communicate with us. Which means that there’s no point in looking for their beacons. ---
**Author:** ![SentientMeat](https://avatars.discourse-cdn.com/v4/letter/s/43a26b/32.png) [@SentientMeat](https://boards.straightdope.com/u/SentientMeat)\ **Post date:** [May 6, 2007, 1:34pm UTC](https://boards.straightdope.com/t/is-seti-a-waste-of-time/402775/73 "2007-05-06T13:34:35Z")
In case anyone’s still listening through all this mathematical static, the main point which **ralph** ’s OP missed is that 40 light years is still a tiny, _tiny_ fraction of our galaxy. In 1974 we aimed a [powerful beam](http://en.wikipedia.org/wiki/Arecibo_message) at a star cluster _25,000_ light years away containing some basic information which any intelligent race should be able to make something of. If an alien civilisation is occasionally sweeping the skies with a similar message, we’ve effectively only just turned on our (extremely poor quality) receiver. Closing down SETI now would be like building your own TV in the middle of the countryside, turning it on once in 1974 at 3am and concluding that there are no TV transmitters in the world if you don’t get a clear signal. And technology exchange _is_ possible - even if they merely mentioned a particular element in the periodic table which seemed rather boring to us but which formed the basis of something amazing on their world, it would be a big clue. ---
**Author:** ![boygenius](https://avatars.discourse-cdn.com/v4/letter/b/c68b51/32.png) [@boygenius](https://boards.straightdope.com/u/boygenius)\ **Post date:** [May 6, 2007, 1:56pm UTC](https://boards.straightdope.com/t/is-seti-a-waste-of-time/402775/74 "2007-05-06T13:56:49Z")
> [@](#): > > Closing down SETI now would be like building your own TV in the middle of the countryside, turning it on once in 1974 at 3am and concluding that there are no TV transmitters in the world if you don’t get a clear signal. In line with your analogy, rather than mucking around constructing TV receivers, it’s easier to simply check your Sears Roebuck and Radio Shack catalogs now and then to see if TV’s are being advertised. If they are, you can conclude that there are TV transmitters out there. If not, then there probably aren’t and anyway it’s likely to be fruitless to look for them by building your own TV. ---
**Author:** ![Indistinguishable](https://avatars.discourse-cdn.com/v4/letter/i/90ced4/32.png) [@Indistinguishable](https://boards.straightdope.com/u/Indistinguishable)\ **Post date:** [May 6, 2007, 7:26pm UTC](https://boards.straightdope.com/t/is-seti-a-waste-of-time/402775/75 "2007-05-06T19:26:40Z")
Sorry to contribute ever more to the mathematical static, but I’ll give it just one more pathetic shot… [QUOTE=aguirretherathofgod] But here’s the thing: In your terminology, the “quantity” signified by a “representation” is different depending on the base you use to interpret it. [/QUOTE] Is it not clear from the post you’re replying to that I understand that? Everyone in this thread understands that. Everyone in this thread agrees that the same representation can signify a prime in one base and a non-prime in another base. What we disagree with you on is this: You seem to feel “13 (base 10)” and “13 (base 5)” count as “the same number” while we all disagree. We can all see that they have the same representation and we can all see that they refer to different quantities. Sameness of representation isn’t what we consider being the same number. Sameness of quantity is what we consider being the same number. ---
**Author:** ![aguirretherathofgod](https://avatars.discourse-cdn.com/v4/letter/a/71e660/32.png) [@aguirretherathofgod](https://boards.straightdope.com/u/aguirretherathofgod)\ **Post date:** [May 7, 2007, 2:51am UTC](https://boards.straightdope.com/t/is-seti-a-waste-of-time/402775/76 "2007-05-07T02:51:11Z")
> [@](#): > > 1310 and 135 are not the same number 13 in base 5 is the same thing as 8 in base 10. 13 is prime; 8 is not. ---
**Author:** ![Voyager](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/voyager/32/133_2.png) [@Voyager](https://boards.straightdope.com/u/Voyager)\ **Post date:** [May 7, 2007, 3:08am UTC](https://boards.straightdope.com/t/is-seti-a-waste-of-time/402775/77 "2007-05-07T03:08:14Z")
[QUOTE=aguirretherathofgod] 13 in base 5 is the same thing as 8 in base 10. 13 is prime; 8 is not. [/QUOTE] Look, forget about bases. We’re not going to send them pictures of numbers, or even numbers in ASCII. We’re going to send information in binary, which everyone understands. If they are smart enough to build computers, they are going to know base 2, base 4, maybe base 8 and base 16. There is no particular reason to think they will consider base 10 any less odd than we consider base 5. So unless you think we are going to communicate with aliens by faxing them something, I don’t get your point. ---
**Author:** ![Indistinguishable](https://avatars.discourse-cdn.com/v4/letter/i/90ced4/32.png) [@Indistinguishable](https://boards.straightdope.com/u/Indistinguishable)\ **Post date:** [May 7, 2007, 3:22am UTC](https://boards.straightdope.com/t/is-seti-a-waste-of-time/402775/78 "2007-05-07T03:22:38Z")
Even if we did encode in weird bases, it’s not like it’s impossible to figure out the system (as noted above by **Chronos** ). I mean, given that cryptographers routinely decrypt messages purposely designed to be hard to read by strangers, you have to figure that messages put forth with the actual intention of being read by the public can’t be that hard to figure out. ---
**Author:** ![LinusK](https://avatars.discourse-cdn.com/v4/letter/l/258eb7/32.png) [@LinusK](https://boards.straightdope.com/u/LinusK)\ **Post date:** [May 7, 2007, 6:18am UTC](https://boards.straightdope.com/t/is-seti-a-waste-of-time/402775/79 "2007-05-07T06:18:21Z")
[QUOTE=Shawn1767] Dear Shawn, No, we couldn’t detect “ourselves” from 30 ly with the type of SETI searches we ourselves run… Well, that’s not quite true. We could hear certain radar transmissions at that distance. [/QUOTE] I thought this was the most interesting point in the whole discussion… and it’s something that I’ve wondered about. I mean, if we couldn’t hear ourselves from 30 light years, what are the chances they’re out there (and perhaps even close by) and our equipment is just too crappy to pick them up? I’m curious what radar transmissions he’s talking about. PS - aguirre, you don’t, by any chance, work for Verizon? ---
**Author:** ![Indistinguishable](https://avatars.discourse-cdn.com/v4/letter/i/90ced4/32.png) [@Indistinguishable](https://boards.straightdope.com/u/Indistinguishable)\ **Post date:** [May 7, 2007, 6:21am UTC](https://boards.straightdope.com/t/is-seti-a-waste-of-time/402775/80 "2007-05-07T06:21:31Z")
[QUOTE=LinusK] PS - aguirre, you don’t, by any chance, work for Verizon? [/QUOTE] :). (For those who don’t catch the reference, [here](http://verizonmath.blogspot.com/2006/12/verizon-doesnt-know-dollars-from-cents.html)) [Previous page](https://boards.straightdope.com/t/is-seti-a-waste-of-time/402775.md?page=3) [Next page](https://boards.straightdope.com/t/is-seti-a-waste-of-time/402775.md?page=5)