ISnt the radioscope looking (hearing?) at only a fraction of the sky? If so... haven't we already looked (heard) all of it?

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does it really matter? apparently we are all here for nothing but the credits anyway

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i WAS searching for another beer, but that is a good question, why not search the whole sky? each segment broken down - SETI3, SETI4....SETI99...

.

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No matter where you go, there you are...

> does it really matter? apparently we are all here for nothing but the credits
> anyway
>
>
>
Well yea... but it would be cooler if you were looking for ETs too

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> ISnt the radioscope looking (hearing?) at only a fraction of the sky? If so...
> haven't we already looked (heard) all of it?

Time presents another dimension: each time Arecibo visits a spot in the sky there is a chance that ET just plain isn't on the phone at that particular moment.

We need to check back later.

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> > ISnt the radioscope looking (hearing?) at only a fraction of the sky? If
> so...
> > haven't we already looked (heard) all of it?
>
> Time presents another dimension: each time Arecibo visits a spot in the sky
> there is a chance that ET just plain isn't on the phone at that particular
> moment.
>
> We need to check back later.
>

good point Ned, i'd hate to think that they were there 5 minutes after we just looked at that spot and they were saying "hey!"......

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No matter where you go, there you are...

> ISnt the radioscope looking (hearing?) at only a fraction of the sky? If so...
> haven't we already looked (heard) all of it?
>
Really we need to look at many parts of the sky many, many times each. We need to crunch many orders of magnitude more workunits to call this a good search. Looking at one part of the sky once (or even four times) isn't going to get us much of a chance of finding a signal. If there are aliens out there what are the chances that they would be beaming a signal at all? What are the chances that they would have their flasher on so we could collect its signal at exactly that precise instant (but many years later, of course)? What is the chance that their beam could be pointed precisely at us? Multiply those things and you get a mighty small number.

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Here's how I see it (in a very, very, very basic form).

You've got 360° horizontal and 360° vertical to chose from. Each degree has 60 minutes, and each minute has 60 seconds. The odds of getting the correct right ascension and declination to within the second of angle is 1 in 1.679616 trillion.

Now let's assume that ET is transmitting. They've also got a 1 in 1.679616 trillion chance at aiming their signal at us. That makes the odds 1 in 2.821109907456×10^21.

I think it'd be more likely that I win the €10,000,000,000 lottery jackpot. But still, we hold out hope...

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Hopefully everyone understands the construction at Arecibo - we'd have to shift the poles of the Earth to see the whole sky from there.... http://www.naic.edu/public/about/photos/photogal.htm

Other points of multiple samples of each spot are also valid. Narrowly focused concentrated signals are more likely to reach us for detection - said narrow beam signal would most likely come from a rotating planet - hence, we'd need to be coincendent...

If i was here "jut for the credits," i would have found a more gratifying way to prop up my self-esteem by now. No, my mission is much more sinister: to bring down all the holier-than-thou, self-centered humans that don't yet realize what a puny, insignificant speck we are in the universe (and yet we are an important part of The Great Story... http://www.thegreatstory.org/ )

Anyone threatened by the existence of other intelligence deserves to be bother by such a discovery.... ;-) That keeps me doing my part!!

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> That makes the odds 1 in 2.821109907456×10^21.

Yes, but let's not forget that the odds sink even more when we're considering that we must listen to the right frequency, the signal isn't destroyed on its way by cosmic noice, and that it's strong enough after a long travel to be detected. Besides, gravity will also bend the signal as it passes stars and other gravitational objects. Probably more considerations too, which I have not mentioned...

Maybe we should invent a new "Drake equation" with constants for this scenario? :)

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I use the Adams Equation

     number of inhabitable planets         n lim
--------------------------------------- = --- --> 0.000000000000... roughly.
 infinte number of planets in universe     ∞

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How much does it take for "new data" to be crunched by us ? I mean, I don't think we crunch as fast as the Aceribo Radioscope is getting data, right?

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> How much does it take for "new data" to be crunched by us ? I mean, I don't
> think we crunch as fast as the Aceribo Radioscope is getting data, right?
>

I have read claims that Classic SETI was sending out repeat work just to keep participants machines busy. Cannot confirm this from my own data.

What I do recall was during 2003 and early 2004 (before I went a BOINCing) the gap between the actual date and the date of the tapes being split was steadily reducing to around a couple of months IIRC.

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> I have read claims that Classic SETI was sending out repeat work just to keep
> participants machines busy. Cannot confirm this from my own data.
>
There was a thread and I can't remember the name. Anyway, Rom Walton (project developer) stated that Seti Classic sent out the same WU as many as 29 times, and regularly 8 or 9 times just to keep users happy. Matt Lebofsky (the guy who puts the tapes on the splitters) tried to lessen it "at most" 29 times but from 6-9 regularly. If I can remember the thread I'll get the Actual quote, but this is real close.

The story I've heard is similar (That users are out-crunching Arecibo's ability to generate new data), but it may be possible that Berkeley is giving us old Classic-ed WUs to run as BOINC WUs until more data becomes available.

In all honesty, if there isn't any data left in SETI, BOINC should switch over to [insert project name here] as a fall-back until new data arrives.

But that's what we all do, right?

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> In all honesty, if there isn't any data left in SETI, BOINC should switch over
> to [insert project name here] as a fall-back until new data arrives.

Matt Lebofsky said that Classic automatically recycles work, and BOINC can't.

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Found it

Matt Lebofsky
Project developer

Joined: Mar 1, 1999
Posts: 105
ID: 122079
Posted: 3 Mar 2005 1:04:31 UTC

I should add that it's usually not as bad as 30-40 results per workunit in SETI@classic. When everything is running smoothly (more often that you think!) we average about 5-6 results per workunit. In times like this when splitting is backlogged, it may get a bit higher than that.

- Matt
BOINC/SETI@home

ID: 83393 / Rating: 0 - rate: + / - [Reply to this post]

Rom Walton
Forum moderator
Project developer

Joined: Apr 28, 2000
Posts: 347
ID: 85465
Posted: 2 Mar 2005 23:24:05 UTC - in response to Message ID 83310.
Last modified: 2 Mar 2005 23:25:17 UTC

> That is interesting -- so what you are saying is that Seti classic doesn't
> really have any new real work to do? That the work units being sent out at
> this point are simply resends of completed work just to keep folks happy?
>
> How long has this been going on?

Actually you can think about it more like, there are about 160,000 workunits sent out a day, classic will send out as many copies of that same set of workunits as clients ask for until the next tape is loaded into the system. BOINC creates four results per workunit and only creates more when a result errors out or another result is needed to make a quorum. So if all the results are being crunched, then the project states there isn't anymore work, and then the client crunches another project until it can get some more work.

So in classic, some workunits have been crunched 30-40 times before the next batch of tapes are loaded into the system. As far as I know, it has been happening for as long as capacity has exceeded work, the scientists really only needed 2-3 results per workunit.

> Has it been in process long enough to drive the total science work ratio down
> to match the designed inefficiency of the data check process in SETI BOINC
> where (as I understand it) the same work unit is sent out to multiple
> workstations to make sure that actual processing effort is verified?

See above.

----- Rom

BOINC Development Team, U.C. Berkeley

SETI Classic is currently splitting tapes:

07 January 2005 (ab)
14 January 2005 (aa)
23 January 2005 (aa)
24 January 2005 (aa)
24 January 2005 (ab)
25 January 2005 (aa)
26 January 2005 (aa)
26 January 2005 (ab)
01 February 2005 (aa)

SETI/BOINC is currently splitting tapes:
23ja05aa philmor 16977
24ja05aa galileo 14736
22ja05aa milkyway 24386

IIRC Classic and BOINC use the same splitters - the input and output data is the same so why not.
As Classic is splitting 23 january 05 and 24 january 05 and so is BOINC (23ja05, 24ja05) then that shows at least two of the splitters must be common.

With Classic recycling units as often as Rom says, and BOINC needing to send each Result a minimum of 4 times (for the validation quorum), I would say that processing is keeping up well with data capture - and may overtake it when Classic closes and many (hopefully) participants move over to BOINC.

Like it or not, die hard SETI crunchers like myself may well have to join other projects to find work to stop our CPUs cooling and to keep that funny sort of digital-clock thingy that's attached to main electricity feed ticking accurately...
(I have tried other projects as my SIG shows, but SETI is my preferred effort, and I might as well get the best credit I can ;)

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> Like it or not, die hard SETI crunchers like myself may well have to join
> other projects to find work to stop our CPUs cooling and to keep that funny
> sort of digital-clock thingy that's attached to main electricity feed ticking
> accurately...
>
And in another post it was made clear that BOINC was developed so that Users CPUs could keep busy when Seti was dry. It was posted right after the implementation of the new server, when people were talking about the "Waiting for validtion" question. I can't remember the name of the thread, maybe I'll look that up as well.

> > Like it or not, die hard SETI crunchers like myself may well have to
> join
> > other projects to find work to stop our CPUs cooling and to keep that
> funny
> > sort of digital-clock thingy that's attached to main electricity feed
> ticking
> > accurately...
> >
> And in another post it was made clear that BOINC was developed so that Users
> CPUs could keep busy when Seti was dry. It was posted right after the
> implementation of the new server, when people were talking about the "Waiting
> for validtion" question. I can't remember the name of the thread, maybe I'll
> look that up as well.
>

I agree entirly, multi-project support is a major BOINC feature.

Frankly though I believe quite a bit of work needs to be done on the scheduler before that aim can be fully realised.

Until about 3 weeks ago, I was running 80% SETI, 10% LHC and 10% Einstein. While SETI was broken for one reason or another every few days, that all worked fine. As SETI got better, I discovered that I was always wasting hours processing Einstein work - getting to 80-90% done, and then missing the deadline. (and there was no LHC work)

I suppose if Einstein were to relax their deadlines, things might work better, but until then, or the scheduler does a better job, I'll stay 100% SETI.

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