Reducing Computer Power Requirements

[scottsAI]

I will take a stab at answering your question. Sorry about the delay, out of town.

I have been running SETI for 2.857 years. My rank out of 5432010 total users is: 1332nd place. (as of writing this).

Why? Because I can. It defines who and what I am. I like to do things others do not.

Like most of you. This is how I do my job. I work in Sales, I'm the geek on the sales team. I help people, make sure they do it right so their project will succeed. So the sales team succeeds.

When the other distributed projects came on I looked at the medical. I thought about it long and hard. Realized pharmaceutical companies will be the larges benefactors of the results. If they thought doing it was so good, the budget for couple thousand computers would be a low ticket item. Same with the finance programs.

Why SETI? What is the chance of results?

I do NOT expect to find anything.

SETI claims to be able to detect signals from 100 light years (LR). Others claim that is not real, more like 70 LR. Considering the number of suns this represents, what chance is there another civilization at or near our technical level of development? SETI is based on the “other” civilization intentionally sending a Tera watt signal out for us to find. Our civilization did this for a few years in the 70's. Many armature radio dudes are beaming signals, most are using 1kw transmitters or pulsing 10kw, rumor of a group at 100kw. This is very far removed from the assumed Tera watt.

So why do it? Well it's kind of like winning the lottery, you have to buy a ticket...

Running SETI is my ticket. And, yes I can afford it. This is my largest hobby expense. I do not rebuild cars, etc. (I used to:)

Two years ago my mother gave me 1k$, I bought 10 computers with a little more cash. Brought me up to 20 SETI computers. Sum of processor speeds was 40Ghz. My electric bill went up to $235/mo. Last year I gave away 6 computers to collage students. I wanted the SETI power bill to be around $100/mo.

Today I'm looking at replacing some of the AMD cpu with AMD XP-Mobile cpu to reduce my power, along with other things mentioned in my other posts.

What should you do? You have access to several computers. I find they last longer when left on all the time, assuming they are protected by a UPS. The power difference running SETI vs nothing is <10 watts using a Kill-o-watt meter. Before SETI, I had 5 computers, turned them off/on everyday. I had one, maybe two fail each year. (I use cheap PS). The PCs PS fail only when turned on. Since running SETI 3 fail of 16 computers each year. When the PS goes, <50-50 chance the motherboard gets fried. All computers are on a UPS, maybe why I have less fried computers, don't know.

So, find something that interest you, medical, SETI, what ever! Feel like your part of something big. Harmless hobby, and who knows, maybe your name will be written down as the co-finder of ET!

Have fun.

[BeenzMeenzWind]

Does the transmitted signal really have to be that big for the SETI recievers to notice it? Surely if the signal pattern was distinctive enough it would be relatively simple to pick out of the background noise even if the amplitude was tiny?

I know from career experience that modern military gear works with signal levels that are miniscule, way below the noise threshold.

Is that what the amateur radio guys are doing, transmitting really distinctive codes in the hope that the content of the signal will make up for lack of amplitude?

Just interested.

[scottsAI]

The speed of Linux was not the problem. It's the actual SETI code that is. The code was written a while ago. No chance of a rewrite. SETI has switched to the new bionic, I have not. If and when I make it to the top 1000 I might switch!

I have looked into Linux running windows programs, was complex. Found a group doing it. The results were mixed. Decided, due to complexity to skip it.

Have fun.

[scottsAI]

Then you know all about the inverse square law.

The Tera watt is assuming the signal is beamed in our direction!!

100 LR is 400 trillion miles away. Cosmic dust gets in the way. Free Hydrogen is part of the dust, Absorbs and scatters some of the signal.

Does it have to be that big? Well depends on how far you want it to go!

Bunch of links: Then do a search on SETI and see why people disagree.

http://seticlassic.ssl.berkeley.edu/

Military gear can see way below the noise floor only when it knows the signal.

A great example of this is GPS. Synchronized sampling of the signal thousands of times gives an effective gain of 20-30dbm, signal can be way below the noise floor.

Unfortunately this does not work for SETI. We don't know the signal.

Amateur radio guys are transmitting signals similar to the government programs of the 70's. Of course, they add their own idea of the ideal signal.

Have fun.

[BeenzMeenzWind]

Interesting stuff. Thanks for the link.

You're right about GPS but there are other military applications where the receiver hasn't got a precise idea what form a signal may take. The cleverest of these are employed in, and in the detection of, LPI (Low Probability of Intercept) radar systems. In some of the cutting-edge radar warning receivers there is a capability, though admittedly a limited one at present, to discriminate a signal at a S/N ratio of 0 dBm to -27 dBm.

These units don't know what they are looking for, only what sort of form the signal will probably take if there is one.

I would argue that any extra-terrestrial civilisation attempting to be heard across such huge distances would realise that the transmission of an easily recognisable signal, such as groups of prime numbers, would be the only way they could even dream of being heard.

The practicalities of transmitting a large radio signal, even using a focussed antenna array to magnify the power, make it a total nonsense. If you were to even try to transmit a terawatt signal you'd need superconducting elements in the aerial (unless you were willing to have an Australia sized phased array), superconductors in the feeders, a power source 3 - 10 times bigger than the current electrical generating output of the earth (depending on transmitter efficiency, which might be very good if you already have the superconductors)

I wouldn't want to live within a couple of hundred million miles of the thing though, unless our hypothetical ETs have a liking for being microwaved.

I don't mean to be cynical, as I have used my own idling PC as a SETI node in the past, but hoping that our neighbours are shouting loud enough to hear is just hoping. And a bucketful of hope is worth the bucket.

Besides, any ET civilisation with a hundredth the brains to transmit such a signal would presumably have the brains not to. Be fair, if ET made contact tomorrow the first thing we'd figure out how to do is kill him in his/her boots while leaving their planet inhabitable and technology intact. Then we might reply, if sending the message is easier than launching the first strike.

I totally agree with the aims of SETI but also agree with most members of the space-science fraternity. We need to start launching spacecraft instead of endlessly redesigning them. The Americans pride themselves on the pioneer spirit that forged their country. Trouble is, their too scared to BE pioneers anymore. People might get hurt or killed and that's bad for political careers. (Though in my honest opinion, the absolutely LAST person who should be in charge of a country is anyone who wants the job. It should be like jury service. You get conscripted for a term, preferably a short one)

Assuming we ever get over our timidity and strange view that the potential for loss of a human life is worth saying 'not safe, don't try', we might start going to these other solar systems and actually taking a look for ourselves. Somehow I doubt it though. The resources are being wasted as we speak. In 200 years we'll have squandered them and will NEVER get them back. Makes all the things people on this board are doing seem a whole lot more valuable.

Just my two-cents, though.