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Astronomers want public funds for intelligent life search

bbc.co.uk

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Re: Astronomers want public funds for intelligent life search

#81

Post by Dominisi »

cletus wrote: post #67

I used to be a big fan of SETI but I've come around to thinking it's probably a complete waste of time. This will probably get dismissed as "optimistic futurism" but I find the argument compelling that the future of any civilization is a Dyson Swarm for many reasons such as: - Planets are inefficient uses of mass to create living area. IIRC 1% of the mass of Mercury could make enough living area from habitats to hous…

What.

IR radiation is bound by the same laws as all other forms of radiation, most namely the inverse square law.

You would have to be radiating monumental amounts of energy, more than say a red dwarf, to be detectable from "millions of light years" away without fading into the cosmic background as noise.

Think about it this way. With the naked eye you can see a bunch of individual distinguishable stars around ~4000 light years away. These stars produce more energy in a second than mankind has ever produced.

But our closest neighbor, Proxima Centuari, you can't see with the naked eye. Its a red dwarf. And while it still produces unfathomable amounts of energy AND is the closest star to our own. You can't see it.

TLDR: No, a Dyson swarm would not be detectable from "Millions of lightyears away"

Re: Astronomers want public funds for intelligent life search

#82

Post by Dominisi »

tgflynn wrote: post #65

There's one simple metric for SETI progress that I would like to see and have always had trouble finding. What is the radius within which SETI can exclude the existence of a civilization currently using Earth-like electromagnetic communications technology and how many star systems are believed to lie within that radius ? How will proposed SETI efforts expand that radius ? I think this is kind of a key metric that cou…

The issue with using general "Earth-like electromagnetic communications technology" is the inverse square law.

Our own communications aren't distinguishable from the cosmic background radiation even at our closest neighbor.

The only way we would find something is if they pointed a VERY powerful noise source directly at us, or us at them. And even then, we are looking at maybe a 100 lightyear bubble (~600 main sequence stars).

Re: Astronomers want public funds for intelligent life search

#83

Post by cletus »

Dominisi wrote: post #81
cletus wrote: post #67

I used to be a big fan of SETI but I've come around to thinking it's probably a complete waste of time. This will probably get dismissed as "optimistic futurism" but I find the argument compelling that the future of any civilization is a Dyson Swarm for many reasons such as: - Planets are inefficient uses of mass to create living area. IIRC 1% of the mass of Mercury could make enough living area from habitats to hous…

What. IR radiation is bound by the same laws as all other forms of radiation, most namely the inverse square law. You would have to be radiating monumental amounts of energy, more than say a red dwarf, to be detectable from "millions of light years" away without fading into the cosmic background as noise. Think about it this way. With the naked eye you can see a bunch of individual distinguishable stars around ~4000…

In what world do you conflate "detectable" with "visible with the naked eye", particularly when talking about IR which isn't in the visible spectrum anyway?

What's more, the ratio of visible light to IR would be... highly abnormal.

> You would have to be radiating monumental amounts of energy,

You mean like the energy output of, you know, a star?

Re: Astronomers want public funds for intelligent life search

#84

Post by abdullahkhalids »

mattkrause wrote: post #78
abdullahkhalids wrote: post #59

Earlier quoted context omitted.

Fundamental physics or esoteric math are funded for several reasons, one of which is that they engender humbleness in society. These fields are among the most intellectually demanding of all, and by trying to do these difficult things, what we should learn as a society is that we are not done and we don't know it all, and can't do it all. SETI particularly has this extra humbleness benefit, because it reminds us as a…

> Fundamental physics or esoteric math are ... most intellectually demanding of all Trying to rank the sciences by "hardness" is silly and counterproductive. Biology gets blown off as "stamp collecting", but it turns out to be frightfully hard in its own way. Look at this "map" of biochemical pathways from Roche: http://biochemical-pathways.com/#/map/1 It's a stupendously complicated dynamical system! This is just pa…

I specifically said "_among_ the most intellectually demanding". Also, I was just listing too commonly known fields that are both difficult and economically useless.

There are many other fields with problems as difficult as math/physics, but those like biology are economically useful. Which is why public+private funding for biology is, rightfully, many times that of fundamental (not applied) physics/math.

Re: Astronomers want public funds for intelligent life search

#85

Post by ddxxdd »

dhimes wrote: post #53
kilroy123 wrote: post #10

I often imagine there is something like "subspace" or faster-than-light communication, and species across our galaxy are a bunch of chatterboxes chatting away. The only problem is we don't know how to tune in to join the conversation. I still think we should keep trying to find them, though.

My suspicion is that they are communicating at frequencies we can't modulate/demodulate yet. Look how short of a time it took us to get from KHz to GHz. Since there's a trade-off in that the higher the frequency- the more data can be transmitted in a given time, it makes sense that intelligent species would try to increase their transmission frequencies as a matter of course- like we did. The downside trade-off is th…

We can detect microwaves, infrared rays, light rays, ultraviolet rays, X-rays, and gamma rays. We might not be able to transmit and receive FM radio in those frequencies, but we are able to detect the presence, polarization, and direction of such radiation.

Re: Astronomers want public funds for intelligent life search

#86

Post by tgflynn »

Dominisi wrote: post #82
tgflynn wrote: post #65

There's one simple metric for SETI progress that I would like to see and have always had trouble finding. What is the radius within which SETI can exclude the existence of a civilization currently using Earth-like electromagnetic communications technology and how many star systems are believed to lie within that radius ? How will proposed SETI efforts expand that radius ? I think this is kind of a key metric that cou…

The issue with using general "Earth-like electromagnetic communications technology" is the inverse square law. Our own communications aren't distinguishable from the cosmic background radiation even at our closest neighbor. The only way we would find something is if they pointed a VERY powerful noise source directly at us, or us at them. And even then, we are looking at maybe a 100 lightyear bubble (~600 main sequenc…

> The only way we would find something is if they pointed a VERY powerful noise source directly at us, or us at them.

Do you mean we could detect ordinary technological EM radiation if we pointed a sufficiently high-gain antenna at the transmitting planet ?

Otherwise if SETI assumes someone is sending an interstellar signal on purpose, I would question its value, because there's no strong reason to think anyone is doing that. I realize we did it once, but an argument can be made (and has been) that it was a fairly stupid thing to do.

Re: Astronomers want public funds for intelligent life search

#87

Post by Nasrudith »

Reminds me of the one theory that SETI was largely cover for signals intelligence spying in the cold war.

Personally I suspect that while we may discover interesting details of radio-astronomy but I highly doubt we will discover anything of worth related to alien life through it.

Re: Astronomers want public funds for intelligent life search

#88

Post by hutzlibu »

abdullahkhalids wrote: post #59
valgor wrote: post #48

I think some commenters are forgetting how science is done. Just because you are researching X does not mean your only output is X. An investment into SETI is an investment in science and technology. All the arguments on this forum about why we should not allocate funds to SETI can be used in the same manner for why we should not investment in pure mathematics or any other potentially "useless" human endeavor. SETI r…

Fundamental physics or esoteric math are funded for several reasons, one of which is that they engender humbleness in society. These fields are among the most intellectually demanding of all, and by trying to do these difficult things, what we should learn as a society is that we are not done and we don't know it all, and can't do it all. SETI particularly has this extra humbleness benefit, because it reminds us as a…

"Fundamental physics"

I actually believe that fundamental physic research is a more effective SETI programm, as with a better understanding of the universe we can also eventually understand potential technologies, that might enable interstellar travel and communication. And than actually communicate and meet with aliens.

Because we have so far not seen a trace of traditional radio or light communication in space, so I guess the odds of finding one are very small.

Or we get more and more disappointed that the bounds are indeed the speed of light. And if that is the case, establishing a contact with an alien race will be very hard, if merely pinging them takes several years.

Re: Astronomers want public funds for intelligent life search

#89

Post by Nasrudith »

mattkrause wrote: post #78
abdullahkhalids wrote: post #59

Earlier quoted context omitted.

Fundamental physics or esoteric math are funded for several reasons, one of which is that they engender humbleness in society. These fields are among the most intellectually demanding of all, and by trying to do these difficult things, what we should learn as a society is that we are not done and we don't know it all, and can't do it all. SETI particularly has this extra humbleness benefit, because it reminds us as a…

> Fundamental physics or esoteric math are ... most intellectually demanding of all Trying to rank the sciences by "hardness" is silly and counterproductive. Biology gets blown off as "stamp collecting", but it turns out to be frightfully hard in its own way. Look at this "map" of biochemical pathways from Roche: http://biochemical-pathways.com/#/map/1 It's a stupendously complicated dynamical system! This is just pa…

Hardness is useful bur in English is a misleading synonym. Hard science is more quantitative and has more rigor in terms of hard proof and mathematical models and less room for fuzziness.

"Soft" science is fuzzier with more qualitative elements. It doesn't necessarily mean less difficult.

Another distinction is that the level of tools limits things. Say studying color before and after the ability to analyze wavelengths.

Re: Astronomers want public funds for intelligent life search

#90

Post by dhimes »

ddxxdd wrote: post #85
dhimes wrote: post #53

Earlier quoted context omitted.

My suspicion is that they are communicating at frequencies we can't modulate/demodulate yet. Look how short of a time it took us to get from KHz to GHz. Since there's a trade-off in that the higher the frequency- the more data can be transmitted in a given time, it makes sense that intelligent species would try to increase their transmission frequencies as a matter of course- like we did. The downside trade-off is th…

We can detect microwaves, infrared rays, light rays, ultraviolet rays, X-rays, and gamma rays. We might not be able to transmit and receive FM radio in those frequencies, but we are able to detect the presence, polarization, and direction of such radiation.

But if you can't modulate or demodulate gamma rays (which is anything above a certain frequency), you can't even see if they are transmitting information or not. Even radio waves modulated with spread spectrum techniques look like noise. Who knows what we'll be using in the future.
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