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ET didn't phone home

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LAN_403

Conundrum

Sat Jun 02 2012, 04:13PM

Registered Member #96 Joined: Thu Feb 09 2006, 05:37PM
Location: CI, Earth
Posts: 4062

Either that or they aren't transmitting on the "water hole" frequency after all because they think everyone else is.
This has been theorised as a reason for the distinct lack of alien signals since the flash in the pan in 1977.

-A

Tetris

Sun Jun 03 2012, 03:33PM

Registered Member #4016 Joined: Thu Jul 21 2011, 01:52AM
Location: Gainesville, FL
Posts: 660

How long ago did they start the project? If it is 20 light years away, wouldn't it take 20 years to reach Gliese 581 and 20 years (and then some. if they reply, there might be some delay) to send the signal back. As far as I know, gliese 581 was discovered in 2008 (I think). For them to already get a signal, wouldn't they have to have sent a signal in 1972? If not, then we'd only get a signal by 2048. Still in most of our lifetimes, yes. By then, I expect we have a better technology to try and scan the skies for intelligent life, or find a closer planet (say, maybe they found one around proxima centurai) But that means, if there is intelligent life, some of the "alien" stories are true, not just cgi. Do I think "Independence Day" will happen? No. Do I think an invasion might happen? maybe, but I think that they are just as likely to invade our planet as they to ours. :P

H8erade

Sun Jun 03 2012, 06:05PM

Registered Member #3451 Joined: Sun Nov 28 2010, 11:13PM
Location: United States
Posts: 100

HighVoltageChick wrote ...

How long ago did they start the project? If it is 20 light years away, wouldn't it take 20 years to reach Gliese 581 and 20 years (and then some. if they reply, there might be some delay) to send the signal back.

I don't believe they're sending signals, just listening for them. Unless any (signal-outputting) intelligent life has cropped up in the last 20 years, the distance doesn't make a difference. However, as Dr. Shostak says, humankind only started to broadcast detectable signals in the last 70 years - so, it's possible.

radiotech

Sun Jun 03 2012, 06:12PM

Registered Member #2463 Joined: Wed Nov 11 2009, 03:49AM
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Posts: 1546

Pehaps ET has changed form and is coming back as a Pine Marten in Wales
which is wonderful news, at least on that BBC site.

Chris Russell

Mon Jun 04 2012, 06:12AM

... not Russel!
Registered Member #1 Joined: Thu Jan 26 2006, 12:18AM
Location: Tempe, Arizona
Posts: 1052

From the paper:

On 2007 June 19, Gliese 581 was observed for 8 hours
at 1230-1544 MHz with the Australian Long Baseline Array. The dataset was
searched for signals appearing on all interferometer baselines above ï¬ve times
the noise limit. A total of 222 potential SETI signals were detected and by
using automated data analysis techniques, were ruled out as originating from
the Gliese 581 system. From our results we place an upper limit of 7 MW Hzâˆ’1
on the power output of any isotropic emitter located in the Gliese 581 system,
within this frequency range.

And here's the problem with SETI. We don't have any transmitters on Earth radiating that much power at those frequencies, so this experiment wouldn't have even found us. The nearest we have is UHF TV signals, most of which no longer use a narrowband carrier. SETI pretty much relies on the assumption that not only is ETI at our technological level or higher, but that they want to be found and are advertising their location with super powerful narrowband radio transmitters. If they're just listening and incidentally radiating a little, like us, we'll never find them with a radiotelescope small enough to construct here on Earth.

Conundrum

Mon Jun 04 2012, 12:42PM

Registered Member #96 Joined: Thu Feb 09 2006, 05:37PM
Location: CI, Earth
Posts: 4062

Yeah, this is indeed a problem.
We might be better off looking for other signs of life such as an oxygen/nitrogen atmosphere around a nearby exoplanet.

I also recall reading that even in the unlikely event any of our signals could be received, it wouldn't be possible to decode them due to the switch to digital and fibre optics.
This means that the L factor in the Drake equation might be very small indeed.

Neutrino SETI on the other hand isn't quite so implausible, we routinely detect solar neutrinos so if anyone is sending data using these to a nearby system we'd detect it pretty quickly.

Also, neutrinos are produced by nuclear explosions so ironically we might detect a nearby alien civilisation's large scale nuclear tests.

-A

Tetris

Mon Jun 04 2012, 04:08PM

Registered Member #4016 Joined: Thu Jul 21 2011, 01:52AM
Location: Gainesville, FL
Posts: 660

What we know is that if we find life in our own solar system, whether or not it's intelligent, then there is infinitely close to 100% chance that there is life somewhere else. Even then. When toying with such a huge number, things get almost certain. Somewhere out there, there is another sunlike star, with a planet in the goldilocks zone, which harbors earth-like life. As long as nitrogen, carbon, hydrogen, and oxygen, are there, and there is energy present, life could spring up. The chances of that happening are HUGE at the same time miniscule, if that makes any sense whatsoever.

plazmatron

Tue Jun 05 2012, 02:05PM

Registered Member #1134 Joined: Tue Nov 20 2007, 04:39PM
Location: Bonnie Scotland
Posts: 351

The Drake equation suggests, that the universe is in fact teeming with intelligent life. Other equations/theories suggest, that if a civilisation mastered interstellar travel, even at conventional speeds (i.e. rockets, not "warp drives"), then they would have the capability to colonise most of the galaxy within a couple of hundred thousand years.

The "Fermi Paradox" puts a different, and arguably more accurate slant on the Drake equation, positing, that intelligent species, are on the whole, short lived.

If you take a quick look at ourselves, we have had radio technology, for a very short period of time, and space technology, for an even shorter period of time.
In this short period, we have successfully managed to strip the planet of most of the available "cheap" energy reserves, and are about to go to war, over what little remains.

As an example of the energy crisis we are facing, in the 19th Century, oil was discovered seeping to the surface. In such locations, trenches were dug, and the oil was shovelled out!
Fast forward to 2012, and now most (and I argue ALL) oil fields are now in decline, to such an extent, that oil companies will attempt to drill in 5 miles of seawater, in a desperate attempt to produce oil!

Once abundant energy sources are gone, will we be able to "afford" to fund large transmitters and receivers? Will we be able to afford to go into space?

I would say it is very likely, that every technologically advanced species comes up against this energy stumbling block.

The real question is, will we as a species, put down the guns, take a good hard look at ourselves, and work together to ensure our survival? Or will we wink out of existence, like so many before us?

Les

Tetris

Tue Jun 05 2012, 03:50PM

Registered Member #4016 Joined: Thu Jul 21 2011, 01:52AM
Location: Gainesville, FL
Posts: 660

@plazmatron Hopefully we get an alternative resource soon, preferrably one that is renewable.
This doesn't exactly apply to the situation, but its basis does.
Human Geographists have theories of human development. Two of those theories are environmental determinism, and possibilism.
Environmental determinism states that the environment puts caps and impedances on human development from going past a certain physical or quantative point.
Possiblism states that despite environmental determinism, human curiosity will find a way. This usually applies to, say, a mountain blocks a path, but possibilism says that humans can make a road over, around, or through the mountain. Here in this case, environmental determinism sort of gives: OK you have one hundred trillion gallons of oil to use per billion years. You are on the verge of using it all up. Possibilism says that we'll suffer for a while, then find a new way. That cycle will go on and on for each of our resources. After all non-renewable resources are gone, we have to find renewable resources and things that use it. Gone is the gas-guzzling age, now go into the pure electric age. Wind power, hydroelectric, solar, geothermal, tidal, and who knows what other thing we'll discover in the next hundred years? Air powered cars, maybe, perpetual motion?

My point is that civilization doesn't kill itself off if some resources are used up. Out of coffee? Drink tea. Out of tea? Drink orange juice! Keep on moving forward and *improvise.* If there is one thing my lack of money has taught me, it is to improvise. Sure, civilization will go to war for a while, but there will be the people, working to develop a technology to replace what's lost!

That's what engineers are for. As for space travel price, well, remember when computers were huge and bulky, and only available to big companies for millions of dollars, and its processing power is a trillionth of what is available in smart phones that half of America owns now? That's what will happen to space travel. Eventually kids will be building not model rockets, but actual rockets in their garage for fun. Think ahead, don't look back on the past. Or, if you must, think of what you need to do to improve it. That's why I do not like history of a country. It has already happened, and I know it is important to know about wars so they don't make the same mistake again, but it can't be improved upon. You can't take the Battle of Bunker Hill, and say "Shoot as soon as you see them" instead of "when you see the whites of their eyes." Anyways, that's what engineers are for. Possiblism says that human curiosity will find a way, and those humans are the engineers. What we need to do really, as a human race: get more engineers. That will solve everything.

:D

Hazmatt_(The Underdog)

Thu Jun 14 2012, 12:43AM

Registered Member #135 Joined: Sat Feb 11 2006, 12:06AM
Location: Anywhere is fine
Posts: 1735

If it were me.. I wouldn't be looking for just a habitable planet, as most astrophysicists are right now, I think that is somewhat silly.

I would be looking for 2 criteria, 1. Habitable
2. IS THERE ANY SPACE JUNK FLOATING AROUND THE FREGGIN PLANET!

If the answer to #2 is yes, then DUH! we may have a winner. Point the Tesla Coil at the planet and transmit on all frequencies with huge doses of RF Splatter, that'll wake someone up on the other side.

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