Alien Life, Coming Slowly Into View

[August]

What would it take to broadcast a signal that can be read on a distant planet? Power obviously. Lots and lots of power, but in what form?
Radio Frequency, Light, Microwave?

No matter what form one uses signal attenuation is gonna be a bear.

[Gerald]

Originally Posted by August

What would it take to broadcast a signal that can be read on a distant planet? Power obviously. Lots and lots of power, but in what form?
Radio Frequency, Light, Microwave?

No matter what form one uses signal attenuation is gonna be a bear.

Exact, in what form will the power come from

[TLAM Strike]

Originally Posted by August

What would it take to broadcast a signal that can be read on a distant planet? Power obviously. Lots and lots of power, but in what form?
Radio Frequency, Light, Microwave?

No matter what form one uses signal attenuation is gonna be a bear.

Radio and Microwaves are light.

Space is a wonderful medium for radio signals. Those involved in SETI seem confident that the signals we sent on purpose to some near by stars could be read if someone was there. Even just a basic repeating signal (like prime numbers) or other unambiguous sign (massive nuclear blasts or a fusion/fission reaction with increasing color shift beyond what is normally observed) would be clear signs of intelligent life.

[August]

Originally Posted by TLAM Strike

Radio and Microwaves are light.

Electromagnetic energy actually, which includes visible "light". All have different frequencies which affect propagation.

Space is a wonderful medium for radio signals. Those involved in SETI seem confident that the signals we sent on purpose to some near by stars could be read if someone was there.

I was reading somewhere awhile back that there is some doubt that those signals could be distinguished from background noise.

[Gerald]

Originally Posted by August

Electromagnetic energy actually, which includes visible "light". All have different frequencies which affect propagation.



I was reading somewhere awhile back that there is some doubt that those signals could be distinguished from background noise.

Possible with the right equipment and qualified personnel, which is not an easy task, when there is always a constant audio stream

[danlisa]

Doesn't the active search for ET Life seem a little pointless?

Correct me if I'm wrong but I understand the following:

Signals we send out: These take an inordinate amount of time to reach anywhere, receiving a response would take double that. Within the transit time it's conceivable that the replying world would no longer exist by the time the signal reached us. This also applies to listening to space 'signals'.

Identifying habitable planets: Again, the time involved is mind boggling. We can ID a planet that's billions of light years away and say that's a possible earth clone but that image we captured has taken billions of years to reach us. The originating planet would now probably be a hunk of space rock.

What am I missing and how much funding is put to this?

[Gerald]

Not a lot of money relating to this, unfortunately, but the future may provide a different perspective

[TLAM Strike]

Originally Posted by danlisa

Doesn't the active search for ET Life seem a little pointless?

Correct me if I'm wrong but I understand the following:

Signals we send out: These take an inordinate amount of time to reach anywhere, receiving a response would take double that. Within the transit time it's conceivable that the replying world would no longer exist by the time the signal reached us. This also applies to listening to space 'signals'.

Identifying habitable planets: Again, the time involved is mind boggling. We can ID a planet that's billions of light years away and say that's a possible earth clone but that image we captured has taken billions of years to reach us. The originating planet would now probably be a hunk of space rock.

What am I missing and how much funding is put to this?

For perspective there are 7 star systems in 16 light years that feature stars like our sun or close to it. The closest confirmed Extrasolar planet is 10 light years away (it orbits Epsilon Eridani a star similar to our own). The distances involved might not be that big on a cosmic scale.

[Gerald]

To mention just one example, as to our sun, it takes "only" 8 light minutes, and there is ZERO in the context

[Torplexed]

Originally Posted by August

What would it take to broadcast a signal that can be read on a distant planet? Power obviously. Lots and lots of power, but in what form?
Radio Frequency, Light, Microwave?

No matter what form one uses signal attenuation is gonna be a bear.

Actually, it was purposely done once here on Earth that I know of from the giant Arecibo radio telescope in Puerto Rico. Although, arguably more as a PR stunt than anything else.

http://en.wikipedia.org/wiki/Arecibo_message

The Arecibo message was broadcast into space a single time (not repeated) via frequency modulated radio waves at a ceremony to mark the remodeling of the Arecibo radio telescope on 16 November 1974. It was aimed at the globular star cluster M13 some 25,000 light years away because M13 was a large and close collection of stars that was available in the sky at the time and place of the ceremony.The message consisted of 1679 binary digits, approximately 210 bytes, transmitted at a frequency of 2380 MHz and modulated by shifting the frequency by 10 Hz, with a power of 1000 kW. The "ones" and "zeros" were transmitted by frequency shifting at the rate of 10 bits per second. The total broadcast was less than three minutes.

The binary 'message' consists of:

1. The numbers one (1) through ten (10)
2. The atomic numbers of the elements hydrogen, carbon, nitrogen, oxygen, and phosphorus, which make up deoxyribonucleic acid (DNA)
3. The formulas for the sugars and bases in the nucleotides of DNA
4. The number of nucleotides in DNA, and a graphic of the double helix structure of DNA
5. A graphic figure of a human, the dimension (physical height) of an average man, and the human population of Earth
6. A graphic of the Solar System
7. A graphic of the Arecibo radio telescope and the dimension (the physical diameter) of the transmitting antenna dish

However, the chances, even if our galaxy is teeming with life, of someone listening, at the right frequency, at the right time, in the right direction is so mathematically remote as to be barely worth considering.

[Gerald]

Originally Posted by Torplexed

Actually, it was purposely done once here on Earth that I know of from the giant Arecibo radio telescope in Puerto Rico. Although, arguably more as a PR stunt than anything else.

http://en.wikipedia.org/wiki/Arecibo_message

However, the chances, even if our galaxy is teeming with life, of someone listening, at the right frequency, at the right time, in the right direction is so mathematically remote as to be barely worth considering.

Interesting reading on the Arecibo message, it is truly an amazing versatility that you can not take on