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Spot ET's Waste Heat For Chance To Find Alien Life
mdsolar passes along this selection from New Scientist describing a (comparatively) low-tech means of scanning the skies for extraterrestrial civilizations: The best-known technique used to search for tech-savvy aliens is eavesdropping on their communications with each other. But this approach assumes ET is chatty in channels we can hear. The new approach, dubbed G-HAT for Glimpsing Heat from Alien Technologies, makes no assumptions about what alien civilisations may be like.
"This approach is very different," says Franck Marchis at the SETI Institute in California, who was not involved in the project. "I like it because it doesn't put any constraints on the origin of the civilisation or their willingness to communicate." Instead, it utilises the laws of thermodynamics. All machines and living things give off heat, and that heat is visible as infrared radiation. The G-HAT team combed through the catalogue of images generated by the Wide-field Infrared Survey Explorer, or WISE, which released an infrared map of the entire sky in 2012. A galaxy should emit about 10 per cent of its light in the mid-infrared range, says team leader Jason Wright at Pennsylvania State University. If it gives off much more, it could be being warmed by vast networks of alien technology – though it could also be a sign of more prosaic processes, such as rapid star formation or an actively feeding black hole at the galaxy's centre.
"This approach is very different," says Franck Marchis at the SETI Institute in California, who was not involved in the project. "I like it because it doesn't put any constraints on the origin of the civilisation or their willingness to communicate." Instead, it utilises the laws of thermodynamics. All machines and living things give off heat, and that heat is visible as infrared radiation. The G-HAT team combed through the catalogue of images generated by the Wide-field Infrared Survey Explorer, or WISE, which released an infrared map of the entire sky in 2012. A galaxy should emit about 10 per cent of its light in the mid-infrared range, says team leader Jason Wright at Pennsylvania State University. If it gives off much more, it could be being warmed by vast networks of alien technology – though it could also be a sign of more prosaic processes, such as rapid star formation or an actively feeding black hole at the galaxy's centre.
Basically, this method of searching for aliens returns a positive whenever there is something producing heat which we don't see/understand. I have a feeling that the universe is quite full of such things. But maybe explaining these will help us make scientific advances. When astronomers first discovered a pulsar, they labeled the signal LGM for "little green men". But since then, we learned a lot about astronomy. Explaining apparent anomalies is good for science, and if you want to make the process sexier by talking about possible alien civilizations, I don't see much harm.
So, they're looking for civili[zs]ations classified as Type 3 in the Kardashev scale:
A civilization in possession of energy on the scale of its own galaxy.
OK, suppose we find their galaxy, conspicuous like a flamingo. How do we hail in order to confirm?
This post contains no rudeness or derision of any kind. All arguments are friendly. Terms and exclusions may apply.
Not really. The luminosity of a Dyson Sphere will be the same as the luminosity of the star it surrounds. The color temperature of the radiation will be lower by a factor of the square root of the ratio of the radius of the star to the radius of the sphere.
It's a very simple, even lower-tech approach. Unstable molecules are unstable, stable ones aren't. Life isn't capable of producing stable molecules from stable molecules. Something, somewhere down the line, therefore must produce unstable molecules.
If you use spectrometry and find a planet that has two or more highly reactive molecules (especially if they cannot coexist naturally), that planet has complex life. If you have one reactive molecule that breaks down in sunlight but is being refreshed, that planet must have at least simple life. If the planet has highly reactive molecules that don't readily form naturally, you have life that is nominally intelligent.
No requirement for any technology capable of generating a specific signature. No requirement for the absence of metamaterials. No requirement for a telescope big enough to detect the signature against natural variation.
SKA would be capable of detecting an alien civilization using Lovelock's method anywhere inside of 1,000 light years, given the size and sensitivity currently being proposed. How big would the James Webb telescope need to be to get an IR signature on the industrialized part of the US at that range?
It's a small world and it smells funny; I'd buy another if it wasn't for the money; Take back what I paid (SoM)
Dyson Spheres are a rather silly thing to search for, as the technology required is too advanced to fathom (perhaps impossible).
Let us recall that the Dyson sphere idea started life as a swarm of satellites around a star, not as a solid shell. I think I can fathom solar panels, satellites, and orbiting the Sun. That's the basics of a Dyson sphere (well, that and a relativistic traffic control problem which can involve at least as many satellites as there are people currently on Earth).
We could even be there in 100 years.
Indeed. Though it would probably involve self-replicating machines tearing apart Mercury.
What if the advanced civilization turned out to be masters of power efficiency? An analogy from the world of computing: the first electronic computers required the power of a house simply to boot up. The smartphone in your pocket is thousands of times more powerful while using no more power than a small light bulb. Does this mean all we'll find are vacuum tube using spacefarers who use nuclear bombs for rocket fuel?