Tag: seti

Kardashev Type II beacon?

If that beacon is transmitting radio waves in all directions, the energy it would need to produce is a whopping 10^20 watts. “That’s a big energy bill even if you’re getting a bulk discount from your local supplier. It’s 100s of times more than all the energy falling on the Earth from sunlight.”

That means the hypothetical beings responsible might be what SETI scientists call a Kardashev Type II civilization, so advanced that they can tap all of the energy being produced by their host star.

Drake equation correlations

Overall, the independence of the terms of the Drake equation is likely fairly strong. However, there are relevant size scales to consider.

  • Over multiple gigaparsec scales there can not be any correlations, not even artificially induced ones, because of limitations due to the expansion of the universe (unless there are super-early or FTL civilizations).
  • Over 100s of megaparsec scales the universe is fairly uniform, so any natural influences will be randomized beyond this scale.
  • Colonization waves in Brin’s model could have scales on the galactic cluster scale, but this is somewhat parameter dependent.
  • The nearest civilization can be expected around , where is the galactic volume. If we are considering parameters such that the number of civilizations per galaxy are low V needs to be increased and the density will go down significantly (by a factor of 100), leading to a modest jump in expected distance.
  • Panspermias, if they exist, will have an upper extent limited by escape from galaxies – they will tend to have galactic scales or smaller. The same is true for galactic habitable zones if they exist. Percolation colonization models are limited to galaxies (or even dense parts of galaxies) and would hence have scales in the kiloparsec range.
  • “Scars” due to gamma ray bursts and other energetic events are below kiloparsecs.
  • The lower limit of panspermias are due to being smaller than the panspermia, presumably at least in the parsec range. This is also the scale of close clusters of stars in percolation models.
  • Time-wise, the temporal correlation length is likely on the gigayear timescale, dominated by stellar processes or advanced civilization survival. The exception may be colonization waves modifying conditions radically.

SETI Lobbying

The only lobbyist pushing for disclosure of E.T. visitation

Stephen Bassett is the only lobbyist of his kind in Washington DC. He’s working to get the government to admit that it has proof of extraterrestrials visiting our planet.

SETI lower bound

we show that we can set a firm lower bound on the probability that 1 or more additional technological species have evolved anywhere and at any time in the history of the observable Universe. We find that as long as the probability that a habitable zone planet develops a technological species is larger than ~$10^{-24}$, then humanity is not the only time technological intelligence has evolved.

50x SETI

Breakthrough Listen will employ the 100-meter Robert C. Byrd Green Bank and the 64-meter Parkes Telescope over a period of 10 years. The search will be 50x more sensitive than any SETI program before it, cover 10x the sky of previous programs, involve the 1M stars closest to Earth, and scan 5x as much radio spectrum 100x faster than before. It will also search for laser transmissions.

12 ga planets

PSR B1620-26 b is an extrasolar planet located 12k light-years away from Earth in the constellation of Scorpius. it is one of the oldest planets in the universe, at 12.7 ga

Can life survive for billions of years longer than the expected timeline on Earth? As scientists discover older and older solar systems, it’s likely that before long we’ll find an ancient planet in a habitable zone. Knowing if life is possible on this exoplanet would have immense implications for habitability and the development of ancient life

New Class of Dyson Sphere

Any civilization that evolves during its sun’s main sequence and then finds a way to survive the red giant and supernova stages, will also probably find a way to create a Dyson sphere around the surviving white dwarf. For that reason, these stars may be more likely to host such a structure.

What’s more, a white dwarf is a better host for a Dyson sphere. The habitable zone around a white dwarf is closer to the star, so such a sphere would be smaller. A 1-meter-thick sphere built in the habitable zone around a white dwarf would require some 10^23 kilograms of matter, just a little less than the mass of our moon.

Possible wormholes

This paper uses the Universal Rotation Curve (URC) dark matter model to obtain analogous results for the central parts of the halo. This result is an important complement to the earlier result, thereby confirming the possible existence of wormholes in most of the spiral galaxies.

that’d be a fun bit of mega scale engineering.