My long time issue with the "they would be too intelligent/evolved to have any interest in us" type scenario, such as he puts as number two here, is that we go through great lengths to try and research and understand very primitive life. There are efforts being made to talk to dolphins and apes. We're looking to build ships to crash or land ships onto Titan to see if there is microbial life on a moon orbiting a gas giant, not to mention work to see if Mars once upon had life. So the very fact we're able to get off our little rock (though not much off it), I think would warrant a stop and look, perhaps to help answer what was life like at such an early stage of evolution.

Not said stop and look doesn't imply any sort of communications. Indeed there may be a Prime Directive like thing with them where by they see and observe, but leave no evidence of such a visit (alien abductions being just mental illness coupled with abuse or other issues).

Now distance is a super valid point, but by far the most likely point is the survivability window, which he talks about in point three. We're still a level zero civilization (Kardashev scale) and decades until we reach a level one civilization (unfortunately it seems delayed even further due to some very anti-science moves being made by certain groups). Moving up that scale is only one thing, avoiding killing ourselves via war is another huge one. With CRISPR technology advancing, there is a very real danger of a Division/Stand/Utopia type disease coming to the foreground, especially if driven by a zealot (ala Division and Utopia). I highly doubt a man made black hole or something, but war or a CRISPR engineered disease... Not to mention the natural disasters he mentioned, and others, such as huge gamma ray bursts and others that we've managed to avoid. And we'd have to think that most civilizations go through somewhat similar phases, with a universe that is fairly hostile to life, even if many planets are capable of at least starting life. Generally I figure that most civilizations never make it past the stage we are at now, and those that do probably don't get to stage two and beyond (to be fair, I doubt any civilization can achieve stage two on Kardashev's scale as it goes beyond knowledge needed, but materials and more).

Back to the technology of communications point. I've generally figured if you are space faring, you gave up on radio communications and are using strange properties or something along those lines.

Not according to David Thompson, a NASA astrophysicist and deputy project director on the Fermi Gamma-ray Space Telescope who compares the risk to Earth from a future gamma-ray burst to "the danger I might face if I found a polar bear in my closet in Bowie, Maryland. It could happen, but it is so unlikely that it is not worth worrying about."

There's a greater chance that one (or more) of the stars within about 6000 light years or so could give off a gamma ray burst that would wipe out any life in the solar system, no matter where we hid it. It's been postulated the previous-to-the-Yucatan-asteroid large scale die-offs could have happened due to GRB.

actually -- Earth being hit by one of those mega gamma ray bursts out there in the universe, that's my favourite

>> ^dag:

In my mind- the only way we're alone in the universe is if there's something that's systematically eradicating life. Galaxy-wide milion-year super gamma ray bursts, or autonomous or von Nuemann seek and destroy nanobots.


Well, there's a school of thought that suggests the logical thing to do on encountering any alien civilization is immediately to destroy it.

(click that link only if you want to be depressed and frightened)

Comment hidden because you are ignoring dag. (show it anyway)

In my mind- the only way we're alone in the universe is if there's something that's systematically eradicating life. Galaxy-wide milion-year super gamma ray bursts, or autonomous or von Nuemann seek and destroy nanobots.

They say one of the 5 big extinctions to take place on earth was from a gamma ray burst from inside our galaxy. Scary stuff if it wasn't so majorly rare.

1. The Planets Move (2000 B.C. – 500 B.C.)
A thousand years of observations reveal that there are stars that move in the sky and follow patterns, showing that the Earth is part of a solar system of planets separate from the fixed stars.

2. The Earth Moves (1543)
Nicolaus Copernicus places the sun, not the Earth, at the center of the solar system.

3. Planetary Orbits Are Elliptical (1605 – 1609)
Johannes Kepler devises mathematical laws that successfully and accurately predict the motions of the planets in elliptical orbits.

4. Jupiter Has Moons (1609 – 1612)
Galileo Galilei discovers that Jupiter has moons like the Earth, proving that Copernicus, not Ptolemy, is right. Copernicus believes that Earth is not unique, but instead resembles the other planets, all of which orbit the sun.

5. Halley's Comet Has a Predictable Orbit (1705 – 1758)
Edmund Halley proves that comets orbit the sun like the planets and successfully predicts the return of Halley's Comet. He determines that comets seen in 1531 and 1607 are the same object following a 76-year orbit. Halley's prediction is proven in 1758 when the comet returns. Unfortunately, Halley had died in 1742, missing the momentous event.

6. The Milky Way Is a Gigantic Disk of Stars (1780 – 1834)
Telescope-maker William Herschel and his sister Carolyn map the entire sky and prove that our solar system resides in a gigantic disk of stars that bulges in the center called the Milky Way. Herschel's technique involves taking a sample count of stars in the field of view of his telescope. His final count shows more than 90,000 stars in 2,400 sample areas. Later studies confirm that our galaxy is disk-shaped, but find that the sun is not near the center and that the system is considerably larger than Herschel's estimation.

7. General Relativity (1915 – 1919)
Albert Einstein unveils his theory of general relativity in which he proposes that mass warps both time and space, therefore large masses can bend light. The theory is proven in 1919 by astronomers using a solar eclipse as a test.

8. The Universe Is Expanding (1924 – 1929)
Edwin Hubble determines the distance to many nearby galaxies and discovers that the farther they are from us, the faster they are flying away from us. His calculations prove that the universe is expanding.

9. The Center of the Milky Way Emits Radio Waves (1932)
Karl Jansky invents radio astronomy and discovers a strange radio-emitting object at the center of the Milky Way. Jansky was conducting experiments on radio wavelength interference for his employer, Bell Telephone Laboratories, when he detected three groups of static; local thunderstorms, distant thunderstorms and a steady hiss-type static. Jansky determines that the static is coming from an unknown source at the center of the Milky Way by its position in the sky.

10. Cosmic Microwave Background Radiation (1964)
Arno Penzias and Robert Wilson discover cosmic microwave background radiation, which they suspect is the afterglow of the big bang. Their measurements, combined with Edwin Hubble's earlier finding that the galaxies are rushing away, make a strong case for the big bang theory of the birth of the universe.

11. Gamma-Ray Bursts (1969 – 1997)
The two-decade-long mystery of gamma-ray bursts is solved by a host of sophisticated ground-based and orbiting telescopes. Gamma-ray bursts are short-lived bursts of gamma-ray photons, which are the most energetic form of light and are associated with nuclear blasts. At least some of the bursts have now been linked with distant supernovae — explosions marking the deaths of especially massive stars.

12. Planets Around Other Stars (1995 – 2004)
Astronomers find a host of extrasolar planets as a result of improved telescope technology and prove that other solar systems exist, although none as yet resembles our own. Astronomers are able to detect extrasolar planets by measuring gravitational influences on stars.

13. The Universe Is Accelerating (1998 – 2000)
Unexpectedly, astronomers find that instead of slowing down due to the pull of gravity, the expansion of the universe at great distances is accelerating. If these observations are correct and the trend continues, it will result in the inability to see other galaxies. A new theory of the end of the universe based on this finding has been called the "big rip."

Absurdly melodramatic narration, immensely cheesy animation and music, condescending MTVesque editing, takes 15 minutes to explain a single simple concept but nonetheless a fairly decent look at gamma ray bursts and the cosmic dark ages.