Filed under: Astronomy, Fermi's Paradox, General Musings, Science, Science Fiction, SETI, Space, Survival | Tags: astronomy, blogging, Drake Equation, exoplanets, Fermi's Paradox, gamma ray bursts, Harvard, Hebrew University, jim downey, life, physics, Raul Jimenez, science, Science Fiction, SETI, space, survival, Tsvi Piran
It really does seem to be a pretty universal law:
As a copious source of gamma-rays, a nearby Galactic Gamma-Ray Burst (GRB) can be a threat to life. Using recent determinations of the rate of GRBs, their luminosity function and properties of their host galaxies, we estimate the probability that a life-threatening (lethal) GRB would take place. Amongst the different kinds of GRBs, long ones are most dangerous. There is a very good chance (but no certainty) that at least one lethal GRB took place during the past 5 Gyr close enough to Earth as to significantly damage life. There is a 50% chance that such a lethal GRB took place during the last 500 Myr causing one of the major mass extinction events. Assuming that a similar level of radiation would be lethal to life on other exoplanets hosting life, we explore the potential effects of GRBs to life elsewhere in the Galaxy and the Universe.
What that means is summed up in this article. Here’s the conclusion:
Astronomers have long known that the Earth occupies a unique position in the solar system that allows life to flourish. This idea of a habitable zone now allows them to focus search for exoplanets that might also have conditions that are right for life. Now they can take this further by excluding inhospitable regions of the galaxy, and searching only those stars and galaxies that exist in the universe’s habitable zones.
Of course, that’s just for life as we know it …
Filed under: Astronomy, Brave New World, Connections, General Musings, NPR, Predictions, Science, Science Fiction, SETI, Space, tech, Titan | Tags: Arecibo, astronomy, blogging, Communion of Dreams, Duncan Lorimer, jim downey, Joe Palca, NPR, Parkes Observatory, predictions, radio astronomy, Robert Gish, Science Fiction, SETI, space, Titan
Interesting news item on NPR this morning:
Astronomers have a mystery on their hands. Two large radio telescopes, on opposite sides of the planet, have detected very brief, very powerful bursts of radio waves.
Right now, astronomers have no idea what’s causing these bursts or where they’re coming from. And nothing has been ruled out at the moment — not even the kind of outrageous claims you’d expect to see in tabloid headlines.
* * *
As you would imagine, there’s been lots of speculation about what’s behind these mysterious bursts. Some astronomers think they’re caused by blitzars, pulses of energy from a supermassive star collapsing into a black hole. Others think they may be caused by power solar flares coming from stars nearer by.
And Lorimer says he has to mention it: “There’s even been discussions in the literature about signatures from extraterrestrial civilizations.”
From Chapter 1 of Communion of Dreams when news of the discovery of an evidently alien artifact on Titan is being discussed:
The man sitting next to him got up, stepped up to the holo of the artifact still rotating there in the center. Robert Gish was a little unkempt, his beard untrimmed, his dark hair matted. He was out of shape, almost flabby in appearance. His scientific reputation was as unconventional as his looks. More so. He had been responsible for the radical change in long-range sensing which led to the development of the Advanced Survey Array. Nobel Prize stuff. A true genius, not just brilliant but able and willing to make leaps that took others years to understand. Which was why Bradsen had him here: Gish had been saying for decades that there was other intelligent life among the stars. Saying it so loud and so often that he was considered a crank, since he had no proof and couldn’t even really explain why he believed it to be so, at least in a way that others could accept.
Reaching out as though he was going to touch the object, he said quietly “We know what it is. It is a crack in our shell.”
Interesting news, indeed.
Filed under: Astronomy, Brave New World, Emergency, Fireworks, General Musings, Humor, NASA, Predictions, Preparedness, SCA, Science, Science Fiction, Society, Space, Steampunk, Survival, tech | Tags: blogging, Daniel Baker, humor, jim downey, NASA, predictions, preppers, SCA, science, Science Fiction, solar storm, space, Steampunk, Sun, survival, technology
Just think — all the folks who are prepping to deal with some global emergency almost got a chance to see how well their theories work in practice. My friends who are into Steampunk and the SCA would have reigned supreme!
Back in 2012, the Sun erupted with a powerful solar storm that just missed the Earth but was big enough to “knock modern civilization back to the 18th century,” NASA said.
The extreme space weather that tore through Earth’s orbit on July 23, 2012, was the most powerful in 150 years, according to a statement posted on the US space agency website Wednesday.
* * *
“If the eruption had occurred only one week earlier, Earth would have been in the line of fire,” said Daniel Baker, professor of atmospheric and space physics at the University of Colorado.
Ah well. Better luck next time!
Filed under: Astronomy, Connections, Fermi's Paradox, National Geographic, Predictions, Science, Science Fiction, SETI, Space, tech | Tags: astronomy, blogging, Drake Equation, Fermi's Paradox, jim downey, National Geographic, predictions, science, Science Fiction, space, technology
It’s this kind of guesswork that tends to inflame the Drake equation’s critics, those who complain that the equation isn’t predictive, is too open-ended, and doesn’t provide any answers. But “predictive” isn’t really what Drake ever intended.
“It’s a way to frame the problem,” says MIT astrophysicist Sara Seager, about the equation. “In science, you always need an equation—but this isn’t one you’re going to solve. It just helps you dissect everything.”
Definitely worth reading, as well as thinking about.
Filed under: Art, Astronomy, Connections, Fermi's Paradox, Humor, Predictions, Science Fiction, SETI, Space, Survival | Tags: astronomy, blogging, Communion of Dreams, Fermi's Paradox, humor, jim downey, predictions, Randall Munroe, Science Fiction, space, xkcd
If you consider the full implications of what is revealed in Communion of Dreams, this might well be a fairly good explanation …
From the brilliant Randall Munroe, of course. Go to his site to see the ‘hidden text’.