There can be no escape. . .

January 8, 2005 5:10 PM

NASA's Chandra X-Ray Observatory recently detected [reg required] the largest explosion ever detected in the universe: an eruption releasing the energy of hundreds of millions of gamma ray bursts. Just to put it in perspective, a single GRB releases enough radiation to wipe out just about everything human beings would require for survival in a 1000 light year radius. (The Milky Way spans ~100,000 light years, while the United Federation of Planets spans about 8,000). Arthur C. Clarke has gone so far as suggesting that GRBs might be one of the reasons for Extra-Terrestrial silence: Gamma Ray Bursts are so large and inescapable, a single one would wipe out even an enormous galactic empire. Makes killer asteroids seem downright quaint.
posted by absalom (23 comments total)

US scientists have detected the largest explosion ever in the universe, which saw a mass equivalent to about 300 million suns sucked into a black hole. - From the first link.

Wow. We're lucky we do not live in any of those systems.
posted by purephase at 5:22 PM on January 8, 2005

Has anyone told Bruce Banner?
posted by Faint of Butt at 5:28 PM on January 8, 2005

Does this mean theres going to be some nice aurora in Mexico?
posted by sled at 5:33 PM on January 8, 2005

NASA news release and hi res images
posted by roboto at 5:34 PM on January 8, 2005

FOOF! I have significant gamma bursts every day.
posted by johnj at 5:44 PM on January 8, 2005

I wonder if we are at risk of one of those, or if we are saved by the anthropic principle (humanity could evolve on Earth because Earth is not subject to the gamma ray bursts.)
posted by TheOnlyCoolTim at 5:46 PM on January 8, 2005

because Earth is not subject to the gamma ray bursts

that could only be, "has not yet been subject to"
posted by mdn at 5:48 PM on January 8, 2005

First a tsunami and now this. I'm moving to another universe.
posted by zerolucid at 6:40 PM on January 8, 2005

Has anyone ever speculated that the "big bang" could have originated with something like this? I mean, if a black hole keeps sucking up matter, getting progressively larger in the process, maybe there's a critical mass limit (let's call it 1 BB) where even a black hole cannot sustain it's mass, and lets loose with a giant explosion? Someone's probably thought of this already.
posted by Civil_Disobedient at 7:21 PM on January 8, 2005

Awesome post, thanks.
posted by interrobang at 7:25 PM on January 8, 2005

HULK SMASH.
posted by keswick at 8:43 PM on January 8, 2005

I was only ten pages away from finishing my Great American Novel. But now it's like...what's the point?
posted by fungible at 8:53 PM on January 8, 2005 [1 favorite]

C_D, I don't know if you can talk about black holes in terms of having critical mass limits. AFAIK, they just keep gobbling up mass and have no upper bound on their size.

If you take the equation for Schwarzschild radius, which gives you a rough radius of a black hole given its mass (2G times mass divided by speed of light squared), and plug a billion solar mass black hole into it, its diameter is 20 AUs. Our solar system has a diameter of roughly 80 AUs, so the mass of a billion suns would be squeezed into a sphere roughly 1/4 the size of our solar system.

Astronomers have observed long jets of plasma and x-rays coming out of the north and south poles of suspected black holes, with large swirling disks of gas around their equator. The explanation of GRBs being black holes that suddenly swallow whole stars that wander too close to them makes sense to me; while there's a lot of gas swirling around them in the normal state, if they ate a whole star in a short amount of time, they would be swallowing an obscene amount of mass very quickly. The jets would progress beyond the normal plasma and x-rays resulting from the black hole's typical low density gas cloud diet and instead start shooting out gamma rays, just from the sheer amount of energy being expended and the star being crushed so quickly.

Galaxies sometimes collide with each other, there are some cool Hubble photographs of that. The space between stars is mostly empty, so there isn't a lot of stellar collisions when this happens. That said, I wonder what would happen if the supermassive black holes at the heart of the two galaxies happened to collide. It would be the very definition of astronomical odds since their respective radii are so small, but I think the energy released from that collision would be fantastically high.
posted by beaverd at 8:57 PM on January 8, 2005

*sobs controllably*
posted by The God Complex at 9:52 PM on January 8, 2005

As far as the threat to "us", it seems that everyone here has assumed that a grb is likely to happen in "our" vicinity.

In one of the links, it states that one of the major reasons that the cause for a grb is not established is that they are confined to a region of the universe which is several billion light years away, and therefore any objects involved are unobservable.

Also--and i am uninformed on this point, so beaverd or whoever if you will please dis/abuse me--but another of the links says that the behavior of the black hole which produced the big event contradicts that of yer average black hole, whose appetite for matter decreases with its own size.

Am i missing something?
Arthur?
posted by gorgor_balabala at 11:48 PM on January 8, 2005

As a Trekkie, I have to correct that link to United Federation of Planets.
posted by Harry at 7:33 AM on January 9, 2005

The Federation must have been affected by the burst--the link no longer works.
posted by ParisParamus at 7:49 AM on January 9, 2005

Perhaps he meant to refer to the Democratic Order of Planets.
posted by SPrintF at 9:27 AM on January 9, 2005

Nova had an episode on this called, appropriately enough, Death Star. Here's the companion site.

If you
posted by Loser at 12:29 PM on January 9, 2005

[Bah!] (If you) can manage to Tivo it, it's a great show.
posted by Loser at 12:31 PM on January 9, 2005

According to the Nova links from Loser, the BATSE instrument (Burst And Transient Source Experiment) was the first to detect a random distribution and duration of gamma ray bursts.

ROTSE (Robotic Optical Transient Search Experiment) was the first to actually observe a gamma ray burst as it happened.

Me? I'm waiting for the Gamma Observatory And Transient Source Experiment to answer all the questions.
posted by hackwolf at 9:19 PM on January 9, 2005 [1 favorite]

I can't remember the source or the exact phrasing, but I was under the notion that the more massive a black hole, the less dense it would need to be. To wit, the density of our universe is consistant with the possibility that we are inside a black hole.

Can anyone help me out here?
posted by PurplePorpoise at 4:43 PM on January 10, 2005

PurplePorpoise's first claim is correct. The reason is that the Schwarzchild radius--the critical size at which any object collapses into a black hole--is directly proportional to the object's mass. Since volume scales with (radius)^3, then the critical density (mass/volume) scales as 1/(mass)^2. In other words, a star twice the mass of our sun would have to be squeezed to (1/4) the density our Sun would need to be squeezed in order to cause a collapse.

This only refers to the average density of an object an instant before collapse, not the density of matter inside a black hole after collapse. New physics must take over as a singularity, a point posited to have infinite density, is created at the center of the collapse.

Although I've read some popular accounts of physics that claim our universe can be thought of as the "inside of a black hole" I would take the analogy with a grain of salt. If there is enough mass in the universe to make it closed (though it is likely flat, which is even more interesting), then it does share a black hole's property that nothing inside can ever travel outside. But that is where the similarity ends. For instance, we see no evidence of anything falling "inside" from "outside" nor (more importantly) do we observe a singularity defining a center of our universe. In fact, instead of everything falling towards some point just the opposite is happening with respect to all points.
posted by fatllama at 11:26 PM on January 10, 2005