A chronology of research and speculation regarding the nature and threat of gamma ray bursts from 1998 up through 2007:
A mind boggling explosion 12 billion years ago rivaled the Big Bang itself in power
I wrote here months ago (maybe years) that it seemed to me the huge explosions producing the gamma ray bursts seemed potentially dangerous to possibly the entire galaxy that happened to host one-- only now am I starting to see mainstream articles noting this danger as well-- like the one cited at the end of this newz item.
Unfortunately, it appears sooner or later we WILL have a possibly fatal gamma ray burst nearby, that could kill off or severely damage all life on Earth (but for certain microbes).
But couldn't we protect ourselves somehow, like we might against an asteroid? Well, if a burster occurred within 3000 lightyears of us, the only potentially safe places would be a quarter-mile or so underwater or underground-- YIKES! Even worse, we might get even less warning about a burster than we might about a dangerous comet or asteroid-- indeed, the radiation could have begun falling on us when you began reading this article, and many of us would already be fatally poisoned before our scientists realized what was happening....
But if we did have super refuges deep underground/undersea to protect us, how long might we have to stay there before we could return to the surface? Only "...many millions of years..."-- or until we learned how to turn ourselves into wholly inorganic machines which were impervious to the killing radiation.
Obviously, if such a near burster's radiation reached us any time before maybe 2600 AD, we'd be goners-- extinct.
Luckily, the stats so far suggest near bursters happen only about once every 100 million years on average-- so we might have a few million years breathing space (or not).
-- "Recently Discovered Cosmic Blast May Be Biggest Since Big Bang" by MALCOLM W. BROWNE, 5-7-98, The New York Times
past five years alone 1700 inexplicable bursts of gamma rays have been
detected from the void.......These mysterious bursts come from all
around us, in every direction-- but they are usually extremely distant;
a billion or more light years away; perhaps even outside our galaxy. Space Today and
the Washington Post, on or about 12-18-96
A region of unusual blue light in the sky about the size of the full Moon may offer a few days warning of a cosmic ray jet striking the Earth. The blue light is created by gamma rays preceding the jet and striking the atmosphere. A few days after this 95% of all animal life on Earth may begin to die, as their central nervous systems are destroyed.
The cosmic rays are emitted in a concentrated, laser-like beam, possibly from collisions of neutron stars. The beam's killing range may be a million lightyears, and it can penetrate with lethal effect half a kilometer underground or undersea. A burst can last as long as a month, enabling it to also wreck a planet's ozone layer, thereby opening the way for more types of killing radiation, over a much longer period.
The creation of such death rays in our own galaxy may take place roughly once every 100 million years-- and the last one looks to have been 200 million years ago.
Earth may be overdue for a mass extinction event by 100 million years. We know of at least five pairs of neutron stars in our galaxy at present, but the soonest of these potential collisions looks to be tens of millions of years away. However, there may be other neutron pairs we still haven't discovered.
-- Extinction is eons overdue by Michael Brooks; Weekly Mail & Guardian; August 07, 1998, and other sources
3-6-99 Newz&Viewz [edited]: The Fermi Paradox Resolved?
The Fermi Paradox basically asks "where are all the aliens"?
Well, just maybe the answer is natural cataclysms which have been sweeping the entire galaxy clean of higher life forms every few million years up until recently.
I'm talking gamma ray bursters here folks. Those mighty galaxy-shaking explosions that have been mystifying scientists now for about 30 years. Long-time readers might remember me writing here maybe a couple years ago that these enormous explosions and gamma radiation baths might be terrible news for the inhabitants of whatever galaxy where they occured. Now mainstream researchers are starting to say the same thing in their papers.
The gist is that these awful radiation bursts may have been occuring just often enough to stop the development of potential star farers in their tracks, throughout all of the history of the universe so far.
Apparently the only adequate protective measure for land-lubbers is being on the shadowed side of a planet when such a radiation bath occurs. Only life sheltered by many tons of seawater might survive on the gamma lit side.
Luckily most bursts won't usually last very long, so an entire planetary hemisphere (the shadowed half) worth of land-based life might escape more or less intact in many cases. But of course then the biosphere has to cope with half a dead planet; an entire hemisphere of dead and rotting corpses, of both plant and animal matter, and likely much dead in shallow sea waters as well. Imagine the awesome forest fires where entire continents of deadwood are set ablaze by lightning storms for decades afterwards. The smoke from these fires might create a brief global nuclear winter type condition, leading to even more death. It's likely a world would lose 30-50% of its total species in the event (since many species exist only locally, and half a world would be killed). And the rampage of disease...! It's a pretty good bet that the planet's climate would be changed significantly for centuries, maybe millennia, after the event. And the overall biosphere? At best it might only be set back by some 5 to 50 million years or so.
But there's still more to consider. In our own case, for millions of years, humanity's predecessors existed on a single continent on one side of the planet: Africa. If that side of the Earth had been fried by gamma rays during that time, present-day humanity likely wouldn't exist at all.
Similar 'dead-ends' in the evolution of intelligent life galaxy-wide could also have happened over the past several billion years. And remember that a single gamma ray burst severely damages the entire galaxy all at once in this fashion. So hundreds or even thousands of potential sentient races could have been wiped out or set back by a single burst at any time during the past.
And apparently there's been not merely one gamma burst over that time, but possibly hundreds or thousands, and possibly with a frequency of one every few million years in the earlier history of our galaxy.
So the great majority of potential intelligent races in our galaxy have almost certainly been killed off or at least severely stunted in development during much of past galactic history.
Now though, finally, the frequency of gamma bursters looks to be decreasing, and thereby giving folks like us a chance to actually crawl out of the muck and into space in a significant way, before we get wiped off the map.
And not only us, but perhaps many other races throughout the galaxy too.
It could well be that the gamma ray bursters have forced many intelligent races throughout the galaxy to begin reaching for the stars all more at less around the same time.
Yes, we're talking the parallel, roughly equivalent development technologically of at least dozens to hundreds of different civilizations now, in something similar to how the Terrans, Vulcans, Romulans, and Klingons seem to have developed in the Star Trek TV series, where none (or few) have a truly decisive headstart over the others.
Yet another implication of all this though would seem to be that sea-based intelligence (which might enjoy better wholesale protection from gamma bursters), might have enjoyed a vastly greater continuity of evolution and technological development than land-based civilizations like our own during the onslaught. In extreme scenarios of virtually 100% ocean worlds, where intelligent squids or something similar lived typically fairly deep in the seas, the core civilizations might have been damaged very little if at all-- with only outposts on land, orbiting stations, and spacecraft/aircraft in transit suffering casualties from any burster in passing.
So the most advanced civilizations in the galaxy might turn out to appear pretty darn alien to us after all, if we ever encounter them.
-- "Cataclysmic Explosions May Have Held Up Alien Visitors", Author: Robert Matthews, New Scientist magazine issue 23rd Jan 99
-- Sorry, we'll be late by Robert Matthews; New Scientist, 23 January 1999
Gamma ray bursts of duration longer than two seconds and shorter than two seconds appear to possess different phenomena for their sources. Some scientists put forth the idea that the briefer bursts are caused by mergers between binary neutron stars.
-- Short And Long Gamma-Ray Bursts Are Of Different Origin; ScienceDaily Magazine; 11/23/2000; Source:NASA's Goddard Space Flight Center (http://www.gsfc.nasa.gov)
The very brief (lasting under 100 milliseconds) gamma ray bursts we detect may stem from microscopic-scale black holes exploding throughout space. As of 2001 these made up around 1.4% of the total bursts detected so far, and appeared to maybe be local in origin.
These tiny black holes could be left-over relics from the Big Bang, only now evaporating away into nothingness in gamma ray burst 'pops'. The 'pops' appear to be somewhat concentrated in the Orion arm of our galaxy.
There could be 10 billion such micro-holes distributed within every few cubic lightyears of space-- which means one could pass through our solar system any time. If this theory is correct, several of these will detonate-- each with the force of a 100 billion megaton nuclear bomb-- every year in this same volume of space. Fortunately these particular gamma ray sources and their blast effects shouldn't much affect Earth unless they occur very, very close to us.
-- Black holes in the neighbourhood by Marcus Chown; 28-Nov-2001; Contact: Claire Bowles
44-207-331-2751; New Scientist issue: 1 December 2001; http://www.newscientist.com
A burst of neutrinos may precede a gamma ray burster by as much as 10 seconds. So here is one possible (if tiny) warning of such phenomena.
-- In Powerful Gamma-Ray Bursts, Neutrinos May Fly Out First, Scientists Say; 11/6/2001; Source: Penn State (http://www.psu.edu/)
As of late 2001 the closest source of a gamma ray burst ever detected was four billion lightyears plus distant. Supernovas may not be the only source of bursters. There may be a burster occuring at some location in the viewable universe every single minute.
-- Three Spacecraft Detect Huge Energy Burst in Distant Cosmos; SPACE.com; 21 December 2001
Other gamma ray source possibilities appear to include the last moments of a dying star which has already been so cannibalized by a Kerr black hole as to be shaped like a doughnut (torus) around the hole. The gamma rays are narrow-beamed from the rotational axis of the central black hole as the last bits of the star are digested.
-- Tango between black hole and star remnant may explain cosmic explosion, MIT team reports; 21-Feb-2002;
Contact: Denise Brehm
Massachusetts Institute of Technology
Hypernovae are supernovae on a larger scale; some reports are attributing gamma bursters to hypernovae rather than supernovae.
-- Hypernovae chief suspects for gamma ray bursts by Stuart Clark; 03 April 02; NewScientist.com news service
Supernova explosions appear much more likely than neutron star collisions for at least some gamma ray burst sources.
-- Death Of Huge Star Seen As Cause Of Gamma Ray Bursts; 05-Apr-2002; UniSci Daily
The side of Earth facing the concentrated beam of an incoming gamma burst from a nearby source would suffer atmospheric shock waves which ignited everything in the air and on the surface of the planet. The immense heating of the atmosphere would begin causing catastrophic weather changes worldwide within only minutes. Everything which could burn would do so. However, taking refuge in sturdy shelters would offer some momentary protection. Following this brief (under one second) blast of gamma rays would be days of cosmic rays raining down upon Earth, and passing with killing energies through everything as deep as half a kilometer. It's unlikely even humanity's elite in the best and deepest underground shelters available could survive. Life in the depths of the oceans will be killed. Everything on the surface will be dead.
Fortunately these death rays consist of beams likely only one degree wide, and so will usually miss a particular world like Earth. Unfortunately, the stats still put us at risk about once every hundred million years. Nearby Eta Carinae may 'go off' this way in just a million years or less, but thankfully is not aimed towards us.
-- Cosmic catastrophe 'a certainty' By Dr David Whitehouse; BBC News Online; 8 May, 2002
"...they can penetrate about 2.5 kilometers of sea water or 900 meters of rock..."
-- Of Cosmic Rays and Dangerous Days -- Berardelli 2007 (801): 1 -- ScienceNOW
Gas atmospheres absorb a substantial amount of gamma rays. Gamma rays also cannot penetrate a star.
-- It's a universal mystery: What are gamma ray bursts? BY CAROLE RUTLAND
Special to the Ledger-Enquirer; May. 13, 2002; http://www.ledgerenquirer.com
At least some gamma ray bursts are definitely related to supernova explosions. The bursts are narrow beams emitted from the axis of the exploding stars, so if the observer isn't in the direct line of the beam all they'll see is the typical lightshow of the explosion.
-- Gamma ray bursts tied to supernovae by Eugenie Samuel; 17 May 02; NewScientist.com news service
Gamma ray bursts seem to be caused by phenomena such as the collision of neutron stars with highly dense regular stars, or the explosions of hypernovae which result in black holes.
A gamma burster happening in our own galaxy would cause a mass extinction on Earth within seconds of the radiation reaching us.
-- Mission: Unravel The Mysteries Of Gamma Ray Bursts
04-Jun-2002; UniSci Daily
There are two different types of gamma bursts: long ones (existing for a few minutes) and short ones (lasting several seconds). Supernovas are probably the source of the longer ones, while the briefer ones remain unexplained.
-- Team may have answer to gamma ray bursts By Becky Oskin; May 17, 2002; Los Angeles Daily News
"The late Ordovician mass extinction approximately 440 million years ago may be at least partly the result of a GRB."
-- Did a gamma-ray burst initiate the late Ordovician mass extinction? (Published Online August 5 2004)
(Received January 12 2004)
(Accepted April 12 2004)
2007 UPDATE REGARDING 'SHORT' GAMMA BURSTS:
Apparently 'short' gamma bursts are far more numerous and closer to us than the horribly dangerous 'long' bursts.
"There's yet another way that nature found to make GRBs, which is very interesting,"
"Those more powerful long GRBs have only been observed in other galaxies and are thought to occur in our own galaxy less than once every 100,000 years. By contrast, Kasliwal says events like the one her team observed may occur once per decade in the Milky Way."
-- Nearby black hole caught burping gamma rays by David Shiga; 07 August 2007; NewScientist.com news service
"Black hole jets are increasingly suspected of sterilising their host galaxies..."
-- Spinning black holes are ultimate cosmic batteries; 26 January 2009 by David Shiga; Magazine issue 2692.