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Sea Life Wiped Out by Neutron Star Collision?
Memorize writes "Scientists report in the Journal of Astrophysical Letters that a mass extinction of marine life 450 million years ago might have been caused by radiation from an exploding star, such as a collision between two neutron stars, or a neutron star collapsing into a black hole. Such an event would cause a ten-second burst of gamma radiation, and if it occurred within our galaxy, it could have wiped out many species on earth. At least if astronomers find out that an asteroid is heading our way, we can do something about it, but if there is a gamma burst, we get no warning. And if we did, would there be any way to protect the planet?"
From reading the article, it didn't seem like there was any evidence of this other than speculation. They talk about using computer models to show how it would have wiped life out, but what about the evidence that brought them to this model to begin with? They could at least start with evidence in rocks or something. I wish that every time I speculated on something, that they would 200 million dollar probe. I speculate that this comment will be modded up to +5 interesting, we should launch a probe to see if this is indeed the case.
Lawrence Person (lawrencepersonh@gmailh.com (remove all "h"s to mail)
http://www.lawrenceperson.com/
Since gamma rays are travelling at the speed of light - we can't possibly get any warning of them without figuring out some kind of faster-than-light transportation or message transmission.
I suppose we could make a REALLY good predictive model of when astronomical objects are likely to do this - and predict the arrival of a gamma ray burst in time to do something about it. But what could we possibly do?
It takes a good few inches of lead (or a good few feet of concrete, dirt, whatever) to significantly attenuate gamma rays - and if the ones were are talking about were powerful enough to get through the full depth of the earth's oceans and still kill things when they got there - then you'd need to wrap the earth in a few feet of lead - or hide down some amazingly deep mine-shafts.
Since gamma rays are electrically neutral, you can't deflect them away with magnets or anything like that.
We'd have to get out of the way - but this radiation will be expanding out equally in all directions from the source. Unless we had thousands of years of warning, we'd have to high-tail it outta here at close to the speed of light in order to get far enough away for the inverse-square law to have an effect. If we're 100 light years from the source (say) and a mile of salt water doesn't attenuate the energy enough - then we'd need to be *way* more than 200 light years away if we could carry a quarter of a mile of water as a shield, 400 light years away if we had a sixteenth of a mile of water....for any reasonable amount of shielding, we need thousands of years notice of the problem happening.
In all likelyhood, we'd just sit back and let our great, great, great grandchildren deal with the problem.
We're basically doomed unless we have some kind of science-fiction technology.
www.sjbaker.org
If it only lasts 10 seconds, then just hope you are on the other side of earth.
"And if we did, would there be any way to protect the planet?"
Uh, no? First, how would you propose we detect a gamma ray burst, which travels at the speed of light (of course), before it gets here? Second, you're talking about a pulse of energy strong enough to destroy life on a planetary scale from 6,000 light years away! How the hell are you going to protect against that?! Tin foil can't help you now!
On a side note, this was a plot device in a book by Stephen Baxter, although I can't remember the title. Every couple million years, two stars in the center part of the galaxy would collide, and knock all life in the galaxy back to single-stage or before; species would struggle back up the evolutionary ladder, and just as they achieved spaceflight, the next stars would collide. Great book-
Would we gain more protection from moving 50 ft underground or living on the surface in another solar system ? We pretty much need to leave the galaxy to escape this type of event. Wouldn't we have to travel about 10000 years to escape this type of event only to get to another location where the same event could happen ? I guess the species is preserved, but since we wouldn't have any quick way of knowing, and no effective interaction, does it really matter any more than other life forms in the universe. I can see leaving the earth, and appreciate to continuation of knowledge via keeping the species alive, but it seem this isn't the type of thing we have the technology to escape by moving far enough away. Maybe an glbal warning system, so if it happens again hits, the other half of the planet can go way underground ?
"Keep in mind the volume of a sphere is 4/3 pi r^3, so the volume of space that this would take up is increased by a factor of 8,000,000."
Exept that our galaxy is a disc, not a sphere. Also, don't forget that we're towards the edge of that disc.
Personally, I see 6000 lt-yr still being pretty "close" (and probably "unlikely") when you consider our galaxy is roughly 100,000 lt-yr in diameter. If it happened often enough for us to be worried about, we'd see more such collisions within our galaxy beyond the 6000 lt-yr theoretical safe distance.
Besides, what are the odds of two stars colliding such a manner, anyway? It seems the odds of a binary star becoming a pair of neutron (or denser) stars seem to be slim to none: you'd think the creation of one neutron star out of one would consume/destroy the other before it had the chance to follow suit. So we're really dealing with an intersection of two previously unassociated stars. And it's called "space" for a reason.
I'd worry more about comets and asteroids at this point and put this one in the category of "When we have to start worrying about it, we'll probably be advanced enough to do something about it," kinda like the sun going nova.
Actually, there might be a way to get a little bit of warning, depending on the source of the gamma ray burst.
Photons (gamma rays) take a long time to get out of a star. But neutrinos, because of their physical properties, pass right through most of the star. Most nuclear reactions that generate photons also generate neutrinos. They're just very hard to detect (because of that same physical property).
Well, I'm working on a neutrino detector at the South Pole right now. http://icecube.wisc.edu/
It could, when it's complete, pinpoint the source of the neutrinos. Given the energy level of the neutrinos and the sudden, large burst of them, a whole lot of scientists are going to be woken up - and I mean that literally.
An earlier version of the project, AMANDA http://amanda.wisc.edu/, already has a supernova detector. It hasn't gone off yet, but when it does it will start a sequence of events that ultimately steers a lot of telescopes to point at that supernova.
1. 2.
- Supernovae may not be predictable, but mergers of neutron stars may be. If theory of gravity waves is correct, we could detect the orbital spin-ups before mergers using laser interferometers.
- If you can stick enough mass in the path of the burst to scatter the gamma rays to lower-energy photons or deflect them entirely, you could prevent this problem. This means having a disc of material at least 8000 miles across in the exact right place to shadow the Earth at the moment of the burst, but I never said it would be a small job.
From this, it follows that long-baseline laser interferometers and GRB research are good things for now. Aiming for serious space-construction capability is a good long-term goal.Sustainability and energy independence essay
Ozymandias
I met a traveler from an antique land
Who said: Two vast and trunkless legs of stone
Stand in the desert. Near them, on the sand,
Half sunk, a shattered visage lies, whose frown,
And wrinkled lip, and sneer of cold command,
Tell that its sculptor well those passions read,
Which yet survive, stamped on these lifeless things,
The hand that mocked them, and the heart that fed,
And on the pedestal these words appear:
"My name is Ozymandias, King of Kings:
Look upon my works, ye Mighty, and despair!"
Nothing beside remains. Round the decay
Of that colossal wreck, boundless and bare
The lone and level sands stretch far away.
Sound familiar?
Fly me to the moon Let me sing among those stars Let me see what spring is like On jupiter and mars
Laws of thermodynamics and entropic considerations ultimately dictate that organized (non-random) systems will eventually decay toward randomness.
However, the question with regard to rate is of the utmost importance in self-replicating systems. Bacteria in a sense do not die, in that they clone themselves (albeit with sometimes intermittant reproduction through genetic exchange with other bacteria) and hence in a sense are immortal (they make identical copies of themselves which persist more or less indefinitely).
Studies of the aging process (ie genes controling catabolism relative to anabolism) in eucaryotic organisms suggest that genetic systems have evolved genes that actually shorten life span. Hence, the question arises as to why, since one might initially assume that being able to live forever (like bacteria) would seem a more effective reproductive strategy.
It turns out that there appears to be selection for genes that produce shorter life spans in situations in which the presence of such genes increases the probability of survival of the offspring, even if their activity/presence takes place at the expense of the parent. It would seem that perpuation of self-replicating systems necessarily requires the need to take some risks to overcome the reality of dynamic environments. Ones current genetic makeup although nearly optimal (or more apply sufficiently near optimal) in the current environment may not be so in a future environment. Hence, a slightly different genetic makeup in ones offspring may be selected for in some future environment. Since prediction of exactly what the future environment might be is to some degree uncertain, most sexual organisms are capable of having more than one offspring, thereby increasing variety and hence the probability that at least some will be nearly optimally suited to survive.
Keep in mind, however, this is only an evolutionary strategy. While only those gene combinations that are successfull in reproducing will persist in subsequent generations, there is no guarantee that a particular gene combination will survive.
As for your arguments regarding "genes not grading anything in levels of mportance or having a perspective", this is really little more than a matter of semantics. The adult phenotype is nothing more than the product of its genes acting in an environment during its ontogeny. While it might seem to we are something more than our genes, at a molecular level there is nothing about us that is not the direct result of metabolic processes that occur (or occurred) as the direct result of the collective response/relative control of our genes to our environment. However, when you consider the shear number of different variatnts of tens of thousands of human genes and the incredible diversity of their responses to slightly different kinds of environments, the complexity is truely something to marvel at; so much so that it is hardly worth worrying about whether or not "something" (like some kind on mystical spiritual essesence or soul or other such unecessary nonsense) is missing.