Slashdot Mirror
Exploding Star May Have Damaged Life on Earth
Reedo writes "Scientists have proposed that an ancient supernova may have damaged our ozone layer, wreaking havok on terrestrial life. Previously no one had realized that a cluster of stars could have been so close to the earth during that time. But don't worry about it happening again anytime soon. The next expected supernova is nearly 500,000 light-years away and is too far from the earth to cause any damage."
But don't worry about it happening again anytime soon. The next expected supernova is nearly 500,000 light-years away and is too far from the earth to cause any damage."
Too bad, I was thinking of a way out of doing my math homework tonight.
and i had come to believe it was all because of the anti-time anomaly
I'm really unhappy with CNN. This theory is insultingly ludicrous.
It's preposterous to think that there could have been even ONE supernova in our vicinity (let alone "several" as stated in the article) without obvious lingering effects, i.e., a remnant special star like a neutron star or a black hole and/or some sort of nebula. "Several million years" is nothing in cosmic time--the nebulae that those stars would have left would barely have dispersed at all.
Not to mention that our position in the galaxy is somewhat peculiar. We are on the rim of a huge and empty vastness called the local bubble. The speculation (since there's a pulsar on the other side of the local bubble) is that the portion of space near us was cleared out by a big supernova some time ago (probably ~5-6 billion years ago, as our sun was almost certainly formed in its wake). How could these researchers possibly think that several supernova could have passed through without leaving similarly obvious signatures?
visit the hwky website for a lyrical genius infusion.
Note that, the article claims that the next star in that cluster expected to go supernova is 500,000 light years away.
Of course, it also claims that that star is Antares, which is actually about 600 light years away.
From the article:
The next member of the gang expected to go supernova is Antares, which at almost 500,000 light-years away is too distant to rattle our planet, they say.
What kind of dope are these astronomers smoking? Antares is 500 light years away.
Still quite distant, but 500000 light years will place you well outside the Milky way. It's about as far as the Magellanic clouds.
Makes you wonder if we're here to discover it happened because it happened.
Some people have a way with words, and some people, um, thingy.
It's a space station!
They talk about this showing up in the marine fossil record, but what about on land? The article mentions some geological data, but is there any on-land paleontological evidence to support this? Also, they only talk about it killing plankton - does that mean that it was too far away to kill anything larger directly? Perhaps this is why we haven't run across it in any other fossil records...
The Galactic core is closer than that, the last I checked. Andromeda is about 2 million LY away, if I recall right. Let's see.
Antares = 520 light years
CNN cites the Scorpius-Centaurus OB Association of stars which is actually about 470 light years away.
So CNN was off only by a factor of a thousand. Interesting theory, if they can get the facts right.
"It is a greater offense to steal men's labor, than their clothes"
Researchers have always worried about there might be in fact a single cause of Mass Extinction. You can refer to this graph for the rough interval of mass extinction.
Most people believe that the meterorite impacts is responsible for the mass extinction, but now this new findings may sparks a new way of thinking - the murderer may be someone else.
If we believed that there's a cycle for Mass Extinction, there we don't have much to worry about - as it's still millions of years away. However, some people also believe that the Sixth Extinction might come earlier, because human was not present in the last 5 extinction, and that makes the great difference.
Thank you for reading my trolling. I quote as much online reference as possible, but actually my point of view are from the books I read. My apology.
I don't even want to contemplate how much energy was given off forming the elements I'm made of. Now there's hardly enough energy left over for me to get up and fetch another beer.
Please read the paper before dismissing the theory.
They know their readers just glance over the numbers. and btw 417 is a small number. when you are talking about space u have to say at least thousands (preferably millions and billions).
"If the life is gone then how can we verify that it even existed at all?? "
You are so right. And to think of it until recently i believed the lies scientists told me about dynasours roaming the earth.
Well firstly like others have pointed out, Antares is nothing like 500,000 light years away. That's a 1000-fold error and lazy journalism on CNN's part.
As for when it's going to happen, the stellar time scale is so big compared with what we're used to that it really comes down to a guess. This is figured out based on studying other stars and coming up with theories about the life cycles that they follow... and the theories are always being revised and revised and revised as more information pours in.
Antares is a red giant star that's used up all it's hydrogen, and now it's fusing together heavier and heavier elements, and starting to run out. It might die tommorrow or it might die a million years from now. All that's known at the moment is that it's very near to the end of its life cycle, and that it's massive enough such that when it dies it'll likely go out with a very big bang, probably about as bright for a while as the rest of the Galaxy put together. (We see this happen with stars in other galaxies every so often when an unknown star that couldn't be seen individually suddenly lights up out of nowhere.)
Nobody knows exactly when it'll happen, though.
I thought the discrepancy came from the fact that neutrinos pass through matter much more easily than light, which needs to bounce its way clear.
The Mongrel Dogs Who Teach
The fossil record is "tied to" Darwinian theory only in that the latter is the most successful explanation of the former. Fossils are found things, not theoretical constructs. Determining their sge depends a lot on physics (through radioactive dating) but only weakly, if at all, on biology.
The Mongrel Dogs Who Teach
This is what happens when you get science news from CNN. Antares IS NOT 500,000 ly away; it is 600 ly away. Big difference. As well, one cannot say that it is the "next expected supernova". It's a good candidate but so is Betelgeuse for that matter. Eta Carinae is much mre likely to go supernova than either of them.
---
I didn't want to leave this space blank.
These finds are unrelated to the theory of evolution. The theory of evolution is one of sciences most impressive theories which has withstood attacks both fair and foul. The basic theory doesn't rely on super nova's millions of years ago.
The theory of evolution doesn't have circular dependencies on the fossil record. That's just creationist wishful thinking.
When you mention errors in radiometric dating, do you refer to the unaccuracies that science knows and accounts for, or do you refer to delibrate misuse of radiometric dating by Steve Austin (the creationist, not the wrestler)?
If NDT was incorrect, the science behind this (ie. supernova ~2 million years ago killed off lots of marine life) would still stand.
Warning: Some ideologies on the Net are smaller than they appear.
If a star supernovaed as it passed us, the remnants would have on average roughly the same velocity as the star group - they would also be 500,000 light years away now.
I doubt CNN made this story out of full cloth, I'm sure the theory has more to back it up than CNN reported - it's not like CNN is a scientific journal, they always trim corroborating details.
(Frankly, I think it's absurd that this comment was moderated to the top.)
"It is our blasphemy which has made us great, and will sustain us, and which the gods secretly admire in us." - Zelazny
best place to lay any media inaccuracies to rest.
here it is again, www.badastronomy.com
Although no-one has mentioned it on there bulletin board yet. Real astronomers visit this board, indeed a real one runs it.
This star group the article refers to is around 500 light years away, not 500,000. Next time, CNN should assign this "reporter" to cover trends in hairstyles or sightings of Elvis or some other topic the "reporter" might be capable of understanding.
Or maybe this is just another example of Time Warner math coming from CNN's parent, the same arithmetic that shows the record studios to be losing billions of dollars due to music "piracy". The multiples are probably similar in both instances.
This all possible, yes, but it's also extremely unlikely.
First the possible. A quick, back of a napkin calculation shows that a supernovae at around 3 light years would appear roughly as bright as the sun (depending on the circumstances). A good opprtunity to work on your tan, for a few days anyway. Nothing to really worry about, but if you're skinned, slap on some SP-40.
Now, if it's much closer, you might have some problems. At ~1.5 light years, the supernova is 4 times as bright as the sun, and at ~1 light year, it's 9 times as bright. Hooray, we know what an inverse square law is.
The real problem is this: there aren't that many stars nearby. The closest, Proxima Centauri, is 4.2 light years away. And there's no chance of it ever going supernova - only comparatively massive stars manage that. Within 10 light years of us, there are only 12 stars (and that includes Sol). Of those there is only one that's ever going to go supernovae - Sirius, at a distance of 8.6 ly. And that's an exceptional case. You have to go to the 70th nearest star before you find another star in the same situation - Altair, at 16.8 ly.
Now, even with Sirius and Altair, they're going to be shining for millions of years to come. Now, what they're suggesting is that one of those really rare large stars just happened to be really close to us when it's lifetime of tens of millions of years came to a close. Right.
Time for those astronomers to come down from the mountain - the altitude seems to be having an effect.
I havent read the article, shoot me ;-) But my guess is that they just look for the most massive star in the solar neighbourhood. The reasoning is:
1) a star can only use about 10% of the available hydrogen, before more rapid evolutionary mechanisms set is (ie before some of them go boom)
2) only 0.7% of the rest mass energy is turned into energy
3) the relation between luminosity (L) and mass (M) is:
- M proportional to L^4 (for massive stars)
Thus nuclear time scale (tn):
tn = 0.007*0.1*Mc^2/L ( = 10^10 year for the Sun)
for other massive stars:
tn = (M/Msun)/(L/Lsun) * 10^10 yr
= (M/Msun)/(M^4/Msun) *10^10yr
= M^-3 * 10^10 yr
so if one would find a 10 Msun star nearby, you could expect it to go boom in 10 million years. In other words, a cosmic 'blink of the eye'.
We are all in the gutter, but some of us are looking at the stars
No, it doesn't. Take as many apes as you please, put them in a dirty nuclear reactor and wind the dial up to `Max' for a few days and see if they evolve at all.
There's a reason you wear a lead coat when you go to have your insides xrayed - and the technician stands behind another lead screen - and it's not the risk of becoming too smart for your family to bear.
Got time? Spend some of it coding or testing
And here's me thinking that fossils of practically everything appear and disappear abruptly in the fossil record. Now where on earth did I get that silly idea? Oh, yes: Earnst Mayer, Stephen Gould, Niles Eldredge, Richard Goldschmidt, Roger Lewin, and let's not forget Charles Darwin. Sounds a bit like a who's who, dunnit?
Ergo: non sequitur.
Got time? Spend some of it coding or testing
True, but you left out a pivotal part of the story: what happened to them and when is a theoretical construct.
Now that's just completely wrong. Biologists extracting blood cells from T-Rex bones can get a fairly good idea of an upper limit for the bone's age, based on home much the organic material has decayed. And it's shy at least four noughts of any figure you're likely have in mind. (-:
Of course, when people dig up fresh dinosaur bones, or extract fresh wood from within Manley sandstone, that generally presents them with a pretty big hint about the age of what they've found. But, of course, the false assumptions undergirding this assertion...
...are so important on philosophical/metaphysical grounds that inconvenient observations like those tend to just get swept under the carpet.
I think the pi in your post is a sign from the gods of science that you're making them do too many beetles, and you need to step outside of your reality bubble for a while so they can discuss things with you. (-:
Got time? Spend some of it coding or testing
Not so much `withstood' as `denied and papered over the wounds from'.
This consists very much of closing one's eyes and crying `It *IS*, dammit!' - only it's generally done professionally and en masse (cf Wistar and similar conferences).
Got time? Spend some of it coding or testing
Thanks for the nod, but I think you meant havoc
Unless, of course, you've slipped into your Middle English Ultima character :)
"I can't give you a brain, so I'll give you a diploma" - The Great Oz (blatently stolen sig)
To paraphrase the article a little more accurately than CNN, I hope.
There is a cluster of young bright stars, currently about 500 ly away from us. They analyse the known movements of cluster (and the Sun) and the likely rate of supernovae in the cluster over the last 5-10 million years. They conclude that there could very plausibly have been enough supernovae from that cluster to account for two things:
1. The "local bubble" a region of space about 500 ly in radius containing the Sun in which the usual interstellar gas is much hotter and thinner than usual.
2. The unusually high levels of a stable, but rare
isotope of iron in seabed sediments laid down at certain times.
The rule out various mechanisms that might have stopped the iron from the supernovae reaching the Earth.
They look, much as an afterthought at the possible biological impacts of these supernovae. These are not strong, and I would not say that the paper
really supports the idea that this is the trigger
of any mass extinctions. The closest of the supernovae would, apparently significantly reduce
ozone levels in the stratosphere (charged particles from the SN catalyse NO formation, which
destroys ozone), and this would increase levels of
UV-B at the surface, to which plankton and corals
are especially susceptible, so there might have been some extinctions there, but that seems to be all.
How do most people think that the heavier elements ended up in this system anyway? Think about it. You need a star of at least 8 solar masses to start the r-process, the rapid heavy-element formation process. There just isn't enough mass in the solar system to account for that. There must have been another close encounter billions of years ago that allowed a young star to "rip" enough material from an old supernova remnant /dense cloud to form the planets with the elements we have today.
nahtanoj
It probably should be clarified that the statement about Antares being the next probable supernova really meant "Antares is the next likely SN candidate in that cluster". For quite some time, astronomers have been keeping an eye on Eta Carinae, which is about somewhere between 7.5K and 10K light years away, but could possibly let go at any time. It will likely be quite harmless except to astronauts and orbiting spacecraft (there is some discussion regarding whether it could become a gamma ray burster), but quite spectacular to see. There just aren't any sufficiently massive stars close enough to us to really worry about supernovas anytime soon.
Please stand clear of the doors, por favor mantenganse alejado de las puertas
Alright, I'll put the catalytic converter back on my nova. Geez, who'd a thought one chevy nova would cause that much of a stir?
Disconnect your television. Do your own research. Draw your own conclusions. They're probably lying. Don't be a sheep.
But without an exploding star, there's no way for any of the elements (lighter or heavier than iron) to get outside of the stars that created them. Hydrogen and helium were the only elements produced in the Big Bang.
You are both right. The sudden burst of fusion in the higher elements (helium to iron) releases both neutrinos and gamma rays in the core of the collapsing star. The neutrinos pass straight out at the speed of light. The gamma rays travel a few feet, are absorbed and re-emitted as somewhat lower power photons, repeating this many, many times and being shifted down to thermally-emitted visible light by the time they make it out of the star. So the neutrinos get a head start leaving the star because they pass through _the star's_ matter easily. Once they are out in space, light and neutrinos travel at the same speed. (Or, if neutrinos have a very tiny rest mass, they travel at just under the speed of light.)
Short version of above: once a large enough star leaves the main sequence, you can come up with an order-of-magnitude guess as to when it will blow. This guess, by the way, would likely be expressed according to observed time (i.e., our time), not absolute time.
These elements are formed as the >= 8 solar mass stars collaspe into neutron stars. The shockwaves of the collaspe initiate the formation of the elements. I don't know about the jets, but you might be right.
nahtanoj
"The next expected supernova is nearly 500,000 light-years away"
That's a neat trick, considering that the Milky Way is only about 100,000 light-years across...
pc=parsec.
A parsec is the distance where an object will have a parallax of one second of arc, using the diameter of Earth's orbit as a baseline. PARallax of one SECond, hence the name "Parsec". This distance is approximately 3.26 light years.
Fascism starts when the efficiency of the government becomes more important than the rights of the people.
Here's an analysis of the risks associated with nearby supernovae. The executive summary is that gamma rays offer the most potential for destruction, and the danger range is within about 100 ly.
So me live in a supernova hole/bubble?
Is it possible that only in these areas of the glaxies suns have a planet system? The elements we all consist of are after all just supernova exhaustion.
Maybe there are far less planet systems than we have expected?
--
Karma 50, and all I got was this lousy T-Shirt.
Makes you wonder if we're here to discover it happened because it happened.
It also makes you wonder if this kind of thing is common enough that it tends to take out intelligent races before they develop interstellar travel.
Or if it might make interstellar travel at sublight speeds sufficiently hazardous that there isn't much of it.
Or perhaps the cluster has made this region sufficiently dangerous that nobody has come here recently (like in the last few million years).
Any (or a combination) of these might help to explain why, as far as we can tell, no little green men have dropped in to visit.
Bantam Dominique roosters crow a four-note song. Once you've heard it as "Happy BIRTHday" you can't NOT hear it that way
at 500,000 light years, the star isn't close enough to do any damage. They're not saying "it won't happen for 500,000 years", they're saying "it won't happen again. The next nearest star is too far away."
It's been a long time.
Or you could close your eyes and shout 'tis! (-:
That must be why Stephen J Gould gets so much mileage out opf catastrophism, and why `benchmark' fossils proving Darwinism are repeatedly being proclaimed, and later silently (or at best very quietly) withdrawn.
Eohippus is no longer part of a series, Archaeopteryx is a variant on the theme `Hoatzin' and Lucy was resting several layers above a modern human skull. Sorry, where was that evidence again?
Behe's `irreducible complexity' and Dembski's `specified complexity' are merely fighting over the carcass. It's time for a completely new theory.
I don't see that evolution counts one way or the other to someone with a flat-earth POV.
Does this guy count as a creationist in your eyes? His `wild' theory of specie development is a mathematical certainty when compared with Darwinism.
Got time? Spend some of it coding or testing
Well, no. All that needs to happen, and it often does without specifically evil intent, is for papers to go unpublished often enough. And evidently they do.
Got time? Spend some of it coding or testing
I recommend extending your education before pontificating. (-:
I'm not talking about C14, I'm talking about meat, bone and blood cells.
Got time? Spend some of it coding or testing
Actually, you do, and even that isn't enough to genetically break even (this extinction mutagenesis link cites deliberately accelerated examples but nicely explains the principle).
Got time? Spend some of it coding or testing