Extinction events - Page 2

mentholated · 12-27-2007, 10:45 AM

Quote:

Originally Posted by Gillespie

Well, the concept of an asteroid impacting with the planet is nothing to be scared about, just as you don't particularly worry about dying in your car on the highway or taking a 37,000 ft. shortcut directly into the ground while flying in an airplane.

It's just interesting and worth giving some consideration, because the odds aren't astronomically (no pun) small that it wouldn't happen; it's happened already in our century (the massive blast at Tunguska that scientists are now certain was some sort of celestial object crashing into the lower levels of the atmosphere above the Tunguska Plain). More importantly, if it did, the resulting damage would be catastrophic. Imagine the comet that impacted above Tunguska had instead fallen above a major city. 10 - 20 megatons of energy released.

For a while there, "Apophis 2004 MN4" had a relatively decent chance of impacting Earth had it passed through a "gravitational keyhole" that would have altered its trajectory and set up an impact in 2038 or so. Recent re-analysis of its trajectory (as it gets closer, better and better predictions can be made) that it would most likely miss the keyhole.

Had it impacted, however, it would have released energy comparable to 880 megatons of TNT. For comparison, Krakatoa was about 200 megatons.

Again, it's nothing to start crapping ourselves over; statistics are on our side. For me, however, it's interesting to consider these things.

Theres also the remote possibility of asteroidal weapons being used to effectively "reboot" a planet's ecosystem, similar to what happened after the dino's got hit and we mammals took over. Some theories posit that advanced races may be able to accelerate bodies such as an asteroid in a particular manner so that they are "grabbed" by the gravitic field of large objects as it passes, slowing it down and aligning it so that it may eventually impact the desired planet or star. (in the case of stars, this would be done continuously to alter the star's ability to convert hydrogen into helium so much that it would be unable to maintain fusion, thus causing the star to eventually collapse under its own weight, forming an artificial singularity) This process would take quite a long time I'd imagine.

Bottom line is though, unless we happen to cross the path of a stray planetary body, its unlikely we'll ever be faced with an NEO that we wouldn't be able to deflect or destroy entirely. The technology already exists to do such things (and no, not with nuclear weapons, that would just create lots of tiny fragments, like the propagandists on the HISTORY channel taught you).

**Eroak** · 12-27-2007, 10:58 AM

What kinda scares me is the gamma ray bursts that our satellites pick up each day. Yes 99.9999% come from galaxy that are so far away that they are tiny little dots on our most powerfull telescopes. But the fact of the matter is if one burst is in our closest 2 our for worse our own galaxy, Then we'll have some drastic issues. But for the better, The smoking gun needs to be aimed at us for it to have any impact.

We have a number of plans that could move or destroy asteroids. But Gamma ray bursts are the most powerfully observed force in nature and for that there is no defense. To note, There bursts that hit's our atmosphere everyday. Just to far away to cause any real damage. That's a scary thought.

For darmatic purpose of power, here's a scale, if Alpha Centauri happened to go nova and produced a gamma ray burst that was aimmed at us. Bear in mind that Alpha Centauri is over 4 light years away, That the burst would destroy the atmosphere, the bioshere. 60% of the crust and 10% of the mantle would just be sheared off. It's jsut a scale of power, Alpha Centauri for what we understand doesn't contain the mass in the 3 stars to cause such a event.

mentholated · 12-27-2007, 11:06 AM

Even in space, the inverse square law applies. I'm sure by the time any large star collapses nearby we'll have developed one of those geodesic spheres that encompass our star entirely. We'll probably have sufficient shielding technology by the time that occurs, too.

(if you're a star trek person you might remember one episode about these.. basically its a very large structure that is built around a star itself and is used to absorb 100% of the star's radiation) Its possible in theory, obviously.. we can't even begin to test it until we're able to create dwarf stars ourselves.

**Rincewind** · 12-27-2007, 12:50 PM

Quote:

Originally Posted by mentholated

Don't buy into this crap. In a few years the US military will disclose the truth about their orbital weapons platforms, under the guise of defense against asteroids. I'll tell you one thing, they aren't for blowing up asteroids. An asteroid would be deflected. These weapons are designed to rip holes in large, non-brittle objects. When the time comes, they'll fail, though.

Wow. I wouldn't hold my breath if I were you. I've been consulting on such a project for the DoD and NASA's Delta division for a number of months now that utilizes EM beams emitted from stationary-orbiting platforms. They are far from being disclosed "in a few years." Ten years minimum.

**Gambit7** · 12-27-2007, 01:31 PM

Quote:

Originally Posted by BigGaayAl

I find the concept of being scared of asteroids quite comical. We could also fear that our universe runs in to a black hole! Movies arent up to that scenario just yet though.

I thought your tread was about the huge number of animal and plant species that are going extinct these days, and how this phenomenon should concern us more then global warming.

I worry about bees going extinct more, then about global cooking, or cataclysmic events.

FINALLY! someone cares about the bees as much as I do. (seriously) I was actually going to open a "Save the Bees" thread because currently the n. american honeybee is dying off slowly... and mysteriously (no one knows why). W/o bees... well, did anyone pay attention in Science class?

**Gambit7** · 12-27-2007, 01:40 PM

Quote:

Originally Posted by Eroak

What kinda scares me is the gamma ray bursts that our satellites pick up each day. Yes 99.9999% come from galaxy that are so far away that they are tiny little dots on our most powerfull telescopes. But the fact of the matter is if one burst is in our closest 2 our for worse our own galaxy, Then we'll have some drastic issues. But for the better, The smoking gun needs to be aimed at us for it to have any impact.

We have a number of plans that could move or destroy asteroids. But Gamma ray bursts are the most powerfully observed force in nature and for that there is no defense. To note, There bursts that hit's our atmosphere everyday. Just to far away to cause any real damage. That's a scary thought.

For darmatic purpose of power, here's a scale, if Alpha Centauri happened to go nova and produced a gamma ray burst that was aimmed at us. Bear in mind that Alpha Centauri is over 4 light years away, That the burst would destroy the atmosphere, the bioshere. 60% of the crust and 10% of the mantle would just be sheared off. It's jsut a scale of power, Alpha Centauri for what we understand doesn't contain the mass in the 3 stars to cause such a event.

I used to be a member of the Gamma Ray Burst Tracking Network. Basically, an orbital satellite would pick up a burst and send an email/page to all the subscribers, prompting them to point their scopes at the target to catch the afterglow. Unfortunately, my rig didnt get bought in time (I actually designed it somewhat for this purpose) and I think now the network is totally institutionalized.

GRBs are indeed the most powerful [physical] force in the Universe. When I learned about them, no one was really interested in them. But, to me... to be able to glimpse the most powerful force in the Universe is kinda like getting a quick view of God's shadow. Kinda awe-inspiring. I dreamt of being able to say to my peers "yeah, I snapped a photo of the most powerful force in the Universe last night after dinner."

Biggest problem with GRBs is that once you know of one you're basically already dead. You cant prepare or prevent one. But, the odds are staggering that one would ever go off and be pointed in our direction at the same time, let alone be close enough. So I wouldn't worry.

"Run along now, nothing to see here folks.."

Kerostasis · 12-27-2007, 01:58 PM

I don't know much about GRBs offhand, but I did just waste an hour of my life reading astronomy articles on Wikipedia thanks to Eroaks link -- and according to those articles, even a GRB located in our own galaxy would probably not be powerful enough to really fry us. The Ionosphere would take most of the heat, and the strong GRBs tend to be extremely short in duration (a few seconds to maybe a few minutes) so that by the time the blast broke through the Ionosphere it would already be ending.

That said, there would be some pretty dramatic climate effects from having that much of the Ionosphere cooked off, but at least it wouldn't be as simple as standing in your yard one moment and dieing of radiation poisoning the next.

**CingularDuality** · 12-27-2007, 02:28 PM

Quote:

Originally Posted by Gambit7

FINALLY! someone cares about the bees as much as I do. (seriously) I was actually going to open a "Save the Bees" thread because currently the n. american honeybee is dying off slowly... and mysteriously (no one knows why). W/o bees... well, did anyone pay attention in Science class?

I know that there was a huge conspiracy/hoax on Art Bell's show a year or so ago about mysterious disappearing bees, but I think our only serious concern is about the africanization of our honeybees.

**Eroak** · 12-27-2007, 02:49 PM

Quote:

Originally Posted by Kerostasis

I don't know much about GRBs offhand, but I did just waste an hour of my life reading astronomy articles on Wikipedia thanks to Eroaks link -- and according to those articles, even a GRB located in our own galaxy would probably not be powerful enough to really fry us. The Ionosphere would take most of the heat, and the strong GRBs tend to be extremely short in duration (a few seconds to maybe a few minutes) so that by the time the blast broke through the Ionosphere it would already be ending.

That said, there would be some pretty dramatic climate effects from having that much of the Ionosphere cooked off, but at least it wouldn't be as simple as standing in your yard one moment and dieing of radiation poisoning the next.

Right oh. Must of the energy would be asorbed my the ion and ozone, But the effect it would have on each is the chain reaction that would cause a global shortage in food sources. It's not the ray itself that kills. It's the chain reaction it causes that kills. It would never be a 100% global killer, but on the lines of 50-80% if one did happen in our back yard. And don't forget that terrible smell that wouldn't go away for 3 years from the ozone being chemicaly changed.

Wasted a hour? I bet you liked it!

**Gambit7** · 12-27-2007, 03:00 PM

Quote:

Originally Posted by CingularDuality

I know that there was a huge conspiracy/hoax on Art Bell's show a year or so ago about mysterious disappearing bees, but I think our only serious concern is about the africanization of our honeybees.

It's still going on right now. 60 minutes (or one of those shows like it) did a show on it. It's not a hoax. I'm confident the problem will be solved though, but as of now I know there's no solution. But, I think they've isolated the problem to some sort of disease.

xTYBALTx · 12-27-2007, 03:28 PM

Quote:

Originally Posted by Gillespie

It's just interesting and worth giving some consideration, because the odds aren't astronomically (no pun) small that it wouldn't happen; it's happened already in our century (the massive blast at Tunguska that scientists are now certain was some sort of celestial object crashing into the lower levels of the atmosphere above the Tunguska Plain). More importantly, if it did, the resulting damage would be catastrophic. Imagine the comet that impacted above Tunguska had instead fallen above a major city. 10 - 20 megatons of energy released.

It would have been the suck for that to happen over a city, for sure. I just read an article on the Tunguska impact last week, the scientists involved now believe that the blast may have been much smaller than previously believed - but still pretty freakin' large:

http://www.newkerala.com/one.php?act...llnews&id=5412

Quote:

Simulations also show that the material of an incoming asteroid is compressed by the increasing resistance of Earth's atmosphere. As it penetrates deeper, the more and more resistant atmospheric wall causes it to explode as an airburst that precipitates the downward flow of heated gas.

Because of the additional energy transported toward the surface by the fireball, what scientists had thought to be an explosion between 10 and 20 megatons was more likely only three to five megatons.

**Gambit7** · 12-27-2007, 03:28 PM

Quote:

Originally Posted by Rincewind

Wow. I wouldn't hold my breath if I were you. I've been consulting on such a project for the DoD and NASA's Delta division for a number of months now that utilizes EM beams emitted from stationary-orbiting platforms. They are far from being disclosed "in a few years." Ten years minimum.

Heh... dont need to disclose anything when anyone with an inkling of electrical engineering knowledge can build an EM bomb. Send it up on a high-altitude balloon and voila. You can cut the power on anything within a 12 mile radius of ground zero. (assuming a 45 degree cone)

Any EM "beam" is just a concentrated version of the same tech at orbital altitudes yes?

I can probably be arrested or censored for even talking about this... this is one of those things that the govt. doesnt want people to know how to do.

However, if you were looking for a justification for such an orbital defense platform... one of them is defense against EM weapons. Ahh yes, escalation is so much fun.

**Gillespie** · 12-27-2007, 05:20 PM

An astronomer had a pretty startling comparison on how "bright" a gamma ray burst is (how much energy is released).

He held up one of those little key-chain electronic light diodes and switched it on so its little white light shined into the camera. Then, the huge spotlight (the type that are used at Hollywood premieres and what-not to shine up on the clouds... or to, uh, call Batman in Gotham City ;P) that he's sitting in front of kicks on, pretty much washing out of the image. He grinned, though, and said that even this comparison was inaccurate. To truly show the magnitude of the scale of energy that's released in a GRB, he said a million or show such spotlights would need to be turned on to properly compare it to the light diode.

Pretty awesome stuff.

Kerostasis · 12-27-2007, 05:32 PM

Um...if the Spotlight (or several thousand spotlights) is/are analogous to the GRB, what is the keychain analagous too? Another keychain? I don't suppose its very impressive if a GRB is a million times more bright than a keychain light, but if it is a million times more bright than our sun, for example, that would be much more impressive.

**Gambit7** · 12-27-2007, 05:56 PM

I have a better analogy to how powerful GRBs are:
"Back in the day" it was thought that GRBs were actually leftovers from the Big Bang, specifically that you were actually looking back in time at the Universe's Creation when you saw one. Think of the speed of light and how time relates to it, then think of how long ago the Big Bang may have occured, then think of how much energy it would take to traverse that distance/time and be picked up via a telescope bought at Toys 'R Us. THAT's how powerful they are.

Here's another analogy:
"In just a few seconds gamma-ray bursts emit as much energy as the Sun does in 10 billion years"

In reality, since the majority of GRBs are still detected at the edge of the visible universe, you ARE in a way looking at an event that most likely occurred while the Universe was still very young. (relatively) It's extremely exciting. I still dont think anyone has actually seen an explosion, only the Afterglow... we're getting closer though (high-res spaceborn video telescopy is the key. Combining many CCDs into a matrix is another idea - as long as you have coverage every 2 seconds it can be done)

12-27-2007, 10:58 AM	#17 (permalink)
Eroak Join Date: Nov 2006 Location: Bucks County, PA Age: 28 Posts: 3,482	Re: Extinction events What kinda scares me is the gamma ray bursts that our satellites pick up each day. Yes 99.9999% come from galaxy that are so far away that they are tiny little dots on our most powerfull telescopes. But the fact of the matter is if one burst is in our closest 2 our for worse our own galaxy, Then we'll have some drastic issues. But for the better, The smoking gun needs to be aimed at us for it to have any impact. We have a number of plans that could move or destroy asteroids. But Gamma ray bursts are the most powerfully observed force in nature and for that there is no defense. To note, There bursts that hit's our atmosphere everyday. Just to far away to cause any real damage. That's a scary thought. For darmatic purpose of power, here's a scale, if Alpha Centauri happened to go nova and produced a gamma ray burst that was aimmed at us. Bear in mind that Alpha Centauri is over 4 light years away, That the burst would destroy the atmosphere, the bioshere. 60% of the crust and 10% of the mantle would just be sheared off. It's jsut a scale of power, Alpha Centauri for what we understand doesn't contain the mass in the 3 stars to cause such a event. __________________ \|Think Tank\|TGU Admin\|BFx Admin\|Community Improvement\| From the TG Primer: 2) Create an environment where there is mutual respect for your fellow gamers and where all members would be working together to advance the enjoyment of their hobby. E² = MV³

12-27-2007, 11:06 AM	#18 (permalink)
mentholated Registered User Join Date: Jan 2007 Posts: 795	Re: Extinction events Even in space, the inverse square law applies. I'm sure by the time any large star collapses nearby we'll have developed one of those geodesic spheres that encompass our star entirely. We'll probably have sufficient shielding technology by the time that occurs, too. (if you're a star trek person you might remember one episode about these.. basically its a very large structure that is built around a star itself and is used to absorb 100% of the star's radiation) Its possible in theory, obviously.. we can't even begin to test it until we're able to create dwarf stars ourselves.

12-27-2007, 05:20 PM	#28 (permalink)
Gillespie Join Date: Nov 2006 Location: Colorado Springs, CO Posts: 1,067	Re: Extinction events An astronomer had a pretty startling comparison on how "bright" a gamma ray burst is (how much energy is released). He held up one of those little key-chain electronic light diodes and switched it on so its little white light shined into the camera. Then, the huge spotlight (the type that are used at Hollywood premieres and what-not to shine up on the clouds... or to, uh, call Batman in Gotham City ;P) that he's sitting in front of kicks on, pretty much washing out of the image. He grinned, though, and said that even this comparison was inaccurate. To truly show the magnitude of the scale of energy that's released in a GRB, he said a million or show such spotlights would need to be turned on to properly compare it to the light diode. Pretty awesome stuff. __________________ <ArmA Information/SOPs> <ArmA Admin Team> <TG Req. Reading>

12-27-2007, 05:56 PM	#30 (permalink)
Gambit7 Join Date: Aug 2004 Location: Hollywood, FL Age: 32 Posts: 2,198	Re: Extinction events I have a better analogy to how powerful GRBs are: "Back in the day" it was thought that GRBs were actually leftovers from the Big Bang, specifically that you were actually looking back in time at the Universe's Creation when you saw one. Think of the speed of light and how time relates to it, then think of how long ago the Big Bang may have occured, then think of how much energy it would take to traverse that distance/time and be picked up via a telescope bought at Toys 'R Us. THAT's how powerful they are. Here's another analogy: "In just a few seconds gamma-ray bursts emit as much energy as the Sun does in 10 billion years" In reality, since the majority of GRBs are still detected at the edge of the visible universe, you ARE in a way looking at an event that most likely occurred while the Universe was still very young. (relatively) It's extremely exciting. I still dont think anyone has actually seen an explosion, only the Afterglow... we're getting closer though (high-res spaceborn video telescopy is the key. Combining many CCDs into a matrix is another idea - as long as you have coverage every 2 seconds it can be done) __________________

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