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(Discover)   Five years ago today, the Earth suffered a massive cosmic onslaught that farked satellites and partially ionized its atmosphere... from an object 50,000 light years away   (blogs.discovermagazine.com ) divider line
    More: Scary, neutron stars, Milky Way galaxy, gamma ray bursts, gamma rays, cubic centimeters, earth, speed of light, magnetic fields  
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9444 clicks; posted to Geek » on 27 Dec 2009 at 8:26 PM (6 years ago)   |   Favorite    |   share:  Share on Twitter share via Email Share on Facebook   more»



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2009-12-27 11:48:50 AM  
Interesting article....we are indeed tiny in the overall picture.
 
2009-12-27 12:06:11 PM  
That dude is too easily excited.
 
2009-12-27 12:07:47 PM  
I, for one, appreciate his enthusiasm.
 
2009-12-27 12:12:41 PM  
What are the odds that the crack that threw the original wave will cause the whole star to spin apart and really hose us down but good?
 
2009-12-27 12:14:32 PM  

unlikely: What are the odds that the crack that threw the original wave will cause the whole star to spin apart and really hose us down but good?


None. Neutron stars have gravity that's a mite stronger than around these here parts.
 
2009-12-27 12:14:48 PM  

PPL_Wannabe: I, for one, appreciate his enthusiasm.


This. He makes astronomy/physics exciting.
 
2009-12-27 12:34:39 PM  

revrendjim: unlikely: What are the odds that the crack that threw the original wave will cause the whole star to spin apart and really hose us down but good?

None. Neutron stars have gravity that's a mite stronger than around these here parts.


Sorry, I wasn't clear.

10 RPM is a pretty fast spin for an object that heavy, isn't it? I'd think that any kind of imbalance would really play havoc.

I don't understand the physics of the material at all. I understand the ultra high mass and gravity, but will it have properties of a liquid and flow to a rounded shape? That's what i've always thought it'd be. But the idea that it can form a crack... suddenly I'm wondering, then, if it's more of a ball of metal. Maybe it has properties like silly putty... malleable when moving slowly, but friable if you move it quickly?

How could such a crack form in the first place if the thing is pure unfiltered high density gravity? What would be able to move that would let it happen? Impact with a smaller ultra-high-density object?
 
2009-12-27 12:38:36 PM  
continued:

I was assuming if it was an impact they'd have said "when the thing collided with another neutron star" or something, rather than just "a crack formed."

So my assumption that it could re-crack and then re-form and do it again possibly even over and over(hence the term hose us down) was based on:
a) it cracked in the first place,
b) therefore it should be a safe assumption that it can do it again, and
c) if a crack closes it's either the cracked material stretching or another crack of equal size opening somewhere else or somewhere in between.

Add in that fairly fast rotation and... well.. that's why I was assuming one flaw/instability could lead to a lot more.
 
ZAZ [TotalFark]
2009-12-27 12:39:14 PM  
Cooling, slowing spin, and loss of magnetic field all change the stress on the crust, which is not superfluid neutrons but very dense normal matter with some shear strength. Eventually something snaps. I suspect the lethal range for this sort of burst is ~100 pc.
 
2009-12-27 01:05:16 PM  

unlikely: unlikely:
10 RPM is a pretty fast spin for an object that heavy, isn't it? I'd think that any kind of imbalance would really play havoc.


Actually, it's very slow. Some neutron stars spin hundreds of times per second.

The crust of a magnetar/NS may be like a crystal, giving it strength but also meaning it can suffer cracking if stressed too much. This sort of physics is still pretty theoretical, as you might imagine, and to be honest I'm not all that familiar with it. But the strain a NS crust is under can be pretty high. When a cubic centimeter of material has a mass of millions of tons, and it's under ten billion times the Earth's gravity, the energy released when it gives way is fairly epic.
 
2009-12-27 01:42:45 PM  
Sentences like this:

In just 200 milliseconds - a fifth of a second - the eruption gave off as much energy as the Sun does in a quarter of a million years.


make me stop and shake my head for a moment of quiet introspection that always ends with my wanting a drink.
 
2009-12-27 01:44:31 PM  

unlikely: revrendjim: unlikely: What are the odds that the crack that threw the original wave will cause the whole star to spin apart and really hose us down but good?

None. Neutron stars have gravity that's a mite stronger than around these here parts.

Sorry, I wasn't clear.

10 RPM is a pretty fast spin for an object that heavy, isn't it? I'd think that any kind of imbalance would really play havoc.

I don't understand the physics of the material at all. I understand the ultra high mass and gravity, but will it have properties of a liquid and flow to a rounded shape? That's what i've always thought it'd be. But the idea that it can form a crack... suddenly I'm wondering, then, if it's more of a ball of metal. Maybe it has properties like silly putty... malleable when moving slowly, but friable if you move it quickly?

How could such a crack form in the first place if the thing is pure unfiltered high density gravity? What would be able to move that would let it happen? Impact with a smaller ultra-high-density object?


A quick calculation shows that the centripetal acceleration at the surface is about 7000 m/s^2, while the gravitational acceleration is about 2.7E12 m/s^2, which is about 400,000,000 times stronger, so it's not going to fly apart.
 
2009-12-27 04:07:33 PM  
Can't we just solve this problem by firing nuclear missiles at the threat? I've been told that solves just about everything.
 
2009-12-27 05:14:42 PM  
The Bad Astronomer:

When a cubic centimeter of material has a mass of millions of tons, and it's under ten billion times the Earth's gravity, the energy released when it gives way is fairly epic.
 
2009-12-27 05:17:03 PM  
Jesus I need to learn how to quote people properly.

Basically I was wondering how much a cubic centimeter of that stuff would weigh on the neutron star, but in Earth-tons. (If that makes any sense)

/been drinking all day watching football
 
ZAZ [TotalFark]
2009-12-27 05:26:30 PM  
A neutron star increases in density towards the middle while gravity decreases. Exactly how much is still an open area of research (see: nuclear equation of state).

The crust material that gave way might be only ~10^5 g/cc, times 10^14 cm/sec^2 gives ~10^19 g or ~10^13 tons. The heaviest (weight instead of mass) material might be a factor of 10^8 or so greater.
 
2009-12-27 06:06:18 PM  

PPL_Wannabe:
Basically I was wondering how much a cubic centimeter of that stuff would weigh on the neutron star, but in Earth-tons. (If that makes any sense)


Well, it's just the mass in grams divided by 454 to get pounds, and then divided by 2000 to get tons. But as I said in the article, it's about a hundred million tons. Don't drop it on your foot!
 
2009-12-27 06:13:20 PM  
The Bad Astronomer:
Well, it's just the mass in grams divided by 454 to get pounds, and then divided by 2000 to get tons. But as I said in the article, it's about a hundred million tons. Don't drop it on your foot!


I understand that it would weigh a hundred million tons here on Earth, but what would it register on a scale sitting on the neutron star (where I'm assuming it would weigh a lot more)? I'm just trying to figure out the relative weights (and I suck at math).
 
2009-12-27 06:57:36 PM  
I had no idea that happened, that's pretty interesting since they always tell us the threat from intergalactic terrorism is like a billionbillion to one. Now I'm gonna wonder about a GRB daily.

Either way, I love the scalar comparisons involved. It hurts my head but its fascinating to think of the mass of two suns squeezed into an area the size of my hometown.
 
2009-12-27 06:58:23 PM  

El Chode: intergalactic terrorism


sorry, I guess it'd technically be intragalactic terrorism
 
2009-12-27 07:05:03 PM  

Pocket Ninja: Sentences like this:

In just 200 milliseconds - a fifth of a second - the eruption gave off as much energy as the Sun does in a quarter of a million years.

make me stop and shake my head for a moment of quiet introspection that always ends with my wanting a drink.


I'll pour. Seriously, if anything can throw our pathetic little problems into perspective, it's stuff like this.
 
ZAZ [TotalFark]
2009-12-27 07:16:41 PM  
I suffered unit failure, mixing dynes and grams. Correct answer is more like 10^10 tons force per cc of crust material (with huge uncertainty because we don't understand the crust).
 
2009-12-27 07:41:20 PM  

PPL_Wannabe: The Bad Astronomer:
Well, it's just the mass in grams divided by 454 to get pounds, and then divided by 2000 to get tons. But as I said in the article, it's about a hundred million tons. Don't drop it on your foot!

I understand that it would weigh a hundred million tons here on Earth, but what would it register on a scale sitting on the neutron star (where I'm assuming it would weigh a lot more)? I'm just trying to figure out the relative weights (and I suck at math).


I just say 'Rosie O'Donnell'. That's all.
 
2009-12-27 08:47:45 PM  
Why are you people just standing around? We need to shoot back!
 
2009-12-27 08:48:10 PM  
This was discussed briefly on an episode of 'The Universe' that aired this season.

It's really impressive when you think about it. There was so much energy that it traveled 50,000 light years (from one side of the galaxy to the other), hit the Earth and still had enough energy to fark with our stuff.
 
2009-12-27 08:58:36 PM  
It was caused by a magnetard?
cricketsoda.com
 
2009-12-27 09:23:22 PM  
The Bad Astronomer:

So was this in the book? Sorry, still haven't picked it up yet.
 
2009-12-27 09:25:28 PM  
So we had 50,000 years to see that coming?
 
2009-12-27 09:25:47 PM  
This makes me feel insignificant. Of course, I always feel insignificant.

/Not obscure.
 
2009-12-27 09:29:04 PM  
... from an object 50,000 light years away

How does the Cubs' World Series chances go under the Geek tab?
 
2009-12-27 09:30:48 PM  

KiwDaWabbit: So we had 50,000 years to see that coming?


No, it just took 50,000 years for us to see it.
 
2009-12-27 09:31:12 PM  

NewportBarGuy: Can't we just solve this problem by firing nuclear missiles at the threat? I've been told that solves just about everything.


Spock: Sensors show the object's hull is solid neutronium. A single ship cannot combat it.
 
2009-12-27 09:37:53 PM  

KiwDaWabbit: So we had 50,000 years to see that coming?


um, but the universe is only ~8k yo
so we didnt see it coming
 
2009-12-27 09:45:52 PM  

PPL_Wannabe: The Bad Astronomer:
Well, it's just the mass in grams divided by 454 to get pounds, and then divided by 2000 to get tons. But as I said in the article, it's about a hundred million tons. Don't drop it on your foot!

I understand that it would weigh a hundred million tons here on Earth, but what would it register on a scale sitting on the neutron star (where I'm assuming it would weigh a lot more)? I'm just trying to figure out the relative weights (and I suck at math).


Well, if you take some numbers for granted, such as:

Neutron star radius = 10km
Density of star = 10^14g/cm3

You can determine the mass of the star as:

V = 4/3*pi*(10km)3
V = 4200 km3
Mass = 4200km3*(10^14g/cm3*(100000cm/km)3*kg/1000g))
Mass = 4.2*10^32 kg (assuming I didn't drop a zero somewhere, which is highly likely)

The weight of an object at the surface (assuming the star is somewhat uniform in density) would follow as such:

F = G*(mass of object on star)*(mass of star)/(radius of star)2
F = (6.67*10^-11 m3kg-1s-2)*(10^11 kg)*(4.2*10^32 kg)/(10000 m)2
F = 2.8*10^25m*kg/s2 (again, may have screwed something up)
F = 2.8*10^25 N

And as 1 N = 0.22 lb

F = 6.2*10^24 lb

or 3.1*10^21 tons.

that would be 3100000000000000000000 tons. (unless I've irreparably botched my calculations.)
 
2009-12-27 09:53:21 PM  
Just a reminder, nobody farks with Mother Nature.
 
2009-12-27 10:09:00 PM  
I got preggers that night and I have been wondering what was up with my son for a while now.

Well this answers that question LOL
 
2009-12-27 10:13:35 PM  
If it rang our bell from that far away, think of any potential extraterrestrial civilizations within about 10k light years or so. Could have wiped them out. Thanks, galaxy, for killing my alien friends :-(
 
ZAZ [TotalFark]
2009-12-27 10:35:36 PM  
attention span of a retarded fruit fly

I know a girl who was conceived, near as I can tell, when SN 1987a blew. I suspect neutrino damage.
 
2009-12-27 10:41:47 PM  

ZAZ: attention span of a retarded fruit fly

I know a girl who was conceived, near as I can tell, when SN 1987a blew. I suspect neutrino damage.


Is that the damage that causes tentacles?

/can never remember
 
2009-12-27 11:04:59 PM  
ffffuuuuuuuuu....
 
2009-12-27 11:06:29 PM  

ZAZ: I know a girl who was conceived, near as I can tell, when SN 1987a blew. I suspect neutrino damage.


And I studied SN1987a for my PhD. I believe that takes this thread full circle.
 
2009-12-27 11:21:03 PM  
I'm pretty sure some Carbon Credits will take care of any problems cosmic rays do to the planet. Please send $10 to: AL GORE /care of the UN. NY NY

do your part.
 
2009-12-28 12:12:03 AM  

revrendjim: A quick calculation shows that the centripetal acceleration at the surface is about 7000 m/s^2, while the gravitational acceleration is about 2.7E12 m/s^2, which is about 400,000,000 times stronger, so it's not going to fly apart.


*sigh*

imgs.xkcd.com

/inertia: it does exist
 
2009-12-28 12:26:33 AM  

The Bad Astronomer: And I studied SN1987a for my PhD. I believe that takes this thread full circle.


As a grad student studying neutrinos, I'm jealous.

I daydream about how turned-on-its-head the field would get if there were a supernova tomorrow.
 
2009-12-28 12:28:33 AM  

Mister Peejay: revrendjim: A quick calculation shows that the centripetal acceleration at the surface is about 7000 m/s^2, while the gravitational acceleration is about 2.7E12 m/s^2, which is about 400,000,000 times stronger, so it's not going to fly apart.

*sigh*

/inertia: it does exist


I love that comic soooo much.
 
2009-12-28 06:46:42 AM  
So, basically some alien civilization beat us by 50,005 years in starting up a LHC.
 
2009-12-28 07:57:58 AM  
I just don't understand some of those measurements unless they are put in terms of football fields or jumbo jets.
 
2009-12-28 09:54:23 AM  
The Bad Astronomer: And I studied SN1987a for my PhD. I believe that takes this thread full circle.

I used SN1987a in a position paper I wrote for a class I took last semester, so I'm getting a kick....
(OK, it was a science education class, so I was preaching to the choir, but the teacher of the class wasn't aware that YEC's must disbelieve in trigonometry, as well as lots of other sciences. She liked it very much...)
 
2009-12-28 10:29:55 AM  
I'm always amazed at the variety of stars and planets that are out there. Even looking at our own solar system, every single planet is unique from one another. And even moons, like those of Jupiter, are different from one another. I bet there are more variety of stars and planets out there than species on Earth.
 
2009-12-28 10:41:50 AM  

Zer0ne: I just don't understand some of those measurements unless they are put in terms of football fields or jumbo jets.


The best example I can come up with on the fly is Rosie O'Donnel taking a dump.
 
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