Asteriod strike?
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Ilíon wrote:
at most, the gravity of Mars will affect the asteroid's trajectory
Really? You don't think the sun or Jupiter will have an effect? You don't think there is a margin of error in estimating the trajectory of an object so small that happens to be moving at high velocity millions of miles away. Also, I'm pretty sure the only estimate for the size of an asteroid at that distance is it's visual magnitude which depends on the color and reflectivity of the asteroid material adding even more uncertainty. So, no given the scale of the objects and the scale of the solar system, no it doesn't seem odd to me at all.
This blanket smells like ham
The main problem would be their inability to accurately produce the mass of the asteroid. Without an solid number to go off of they can't predict the asteroid orbit or path through our solar system. Depending on how long they've been tracking, it's probably a matter of needing more data points.
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Steve Mayfield wrote:
currently a 1 in 75 chance it may hit Mars on January 30
Doesn't this strike anyone else as odd? These 'scientists' know where Mars is (and where it will be); they know where the asteroid is (and where it will be); yet that can't say for certain that the asteroid will or will not strike the planet.
Elementary physics, my dear Ilíon.
We are a big screwed up dysfunctional psychotic happy family - some more screwed up, others more happy, but everybody's psychotic joint venture definition of CP
My first real C# project | Linkify!| FoldWithUs! | sighist -
Tad McClellan wrote:
The story says that the odds are supposed to go down (not a good thing for the martians) as time goes on. I suspect that as the astriod and mars move and they get more data about tragetory and that sort of thing they can get thier math more correct. Its calculas and the more data you throw into the function the better the answer. They have probably run all the probably numbers to even get the odds right so the 1 in 75 is probably best case for mars (again viewing it from teh martians perspective).
Think about this, will you? How can they not already know the trajectory? The asteroid wasn't discovered just today, it was discovered a month ago -- they know where it was a month ago and they know where it is today. These things don't weave and bob, there are no cross-winds to deflect the trajectory; at most, the gravity of Mars will affect the asteroid's trajectory (when it gets close to the planet) -- and, supposedly, Mars' mass and gravity is well understood.
modified on Friday, December 21, 2007 7:34:09 AM
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Ilíon wrote:
Sonny Boy (like I really believe you're 14)
No, because that would mean that I'm smarter than you are, and that couldn't be, could it? And I'm thirteen, by the way. Idiot.
Ilíon wrote:
I'm not the one who believes that "Science" == TrVth.
No, you believe that whatever you say is truth. I believe that science is working towards truth, and that even though it may not always be right, it constantly readjusts itself whenever truths are found. It's not as dull and stubborn as you are.
"We were backstage, playing Monopoly. Totally forgot there was a show, so sorry we are late." - Maynard James Keenan
Don't play with your food. On second thoughts do, it keeps us amused and him frustrated :laugh: Actually you are showing much greater maturity then your err...oponent. Elaine :rose:
Visit http://www.notreadytogiveup.com/[^] and do something special today.
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I suggest you study metrology - the science of measurements. Elaine :rose:
Visit http://www.notreadytogiveup.com/[^] and do something special today.
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You might want to explain what "already part of the solar system" is. From the common definition, I'd guess anything within a certain radius of the sun's center is part of the solar system. Anyhow, so what? That doesn't exclude objects within the solar system from the laws of physics.
Ilíon wrote:
You people simply refuse to think, don't you?
It could be quite the contrary—you are refusing to think. In fact, you might be so full of your own sh*t that you can't see you're the only one not thinking.
ROFLOLMFAO
Ri Qen-Sin wrote:
Anyhow, so what? That doesn't exclude objects within the solar system from the laws of physics.
Why don't you try to explain this to Mr Brummer ... and to yourself, of course? :doh: Allow me to remind you of his silly "challenge" to me: "Really? You don't think the sun or Jupiter will have an effect?" :laugh:
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Elementary physics, my dear Ilíon.
We are a big screwed up dysfunctional psychotic happy family - some more screwed up, others more happy, but everybody's psychotic joint venture definition of CP
My first real C# project | Linkify!| FoldWithUs! | sighist -
The main problem would be their inability to accurately produce the mass of the asteroid. Without an solid number to go off of they can't predict the asteroid orbit or path through our solar system. Depending on how long they've been tracking, it's probably a matter of needing more data points.
Regardless of the mass of any object, it doesn't go just bouncing around in space. You know, inertia and all that. ............... Also, this object is right in front of our eyes, so to speak. If our scientific "truth" can't determine the mass of something that can be observed up close and in real time, why would you trust that it can determine the mass of objects thousands or millions (or billions) of light years away?
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Tad McClellan wrote:
The story says that the odds are supposed to go down (not a good thing for the martians) as time goes on. I suspect that as the astriod and mars move and they get more data about tragetory and that sort of thing they can get thier math more correct. Its calculas and the more data you throw into the function the better the answer. They have probably run all the probably numbers to even get the odds right so the 1 in 75 is probably best case for mars (again viewing it from teh martians perspective).
Think about this, will you? How can they not already know the trajectory? The asteroid wasn't discovered just today, it was discovered a month ago -- they know where it was a month ago and they know where it is today. These things don't weave and bob, there are no cross-winds to deflect the trajectory; at most, the gravity of Mars will affect the asteroid's trajectory (when it gets close to the planet) -- and, supposedly, Mars' mass and gravity is well understood.
modified on Friday, December 21, 2007 7:34:09 AM
I think we have discovered the problem here. They didn't account for the gravity generated by the mass of your far superior brain. That must be effecting the path of the thing. Actually you are correct they know all those things but what they don't know is the mass of the object itself. Gravity is a two way street and the gravity of an object is based on it's mass. They actually do "weave and bob" (although not sharply of course) based on how they are effected by the gravity of other objects of around it. It's all relativity. Even light doesn't move in a straight path. It's effected by gravity as well. This is predictable but you have to understand the mass of all the objects involved.
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the odds are supposed to go down the wording is misleading...in the main text, it says the odds should diminish again early next month after getting new observations of the asteroid's orbit which means that the odds of a strike will probably become less likely...but still, the possibility of observing an asteroid strike in real time would be amazing...especially with all of the probes currently on and near Mars. I would expect that if the odds become more likely, even the Hubble would get involved.
Steve
Ah. The odds of a strike will go down, not the odds of it missing. I understand. Well, I'm sure the martians will be releaved.
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He reminds me of those Creationists. No matter how much evidence you give them, they don't get it.
ROFLOLMFAO
That's because he is one.. ;)
-- Kein Mitleid Für Die Mehrheit
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http://www.msnbc.msn.com/id/22350742/[^] I wonder what kinda pictures the rover will get, cause its supposed to hit close to it.
It would be an extraordinary opportunity, instead of sending a Caterpillar Bulldozer to get at several meter's worth Martian soil not exposed for awhile. :-)
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Tad McClellan wrote:
The story says that the odds are supposed to go down (not a good thing for the martians) as time goes on. I suspect that as the astriod and mars move and they get more data about tragetory and that sort of thing they can get thier math more correct. Its calculas and the more data you throw into the function the better the answer. They have probably run all the probably numbers to even get the odds right so the 1 in 75 is probably best case for mars (again viewing it from teh martians perspective).
Think about this, will you? How can they not already know the trajectory? The asteroid wasn't discovered just today, it was discovered a month ago -- they know where it was a month ago and they know where it is today. These things don't weave and bob, there are no cross-winds to deflect the trajectory; at most, the gravity of Mars will affect the asteroid's trajectory (when it gets close to the planet) -- and, supposedly, Mars' mass and gravity is well understood.
modified on Friday, December 21, 2007 7:34:09 AM
Ilíon wrote:
Think about this, will you? How can they not already know the trajectory? The asteroid wasn't discovered just today, it was discovered a month ago -- they know where it was a month ago and they know where it is today. These things don't weave and bob, there are no cross-winds to deflect the trajectory; at most, the gravity of Mars will affect the asteroid's trajectory (when it gets close to the planet) -- and, supposedly, Mars' mass and gravity is well understood.
First of all, a month, in astronomical terms, is not a very long time. Second, small asteroids do in fact weave and bob. Picture this 50-meter diameter chunk of rock moving in space at 8 miles a second - not only is it moving forward but it's also rotating. And given that these things don't have an axis and can be very irregular in shape, I would imagine that it's movement looks something like a screwball heading for home plate (if you can make the baseball connection). Heck, just earlier this year scientists discovered that sunlight, yes sunlight, impacts asteroid trajectory - the subtle warming of one side changes the rotation rate and impacts the trajectory. There are many small factors that can have big effects on trajectories. My 2 cents.
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Trollslayer was giving you the scoop, you should do what he says. The reason we don't have a good grasp on where it is going is because we do not have a good grasp of it's current velocity vector. We have a number of sightings, each of which has error associated with it. When you use the sightings to determine velocity, you get a vector with error associated with it. The current (as of the writing of the article) position and velocity vectors and errors give a volume of space at a particular time the the asteroid will be in, that has a 1 in 75 chance of being coincident with the volume of space that mars is in. There is no large conspiracy by the astronomical community to keep you knowing if it will hit. There IS a large conspiracy to get people to understand the odds of it hitting. That conspiracy involves large parts of the astronomy community, big chunks of the media, including the code project, trollslayer and I. Clearly, our conspiracy is failing
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I think we have discovered the problem here. They didn't account for the gravity generated by the mass of your far superior brain. That must be effecting the path of the thing. Actually you are correct they know all those things but what they don't know is the mass of the object itself. Gravity is a two way street and the gravity of an object is based on it's mass. They actually do "weave and bob" (although not sharply of course) based on how they are effected by the gravity of other objects of around it. It's all relativity. Even light doesn't move in a straight path. It's effected by gravity as well. This is predictable but you have to understand the mass of all the objects involved.
The error in the trajectory that is caused by the error in the knowledge of the asteroids mass is negligible. The acceleration component contributed by the asteroid mass could be zero and the error in impact location would be on the order of miles, over the 45 days remaining. The real problem is location measurement error, both because it changes the possible starting point, and because it changes the velocity vector. To determine it's effects, we can use a radius of 6,300,000 meters for the earth (it is really larger), and 100 meters for the asteroid (it is less than half that). The ratio of the mass of the asteroid to the mass of the earth, as a first order approximation, is linear to the ratio of the volumes. The volume is proportional to the radius cubed, so the ratio of masses is, as well. The ratios of radii is 63,000 to 1. The ratio of volumes is 250,047,000,000,000 to 1. The gravitational attraction is proportional to the mass, so the difference is 2.50*10^14, which we can round to 1*10^14, just for ease. So 9.8 m/s^2 becomes 9.8*10^-14 m/s^2, if it were at the surface of the earth the whole time (it's not). Assuming it was adding this whole amount in the worst possible way(it's not) the whole time (45 days * 86,400 secs/day) yields a delta v of 3.81024*10^-7 meters per second. Over 45 days, assuming it was at that velocity the whole time, that would lead to a total change of location of about 1.5 meters. :omg: We would have the same error if it was 45 days between observations, and the entire positional error was 1.5 meters (same velocity error budget). The error gets bigger as the time between measurements gets smaller, and as the positional error goes up. I suspect the error is at least in the hundreds of meters, and probably in kilometers.
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http://www.msnbc.msn.com/id/22350742/[^] I wonder what kinda pictures the rover will get, cause its supposed to hit close to it.
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Ri Qen-Sin wrote:
Anyhow, so what? That doesn't exclude objects within the solar system from the laws of physics.
Why don't you try to explain this to Mr Brummer ... and to yourself, of course? :doh: Allow me to remind you of his silly "challenge" to me: "Really? You don't think the sun or Jupiter will have an effect?" :laugh:
He's right: you are full of it. Brummer was on the right track with regard to the fact that there are a lot of variables and levels of indirection that are used to watch these things. A lot of it is "probabilistic," not deterministic. As in, there are varying levels of uncertainty, not to mention error margins. With these, they can't be sure. You might want to study a little concept called chaos. In stochastic, or partly-random, systems there is always uncertainty, and small changes (like Jupiter's gravity) can have large effects throughout the system (like making it miss). You should read up on this stuff before you make any claims. Obviously, figuring it out takes supercomputers and physics/math wizes at NASA for a reason. It's not so linear, dude. This ain't a game of Asteroids. ;)
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The error in the trajectory that is caused by the error in the knowledge of the asteroids mass is negligible. The acceleration component contributed by the asteroid mass could be zero and the error in impact location would be on the order of miles, over the 45 days remaining. The real problem is location measurement error, both because it changes the possible starting point, and because it changes the velocity vector. To determine it's effects, we can use a radius of 6,300,000 meters for the earth (it is really larger), and 100 meters for the asteroid (it is less than half that). The ratio of the mass of the asteroid to the mass of the earth, as a first order approximation, is linear to the ratio of the volumes. The volume is proportional to the radius cubed, so the ratio of masses is, as well. The ratios of radii is 63,000 to 1. The ratio of volumes is 250,047,000,000,000 to 1. The gravitational attraction is proportional to the mass, so the difference is 2.50*10^14, which we can round to 1*10^14, just for ease. So 9.8 m/s^2 becomes 9.8*10^-14 m/s^2, if it were at the surface of the earth the whole time (it's not). Assuming it was adding this whole amount in the worst possible way(it's not) the whole time (45 days * 86,400 secs/day) yields a delta v of 3.81024*10^-7 meters per second. Over 45 days, assuming it was at that velocity the whole time, that would lead to a total change of location of about 1.5 meters. :omg: We would have the same error if it was 45 days between observations, and the entire positional error was 1.5 meters (same velocity error budget). The error gets bigger as the time between measurements gets smaller, and as the positional error goes up. I suspect the error is at least in the hundreds of meters, and probably in kilometers.
At least I now know whos paper I should copy next time I'm taking a test.
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He's right: you are full of it. Brummer was on the right track with regard to the fact that there are a lot of variables and levels of indirection that are used to watch these things. A lot of it is "probabilistic," not deterministic. As in, there are varying levels of uncertainty, not to mention error margins. With these, they can't be sure. You might want to study a little concept called chaos. In stochastic, or partly-random, systems there is always uncertainty, and small changes (like Jupiter's gravity) can have large effects throughout the system (like making it miss). You should read up on this stuff before you make any claims. Obviously, figuring it out takes supercomputers and physics/math wizes at NASA for a reason. It's not so linear, dude. This ain't a game of Asteroids. ;)
NimitySSJ wrote:
He's right: you are full of it.
And you intentionally stuff yourself full of "it."
NimitySSJ wrote:
You might want to study a little concept called chaos.
You might want to study a little concept called 'logic,' or another called 'reason.'
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Trollslayer was giving you the scoop, you should do what he says. The reason we don't have a good grasp on where it is going is because we do not have a good grasp of it's current velocity vector. We have a number of sightings, each of which has error associated with it. When you use the sightings to determine velocity, you get a vector with error associated with it. The current (as of the writing of the article) position and velocity vectors and errors give a volume of space at a particular time the the asteroid will be in, that has a 1 in 75 chance of being coincident with the volume of space that mars is in. There is no large conspiracy by the astronomical community to keep you knowing if it will hit. There IS a large conspiracy to get people to understand the odds of it hitting. That conspiracy involves large parts of the astronomy community, big chunks of the media, including the code project, trollslayer and I. Clearly, our conspiracy is failing
RichardM1 wrote:
Trollslayer was giving you the scoop, you should do what he says.
Trollslayer was refusing to think critically -- as are you. You both (to say nothing of the childish "responders") are refusing to think critically about what I've said (which is very little, really) or about what you yourselves are saying in "response." You (singular, dual, plural) refuse to let go of the false concept that "Science" == Truth.
RichardM1 wrote:
Clearly, our conspiracy is failing
Clearly, you people refuse to reason.