Aw, what a brave little soldier. But look, you don't have to suffer anymore. We've already demonstrated the capability. I'm going to start a collection and by God we're going to get you a beak!
If the chances are one in millions, then no, it shouldn't be. Even a "city-killer"
"Even"? Objects like that are common. Apophis alone has more than one-in-a-million odds as currently estimated, and the estimated 500MT impact would be over 10,000 times larger than "city killer". There are plenty of objects out there of sufficient size where it's a global extinction event wherever they hit. We just don't know where they are, or if their orbits are such that they threaten us.
You can't just look at the odds,. You also have to look at the impact. The die has already been cast. There are objects out there that are either a threat to us, or they aren't, and while the odds of an impact in any given year are terribly low, we don't know if that means we're not going to see one for a million years, or if we're going to get hit and then not see one for a million years.
I approve of a token effort that ramps up along with civilization
A token effort is a useless effort. Might as well say you approve burning a pile of cash and hoping it appeases the asteroid gods. And what does the ramping up of civilization have to do with it? We're just as screwed regardless of our civilization level. The relevant benchmarks are 1) are we capable of detecting them and 2) are we capable of doing something about it, and we're past both.
there are higher priority things to worry about, like extreme solar flare events.
And studying solar weather to try to predict such events necessarily means our asteroid detection effort must be token, eh? Prioritization doesn't mean ignoring other problems.
Solar flares are more common but less likely to cause major damage not counting communication satellites but rather human death, and are tougher to actually mitigate the effects of if one is dangerous. Impacts are less common but have vastly more destructive potential, and if our detection effort is adequate we have the ability to completely nullify them.
To me that puts them pretty close in priority. And if we had our priorities straight, there would be ample money to do both along with many other priorities.
3) Cassegrain: , which is like an optically "folded" newtonian - they're small, light, and powerful, but not as cheap as newtonians.
As the owner of a Celestron 11" SCT, I'd say the main advantage is the size. Weight isn't dominated so much by the tube, but by the optics, and a SCT has more optics. Also, a lot of SCTs use fork mounts which can't be easily removed from the tube. So even if the body was lighter, the actual thing you have to pick up and lug around is significantly heavier than an equivalent Newton.
But if size matters, it's definitely the way to go. There's no way I'd get even an 8" Newton into my two-door Toyota Echo. With the C11, it's only a small miracle.:)
And of course I guess you could avoid the fork mount.
The math on the density of the asteroid field was done well before the Voyagers were conceived, and it was based on that math that they decided that no mitigation was necessary. So not literally zero, but rounding...:)
But the odds of some *specific* object disturbed by Jupiter hitting the Earth may be vastly *higher*.
The odds of such an object existing are low.
I mean at the end of the day Apophis may have a 100% chance of hitting us, or it might have a 0% chance of hitting us. We can only estimate based on what we know if its orbit. Without knowledge of a specific Jupiter-orbit object, we can only estimate based on the odds of potential disturbed orbits intersecting earth. This is how conditional probability works.
As far as the "maybes" go, NEOs are more likely to be dangerous than objects kicked around by Jupiter.
we've had more than 5 'city-killer' sized objects pass inside the Moon's orbit.
First let's keep in mind that even at that close earth is still a small target. A bulls-eye 1/3700th the size of the dartboard.
I'm not sure what counts as "city-killer", but this NASA chart shows 8 objects at less than 1 Lunar Distance, all of greater than 50km at the low end of estimated size and at greater than 8 km/s relative velocity.
Of course before getting too scared about the term "city killer", we would then have to look at the odds that such an impact hits a city (extremely low) or even land (not that high).
You're unlikely to get hit by a truck on any given crossing, but that doesn't mean it's a good idea to keep doing it.
Yes. The correct reason to worry is because we aren't watching the skies well enough, not because an impact on Jupiter means there might be some other object from the vicinity headed to earth. It doesn't.
We definitely need more asteroid discovery and tracking.
Fund more telescopes for NEO (and other object) discovery and tracking. We have a network of telescopes doing this, but it is woefully inadequate for searching the skies sufficiently thoroughly. Early detection of potential impactors is the only chance we have of saving ourselves if/when the Big One comes. And it's only an "if" because it might not happen for many millions of years and who knows if our ancestors will be around then.
We should also be funding the development of the actual capability to deflect one. A gravity tractor craft is actually a pretty simple concept and achievable with todays tech given sufficient lead time, but I don't think we should risk the extra time it takes to go from concept to implementation once we do find one.
The main thing is more detection and tracking, though, because the lead time is essential. This should be considered a major defense priority. But it seems to be hard for people to take it seriously enough, because nobody can say if it will happen in any of our lifetime's.
Of course there's also the remote chance that an long-period comet hits us from the direction of the sun and we end up with basically no warning even with a ridiculously extensive discovery effort. In that case it's que sera sera.
It's been going 38,000 mph for 35 years. And it's just now leaving our local solar system.
Another stat I love: How many man-hours of effort have been put into determining safe courses for our probes to pass through the main asteroid belt, in total over all outer-solar-system probes?
Why would someone who actually knew anything about orbital mechanics require 100% certainty to feel safe? Even Apophis, an object known to actually have a pretty good chance of hitting earth as such things go was estimated at 1 in 250,000 a few years ago. The odds of some random object disturbed by Jupiter hitting earth is going to be vastly lower.
This is exactly like complaining that a professional ballet company isn't auditioning for So You Think You Can Dance, the television dance competition show.
I promise to be more trusting and less vigilant in the future.
Why don't you try being more vigilant, as in actually trying to discover the answer to your questions instead of asking them rhetorically and trusting that your own assumptions must be right?
I think they meant stepping stone in the technological progression sense -- establishing a permanent colony on our satellite would be an evolutionary step towards colonies on other worlds.
As far as a literal usage of the stepping-stone metaphor, LEO is the best stepping stone. By far the most difficult part of any journey to any part of the solar system is leaving earth's atmosphere. In terms of delta-v, LEO is halfway to Mars. In terms of requirements for the launch vehicle, the steep gravity well and atmosphere limit the choice of technologies, while once in space many highly efficient methods of propulsion become feasible.
No, it really isn't, though that would be the leading hypothesis and if there were betting pools on particle physics that's where the smart money would be. But much like how you can argue and bet on a sporting event but at the end of the day you need to wait for the game to play out, so too do they need to conduct many more experiments to actually figure out if it is what they think it is.
And for some people cost is more important than volume or mass when stocking up on a year's worth of food.
But yes, those are reasonable considerations for an actual tradeoff assessment which will vary greatly between situations, and is not primary affected by the lack of infinite space or storage capacity.
Yes, because a pantry, garage, or storm shelter are finite, and neither is a soldier's backpack, the storage issues are the same and the tiny improvement in density that is worth it for a soldier is also obviously a good tradeoff for a civie stocking up said pantry, garage, or storm shelter.
It's true that Mars is chosen as a target for rover missions because it's "easy" enough as such things go. Before sending rovers to farther and/or vastly more hostile places, it makes sense to bone up on the tech on Mars, eh?
But the reason the "scientific establishment" maintains interest in Mars is because, rather than being happy with unsubstantiated declaratory statements like the above, they actually want to know.
What he means is that our current understanding of physics might be wrong and maybe Quantum Entanglement does allow FTL communication.
Which kind of ignores that the only reason we thought QE was possible -- and then actually did it -- was because our current theory said so.
It's possible that the theory is wrong in exactly the way he thinks, of course, but it's a bit ridiculously presumptive to believe it is (and in the process accuse scientists of the baseless assumptions).
which then brings up my other question...if by determining a state at A, you cause a state at B....how does the "reciever" at B for these experiments determine the state on their side without affecting A? always wondered.
They don't. If B measures on their end first, then when A measures they will see a result correlated with what B measured. It's a symmetric relationship.
That's why you can't send information by the timing of A's measurements. For B to try to figure out if A measured, they'd have to measure themselves, which would have results indistinguishable from B being the first to measure so they can't actually tell if A measured or not.
All A and B know is that when the other measures, they'll see correlated results.
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Aw, what a brave little soldier. But look, you don't have to suffer anymore. We've already demonstrated the capability. I'm going to start a collection and by God we're going to get you a beak!
"There's no such thing as a stupid question, but there sure are a lot of inquisitive idiots."
That said, I approve of potentially making a fool of oneself in an effort to cease being one.
If the chances are one in millions, then no, it shouldn't be. Even a "city-killer"
"Even"? Objects like that are common. Apophis alone has more than one-in-a-million odds as currently estimated, and the estimated 500MT impact would be over 10,000 times larger than "city killer". There are plenty of objects out there of sufficient size where it's a global extinction event wherever they hit. We just don't know where they are, or if their orbits are such that they threaten us.
You can't just look at the odds,. You also have to look at the impact. The die has already been cast. There are objects out there that are either a threat to us, or they aren't, and while the odds of an impact in any given year are terribly low, we don't know if that means we're not going to see one for a million years, or if we're going to get hit and then not see one for a million years.
I approve of a token effort that ramps up along with civilization
A token effort is a useless effort. Might as well say you approve burning a pile of cash and hoping it appeases the asteroid gods. And what does the ramping up of civilization have to do with it? We're just as screwed regardless of our civilization level. The relevant benchmarks are 1) are we capable of detecting them and 2) are we capable of doing something about it, and we're past both.
there are higher priority things to worry about, like extreme solar flare events.
And studying solar weather to try to predict such events necessarily means our asteroid detection effort must be token, eh? Prioritization doesn't mean ignoring other problems.
Solar flares are more common but less likely to cause major damage not counting communication satellites but rather human death, and are tougher to actually mitigate the effects of if one is dangerous. Impacts are less common but have vastly more destructive potential, and if our detection effort is adequate we have the ability to completely nullify them.
To me that puts them pretty close in priority. And if we had our priorities straight, there would be ample money to do both along with many other priorities.
My grandparents are long dead
Oh sure, but who knows where there might be a vampire in your family tree?
3) Cassegrain: , which is like an optically "folded" newtonian - they're small, light, and powerful, but not as cheap as newtonians.
As the owner of a Celestron 11" SCT, I'd say the main advantage is the size. Weight isn't dominated so much by the tube, but by the optics, and a SCT has more optics. Also, a lot of SCTs use fork mounts which can't be easily removed from the tube. So even if the body was lighter, the actual thing you have to pick up and lug around is significantly heavier than an equivalent Newton.
But if size matters, it's definitely the way to go. There's no way I'd get even an 8" Newton into my two-door Toyota Echo. With the C11, it's only a small miracle. :)
And of course I guess you could avoid the fork mount.
Yeah, I like to think of it in terms of risk analysis, as P(event) * Cost(event).
The odds of me stepping on a grass burr walking around my neighborhood is high, but the cost is just a little poke in my toe if I'm wearing sandals.
The odds of an ELE impact is astronomically low, but the cost is astronomically high.
The math on the density of the asteroid field was done well before the Voyagers were conceived, and it was based on that math that they decided that no mitigation was necessary. So not literally zero, but rounding... :)
That's 50 m, not km... But what's a few orders of magnitude between friends who just want to give our planet a hug?
Though with Jupiter's potential to pull in TNOs or Oort Cloud objects, it's actually unclear whether Jupiter is a net benefit or detriment.
But the odds of some *specific* object disturbed by Jupiter hitting the Earth may be vastly *higher*.
The odds of such an object existing are low.
I mean at the end of the day Apophis may have a 100% chance of hitting us, or it might have a 0% chance of hitting us. We can only estimate based on what we know if its orbit. Without knowledge of a specific Jupiter-orbit object, we can only estimate based on the odds of potential disturbed orbits intersecting earth. This is how conditional probability works.
As far as the "maybes" go, NEOs are more likely to be dangerous than objects kicked around by Jupiter.
we've had more than 5 'city-killer' sized objects pass inside the Moon's orbit.
First let's keep in mind that even at that close earth is still a small target. A bulls-eye 1/3700th the size of the dartboard.
I'm not sure what counts as "city-killer", but this NASA chart shows 8 objects at less than 1 Lunar Distance, all of greater than 50km at the low end of estimated size and at greater than 8 km/s relative velocity.
Of course before getting too scared about the term "city killer", we would then have to look at the odds that such an impact hits a city (extremely low) or even land (not that high).
You're unlikely to get hit by a truck on any given crossing, but that doesn't mean it's a good idea to keep doing it.
Yes. The correct reason to worry is because we aren't watching the skies well enough, not because an impact on Jupiter means there might be some other object from the vicinity headed to earth. It doesn't.
We definitely need more asteroid discovery and tracking.
Soooo, and you suggestion is??
Fund more telescopes for NEO (and other object) discovery and tracking. We have a network of telescopes doing this, but it is woefully inadequate for searching the skies sufficiently thoroughly. Early detection of potential impactors is the only chance we have of saving ourselves if/when the Big One comes. And it's only an "if" because it might not happen for many millions of years and who knows if our ancestors will be around then.
We should also be funding the development of the actual capability to deflect one. A gravity tractor craft is actually a pretty simple concept and achievable with todays tech given sufficient lead time, but I don't think we should risk the extra time it takes to go from concept to implementation once we do find one.
The main thing is more detection and tracking, though, because the lead time is essential. This should be considered a major defense priority. But it seems to be hard for people to take it seriously enough, because nobody can say if it will happen in any of our lifetime's.
Of course there's also the remote chance that an long-period comet hits us from the direction of the sun and we end up with basically no warning even with a ridiculously extensive discovery effort. In that case it's que sera sera.
It's been going 38,000 mph for 35 years. And it's just now leaving our local solar system.
Another stat I love: How many man-hours of effort have been put into determining safe courses for our probes to pass through the main asteroid belt, in total over all outer-solar-system probes?
Zero.
Why would someone who actually knew anything about orbital mechanics require 100% certainty to feel safe? Even Apophis, an object known to actually have a pretty good chance of hitting earth as such things go was estimated at 1 in 250,000 a few years ago. The odds of some random object disturbed by Jupiter hitting earth is going to be vastly lower.
Space is big. You wouldn't believe...
I did it as a college electronics lab project as an unnecessary but neat part of building an FM radio, linking the radio and the speakers via the LED.
Which I also remember because the TA's demonstration breadboard played the music for about three seconds before one of the caps exploded. Good times.
This is exactly like complaining that a professional ballet company isn't auditioning for So You Think You Can Dance, the television dance competition show.
That's an amazingly good analogy.
I promise to be more trusting and less vigilant in the future.
Why don't you try being more vigilant, as in actually trying to discover the answer to your questions instead of asking them rhetorically and trusting that your own assumptions must be right?
I think they meant stepping stone in the technological progression sense -- establishing a permanent colony on our satellite would be an evolutionary step towards colonies on other worlds.
As far as a literal usage of the stepping-stone metaphor, LEO is the best stepping stone. By far the most difficult part of any journey to any part of the solar system is leaving earth's atmosphere. In terms of delta-v, LEO is halfway to Mars. In terms of requirements for the launch vehicle, the steep gravity well and atmosphere limit the choice of technologies, while once in space many highly efficient methods of propulsion become feasible.
The effects of gravity die off exponentially the farther away you are from the source.
Polynomially.
No, it really isn't, though that would be the leading hypothesis and if there were betting pools on particle physics that's where the smart money would be. But much like how you can argue and bet on a sporting event but at the end of the day you need to wait for the game to play out, so too do they need to conduct many more experiments to actually figure out if it is what they think it is.
And for some people cost is more important than volume or mass when stocking up on a year's worth of food.
But yes, those are reasonable considerations for an actual tradeoff assessment which will vary greatly between situations, and is not primary affected by the lack of infinite space or storage capacity.
Well the purpose of a flashlight is to illuminate, so a day flashlight could just be an empty tube and it'd still accomplish the goal.
Yes, because a pantry, garage, or storm shelter are finite, and neither is a soldier's backpack, the storage issues are the same and the tiny improvement in density that is worth it for a soldier is also obviously a good tradeoff for a civie stocking up said pantry, garage, or storm shelter.
Mars is pretty much way too dry and has been.
It's true that Mars is chosen as a target for rover missions because it's "easy" enough as such things go. Before sending rovers to farther and/or vastly more hostile places, it makes sense to bone up on the tech on Mars, eh?
But the reason the "scientific establishment" maintains interest in Mars is because, rather than being happy with unsubstantiated declaratory statements like the above, they actually want to know.
What he means is that our current understanding of physics might be wrong and maybe Quantum Entanglement does allow FTL communication.
Which kind of ignores that the only reason we thought QE was possible -- and then actually did it -- was because our current theory said so.
It's possible that the theory is wrong in exactly the way he thinks, of course, but it's a bit ridiculously presumptive to believe it is (and in the process accuse scientists of the baseless assumptions).
which then brings up my other question...if by determining a state at A, you cause a state at B....how does the "reciever" at B for these experiments determine the state on their side without affecting A? always wondered.
They don't. If B measures on their end first, then when A measures they will see a result correlated with what B measured. It's a symmetric relationship.
That's why you can't send information by the timing of A's measurements. For B to try to figure out if A measured, they'd have to measure themselves, which would have results indistinguishable from B being the first to measure so they can't actually tell if A measured or not.
All A and B know is that when the other measures, they'll see correlated results.