I should probably clear up what I meant by this "class of theories" nonsense here. If someone says, "string theory is untestable" they are saying "all theories which can be classified as string theories are untestable", because of course there is no one "string theory". The existence of even one testable string theory (which we have) disproves this assertion. "Some string theories are untestable" is the strongest assertion you can make.
Indeed, and I suspect the amount of nitrate produced would be pretty high. A quick google puts urban NOx production at the thousands of tonnes per day. Ignoring chemistry for the sake of simplicity, that'd equate to thousands of tonnes of nitrate being produced per day. If my maths is accurate. that's of the same order of magnitude as fertiliser nitrate runoff from the Mississippi to the Gulf of Mexico.
(This isn't to say that string theories which don't have testable predictions, or whose only predictions are practically untestable, get off because their neighbours are well-behaved. I'm just saying it's absurd to talk of the untestability of the entire class of string theories when a practical test for favoured theories has just been outlined in the post you're replying to.)
You argue that string theory would have to be reformulated to remain valid if it faced contradictory evidence, like all scientific theories. And then you compare it to young earth creationism, where the "god is tricking us" gambit means that YEC is equally valid regardless of the evidence presented. I'm not sure how this works.
If string theory could remain valid even when contradictory evidence was presented, then it would be equivalent to young earth creationism, but as you point out, that is not the case.
If there exists a higgs mass which would falsify a "wide class" of string theories, then that is a testable prediction of those theories. ("Higgs mass must be less than X"). Therefore, it is no longer valid to state that string theories as a class are untestable.
Don't joke about that, I'm sure I read about a paper last year which predicted a minimum Higgs mass just outside of the LHC's range. It must keep those involved awake at night.
I've always found the whole US healthcare system bizarre in the context of the Emergency Services. If your house catches fire or you're mugged, then a team of government-funded professionals come to your aid, but if you get hit by a car, you've got to cut a deal with a medic on your own?
"where are you going to get the mass to deflect it in given time?"
That depends on how much time you need. On a long enough timeline, you could use a gram. On a shorter timeline, you could chip off part of the asteroid, or corall something from its neighbourhood. As the article explains, a one tonne payload, well within our means, could be enough to deflect the asteroid in a single year.
A manned nuclear mission is simply not an option. We cannot execute a manned interplanetary mission at this time, period. We do not know how to use nuclear weapons to demolish asteroids in a controlled fashion, period. Even excusing these, demolishing an asteroid in itself does not necessarily achieve anything.
Hitting an asteroid with a nuclear weapon from a conventional rocket to deflect it off-course? That might be an option, perhaps as an alternative to the first-stage kinetic payload described in the article. The Bruce Willis scenario is not feasable.
Of course, and pound for pound it's hard to think of a better gadget for nudging rocks about, but that's not what this guy is suggesting. He has stated time and again that we must blow asteroids into little bits. I'm not sure why.
Yes, the world's opposed to nuclear intervention against asteroids because of the words of one scientist whose name even you can't remember. That sounds about right.
Sounds plausible to me. One of the big draws of the iPhone is its selection of apps, and they wouldn't want to cannibalise that. An iPhone Nano which just came with the iPod, phone book, and web browser features would be nice and distinct.
Well, you've got a choice between one large deflecting mission, with one gravity tug, against one object on a known orbit, or dozens to hundreds of deflecting missions, each with their own tug, for dozens to hundreds of fragments whose paths we won't know until days to weeks to months after the nuke has gone off.
I'm going to have to opt for simplicity on this one.
I guess the gravitational interaction between the tractor and the rock, derangedly complex as their motions would become in the long run, is more predictable than the conditions on the rock itself for mounting engines. Inefficient, but with fewer unknowns. Although I suppose if you wanted a sufficiently massive gravity tractor you'd probably have to mount engines on an asteroid or some other garbage you'd picked up out there anyway.
So, you believe we don't have the experience to send out and control an inert object with rocket boosters on it, but we do have the experience needed to make an interplanetary manned nuclear demolition mission on an asteroid? Seriously? The only untested requirements for a gravity tractor (reach and orbit asteroid) are prerequisites for the manned mission!
Plus you've got to somehow figure out how to cut up rocks in a predictable fashion using nuclear weapons, for which there is no experience on Earth, let alone in space. Plus all of the problems of a manned interstellar mission. Plus all the problems of landing on an asteroid.
No. For starters, no asteroid in existence is going to make the earth shatter like a watermelon, so the threat you're hypothesising against doesn't exist. For follow-up, you're overlooking the threats which do exist, one of which I explicitly stated in my comment, namely dumping a collosal (potentially multi-gigaton) amount of energy into the earth's atmosphere. It doesn't matter whether the debris burns up (in your words "explodes") 1cm above the surface or 1km above the surface, it's still reaching us. So nothing about your reasoning makes sense.
A better analogy on this basis might be shooting at a human being. Being shot with a rifle is bad for you in the sense that a particular local area is damaged and there may be seconary global damage. Being shot with a shotgun is bad for you in the sense that the shot can dump its energy into you, and without even having to break the skin, cause your internal organs to rupture.
"Don't give me that shotgun crap"? It's simple physics. Even if you somehow reduce the astroid to a monomolecular dust, that cloud of dust is still dumping the same kinetic energy into the planet's atmosphere. It's like an airburst versus a ground explosion for a nuke. Thermally, you're no better off than when you started. What you want is for the asteroid's payload of kinetic energy to not hit the planet at all.
Slashdot Mirror
I should probably clear up what I meant by this "class of theories" nonsense here. If someone says, "string theory is untestable" they are saying "all theories which can be classified as string theories are untestable", because of course there is no one "string theory". The existence of even one testable string theory (which we have) disproves this assertion. "Some string theories are untestable" is the strongest assertion you can make.
You think the good string theorists are the ones who can't come up with testable models?
Indeed, and I suspect the amount of nitrate produced would be pretty high. A quick google puts urban NOx production at the thousands of tonnes per day. Ignoring chemistry for the sake of simplicity, that'd equate to thousands of tonnes of nitrate being produced per day. If my maths is accurate. that's of the same order of magnitude as fertiliser nitrate runoff from the Mississippi to the Gulf of Mexico.
(This isn't to say that string theories which don't have testable predictions, or whose only predictions are practically untestable, get off because their neighbours are well-behaved. I'm just saying it's absurd to talk of the untestability of the entire class of string theories when a practical test for favoured theories has just been outlined in the post you're replying to.)
You argue that string theory would have to be reformulated to remain valid if it faced contradictory evidence, like all scientific theories. And then you compare it to young earth creationism, where the "god is tricking us" gambit means that YEC is equally valid regardless of the evidence presented. I'm not sure how this works.
If string theory could remain valid even when contradictory evidence was presented, then it would be equivalent to young earth creationism, but as you point out, that is not the case.
If there exists a higgs mass which would falsify a "wide class" of string theories, then that is a testable prediction of those theories. ("Higgs mass must be less than X"). Therefore, it is no longer valid to state that string theories as a class are untestable.
You didn't read the parent post at all, did you? I mean, it says right there that higgs mass is one of the testable predictions of string theory.
Don't joke about that, I'm sure I read about a paper last year which predicted a minimum Higgs mass just outside of the LHC's range. It must keep those involved awake at night.
*googly googly*
Ah, I see, the EMTALA means that hospitals have to eat the cost of emergency treatment for people who can't pay. So my puzzled objection was mistaken.
I'm happy to let it lie, I think you've followed my argument and you're just not buying it, which is fair enough.
(Clearly we would have to send Brian May.)
I've always found the whole US healthcare system bizarre in the context of the Emergency Services. If your house catches fire or you're mugged, then a team of government-funded professionals come to your aid, but if you get hit by a car, you've got to cut a deal with a medic on your own?
So your reasoning is, if your insurance won't cover effective treatments, you should switch to the ineffective treatments it also doesn't cover?
"Do not attribute to benevolence that which may be adequately explained by ignorance or stupidity"?
"where are you going to get the mass to deflect it in given time?"
That depends on how much time you need. On a long enough timeline, you could use a gram. On a shorter timeline, you could chip off part of the asteroid, or corall something from its neighbourhood. As the article explains, a one tonne payload, well within our means, could be enough to deflect the asteroid in a single year.
A manned nuclear mission is simply not an option. We cannot execute a manned interplanetary mission at this time, period. We do not know how to use nuclear weapons to demolish asteroids in a controlled fashion, period. Even excusing these, demolishing an asteroid in itself does not necessarily achieve anything.
Hitting an asteroid with a nuclear weapon from a conventional rocket to deflect it off-course? That might be an option, perhaps as an alternative to the first-stage kinetic payload described in the article. The Bruce Willis scenario is not feasable.
And of course your inaccurate rant and refusal to accept people's responses to it have brightened up this story immensely.
Of course, and pound for pound it's hard to think of a better gadget for nudging rocks about, but that's not what this guy is suggesting. He has stated time and again that we must blow asteroids into little bits. I'm not sure why.
Yes, the world's opposed to nuclear intervention against asteroids because of the words of one scientist whose name even you can't remember. That sounds about right.
Sounds plausible to me. One of the big draws of the iPhone is its selection of apps, and they wouldn't want to cannibalise that. An iPhone Nano which just came with the iPod, phone book, and web browser features would be nice and distinct.
Well, you've got a choice between one large deflecting mission, with one gravity tug, against one object on a known orbit, or dozens to hundreds of deflecting missions, each with their own tug, for dozens to hundreds of fragments whose paths we won't know until days to weeks to months after the nuke has gone off.
I'm going to have to opt for simplicity on this one.
I guess the gravitational interaction between the tractor and the rock, derangedly complex as their motions would become in the long run, is more predictable than the conditions on the rock itself for mounting engines. Inefficient, but with fewer unknowns. Although I suppose if you wanted a sufficiently massive gravity tractor you'd probably have to mount engines on an asteroid or some other garbage you'd picked up out there anyway.
I imagine whatever guy in the office came up with this rumour decided to throw in some of (Microsoft's?) "see-thru tablet PC" idea for good measure.
So, you believe we don't have the experience to send out and control an inert object with rocket boosters on it, but we do have the experience needed to make an interplanetary manned nuclear demolition mission on an asteroid? Seriously? The only untested requirements for a gravity tractor (reach and orbit asteroid) are prerequisites for the manned mission!
Plus you've got to somehow figure out how to cut up rocks in a predictable fashion using nuclear weapons, for which there is no experience on Earth, let alone in space. Plus all of the problems of a manned interstellar mission. Plus all the problems of landing on an asteroid.
It's the Daily Mail, FFS. They're as gullible as they are deranged.
No. For starters, no asteroid in existence is going to make the earth shatter like a watermelon, so the threat you're hypothesising against doesn't exist. For follow-up, you're overlooking the threats which do exist, one of which I explicitly stated in my comment, namely dumping a collosal (potentially multi-gigaton) amount of energy into the earth's atmosphere. It doesn't matter whether the debris burns up (in your words "explodes") 1cm above the surface or 1km above the surface, it's still reaching us. So nothing about your reasoning makes sense.
A better analogy on this basis might be shooting at a human being. Being shot with a rifle is bad for you in the sense that a particular local area is damaged and there may be seconary global damage. Being shot with a shotgun is bad for you in the sense that the shot can dump its energy into you, and without even having to break the skin, cause your internal organs to rupture.
"Don't give me that shotgun crap"? It's simple physics. Even if you somehow reduce the astroid to a monomolecular dust, that cloud of dust is still dumping the same kinetic energy into the planet's atmosphere. It's like an airburst versus a ground explosion for a nuke. Thermally, you're no better off than when you started. What you want is for the asteroid's payload of kinetic energy to not hit the planet at all.