At the platinum level, a special culinary course is offered on the best way to cook and eat coach survivors, should you be stranded on a desert island.
'The importance of concision is clear: other things being equal, shorter code is easier to read, easier to write, and easier to maintain.'
That was the idea behind APL. You could do amazing things in one line of code. I never, however, knew anyone who used it who thought it was easier to read, easier to write or easier to maintain.
The Apple stores I go to are way too busy to provide a "relaxed environment." They don't have the room, and I suspect they don't need to have people stick around and socialize. The recent trend is in the other direction - the Genius bar gets 15 minutes / problem, and I was told there was strong pressure to get people rotated out, even if a fix could be done in a longer time.
I was there for the talk, and had a little chat with Mr. Musk beforehand. The first thing to note is that he said that the video (which should go on their web page soon) is incomplete and may be vague about certain things, for proprietary reasons. What follows is my reverse engineering.
This is what the Grasshopper described previously in Slashdot is all about. Mr. Musk didn't use the word Grasshopper at all, so it must have been some sort of code word, but the tests in Texas will clearly be for Falcon reuse engineering.
Now, it makes no sense to return the first stage to the landing pad (as he said). The first stage is on a ballistic trajectory which (for a launch from Cape Canaveral) would have it impact somewhere far out at sea. It makes no sense at all to have the first stage reverse course and fly back to the Cape, as that would take as much delta-V as the original launch. It would make a lot more sense to land that stage in Ascension Island, Africa or Nova Scotia (depending on the inclination of the orbit). The first stage could then brought back by ship or plane.
The second stage actually goes into orbit, and the plan is to deorbit it one rev later. The trouble with that is the Earth rotates and the Earth will have rotated by ~ 20 degrees of longitude. That (again for a launch from the Cape) puts it over Texas, and it could conveniently land at McGregor, Texas, where SpaceX is doing their Grasshopper tests. So, although they haven't said so, I bet that McGregor will be the second stage landing area, and probably the Dragon landing area as well.
That sure ain't how it seems from here. Do you really think that your MPs went to their ridings and got the considered opinion of their constituents before they cobbled together this bill ? Or, rather, that when the lobbyists said jump, the Canadian House of Commons said, "How high?"
The 1987a SuperKAK measurements (at least) got the direction (approximately, +- 20 deg or so) and energy (again approximiately) of the incoming neutrinos; they came from the right direction (except for one, IIRC), and had "normal" energies, so the identification is pretty robust. The energies for this experiment were much higher. Now, for tachyons, that means that the 1987a guys should have been much faster, and arrived earlier. If the SuperKAK guys are smart (and they are) they should be looking through the old data right now for a FTL burst prior to 1987.
I am going out on a long limb here, but my physical intuition is tell me that supersymmetry may be involved. In simple supersymmetry, neutrino masses are zero, but there is some discussion out there where supersymmetric neutrinos are tachyonic.
I robustly predict a bunch of theoretical... whimsy before this is resolved.
Dude, look at the paper (Figure 7). Not only did they measure the continental drift, they also measured the effects of an Earthquake that happened mid-way through. And, all of those effects were orders of magnitude too small.
You don't add speeds to the speed of light, you need to do Lorentz transforms. The effect of the Earth's rotation (or any other rotation) is called the Sagnac effect and, yes, it's included in their calculations.
First, at the high end, I suspect that a $ 400 per hour lawyer with a robot assistant would run rings around a robot lawyer, and that that would be true regardless of the quality of the robot lawyer (as the $ 400 / hour guy would be able to afford a robot assistant of the same quality.
Second, there is something that is not being broached here - who benefits from this ? And what determines that ? Suppose that robots could do all jobs. So, what, everyone, being unemployed, just sits in the dark and starves ? Or, everyone except a few robot owners sits in the dark and starves ? And, how, exactly, would those starving people afford the goods and services being turned out by the robots ? Believing that would happen is naive in the extreme. Doesn't mean what will happen is necessarily going to be good, but it will be different.
Or, there could be flavors of neutrinos with different amounts of tachyonistic behavior.
In other words, if some neutrinos went at c, or very close to c (above or below), while others were tachyons, then the two results could be reconciled. If there was a neutrino burst 4 years before 1987A, no one would have noticed it. So, maybe neutrinos have tachyonic hair.
By the way, if these results are true, your sig will need to be changed.
If they succeed in recreating the measurements, doesn't it just mean that c was set at too low a value, and that the true speed to light in a vacuum is slightly faster than originally thought?
No, probably not. Einstein came up with relativity after a thought experiment concerning what a light wave would look like if you were traveling at its velocity. Electro-magnetisim does not allow for a stationary vacuum solution, so he figured out that the way out was to have time stopped at the speed of light. If the speed of light isn't the speed of light, this problem reoccurs. Now, you could postulate a material (let's call it the... ether), so that light is traveling slow, while neutrino's bound on ahead, but that also would disagree with various experiments.
One way out is to have the neutrinos be tachyons, traveling faster than light, but that does allow for causality violations. (Read the link.) That is based on pretty basic stuff, so it's hard to escape it. That would trouble a lot of people, but it would allow for neutrino oscillations (changes from one type to another). You can't do that at the speed of light, as time is frozen there. (As oscillations have been observed, that is additional strong evidence that the neutrino velocity is not the new "speed of light.")
And, there is also the Supernova 1987a results, which conflict with these results (as the 1987A neutrinos do travel near c). Maybe there are oscillations between tachyonic neutrinos and non-tachyonic ones, which would be mind-blowing all by itself.
I think that a bunch of theorists will spin their wheels until this is better constrained experimentally.
The MINOS collaboration reported a measurement of the muonic neutrino velocities that hints to super-luminal propagation, very recently confirmed at 6 [sigma] by OPERA.
They already did the experiment, and actually found similar results but did not claim any significance. Of course they are going to repeat this, once they finish kicking themselves.
The LMC (home of SN1987A) is 160,000 light years away, so this would have the neutrino signal arriving several years ahead of the optical signal.
Interestingly, if some neutrinos had arrived in a burst 3 or 4 years in advance of 1987A,, I don't think they would have been observed (as 1987A was observed with some new neutrino observatories). And, even they had, I don't think anyone would have made the connection. The neutrino beam width for the 1987A data was something like 20 degrees, so it's not like it would have stood out.
This has been a racket perpetrated since at least the Reagan administration, if not the beginning of time. Politicians make a big noise about how they are cutting government spending and gaining the efficiencies of the private market, by replacing civil servants with contractors. The contractors are much more expensive, which makes the companies hiring them a lot of money, some of which they use to lobby the politicians for more outsourcing. Politicians get campaign contributions, beltway bandits get rich, but somehow the government doesn't get more efficient.
(Yes, there is a little bit of truth in the quick hiring and firing abilities of private contractors. It is true that it is hard to fire people from the government - but you can RIF them, if their program goes away. In practice, however, people rarely get fired or let go from either side of the divide, at least at the professional level. They get transferred around, but rarely laid off, and almost never fired. And, note well, civil servants are forbidden to directly lobby for their programs; contractors aren't. It can make a difference, and it makes it hard to perform mass layoffs of contractors.)
Slashdot Mirror
At the platinum level, a special culinary course is offered on the best way to cook and eat coach survivors, should you be stranded on a desert island.
No, no no. It should be:
I have the perfect hammer.
Everything is a nail.
'The importance of concision is clear: other things being equal, shorter code is easier to read, easier to write, and easier to maintain.'
That was the idea behind APL. You could do amazing things in one line of code. I never, however, knew anyone who used it who thought it was easier to read, easier to write or easier to maintain.
The Apple stores I go to are way too busy to provide a "relaxed environment." They don't have the room, and I suspect they don't need to have people stick around and socialize. The recent trend is in the other direction - the Genius bar gets 15 minutes / problem, and I was told there was strong pressure to get people rotated out, even if a fix could be done in a longer time.
Mr Musk specifically said that they don't really want to use the Kwaj facility as due to the logistics problems it creates.
That may be the plan, but that was not what Mr. Musk said, or what the video showed.
I was there for the talk, and had a little chat with Mr. Musk beforehand. The first thing to note is that he said that the video (which should go on their web page soon) is incomplete and may be vague about certain things, for proprietary reasons. What follows is my reverse engineering.
This is what the Grasshopper described previously in Slashdot is all about. Mr. Musk didn't use the word Grasshopper at all, so it must have been some sort of code word, but the tests in Texas will clearly be for Falcon reuse engineering.
Now, it makes no sense to return the first stage to the landing pad (as he said). The first stage is on a ballistic trajectory which (for a launch from Cape Canaveral) would have it impact somewhere far out at sea. It makes no sense at all to have the first stage reverse course and fly back to the Cape, as that would take as much delta-V as the original launch. It would make a lot more sense to land that stage in Ascension Island, Africa or Nova Scotia (depending on the inclination of the orbit). The first stage could then brought back by ship or plane.
The second stage actually goes into orbit, and the plan is to deorbit it one rev later. The trouble with that is the Earth rotates and the Earth will have rotated by ~ 20 degrees of longitude. That (again for a launch from the Cape) puts it over Texas, and it could conveniently land at McGregor, Texas, where SpaceX is doing their Grasshopper tests. So, although they haven't said so, I bet that McGregor will be the second stage landing area, and probably the Dragon landing area as well.
That sure ain't how it seems from here. Do you really think that your MPs went to their ridings and got the considered opinion of their constituents before they cobbled together this bill ? Or, rather, that when the lobbyists said jump, the Canadian House of Commons said, "How high?"
The 1987a SuperKAK measurements (at least) got the direction (approximately, +- 20 deg or so) and energy (again approximiately) of the incoming neutrinos; they came from the right direction (except for one, IIRC), and had "normal" energies, so the identification is pretty robust. The energies for this experiment were much higher. Now, for tachyons, that means that the 1987a guys should have been much faster, and arrived earlier. If the SuperKAK guys are smart (and they are) they should be looking through the old data right now for a FTL burst prior to 1987.
I am going out on a long limb here, but my physical intuition is tell me that supersymmetry may be involved. In simple supersymmetry, neutrino masses are zero, but there is some discussion out there where supersymmetric neutrinos are tachyonic.
I robustly predict a bunch of theoretical ... whimsy before this is resolved.
Dude, look at the paper (Figure 7). Not only did they measure the continental drift, they also measured the effects of an Earthquake that happened mid-way through. And, all of those effects were orders of magnitude too small.
Well, 20 meters is such a huge error that if you DID get it wrong, someone's physics career will be remembered for a sign error.
You don't add speeds to the speed of light, you need to do Lorentz transforms. The effect of the Earth's rotation (or any other rotation) is called the Sagnac effect and, yes, it's included in their calculations.
First, at the high end, I suspect that a $ 400 per hour lawyer with a robot assistant would run rings around a robot lawyer, and that that would be true regardless of the quality of the robot lawyer (as the $ 400 / hour guy would be able to afford a robot assistant of the same quality.
Second, there is something that is not being broached here - who benefits from this ? And what determines that ? Suppose that robots could do all jobs. So, what, everyone, being unemployed, just sits in the dark and starves ? Or, everyone except a few robot owners sits in the dark and starves ? And, how, exactly, would those starving people afford the goods and services being turned out by the robots ? Believing that would happen is naive in the extreme. Doesn't mean what will happen is necessarily going to be good, but it will be different.
That is very informative and should be modded up. Thanks.
Or, there could be flavors of neutrinos with different amounts of tachyonistic behavior.
In other words, if some neutrinos went at c, or very close to c (above or below), while others were tachyons, then the two results could be reconciled. If there
was a neutrino burst 4 years before 1987A, no one would have noticed it. So, maybe neutrinos have tachyonic hair.
By the way, if these results are true, your sig will need to be changed.
The back of the envelope for all of the General Relativity effects are too small by 3-4 orders of magnitude.
If they succeed in recreating the measurements, doesn't it just mean that c was set at too low a value, and that the true speed to light in a vacuum is slightly faster than originally thought?
No, probably not. Einstein came up with relativity after a thought experiment concerning what a light wave would look like if you were traveling at its velocity. Electro-magnetisim does not allow for a stationary vacuum solution, so he figured out that the way out was to have time stopped at the speed of light. If the speed of light isn't the speed of light, this problem reoccurs. Now, you could postulate a material (let's call it the... ether), so that light is traveling slow, while neutrino's bound on ahead, but that also would disagree with various experiments.
One way out is to have the neutrinos be tachyons, traveling faster than light, but that does allow for causality violations. (Read the link.) That is based on pretty basic stuff, so it's hard to escape it. That would trouble a lot of people, but it would allow for neutrino oscillations (changes from one type to another). You can't do that at the speed of light, as time is frozen there. (As oscillations have been observed, that is additional strong evidence that the neutrino velocity is not the new "speed of light.")
And, there is also the Supernova 1987a results, which conflict with these results (as the 1987A neutrinos do travel near c). Maybe there are oscillations between tachyonic neutrinos and non-tachyonic ones, which would be mind-blowing all by itself.
I think that a bunch of theorists will spin their wheels until this is better constrained experimentally.
Yes, I would agree. 184 coauthors can keep a secret, if 183 are dead.
Note that there is already a theoretical paper out on these results, so it has been percolating around a little. Note also that this paper says
The MINOS collaboration reported a measurement of the muonic neutrino velocities that hints to super-luminal propagation, very recently confirmed at 6 [sigma] by OPERA.
Do I smell a priority fight coming ?
They already did the experiment, and actually found similar results but did not claim any significance. Of course they are going to repeat this, once they finish kicking themselves.
Anyone who does numerical work knows C++ is typically slower than C.
Look at Figure 7 in their paper - http://arxiv.org/ftp/arxiv/papers/1109/1109.4897.pdf
They see (and account for) both continental drift and the L’Aquila earthquake.
Almost certainly not to all of your questions.
The LMC (home of SN1987A) is 160,000 light years away, so this would have the neutrino signal arriving several years ahead of the optical signal.
Interestingly, if some neutrinos had arrived in a burst 3 or 4 years in advance of 1987A,, I don't think they would have been observed (as 1987A was observed with some new neutrino observatories). And, even they had, I don't think anyone would have made the connection. The neutrino beam width for the 1987A data was something like 20 degrees, so it's not like it would have stood out.
I'm surprised it's only a factor of 2.
This has been a racket perpetrated since at least the Reagan administration, if not the beginning of time. Politicians make a big noise about how they are cutting government spending and gaining the efficiencies of the private market, by replacing civil servants with contractors. The contractors are much more expensive, which makes the companies hiring them a lot of money, some of which they use to lobby the politicians for more outsourcing. Politicians get campaign contributions, beltway bandits get rich, but somehow the government doesn't get more efficient.
(Yes, there is a little bit of truth in the quick hiring and firing abilities of private contractors. It is true that it is hard to fire people from the government - but you can RIF them, if their program goes away. In practice, however, people rarely get fired or let go from either side of the divide, at least at the professional level. They get transferred around, but rarely laid off, and almost never fired. And, note well, civil servants are forbidden to directly lobby for their programs; contractors aren't. It can make a difference, and it makes it hard to perform mass layoffs of contractors.)
Yes, it does, but this would move it into the classical regime, where (at least in principle) it could be used.
Again, that's assuming that this finding is correct, etc.