I know that failure to read TFA is a thing, but you could at least read the summary where it says "generic access was not granted by the court's mandate, which referred only to a few specific email accounts."
For an actual summary of this research see http://www.scottaaronson.com/blog/?p=2673 by Scott Aaronson who is a quantum computing expert. The key thing here is that they factored 15 with high probability without having to sort of cheat by making a circuit that was more likely to work if one suspected that 15 had factorization resembling 3*5. As usual, this is getting completely overblown by the popular press. It is an important step towards actually making quantum computers that can factor big numbers, but it is nowhere near anything that would make RSA or other factoring based crypto obsolete.
Some government agencies were much more responsive than others. Some of the responses are scary. From TFA:
According to the FAA, just knowing what kinds of computers the FAA is using would endanger the security of national air traffic. That's pretty bad, both for this project and my confidence in our air traffic system.After all, despite my vague wording, the FAA found 11 pages of documents responsive to the same request.
But!
They refused to release any of their records to me, citing the blanket Exemption 3 because they deemed, "disclosure would be detrimental to the safety of persons traveling in air transportation."
He does say in the article that some agencies have confirmed mainframes from circa 1970, but doesn't say which specifically. It should be interesting to see how this project goes over the next few months.
The rocket is not designed to handle stress from all angles. Flopping into a net would entail coming down hard in a direction that it is not designed to handle stress. The primary advantage of a vertical landing is that most of the stress remains vertical just like when the rocket is being launched. Building it to handle other directions would require much more mass. They'll get this to work eventually, and this was a very difficult run anyways because the orbital profile required the rocket coming down from higher up, at a higher velocity and with less fuel to work with. Please be patient.
That would require a much more precise landing. Moreover, the strongback which holds the Falcon 9 steady before launch wouldn't work here since that's dealing with very tiny amounts of being pushed in one direction or another, orders of magnitude less than what would occur during landing. The rocket is not designed to have a lot of pressure from one side like that, and making it so that it could would add a lot of mass.
This actually makes a bit more sense than it did in the 1980s. The technology has improved but more importantly this will be only defending against a small number of missiles. One of the big issues was that it wasn't feasible to scale up a system that could defend against a massive number of advanced missiles with good countermeasures and decoys from the USSR or China. But this would only need to defend against a very small number of missiles without sophisticated countermeasures. Probably not worth the cost but it at least makes more sense than it did in the 1980s.
Please reread my comment. The statement I made was that factoring *not being in P* would imply that P is not equal to NP. This is because factoring is in NP (although conjecturally not NP-hard). You are correct that proving that factoring is in P would not prove that P = NP, but that's the converse of the relevant statement.
It is about time. The primary Diffie-Hellman key exchange https://en.wikipedia.org/wiki/Diffie%E2%80%93Hellman_key_exchange is one of the most basic cryptographic algorithms out there and is still used practically today. The simplest version of it is simple enough that you can explain it to a bright 8th grader. Variants of it, including both the original version and others such as those using elliptic curves are mainstays of practical crypto today.
Moreover, DH key exchange along with RSA started modern crypto in a fundamental way. Prior to that work, the idea was to have the key be completely secret and maximize the fundamental entropy of the encrypted messages, leading to the ultimate logical conclusion of the one-time pad. RSA and DH both showed that instead of relying on high entropy, one can rely on the computational difficulty of actually understanding the order that really is in the encrypted message.
The upshot of DH key exchange is that two people (or computers) have a conversation and at the end of it they will have a shared secret, but no one who is listening even if they hear the entire conversation will have any hope of finding out the shared secret unless they have far more computational power. This is a wildly counterintuitive claim once you hear it, and that lasts for about ten minutes (about as long as it takes to explain their algorithm). It is true that DH iand RSA are both only conjecturally secure, since the difficulty of discrete log and factoring would imply that P != NP (and in fact appear to be much stronger claims), and there are some serious thinkers who have expressed skepticism that such systems really are theoretically secure. (See for example Henry Cohn's short essay here http://research.microsoft.com/en-us/um/people/cohn/Thoughts/factoring.html which focuses on factoring but most of it applies just as well to discrete log). And we know that if we can ever get practical quantum computers working then DH will be breakable, but the overall impact of this work is absolutely undeniable.
So let's be clear: pretty much all of these situations are completely unacceptable, and most disturbingly they show a tendency for much of these sorts of problems to occur on the left, what essentially amounts to the "illiberal left" http://www.theatlantic.com/politics/archive/2015/01/liberals-and-the-illiberal-left/384988/. However, FIRE's own biases are coming into play in this list, in that every example they decide to include is on the left or has no political aspect. But there were a lot of rimilar activities with an apparently right-wing bent, such as the situation at Wheaton College https://www.insidehighered.com/news/2016/01/06/wheaton-illinois-moves-fire-professor-who-wore-hijab. It may be that FIRE's top list is still more of an issue for legitimate reasons because many of these universities are large, public universities and thus engaging in trampling on free speech is even more serious, but it does seem like FIRE's own biases may be having a role in what they've decided to highlight.
However, the general upshot should be clear: trampling on free speech is not ok. And we should support free speech whether or not it is speech we agree with. Universities must be bastions of free expression for them to effectively do their jobs. And groups of all sorts should remember that even if they have power now to censor others, they may not always be the ones in power.
No, obviously we can't demonstrate it other than to say that it looks reasonable given the laws of physics. But that's not the point. Sure, it could turn out that it is wrong, but the idea that maybe we're wrong on estimating things isn't enough to make the Filter concern go away. Having a happy explanation won't get rid of the Filter if it is front of us. That's why we need to figure out what the explanation is for this *now*. It could turn out to be something like what you suggest, but we need to actually investigate and not just simply say here's an idea so wow we can go back to doing everything else because we have a semiplausible explanation.
Radio transmission is one of the less concerning issues certainly, but you are deeply wrong about megastructures. We have a pretty good idea what their light profiles look like and we know how to detect them. There have been a lot of papers on this aspect of things. That's how they did the search for K3 civilizations I linked to in m first comment. Meanwhile, to answer your question, yes we have looked for Dyson spheres and swarms. See e.g. .
No, you haven't. That just means you have enough energy to go and build large-scale structures. The estimated energy put about by a star is many orders of magnitude more than the amount you need to build most proposed megastructures.
You want megastructures primarily to get large amounts of energy and to do heavy computations which require a lot of mass and energy. It is possible these things are just nerd projections, but how likely is that? And then that every single civilization out there doesn't try to build such things?
Yes, radio and visitors are the two less serious worries. Megastructures are the big ones. But the problem is how long do you have? Do you find it implausible for example that a civilization that arose 10 million years before we did (which would be in geologic time a very short time span) wouldn't have had time to build any? You don't think in 10 or 20 million years we won't plausibly have that tech level?
Honest question, why do you think we should be able to see megastructures even if they do exist? We can barely see galaxies and there's no way a megastructure is going to be the size of a galaxy! Additionally, lets say there's a megastructure the size of a solar system. Why would we be able to see it exactly? Are they going to cover the thing with lights and make it glow brighter than a star?
We can easily see galaxies, I'm not sure where you get the idea that that is tough. Megastructures change the resulting light curve of stars, making them dimmer (and if one is using it to harvest energy at all) redder. We know pretty well what they would look like. There's been a lot of thinking about this. See e.g. http://home.fnal.gov/~carrigan/infrared_astronomy/Fermilab_search.htm. Moreover, if a large fraction of the stars (say around 1%) of the stars in a galaxy have substantial megastructures, then the infrared signature of the galaxy as a whole will change. This is how they tried to look for K3 civilizations in the link I gave above that looked at 100,000 galaxies.
Remember, that's what they'd have to make it visible. Planets are only visible because they block the light from stars. They show up as absence of light, we don't actually see them.
Right, planets are much harder to detect than Dyson swarms because if they aren't in the way, they are very hard to see. But if you for example took something even the size of Mercury and broke it up in an orbit about where Mercury is now, it would be very noticeable from many parsecs away- we could spot that sort of thing out to at least 10,000 parsecs and probably farther if one had the highest quality instruments available.
As for radio waves, how do you know we don't see them. Remember, seeing them isn't enough, we'd also need to recognize them. I'd be very surprised if a far off civilization received our TV broadcasts and had any idea they were artificial and what the hell to do with them.
The for radio waves is actually even more severe than that, because of spread spectrum techniques https://en.wikipedia.org/wiki/Spread_spectrum which would make it even harder to recognize that a broadcast was artificial, although classical broadcasting techniques would be very easy to notice. But yes, radios are one of the harder things since they'd very likely require some sort of deliberate beacon. As I said, the primary issue by far is the lack of large scale structures.
I find it interesting that you haven't discussed the megastructure issue. Does that mean you are essentially in agreement there?
I agree that beacons are tough although if one wants it to work well you use a more directional system and you aim it at planets you've found. This has a lot more range.
I don't think anybody has good estimates, but you don't need extreme values to get the expected spread factor below 1.
Yes, you do, because once one civilization figures it out, they can do it. They don't need to reinvent the wheel every time. Moreover, this requires that the numbers are too small for *every civilization out there* and that none of them try to self-modify or upload or anything similar to get around these issues.
If you want to do heavy-duty computations, you are limited by the amount of energy you have access to. Moreover, this explanation would then require that every civilization is making the exact same set of choices, which seems at best unlikely. If some mildly optimistic thing like this turns out to be correct, that's great. But if there is a Filter in front of us, no amount of shouting at it that we had this happy, alternative explanation will make the Filter go away. So having a potential explanation is insufficient unless we have some real info about it. It isn't necessarily the case that there's a Great Filter or even a Great Filter in our future, but that's something we need to figure out. Right now, we're putting very few resources into it.
I'm not sure what assumption you are objecting to. The conclusion of a Filter is made likely based on our current understanding of basic physics being very approximably correct. And many of the things that people would like to imagine highly advanced civilizations having access to (e.g. FTL drives) make the problems more severe rather than less so. We have to work with the base we have, and we can't just dismiss the possibility of a Filter because we might be wrong. If it turns out that there's some nice happy explanation, that will be great, but if there is a Filter, no number of optimistic, wishful explanations will make it go away.
It would be really nice if this were the case, but it doesn't seem to be. To not want large amounts of energy to do things requires us to be not just wrong about basic physics, but drastically, completely wrong about thermodynamics and many other things. How likely does that seem? This is a common problem when people are faced with the Great Filter. They pick a single, really optimistic explanation, decide it is the simplest and then decide that that solves the problem. Unfortunately, if there is a Filter in front of us, no amount of shouting at it that we had this happy, alternative explanation will make the Filter go away. We need to figure this out.
As I said, the most serious issue is the absence of megastructures, but the concern about radio waves is precisely that: it would take only a small fraction of inhabited planets making radio beacons to notice them.
At that speed it may take several thousand years to reach another habitable planet. With a million things that could wrong, I can see people voting against the idea of embarking on such a crazy adventure. And even assuming a bunch of people make it to another planet, they have to survive there, and rebuild another civilization capable of doing it again. If the failure rate is too high, the spread will stop.
Yes, this would all be problems if you did something like this with something approaching base-line humans with regular human lifespans and no advanced robotics or other aspects to help out. How plausible is it to you that all civilized species end up with a life expectancy close to that of a human and that they aren't able to extend it at all, or to bring along robots to help build new things when they get there?
If that's at all the case, then we should be taking steps to either a) prepare for that eventuality or b) try to avert it. Essentially you aren't dismissing the Fermi Paradox at all, you are concluding that the explanation is a nigh-unstoppable Filter. That's a possible explanation, and I don't know about you, but if that's the case I'm going to favor putting in every last bit of effort we can to maybe avoid the situation. It is better to strive and to struggle than to just give up.
Dyson spheres are not the only type of megastructure, and you don't need them just for population. The primary use of most megastructure proposals is to get a lot of solar energy. No matter what you want to do, you want energy. Want to do heavy-duty computations? That takes energy. Want to find out more abut the structure of the universe with big particle accelerators? That takes energy. Want to send a very high speed probe to another region of the universe? That takes energy.
Slashdot Mirror
I know that failure to read TFA is a thing, but you could at least read the summary where it says "generic access was not granted by the court's mandate, which referred only to a few specific email accounts."
For an actual summary of this research see http://www.scottaaronson.com/blog/?p=2673 by Scott Aaronson who is a quantum computing expert. The key thing here is that they factored 15 with high probability without having to sort of cheat by making a circuit that was more likely to work if one suspected that 15 had factorization resembling 3*5. As usual, this is getting completely overblown by the popular press. It is an important step towards actually making quantum computers that can factor big numbers, but it is nowhere near anything that would make RSA or other factoring based crypto obsolete.
According to the FAA, just knowing what kinds of computers the FAA is using would endanger the security of national air traffic. That's pretty bad, both for this project and my confidence in our air traffic system.After all, despite my vague wording, the FAA found 11 pages of documents responsive to the same request. But! They refused to release any of their records to me, citing the blanket Exemption 3 because they deemed, "disclosure would be detrimental to the safety of persons traveling in air transportation."
He does say in the article that some agencies have confirmed mainframes from circa 1970, but doesn't say which specifically. It should be interesting to see how this project goes over the next few months.
The rocket is not designed to handle stress from all angles. Flopping into a net would entail coming down hard in a direction that it is not designed to handle stress. The primary advantage of a vertical landing is that most of the stress remains vertical just like when the rocket is being launched. Building it to handle other directions would require much more mass. They'll get this to work eventually, and this was a very difficult run anyways because the orbital profile required the rocket coming down from higher up, at a higher velocity and with less fuel to work with. Please be patient.
That would require a much more precise landing. Moreover, the strongback which holds the Falcon 9 steady before launch wouldn't work here since that's dealing with very tiny amounts of being pushed in one direction or another, orders of magnitude less than what would occur during landing. The rocket is not designed to have a lot of pressure from one side like that, and making it so that it could would add a lot of mass.
This actually makes a bit more sense than it did in the 1980s. The technology has improved but more importantly this will be only defending against a small number of missiles. One of the big issues was that it wasn't feasible to scale up a system that could defend against a massive number of advanced missiles with good countermeasures and decoys from the USSR or China. But this would only need to defend against a very small number of missiles without sophisticated countermeasures. Probably not worth the cost but it at least makes more sense than it did in the 1980s.
Please reread my comment. The statement I made was that factoring *not being in P* would imply that P is not equal to NP. This is because factoring is in NP (although conjecturally not NP-hard). You are correct that proving that factoring is in P would not prove that P = NP, but that's the converse of the relevant statement.
It is about time. The primary Diffie-Hellman key exchange https://en.wikipedia.org/wiki/Diffie%E2%80%93Hellman_key_exchange is one of the most basic cryptographic algorithms out there and is still used practically today. The simplest version of it is simple enough that you can explain it to a bright 8th grader. Variants of it, including both the original version and others such as those using elliptic curves are mainstays of practical crypto today.
Moreover, DH key exchange along with RSA started modern crypto in a fundamental way. Prior to that work, the idea was to have the key be completely secret and maximize the fundamental entropy of the encrypted messages, leading to the ultimate logical conclusion of the one-time pad. RSA and DH both showed that instead of relying on high entropy, one can rely on the computational difficulty of actually understanding the order that really is in the encrypted message.
The upshot of DH key exchange is that two people (or computers) have a conversation and at the end of it they will have a shared secret, but no one who is listening even if they hear the entire conversation will have any hope of finding out the shared secret unless they have far more computational power. This is a wildly counterintuitive claim once you hear it, and that lasts for about ten minutes (about as long as it takes to explain their algorithm). It is true that DH iand RSA are both only conjecturally secure, since the difficulty of discrete log and factoring would imply that P != NP (and in fact appear to be much stronger claims), and there are some serious thinkers who have expressed skepticism that such systems really are theoretically secure. (See for example Henry Cohn's short essay here http://research.microsoft.com/en-us/um/people/cohn/Thoughts/factoring.html which focuses on factoring but most of it applies just as well to discrete log). And we know that if we can ever get practical quantum computers working then DH will be breakable, but the overall impact of this work is absolutely undeniable.
So let's be clear: pretty much all of these situations are completely unacceptable, and most disturbingly they show a tendency for much of these sorts of problems to occur on the left, what essentially amounts to the "illiberal left" http://www.theatlantic.com/politics/archive/2015/01/liberals-and-the-illiberal-left/384988/. However, FIRE's own biases are coming into play in this list, in that every example they decide to include is on the left or has no political aspect. But there were a lot of rimilar activities with an apparently right-wing bent, such as the situation at Wheaton College https://www.insidehighered.com/news/2016/01/06/wheaton-illinois-moves-fire-professor-who-wore-hijab. It may be that FIRE's top list is still more of an issue for legitimate reasons because many of these universities are large, public universities and thus engaging in trampling on free speech is even more serious, but it does seem like FIRE's own biases may be having a role in what they've decided to highlight.
However, the general upshot should be clear: trampling on free speech is not ok. And we should support free speech whether or not it is speech we agree with. Universities must be bastions of free expression for them to effectively do their jobs. And groups of all sorts should remember that even if they have power now to censor others, they may not always be the ones in power.
No, obviously we can't demonstrate it other than to say that it looks reasonable given the laws of physics. But that's not the point. Sure, it could turn out that it is wrong, but the idea that maybe we're wrong on estimating things isn't enough to make the Filter concern go away. Having a happy explanation won't get rid of the Filter if it is front of us. That's why we need to figure out what the explanation is for this *now*. It could turn out to be something like what you suggest, but we need to actually investigate and not just simply say here's an idea so wow we can go back to doing everything else because we have a semiplausible explanation.
Radio transmission is one of the less concerning issues certainly, but you are deeply wrong about megastructures. We have a pretty good idea what their light profiles look like and we know how to detect them. There have been a lot of papers on this aspect of things. That's how they did the search for K3 civilizations I linked to in m first comment. Meanwhile, to answer your question, yes we have looked for Dyson spheres and swarms. See e.g. .
Do you have a citation for this?
No, you haven't. That just means you have enough energy to go and build large-scale structures. The estimated energy put about by a star is many orders of magnitude more than the amount you need to build most proposed megastructures.
You want megastructures primarily to get large amounts of energy and to do heavy computations which require a lot of mass and energy. It is possible these things are just nerd projections, but how likely is that? And then that every single civilization out there doesn't try to build such things?
Hah! Actually, I disagree pretty strongly with Nick on that score. But for Filter issues he's pretty correct.
Yes, radio and visitors are the two less serious worries. Megastructures are the big ones. But the problem is how long do you have? Do you find it implausible for example that a civilization that arose 10 million years before we did (which would be in geologic time a very short time span) wouldn't have had time to build any? You don't think in 10 or 20 million years we won't plausibly have that tech level?
Honest question, why do you think we should be able to see megastructures even if they do exist? We can barely see galaxies and there's no way a megastructure is going to be the size of a galaxy! Additionally, lets say there's a megastructure the size of a solar system. Why would we be able to see it exactly? Are they going to cover the thing with lights and make it glow brighter than a star?
We can easily see galaxies, I'm not sure where you get the idea that that is tough. Megastructures change the resulting light curve of stars, making them dimmer (and if one is using it to harvest energy at all) redder. We know pretty well what they would look like. There's been a lot of thinking about this. See e.g. http://home.fnal.gov/~carrigan/infrared_astronomy/Fermilab_search.htm. Moreover, if a large fraction of the stars (say around 1%) of the stars in a galaxy have substantial megastructures, then the infrared signature of the galaxy as a whole will change. This is how they tried to look for K3 civilizations in the link I gave above that looked at 100,000 galaxies.
Remember, that's what they'd have to make it visible. Planets are only visible because they block the light from stars. They show up as absence of light, we don't actually see them.
Right, planets are much harder to detect than Dyson swarms because if they aren't in the way, they are very hard to see. But if you for example took something even the size of Mercury and broke it up in an orbit about where Mercury is now, it would be very noticeable from many parsecs away- we could spot that sort of thing out to at least 10,000 parsecs and probably farther if one had the highest quality instruments available.
As for radio waves, how do you know we don't see them. Remember, seeing them isn't enough, we'd also need to recognize them. I'd be very surprised if a far off civilization received our TV broadcasts and had any idea they were artificial and what the hell to do with them.
The for radio waves is actually even more severe than that, because of spread spectrum techniques https://en.wikipedia.org/wiki/Spread_spectrum which would make it even harder to recognize that a broadcast was artificial, although classical broadcasting techniques would be very easy to notice. But yes, radios are one of the harder things since they'd very likely require some sort of deliberate beacon. As I said, the primary issue by far is the lack of large scale structures.
I don't think anybody has good estimates, but you don't need extreme values to get the expected spread factor below 1.
Yes, you do, because once one civilization figures it out, they can do it. They don't need to reinvent the wheel every time. Moreover, this requires that the numbers are too small for *every civilization out there* and that none of them try to self-modify or upload or anything similar to get around these issues.
Do you have any loved-ones? Any children? Nieces? Nephews? Grandchildren? Do you want them to suffer and die?
If you want to do heavy-duty computations, you are limited by the amount of energy you have access to. Moreover, this explanation would then require that every civilization is making the exact same set of choices, which seems at best unlikely. If some mildly optimistic thing like this turns out to be correct, that's great. But if there is a Filter in front of us, no amount of shouting at it that we had this happy, alternative explanation will make the Filter go away. So having a potential explanation is insufficient unless we have some real info about it. It isn't necessarily the case that there's a Great Filter or even a Great Filter in our future, but that's something we need to figure out. Right now, we're putting very few resources into it.
I'm not sure what assumption you are objecting to. The conclusion of a Filter is made likely based on our current understanding of basic physics being very approximably correct. And many of the things that people would like to imagine highly advanced civilizations having access to (e.g. FTL drives) make the problems more severe rather than less so. We have to work with the base we have, and we can't just dismiss the possibility of a Filter because we might be wrong. If it turns out that there's some nice happy explanation, that will be great, but if there is a Filter, no number of optimistic, wishful explanations will make it go away.
It would be really nice if this were the case, but it doesn't seem to be. To not want large amounts of energy to do things requires us to be not just wrong about basic physics, but drastically, completely wrong about thermodynamics and many other things. How likely does that seem? This is a common problem when people are faced with the Great Filter. They pick a single, really optimistic explanation, decide it is the simplest and then decide that that solves the problem. Unfortunately, if there is a Filter in front of us, no amount of shouting at it that we had this happy, alternative explanation will make the Filter go away. We need to figure this out.
As I said, the most serious issue is the absence of megastructures, but the concern about radio waves is precisely that: it would take only a small fraction of inhabited planets making radio beacons to notice them.
At that speed it may take several thousand years to reach another habitable planet. With a million things that could wrong, I can see people voting against the idea of embarking on such a crazy adventure. And even assuming a bunch of people make it to another planet, they have to survive there, and rebuild another civilization capable of doing it again. If the failure rate is too high, the spread will stop.
Yes, this would all be problems if you did something like this with something approaching base-line humans with regular human lifespans and no advanced robotics or other aspects to help out. How plausible is it to you that all civilized species end up with a life expectancy close to that of a human and that they aren't able to extend it at all, or to bring along robots to help build new things when they get there?
If that's at all the case, then we should be taking steps to either a) prepare for that eventuality or b) try to avert it. Essentially you aren't dismissing the Fermi Paradox at all, you are concluding that the explanation is a nigh-unstoppable Filter. That's a possible explanation, and I don't know about you, but if that's the case I'm going to favor putting in every last bit of effort we can to maybe avoid the situation. It is better to strive and to struggle than to just give up.
Dyson spheres are not the only type of megastructure, and you don't need them just for population. The primary use of most megastructure proposals is to get a lot of solar energy. No matter what you want to do, you want energy. Want to do heavy-duty computations? That takes energy. Want to find out more abut the structure of the universe with big particle accelerators? That takes energy. Want to send a very high speed probe to another region of the universe? That takes energy.