Yes, in the case of file sharing the content industries have bribed the Congress into granting them statutory damages. The spammers haven't been nearly as industrious... yet.
Read the paper. He bought or built a "Farnsworth Fusor" to send 2.5 MeV neutrons into a package, and then look for high energy products of neutron induced fission from the package. These would be high enough in energy that the natural background would be quite low, making false positives low. There is no reason why this shouldn't work (although whether its practical is another question.)
He tested it on "20 grams of Natural Uranium Trioxide (UO3) containing - 99.3% U238 and 0.7% U235." (In other words, about 0.1 grams of U235.) The integration time he found he needed was 10 minutes, rather than the 15 seconds desired by DHS, but it's an interesting concept. He doesn't do any calculations as to the expected return from an interesting about of U235 (say, 100 grams), but it would be higher, and so integration times should be less.
He also says that the incident beam is low enough not to be harmful : "the system has low enough does as to not affect the health or functionality of the cargo and operator, However, he doesn't state any dosage information, which I would fault him on if I were grading this paper.
Just look at the situation in the UK - for example, this analysis from the Morton Report :
The result is that Britain is suffering from a severe case of 'libel chill', where publishers and newspapers are afraid to publish a story because the subject, usually a celebrity, might decide to sue.
Freedom of Speech is in many ways the most fundamental of all freedoms, because without it repressions of the other freedoms cannot be corrected.
The question is not could, but should. Clearly we could.
In some ways, I am not sure it matters much, as it will take so long that several different government will have to approve it, and minds can change.
The Fukushima disaster should not have happened, period. The reactors themselves survived the earthquake and tsunami just fine; the disaster was caused by a cascade of secondary failures. It's as if your house burned down because of a power failure. The operators and regulators knew that this was a possibility in these old designs, but it was "too expensive" to rebuild or replace 50 year old gear. That thinking will have to change. Clearly a lot of money will have to be spent on existing nuclear plants, regardless of whether they are wound down or kept going. The "stress tests" ordered by the EU are just the beginning.
(1) is in fact a matter of which interpretation of QM you choose, and ultimately a question of metaphysics, since any non-deterministic theory could be postulated to be the result of a deterministic underlying 'reality' (as is the case with the Bohm interpretation of QM), or vice-versa.
Uh, not so easy. The whole point of the Bell's Theorem tests is that QM is not reducible to a local deterministic theory. Bohm's theory is deterministic, but non-local, which means that it is not causal. So, chose your poison. You can't have it all; QM is not just a normal classical theory hiding behind some measurement weirdness.
Our brains, of course, are quantum in nature. So are our shoes and our light bulbs and everything else we see and touch, so that doesn't necessarily mean much. But it certainly means that there is a connection of some sort between our brains and quantum mechanics. It may or may be an interesting connection, but it certainly exists. (I don't really know what the OP means by a "causal connection" in this context, but I assume they mean that one requires the other.)
The real question is, does consciousness have anything to do with Boolean logic ? Or, to be a little fancier, can consciousness be computed on a Turing machine ?
AI types tend to assume this as a given, but there is of course no actual evidence for it, and the abysmal progress of AI doesn't give much confidence in their assumptions. If our consciousness isn't calculable on a Turing machine, then suspecting a deep connection with quantum mechanics is very reasonable.
In any case, hypothesizing a physical cause for a physical phenomenon is not a logical fallacy. It may or may not be correct, but it's not a logical fallacy.
Ah, yes, our friends the spammers. As someone who has an active enough twitter account to attract "backscatter spam" (i.e., spam tweeted to my account but intended for others to pick up), I don't think you are going to be able to make that totally automatic.
You could make the trending list into a "honeypot" - make it a pure popularity contest, and hire 5-10 employees to watch it and banish trending spam. (5 to 10 for 24x7 surveillance). That way, you could whack lots of spam accounts at once. And, providing more ways for trusted tweeters to identify spam would be useful.
First, of course, removing something from the trend list is not censorship. It's a top ten type list, not the content itself.
Second, there have been complaints about the twitter trend list for a long time. The trend list has never seemed to be just a numerical ranking of tweets - I don't regard it as any more reliable than a Slashdot poll. Whatever they are doing here is probably not new.
I have also heard rumors that the trend list is particularized for the viewer (i.e., we don't all see the same trend lists), probably on a geographic basis. I wonder if people in the UK can see trends for He Who Must Not Be Named ?
Yes, as to the lack of cuddliness. However, we both participated in IGY, we shared data through COSPAR, we went to each other's meetings, we even shared lunar samples (and ranged the Lunakhod LLR retroreflectors). Later, when things warmed a little, there was also the US tracking of the VEGA mission and the VEGA balloon.
So, while there was lots of tit-for-tat, some very stupid (my favorite was denying Kruschev a visit to Disneyland, ostensibly for security reasons!), I am not aware of any blanket ban on science.
Oh, I was just responding to his quote about Stalin, reminding him (on the off chance he reads Slashdot), that we did have programs in place with Stalin, when they suited our purposes.
I live in Virginia, and know (distantly) Frank Wolf. He may be many things, but he is no tea-bagger. In fact, he got a primary challenge from a tea-bagger. Now, as to whether that has softened his brain, I wouldn't know.
I don't remember this level of exclusion even in the bad old days of the USSR. I would also remind
I wonder, though, what this will actually stop ? For example, the Chinese are apparently expressing some interest in participating with the ISS (the space station). Is that a " bilateral policy, program, order, or contract" ? No, it isn't. It is multinational and multilateral. Any Mars mission (the Chinese have an orbiter, Yinghuo-1, on Phobos-Grunt), likewise. And, who decides whether a visitor is "official" ? Well, the bureaucracy does; no visitor (except maybe for the President or Premier) has to be official. So, if the NASA administrator wants to do something. I am not sure this would stop him.
I would also remind Rep. Frank Wolf (R-VA) that we fought World War II with Stalin, although that was of course a multilateral program.
The galaxy is a complicated place, dynamically speaking. There is the galactic rotation (~ 250 million years), which is roughly constant velocity around us, so there is a shear (stars closer to the center of the galaxy will orbit faster, as their orbits are physically smaller). There is the out of plane oscillation (most stars, including ours, bob up and down out of the galactic plane, like a cork). That has an estimated period for the Sun of 52 million years. There are in plane epicyclic motions (because of the spiral arms) with periods of order 175 million years. And, there are the accelerations from all of the local mass, most of which is "missing" - i.e., not associated with stars. Nearby stars have different velocities, and so close stars will drift apparent, and undergo different oscillatory motions.
None of these accelerations is observationally determined, and so must be estimated from models, which are pretty imprecise. Spacecraft in interstellar space will, of course, also be subject to all of these accelerations.
If you run the numbers, the total acceleration is about 2 x 10^-12 light years / year^2, and the error in that estimate might be as large as 50%, which would amount to 1 light year after a million years. Remember, in a million years, most stars will spread apart from each other by order 1000 light years. We don't even know all of the stars 100 light years away, much less 1000 light years away, and that far away our knowledge of the velocity (especially the transverse velocity) of the stars we do know is also poor.
So, after as short a time as 1 million years, we won't where the Voyagers (or Pioneers, or Pluto Express) are, or what stars they might be nearby, to within light years, and that is a lot of space.
It's not aimed at any other solar system, and the times involved are such that we can't predict what's going to happen very well.
In places like Wikipedia you will read things like
"in about 40,000 years [Voyager 1] will pass within 1.6 light years of the star AC+79 3888 in the constellation Camelopardalis."
but this is highly misleading. 1.6 light years is almost 1000 times further away from that star than either Voyager is from the Sun right now, so it won't in any sense be "in" that stellar system.
Worse, stars travel (relative to each other) at ~ 0.001 c, so even in 40,000 years all the nearby stars will move around by 10's of light years. We can estimate stellar velocities reasonably well, but their accelerations are very poorly measured, and so, after a few million years at most, we really don't know which star will go where.
The bottom line is, it will be millions of years before any of these spacecraft get as close to another star as they are now, and we have no idea which star that will be...... unless, of course, our descendants pick them up and put them in a museum somewhere, which is what I would predict.
Just wait until the divorce industry starts trying to get their hands on all of this.
By the way, I don't see how you can really anomymize location data. Traffic analysis will pierce that veil in many case. Let's do a scenario. Suppose a car leaves Senator X's house and goes to Miss Y's house at 11:00 PM, and does that almost every Wednesday night, and there is a return car (Y to X) every Thursday morning at 2:00 AM, but only on the days where the first trip was made. Suppose all of this information is revealed to a Supermarket tabloid. Is the fact that it doesn't actually have Senator X's name on it much protection ?
Yeah, any radio astronomer should be able to do this in their sleep.
The classical response is that Arecibo (our biggest telescope, supporting the Earth's most powerful radar) could detect a clone of itself across most of the galaxy. Even this pessimistic (or conservative) estimate is 10,000 light years, a considerable distance.
However, that is detection (with a 1 or more hour integration time). If you want to communicate at a reasonable rate (say, 100 bits per second), you need to be maybe 100 times closer, so the distance you could actually communicate is more like a few hundred light years at best. Optical communications have some advantages, and could certainly match and maybe exceed these distances with existing technology. Note that any probe we are likely to send for a very long time to come will be within these sorts of communication ranges.
The linked PDF you provided speculates that "object X" might be a self-obscured star, obscured by its own ejecta.
If we assume that this is indeed a dyson swarm, then the purpose might not be exclusively for collecting energy.
A category II or III civilization would be doing asto-architecture, and would need tremendous amounts of raw materials. Heavy atoms are only produced naturally in one kind of environment: in the hearts of stars. If this star is regularly expelling large quantities of cosmic dust, as the linked article postulates, then it would make an excellent "Factory". Energy would be in copious abundance, and the star itself would be churning out millions of tons of heavy atoms every minute. Even with a short (compared to other stars) lifespan, it would make an excellent factory site for other large astro-engineering projects.
Yes, that was sort of along the lines of my thought. This seems like a poor location for a long-term agricultural project, but conceivably an excellent site for astroengineering. In that case there might be detectable byproducts (for example,as you suggest, the distributions of various elements might be depleted or rearranged). Also, they might use nuclear fusion to synthesize missing very heavy elements or for some other purpose requiring high energies (there is, after all, lots of gas as well), and that might have a detectable signature at high energies.
Finally, Luc Arnold has an interesting paper about detection of artificial structures in transit about their star, and concludes that "multiple artificial objects would produce light curves easily distinguishable from natural transits." If the purpose of this megaengineering is to build structures (or coherent swarms) on a suitable scale, they might be detected in transit about the central star, which might provide the most conclusive proof of all.
A Dyson Sphere would block all light but a massive structure like in Ringworld would cause a dim band around a star rather than the brief dimming that means simply there's a planet. There's no known natural object that would block a region of a star for an extended period. A tight asteroid belt would cause dimming but not block most of the light. Look for a star with a significantly dimmed region or one that appears to be in two parts. Current telescopes would more than likely see most stars are solid even if there was a dim band so when higher powered ones become available it could be another thing to look for.
The Tsar bomb (57 megatons) was about 2 x 10^17 joules. Suppose all of that energy was released as visible light at a wavelength of 0.5 microns; that's about 6 x 10^35 photons, which sounds like (and is) a lot. However, at one light year (assuming a uniform blast of radiation), that works out to 500 photons per square meter.
Now, that could be detected, if you were looking for it. At 4.4 light years (Alpha Centauri), that's 26 photons per square meter, which would be detectable with a big telescope (maybe). Go out as far as 100 light years (0.05 photons / square meter) and there is no way that could be separated from the flood of photons coming from the Sun. Also, we set off bombs on a very irregular basis (thankfully). These occasional dim flashes would have been very hard to notice and pull out of the background clutter, even with big telescopes, and even as close as Alpha Centauri. It would likewise be very hard for us to detect them, if aliens were setting them off at Alpha Centauri, even as we speak.
Now, in reality, a bomb in space puts out most of its signal at higher energies (thus smaller numbers of photons / square meter), while blasts in the atmosphere put a lot of energy into the shock wave, heating of the air and ground, etc. These are very optimistic calculations.
So, if the ETs are setting off anything like human type bombs at human type frequencies, I don't think that we are going to find them from it, even if they are doing it right next door (astronomically speaking).
Dyson spheres (or swarms) would probably be the best way to detect an advanced civilization, especially a Kardashev Type II or Type III civilization.
In a Dyson sphere (or swarm) a civilization surrounds an entire star to capture most or all of its luminosity; severely cutting down on its optical luminosity but accentuating the IR luminosity. (The physics of a rigid sphere surrounding a star are pretty challenging, and some sort of swarm or cloud seems more likely, at least to our limited technological understanding.) So, to hunt for a Dyson sphere, you look for objects with an unusual excess of IR, and a lack of optical light. The IRAS IR satellite was used to search for Dyson spheres within ~ 1000 light years of the Earth (producing a handful of so-so candidates). Carrigan calls these sorts of searches "Interstellar Archaeology." They have one great advantage in that they don't require any cooperation from the other end (i.e., no beacons or other signals).
As it happens, I have recently speculated that "Object X" in M33 (the Triangulum Galaxy) could represent the signature of a Dyson sphere / swarm from 3 million light years away. If this (unlikely) possibility were to be true, it would represent the signature of a Kardashev Type III or near Type III civilization. Interstellar Archaeology is the only possible form of SETI across such vast distances.
Slashdot Mirror
Yes, in the case of file sharing the content industries have bribed the Congress into granting them statutory damages. The spammers haven't been nearly as industrious... yet.
RIAA and the MPAA claim damages in the trillions, more than their industries have ever made. I don't recall hearing any judges berating them.
Read the paper. He bought or built a "Farnsworth Fusor" to send 2.5 MeV neutrons into a package, and then look for high energy products of neutron induced fission from the package. These would be high enough in energy that the natural background would be quite low, making false positives low. There is no reason why this shouldn't work (although whether its practical is another question.)
He tested it on "20 grams of Natural Uranium Trioxide (UO3) containing - 99.3% U238 and 0.7% U235." (In other words, about 0.1 grams of U235.) The integration time he found he needed was 10 minutes, rather than the 15 seconds desired by DHS, but it's an interesting concept. He doesn't do any calculations as to the expected return from an interesting about of U235 (say, 100 grams), but it would be higher, and so integration times should be less.
He also says that the incident beam is low enough not to be harmful : "the system has low enough does as to not affect the health or functionality of the cargo and operator, However, he doesn't state any dosage information, which I would fault him on if I were grading this paper.
Just look at the situation in the UK - for example, this analysis from the Morton Report :
The result is that Britain is suffering from a severe case of 'libel chill', where publishers and newspapers are afraid to publish a story because the subject, usually a celebrity, might decide to sue.
Freedom of Speech is in many ways the most fundamental of all freedoms, because without it repressions of the other freedoms cannot be corrected.
The question is not could, but should. Clearly we could.
In some ways, I am not sure it matters much, as it will take so long that several different government will have to approve it, and minds can change.
The Fukushima disaster should not have happened, period. The reactors themselves survived the earthquake and tsunami just fine; the disaster was caused by a cascade of secondary failures. It's as if your house burned down because of a power failure. The operators and regulators knew that this was a possibility in these old designs, but it was "too expensive" to rebuild or replace 50 year old gear. That thinking will have to change. Clearly a lot of money will have to be spent on existing nuclear plants, regardless of whether they are wound down or kept going. The "stress tests" ordered by the EU are just the beginning.
I wonder if 4 years ago Cicso was saying that streaming video was going to account for the majority of internet traffic in 2011?
Yes, they were
Come on guys, 966 EB ? Why hold back ? Why not 966.1415927 EB in 2015 ?
Seriously, I would doubt any claim to know this number to better than about 50%.
Let's stigmatize SAIC analysts who have internalized the mind-set of the Soviet Union.
It will save lots of time in the long run.
1) QM is non-deterministic
(1) is in fact a matter of which interpretation of QM you choose, and ultimately a question of metaphysics, since any non-deterministic theory could be postulated to be the result of a deterministic underlying 'reality' (as is the case with the Bohm interpretation of QM), or vice-versa.
Uh, not so easy. The whole point of the Bell's Theorem tests is that QM is not reducible to a local deterministic theory. Bohm's theory is deterministic, but non-local, which means that it is not causal. So, chose your poison. You can't have it all; QM is not just a normal classical theory hiding behind some measurement weirdness.
That's OK, I viewed Marvin Minsky et al. skeptically back then, too, and none of those predictions have panned out either.
Our brains, of course, are quantum in nature. So are our shoes and our light bulbs and everything else we see and touch, so that doesn't necessarily mean much. But it certainly means that there is a connection of some sort between our brains and quantum mechanics. It may or may be an interesting connection, but it certainly exists. (I don't really know what the OP means by a "causal connection" in this context, but I assume they mean that one requires the other.)
The real question is, does consciousness have anything to do with Boolean logic ? Or, to be a little fancier, can consciousness be computed on a Turing machine ?
AI types tend to assume this as a given, but there is of course no actual evidence for it, and the abysmal progress of AI doesn't give much confidence in their assumptions. If our consciousness isn't calculable on a Turing machine, then suspecting a deep connection with quantum mechanics is very reasonable.
In any case, hypothesizing a physical cause for a physical phenomenon is not a logical fallacy. It may or may not be correct, but it's not a logical fallacy.
It's working fine for me in Northern Virginia at 9:33 AM EDT - Cox Cable.
Ah, yes, our friends the spammers. As someone who has an active enough twitter account to attract "backscatter spam" (i.e., spam tweeted to my account but intended for others to pick up), I don't think you are going to be able to make that totally automatic.
You could make the trending list into a "honeypot" - make it a pure popularity contest, and hire 5-10 employees to watch it and banish trending spam. (5 to 10 for 24x7 surveillance). That way, you could whack lots of spam accounts at once. And, providing more ways for trusted tweeters to identify spam would be useful.
First, of course, removing something from the trend list is not censorship. It's a top ten type list, not the content itself.
Second, there have been complaints about the twitter trend list for a long time. The trend list has never seemed to be just a numerical ranking of tweets - I don't regard it as any more reliable than a Slashdot poll. Whatever they are doing here is probably not new.
I have also heard rumors that the trend list is particularized for the viewer (i.e., we don't all see the same trend lists), probably on a geographic basis. I wonder if people in the UK can see trends for He Who Must Not Be Named ?
Yes, as to the lack of cuddliness. However, we both participated in IGY, we shared data through COSPAR, we went to each other's meetings, we even shared lunar samples (and ranged the Lunakhod LLR retroreflectors). Later, when things warmed a little, there was also the US tracking of the VEGA mission and the VEGA balloon.
So, while there was lots of tit-for-tat, some very stupid (my favorite was denying Kruschev a visit to Disneyland, ostensibly for security reasons!), I am not aware of any blanket ban on science.
Oh, I was just responding to his quote about Stalin, reminding him (on the off chance he reads Slashdot), that we did have programs in place with Stalin, when they suited our purposes.
I live in Virginia, and know (distantly) Frank Wolf. He may be many things, but he is no tea-bagger. In fact, he got a primary challenge from a tea-bagger. Now, as to whether that has softened his brain, I wouldn't know.
I don't remember this level of exclusion even in the bad old days of the USSR. I would also remind
I wonder, though, what this will actually stop ? For example, the Chinese are apparently expressing some interest in participating with the ISS (the space station). Is that a " bilateral policy, program, order, or contract" ? No, it isn't. It is multinational and multilateral. Any Mars mission (the Chinese have an orbiter, Yinghuo-1, on Phobos-Grunt), likewise. And, who decides whether a visitor is "official" ? Well, the bureaucracy does; no visitor (except maybe for the President or Premier) has to be official. So, if the NASA administrator wants to do something. I am not sure this would stop him.
I would also remind Rep. Frank Wolf (R-VA) that we fought World War II with Stalin, although that was of course a multilateral program.
The galaxy is a complicated place, dynamically speaking. There is the galactic rotation (~ 250 million years), which is roughly constant velocity around us, so there is a shear (stars closer to the center of the galaxy will orbit faster, as their orbits are physically smaller). There is the out of plane oscillation (most stars, including ours, bob up and down out of the galactic plane, like a cork). That has an estimated period for the Sun of 52 million years. There are in plane epicyclic motions (because of the spiral arms) with periods of order 175 million years. And, there are the accelerations from all of the local mass, most of which is "missing" - i.e., not associated with stars. Nearby stars have different velocities, and so close stars will drift apparent, and undergo different oscillatory motions.
None of these accelerations is observationally determined, and so must be estimated from models, which are pretty imprecise. Spacecraft in interstellar space will, of course, also be subject to all of these accelerations.
If you run the numbers, the total acceleration is about 2 x 10^-12 light years / year^2, and the error in that estimate might be as large as 50%, which would amount to 1 light year after a million years. Remember, in a million years, most stars will spread apart from each other by order 1000 light years. We don't even know all of the stars 100 light years away, much less 1000 light years away, and that far away our knowledge of the velocity (especially the transverse velocity) of the stars we do know is also poor.
So, after as short a time as 1 million years, we won't where the Voyagers (or Pioneers, or Pluto Express) are, or what stars they might be nearby, to within light years, and that is a lot of space.
It's not aimed at any other solar system, and the times involved are such that we can't predict what's going to happen very well.
In places like Wikipedia you will read things like
"in about 40,000 years [Voyager 1] will pass within 1.6 light years of the star AC+79 3888 in the constellation Camelopardalis."
but this is highly misleading. 1.6 light years is almost 1000 times further away from that star than either Voyager is from the Sun right now, so it won't in any sense be "in" that stellar system.
Worse, stars travel (relative to each other) at ~ 0.001 c, so even in 40,000 years all the nearby stars will move around by 10's of light years. We can estimate stellar velocities reasonably well, but their accelerations are very poorly measured, and so, after a few million years at most, we really don't know which star will go where.
The bottom line is, it will be millions of years before any of these spacecraft get as close to another star as they are now, and we have no idea which star that will be... ... unless, of course, our descendants pick them up and put them in a museum somewhere, which is what I would predict.
Just wait until the divorce industry starts trying to get their hands on all of this.
By the way, I don't see how you can really anomymize location data. Traffic analysis will pierce that veil in many case. Let's do a scenario. Suppose a car leaves Senator X's house and goes to Miss Y's house at 11:00 PM, and does that almost every Wednesday night, and there is a return car (Y to X) every Thursday morning at 2:00 AM, but only on the days where the first trip was made. Suppose all of this information is revealed to a Supermarket tabloid. Is the fact that it doesn't actually have Senator X's name on it much protection ?
Yeah, any radio astronomer should be able to do this in their sleep.
The classical response is that Arecibo (our biggest telescope, supporting the Earth's most powerful radar) could detect a clone of itself across most of the galaxy. Even this pessimistic (or conservative) estimate is 10,000 light years, a considerable distance.
However, that is detection (with a 1 or more hour integration time). If you want to communicate at a reasonable rate (say, 100 bits per second), you need to be maybe 100 times closer, so the distance you could actually communicate is more like a few hundred light years at best. Optical communications have some advantages, and could certainly match and maybe exceed these distances with existing technology. Note that any probe we are likely to send for a very long time to come will be within these sorts of communication ranges.
The linked PDF you provided speculates that "object X" might be a self-obscured star, obscured by its own ejecta.
If we assume that this is indeed a dyson swarm, then the purpose might not be exclusively for collecting energy.
A category II or III civilization would be doing asto-architecture, and would need tremendous amounts of raw materials. Heavy atoms are only produced naturally in one kind of environment: in the hearts of stars. If this star is regularly expelling large quantities of cosmic dust, as the linked article postulates, then it would make an excellent "Factory". Energy would be in copious abundance, and the star itself would be churning out millions of tons of heavy atoms every minute. Even with a short (compared to other stars) lifespan, it would make an excellent factory site for other large astro-engineering projects.
Yes, that was sort of along the lines of my thought. This seems like a poor location for a long-term agricultural project, but conceivably an excellent site for astroengineering. In that case there might be detectable byproducts (for example,as you suggest, the distributions of various elements might be depleted or rearranged). Also, they might use nuclear fusion to synthesize missing very heavy elements or for some other purpose requiring high energies (there is, after all, lots of gas as well), and that might have a detectable signature at high energies.
Finally, Luc Arnold has an interesting paper about detection of artificial structures in transit about their star, and concludes that "multiple artificial objects would produce light curves easily distinguishable from natural transits." If the purpose of this megaengineering is to build structures (or coherent swarms) on a suitable scale, they might be detected in transit about the central star, which might provide the most conclusive proof of all.
A Dyson Sphere would block all light but a massive structure like in Ringworld would cause a dim band around a star rather than the brief dimming that means simply there's a planet. There's no known natural object that would block a region of a star for an extended period. A tight asteroid belt would cause dimming but not block most of the light. Look for a star with a significantly dimmed region or one that appears to be in two parts. Current telescopes would more than likely see most stars are solid even if there was a dim band so when higher powered ones become available it could be another thing to look for.
Luc Arnold looked into this and concluded that
Multiple artificial objects would produce light curves easily distinguishable from natural transits.
He is including structures like the Ring World (or the Culture's Orbitals) in such "multiple artificial objects."
The Tsar bomb (57 megatons) was about 2 x 10^17 joules. Suppose all of that energy was released as visible light at a wavelength of 0.5 microns; that's about 6 x 10^35 photons, which sounds like (and is) a lot. However, at one light year (assuming a uniform blast of radiation), that works out to 500 photons per square meter.
Now, that could be detected, if you were looking for it. At 4.4 light years (Alpha Centauri), that's 26 photons per square meter, which would be detectable with a big telescope (maybe). Go out as far as 100 light years (0.05 photons / square meter) and there is no way that could be separated from the flood of photons coming from the Sun. Also, we set off bombs on a very irregular basis (thankfully). These occasional dim flashes would have been very hard to notice and pull out of the background clutter, even with big telescopes, and even as close as Alpha Centauri. It would likewise be very hard for us to detect them, if aliens were setting them off at Alpha Centauri, even as we speak.
Now, in reality, a bomb in space puts out most of its signal at higher energies (thus smaller numbers of photons / square meter), while blasts in the atmosphere put a lot of energy into the shock wave, heating of the air and ground, etc. These are very optimistic calculations.
So, if the ETs are setting off anything like human type bombs at human type frequencies, I don't think that we are going to find them from it, even if they are doing it right next door (astronomically speaking).
Dyson spheres (or swarms) would probably be the best way to detect an advanced civilization, especially a Kardashev Type II or Type III civilization.
In a Dyson sphere (or swarm) a civilization surrounds an entire star to capture most or all of its luminosity; severely cutting down on its optical luminosity but accentuating the IR luminosity. (The physics of a rigid sphere surrounding a star are pretty challenging, and some sort of swarm or cloud seems more likely, at least to our limited technological understanding.) So, to hunt for a Dyson sphere, you look for objects with an unusual excess of IR, and a lack of optical light. The IRAS IR satellite was used to search for Dyson spheres within ~ 1000 light years of the Earth (producing a handful of so-so candidates). Carrigan calls these sorts of searches "Interstellar Archaeology." They have one great advantage in that they don't require any cooperation from the other end (i.e., no beacons or other signals).
As it happens, I have recently speculated that "Object X" in M33 (the Triangulum Galaxy) could represent the signature of a Dyson sphere / swarm from 3 million light years away. If this (unlikely) possibility were to be true, it would represent the signature of a Kardashev Type III or near Type III civilization. Interstellar Archaeology is the only possible form of SETI across such vast distances.