There are tests for inflation. Depending on the version of inflation in question one can get different predictions, but one major issue is how close to flat the universe is. Another major aspect is the exact behavior of the cosmic microwave background. Study of these issues are both ongoing.
Now, the story I’ve told you is a conservative one. In this version of the story, the fundamental constants are the same in all the different regions of the multiverse, and the other Universes have the same laws of physics—with the same quantum vacuum and all—as our own. But most of what you hear about the multiverse these days are from people who have speculated much farther than that.
They don't discuss any of the ideas about differing constants although others have done so.
Note that this isn't talking about the quantum mechanical multiverse where whenever a decoherence occurs you get branching of different copies. This is talking about a more concrete notion of multiverse where the early inflation spreads out so much that there are lots of little regions of observable space time which cannot observe each other.
This is ok. For many purposes, software improvements in terms of new algorithms that are faster and use less memory have done more for heavy-dute computation than hardware improvement has. Between 1988 and 2003, linear programmng on a standard benchmark improved by a factor of about 40 million. Out of that improvement, about 40,000 was from improvements in software and only about 1000 in hardware improvements (these numbers are partially not well-defined because there's some interaction between how one optimizes software for hardware and the reverse). See this report http://www.whitehouse.gov/sites/default/files/microsites/ostp/pcast-nitrd-report-2010.pdf. Similar remarks apply to integer factorization and a variety of other important problems.
The other important issue related to this, is that improvements in algorithms provide ever-growing returns because they can actually improve on the asymptotics, whereas any hardware improvement is a single event. And for many practical algorithms, asymptotic improvements are occurring still. Just a few days ago a new algorithm was published that was much more efficient for approximating max cut on undirected graphs. See http://arxiv.org/abs/1304.2338.
If all forms of hardware improvement stopped today, there would still be massive improvement in the next few years on what we can do with computers simply from the algorithms and software improvements.
Sure, hence I said this was evidence, not that this was a perfect argument. There are massive selection issues. And there are other issues besides. For example, you could conceive of a situation where the NAS was less likely to give membership to believers.
There's actually evidence for this sort of claim. For example the majority of American scientists are atheists or agnostics, and over the numbers for members of the National Academy of Science are even higher. See http://www.stephenjaygould.org/ctrl/news/file002.html. There's other data that suggests a similar pattern in terms of education. The GSS data shows that more educated people are less likely to believe in God. Curiously, there is evidence that people who don't self-identify as atheist or agnostic but don't identify as religious (e.g. "spiritual but not religious" or believe in God but no particular religion, or just don't care, etc.) know less about religion than most other groups, even as atheists and agnostics are some of the highest knowledge groups. See http://www.pewforum.org/2010/09/28/u-s-religious-knowledge-survey/.
Doesn't really work. Even if you go to a small scale and download into very small computers, you can still do more with a larger computer. You can always do more with more computing power.
You cannot use quantum entanglement to transmit information. You can use it to make two people have secret shared data. You can't control at all what this shared data is. The analogy that may help would be if Alice and Bob have a magic pair of coins, and it is guaranteed that if they both flip them at the same time, both coins will turn up heads or both coins will turn up tails. They cannot use this to transmit information to each other. As to your claim that "Radio transmissions are WEAK, they're probably swallowed by the outer rim of the solar system"- there's no special barrier at the end of the solar system. If there were, we'd see it blocking radio astronomy.
I think your first point is the strongest, there may not have been enough time for life to evolve to any substantial intelligence in this state. However, I'd be more worried that given a few million years to evolve, the life could then survive in areas that are more harsh. Life could never have originated in the Sahara for example, but that doesn't stop there from being life that has evolved to survive and prosper there. The last sentence is interesting: do you mean that they wipe themselves out using nuclear weapons or do you mean something else?
We don't have a complete theory of abiogenesis, true. But we don't need it to see that our plausible hypotheses don't make life arising to be that unlikely. And we have empirical evidence as well: we have traces of life that date back to very soon after Earth became hospitable. The Late Heavy Bombardment http://en.wikipedia.org/wiki/Late_Heavy_Bombardment ended some 3.8 billion years ago. The oldest fossils date to around 3.5 billion years ago. See http://www.paleosoc.org/Oldest_Fossil.pdf This suggests that life can arise in under 300 million years. It is possible of course that life arose during the LHB, and we cannot rule out panspermia. But together with the fact that many of the basic chemicals (e.g. many amino acid) used in life are not much more complicated than those that occur through non-living processes, we shouldn't at all expect there to be some magic time period it takes before life can form.
As to your statement that "primordial soup experiment was bullshit"- I presume you are taking about the Miller-Urey experiments http://en.wikipedia.org/wiki/Miller-Urey_experiment. Why don't I just quote from the introduction of that Wikipedia article.
After Miller's death in 2007, scientists examining sealed vials preserved from the original experiments were able to show that there were actually well over 20 different amino acids produced in Miller's original experiments. That is considerably more than what Miller originally reported, and more than the 20 that naturally occur in life.[7] Moreover, some evidence suggests that Earth's original atmosphere might have had a different composition from the gas used in the Miller–Urey experiment. There is abundant evidence of major volcanic eruptions 4 billion years ago, which would have released carbon dioxide (CO2), nitrogen (N2), hydrogen sulfide (H2S), and sulfur dioxide (SO2) into the atmosphere. Experiments using these gases in addition to the ones in the original Miller–Urey experiment have produced more diverse molecules.[8]
You may want to look at the section "Other experiments http://en.wikipedia.org/wiki/Miller-Urey_experiment#Other_experiments.
So, yes by all means, please point me and others where to go to read up on how Milley's work was "bullshit" since I don't see it in any of the obvious places.
The issue isn't the use of radio waves as an incidental. Radio waves come out from deliberate attempts by civilizations try to set up beacons and say "Hey! We're here." I agree that are normal radio use is insufficient to be detected. Heck, even if you were at Alpha Centauri, telling that our radio transmissions are not natural would be tough. As to the large scale projects in question, simply calling them myths and saying "lol" is not a logical response, but essentially the absurdity heuristic http://lesswrong.com/lw/j4/absurdity_heuristic_absurdity_bias/. As to stellar lifting, you could instead of just declaring your ignorance spend a few seconds Googling or looking at Wikipedia. See here: https://en.wikipedia.org/wiki/Stellar_uplift. And no, you don't generally do stellar uplifting to your own home star (unless you are doing something to extend its lifespan which seems dubious). You'd do stellar uplifting and similar techniques to get useful mass out of stars that don't have habitable planets near them (at least if you were remotely ethical from a human standpoint).
Radio waves aren't useful as much as a method of communication from incidental power. Indeed, even in the last few years, as our radio systems have become more efficient, Earth has become on many frequencies darker than it was in the 1960s. The key isn't use of radio waves as an incidental, but as a method a culture might deliberately use to say "hey! Look! We're out here!" As to Dyson spheres, they are one example of many possible large scale projects, but I'm curious why you consider them in particular to be "obserd[sic] joke"- they are if possible, an extremely useful way of using a large amount of available energy.
, it's just not possible to build the kind of things you'd see at stellar distances.
I'm curious why you think that given that for example a small Class A stellar engine https://en.wikipedia.org/wiki/Stellar_engine appears to be buildable with what we know about materials science. And this isn't the only example of such. The requirements are purely on the amount of resources that need to go in, not physical limitations. Yes, some specific suggestions would require materials that look impossible. For example, an inflexible single piece ringworld is likely to be impossible (the tensile strength among other requirements make it implausible). But many megascale structures aren't in that category.
But let me guess, you believe the aliens use magical particles like tachyons and gravitons to communicate and we're just too stupid to figure it out but when we do we'll be invited to the galactic fraternity, right?
No. Absolutely not. First note that tachyons and gravitons aren't "magical" there's a massive difference between theoretical particles consistent with the laws of physics. It is likely that tachyons do not exist, since they'd either allow causality violations (unlikely) or they'd not allow communication. Similarly, thinking that one could use something like gravitons to communicate is just silly since they'd be incredibly weak.
I don't have any belief in some galactic fraternity, but your attempt to pigeon hole rather than read what people write is interesting. Concerns about the Great Filter arise specifically from there being no evidence of anything remotely like that. If there were any reason to think that was at all likely, we could breath a lot easier.
For the record I think that there is life everywhere in the universe because the laws of physics will be the same.
So, we're in complete agreement here. But the problem is what this leads to: it means that out of the civilizations, none of them are trying anything on a large scale, not even the few more ambitious ones. This suggests that once life gets sufficiently advanced, it gets wiped out somehow. The Great Filter is a serious problem: Nick Bostrom and his colleagues at the Future of Humanity Institute for example have given this a lot of thought. See for example http://www.nickbostrom.com/extraterrestrial.pdf. And this is very much the sort of problem where if it exists, pretending it doesn't won't make it go away.
Doesn't work. It isn't just a lack of Dyson spheres. It is a complete lack of any signs of artificial structure, or of use of the vast amounts of energy available from stars. As far as we can tell, everything looks natural.
This is pretty scary. One of the major unsolved problems right now is the Fermi problem- why we don't see any signs of civilizations other than our own, not just no radio transmissions but no Dyson spheres (and yes, we've looked http://home.fnal.gov/~carrigan/infrared_astronomy/Fermilab_search.htm, stellar uplifting, ringworlds or the like. Whatever is blocking this is the so-called Great Filter https://en.wikipedia.org/wiki/Great_Filter. Now, some of the Filter could be in our past. It may be tough for life to arise or for multicellular life to arise, etc. However, the more disturbing possibility is that it exists in our future: maybe civilizations before they can spread out manage to wipe themselves out with their technologies, such as through nuclear war, bad nanotech, engineered bioweapons, resource depletion, environmental damage, or something we haven't even thought about before.
Over the last few years, more and more evidence has suggested that a lot of the obvious filtration events in the past aren't serious filters. For example, we've found that planets are common. This is not only an example of more such evidence, but it suggests that if life got started it would have had billions years more to evolve, meaning that evolutionarily based filters will be substantially less effective. Worse, it undermines one of the easier ways to try and get around a filter, to suggest that the conditions for complex life didn't arise until recently. There are serious problems with that idea already (especially the fact that life on Earth spent hundreds of millions of years in near stasis), and this makes those problems even more severe. If this checks out, it will be strong evidence that a substantial portion of the filter is in the future. If so, it is likely that the Filter is something that is going to happen to us within the next few hundred years, since it gets harder to wipe out a civilization once they spread beyond their initial planet, and most obvious things that would do so are also more noticeable.
One of the strangest things about the hexagon is that other gas giants don't see to have anything like it. And it rotates with the same period as Saturn's natural radio emissions, which is not the period of rotation of Saturn itself. See http://www.sciencemag.org/content/247/4947/1206. Also, relevant SMBC: http://www.smbc-comics.com/?id=1930.
So, aside from the issues already pointed out (you weren't running a 600 hp car), it is worth noting that actually a lot of older cars really were terribly unsafe to the point where we'd likely find them unacceptable for large-scale modern use. The technology has been steadily improving. The likelyhood that you will die car in accident in the US has been going down since the late 1960s, and that's even as the amount of driving per a person has gone up. See http://en.wikipedia.org/wiki/List_of_motor_vehicle_deaths_in_U.S._by_year for example.
Well, let's see, Warren Buffet and Bill Gates have both been heavily involved in massive charity to the developing world, especially in regards to malaria. Apparently some billionaires are more than willing to do so without having guns pointed at them. And then there's the Giving Pledge http://givingpledge.org/ where a group of wealthy philanthropists have committed to giving most of their wealth to charity. That motivation is clearly partially out of peer pressure. So apparently peer pessure and empathy both work to get billionaires to listen, which is just like how normal people work. Imagine that. Of course, none of this is at all relevant to the issue at an, since neither assisted suicide laws nor the vast majority of our other laws are decided on by billionaires.
At this point, we have a pretty good understanding of using genetics to estimate roughly when two populations diverged. If we find such life, we can first test if it at all resembles Earth life. If it does (in the sense that it uses most of the same amino acids, and uses similar machinery for DNA and replicating DNA), then we should be able to get a rough estimate of when it separated from Earth life based on how genetically different it is. There will be some difficulty with this sort of technique, since the life on alien worlds may be subject to extreme selection pressures, but that should be something we can roughly account for.
On the contrary, if you talk to the people who are doing this, many of them acknowledge that something might not work, and they are eager for that because it would be a glimpse of new physics. At this point, we know that the Standard Model isn't all there is, but we don't know exactly where it breaks down. If we can set up what should be fully functioning quantum computers and then they don't do what we want, that will be Nobel Prize level discoveries by itself. As to your last bit, I don't know what you mean by "failing to take into account the effects of the outside world"- if anything quantum mechanical demonstrations generally require very careful consideration of external effects, because superposition breaks down very easily when contact with outside objects occurs. As to the claim that there's any sort of "cloak" or "thick armor of complexity"-most of the math involved doesn't require anything beyond linear algebra, but it is worth considering that somethings in life have complicated math because they are genuinely complicated.
Actually, this does not follow either. Right now it is open if BQP (the set of decision problems solveable by a quantum computer in polynomial time http://en.wikipedia.org/wiki/BQP) lives in the polynomial hierarchy http://en.wikipedia.org/wiki/PH_(complexity). Most complexity classes we care about live between P and NP, but it turns out that PH (a class believed to be much larger than even NP) will also collapse to P if P=NP, so there are larger complexity classes that also collapse if P=NP. However, it is open as to whether BQP lives in PH. So it is consistent with what we know now for it to be true that P=NP but BQP != P. That would be a weird situation, but possible.
But we have gotten quantum mechanics to work well on single particles. There have been many experiments involving individual electrons or individual photons (fewer with photons since it is very difficult to send out a single photon). Moreover, this actually misses what quantum computers rely on: they aren't relying on the behavior of the individual particle as much as on the entangled state, exactly where you seem to think that the statistics works well. You may also want to look into Boson Sampling http://www.scottaaronson.com/papers/optics.pdf a very neat process which lets us verify in a very controlled setting that quantum systems can be used to compute classically difficult stuff. For small numbers of photons, Boson Sampling has been verified to do exactly this in experimental contexts: http://www.nature.com/nphoton/journal/v7/n7/full/nphoton.2013.102.html
But we cannot depend on success any more than buying a lottery ticket to feed a family.
No one is saying that we should "depend" on it. And there are serious physicists and mathematicians who do doubt that these systems will ever work, but most of that concern is practical: that the fundamental difficulties involved are just too big to ever scale to practical sizes.
Because my career isn't in theoretical physics, I can get away with making controversial statements that at least should be considered.
That you can "get away" with something isn't a reason to do it. And if your career isn't in theoretical physics, computer science, math, or particle physics, then that's all the more reason you shouldn't throw out controversial statements as gospel when they likely are wrong. There's a massive difference between "We should consider if maybe X is true" and "X is true."
So, the result for encryption may not be that large, but that's by far not the only thing that people want to use quantum computers for. They can be used to optimize a number of problems that show up in real world conditions, and do quantum simulations for chemistry where actually observing the reactions in detail would be too difficult.
Your point that the word "quantum" originally referred to the discretized nature of energy states is true but unhelpful. Words have distinct meanings apart from their etymology. Don't think that because scientists started using a word because of it having one Greek root doesn't mean they cannot use the word in a more general context when they are clear about what they mean.
The underpinning of quantum computing is the idea that a qubit has the ability to be in more than one state simultaneously. This is simply illogical. Don't shrug it off and say "things work counter-intuitively at the subatomic level"; that's a philosophical cop out and is not science.
Actually, if anything, this is a biological/psychological statement. You are confusing logic with intuition. Humans evolved on the medium scale, where things aren't very large or very small, not very hot and not very cold, etc. So we have good physical intuition there. You shouldn't expect your intuition to be more than a rough guide outside that range. When math and empirical experiments contradict intuition, the thing that needs to be adjusted is almost invariably intuition, not math.
Quantum superposition is a useful statistical tool and that is all
So, whether or not some deep weird thing is happening, if you agree that these statistics do describe accurately what results to get, then you should expect a quantum computer work. But it may be worth noting that this is a common response to things people don't like. When the Copernican system arose, people tried to argue that it should be seen as only a calculational tool, rather than an actual description of the solar system, and that got extended even to Kepler's system. Similarly, in the 19th century, people suggested that one should view atoms as a convenient fiction. In general, arguing that some state of nature implied by a model is fictitious even while you think that the model gives near perfect descriptions has a bad track record. The only times this turns out to be the case is when it turns out something is genuinely wrong with the model itself, such as the plum-pudding model of the atom. But in fact this is part of why physicists are interested in quantum computers- they provide a novel way of testing how quantum mechanics functions. If in fact it turns out that they don't do what we expect them to do, then that will mean basic aspects of physics as we understand them are wrong, and so we'll learn from that.
Er, "strongly conjectured to occur" should be "strongly conjectured to *not occur*. Need to proofread more when using preview. Also, as long as I'm replying to myself, note that the set of problems which can be solved easily by a quantum computer is BQP http://en.wikipedia.org/wiki/BQP, but it is likely that for many practical applications, one will want the set of problems where a quantum computer can quickly convince a classical computer that it really has a solution, and this set, ZBQP, is likely much much smaller https://complexityzoo.uwaterloo.ca/Complexity_Zoo:Z#zbqp. Factoring lives in this smaller set because the classical computer can check the quantum computer's work essentially by just multiplying together the factors given by the quantum machine.
Slashdot Mirror
There are tests for inflation. Depending on the version of inflation in question one can get different predictions, but one major issue is how close to flat the universe is. Another major aspect is the exact behavior of the cosmic microwave background. Study of these issues are both ongoing.
Now, the story I’ve told you is a conservative one. In this version of the story, the fundamental constants are the same in all the different regions of the multiverse, and the other Universes have the same laws of physics—with the same quantum vacuum and all—as our own. But most of what you hear about the multiverse these days are from people who have speculated much farther than that.
They don't discuss any of the ideas about differing constants although others have done so.
Note that this isn't talking about the quantum mechanical multiverse where whenever a decoherence occurs you get branching of different copies. This is talking about a more concrete notion of multiverse where the early inflation spreads out so much that there are lots of little regions of observable space time which cannot observe each other.
This is ok. For many purposes, software improvements in terms of new algorithms that are faster and use less memory have done more for heavy-dute computation than hardware improvement has. Between 1988 and 2003, linear programmng on a standard benchmark improved by a factor of about 40 million. Out of that improvement, about 40,000 was from improvements in software and only about 1000 in hardware improvements (these numbers are partially not well-defined because there's some interaction between how one optimizes software for hardware and the reverse). See this report http://www.whitehouse.gov/sites/default/files/microsites/ostp/pcast-nitrd-report-2010.pdf. Similar remarks apply to integer factorization and a variety of other important problems.
The other important issue related to this, is that improvements in algorithms provide ever-growing returns because they can actually improve on the asymptotics, whereas any hardware improvement is a single event. And for many practical algorithms, asymptotic improvements are occurring still. Just a few days ago a new algorithm was published that was much more efficient for approximating max cut on undirected graphs. See http://arxiv.org/abs/1304.2338.
If all forms of hardware improvement stopped today, there would still be massive improvement in the next few years on what we can do with computers simply from the algorithms and software improvements.
Sure, hence I said this was evidence, not that this was a perfect argument. There are massive selection issues. And there are other issues besides. For example, you could conceive of a situation where the NAS was less likely to give membership to believers.
There's actually evidence for this sort of claim. For example the majority of American scientists are atheists or agnostics, and over the numbers for members of the National Academy of Science are even higher. See http://www.stephenjaygould.org/ctrl/news/file002.html. There's other data that suggests a similar pattern in terms of education. The GSS data shows that more educated people are less likely to believe in God. Curiously, there is evidence that people who don't self-identify as atheist or agnostic but don't identify as religious (e.g. "spiritual but not religious" or believe in God but no particular religion, or just don't care, etc.) know less about religion than most other groups, even as atheists and agnostics are some of the highest knowledge groups. See http://www.pewforum.org/2010/09/28/u-s-religious-knowledge-survey/.
Doesn't really work. Even if you go to a small scale and download into very small computers, you can still do more with a larger computer. You can always do more with more computing power.
You cannot use quantum entanglement to transmit information. You can use it to make two people have secret shared data. You can't control at all what this shared data is. The analogy that may help would be if Alice and Bob have a magic pair of coins, and it is guaranteed that if they both flip them at the same time, both coins will turn up heads or both coins will turn up tails. They cannot use this to transmit information to each other. As to your claim that "Radio transmissions are WEAK, they're probably swallowed by the outer rim of the solar system"- there's no special barrier at the end of the solar system. If there were, we'd see it blocking radio astronomy.
I think your first point is the strongest, there may not have been enough time for life to evolve to any substantial intelligence in this state. However, I'd be more worried that given a few million years to evolve, the life could then survive in areas that are more harsh. Life could never have originated in the Sahara for example, but that doesn't stop there from being life that has evolved to survive and prosper there. The last sentence is interesting: do you mean that they wipe themselves out using nuclear weapons or do you mean something else?
We don't have a complete theory of abiogenesis, true. But we don't need it to see that our plausible hypotheses don't make life arising to be that unlikely. And we have empirical evidence as well: we have traces of life that date back to very soon after Earth became hospitable. The Late Heavy Bombardment http://en.wikipedia.org/wiki/Late_Heavy_Bombardment ended some 3.8 billion years ago. The oldest fossils date to around 3.5 billion years ago. See http://www.paleosoc.org/Oldest_Fossil.pdf This suggests that life can arise in under 300 million years. It is possible of course that life arose during the LHB, and we cannot rule out panspermia. But together with the fact that many of the basic chemicals (e.g. many amino acid) used in life are not much more complicated than those that occur through non-living processes, we shouldn't at all expect there to be some magic time period it takes before life can form.
As to your statement that "primordial soup experiment was bullshit"- I presume you are taking about the Miller-Urey experiments http://en.wikipedia.org/wiki/Miller-Urey_experiment. Why don't I just quote from the introduction of that Wikipedia article.
After Miller's death in 2007, scientists examining sealed vials preserved from the original experiments were able to show that there were actually well over 20 different amino acids produced in Miller's original experiments. That is considerably more than what Miller originally reported, and more than the 20 that naturally occur in life.[7] Moreover, some evidence suggests that Earth's original atmosphere might have had a different composition from the gas used in the Miller–Urey experiment. There is abundant evidence of major volcanic eruptions 4 billion years ago, which would have released carbon dioxide (CO2), nitrogen (N2), hydrogen sulfide (H2S), and sulfur dioxide (SO2) into the atmosphere. Experiments using these gases in addition to the ones in the original Miller–Urey experiment have produced more diverse molecules.[8]
You may want to look at the section "Other experiments http://en.wikipedia.org/wiki/Miller-Urey_experiment#Other_experiments. So, yes by all means, please point me and others where to go to read up on how Milley's work was "bullshit" since I don't see it in any of the obvious places.
The issue isn't the use of radio waves as an incidental. Radio waves come out from deliberate attempts by civilizations try to set up beacons and say "Hey! We're here." I agree that are normal radio use is insufficient to be detected. Heck, even if you were at Alpha Centauri, telling that our radio transmissions are not natural would be tough. As to the large scale projects in question, simply calling them myths and saying "lol" is not a logical response, but essentially the absurdity heuristic http://lesswrong.com/lw/j4/absurdity_heuristic_absurdity_bias/. As to stellar lifting, you could instead of just declaring your ignorance spend a few seconds Googling or looking at Wikipedia. See here: https://en.wikipedia.org/wiki/Stellar_uplift. And no, you don't generally do stellar uplifting to your own home star (unless you are doing something to extend its lifespan which seems dubious). You'd do stellar uplifting and similar techniques to get useful mass out of stars that don't have habitable planets near them (at least if you were remotely ethical from a human standpoint).
Radio waves aren't useful as much as a method of communication from incidental power. Indeed, even in the last few years, as our radio systems have become more efficient, Earth has become on many frequencies darker than it was in the 1960s. The key isn't use of radio waves as an incidental, but as a method a culture might deliberately use to say "hey! Look! We're out here!" As to Dyson spheres, they are one example of many possible large scale projects, but I'm curious why you consider them in particular to be "obserd[sic] joke"- they are if possible, an extremely useful way of using a large amount of available energy.
, it's just not possible to build the kind of things you'd see at stellar distances.
I'm curious why you think that given that for example a small Class A stellar engine https://en.wikipedia.org/wiki/Stellar_engine appears to be buildable with what we know about materials science. And this isn't the only example of such. The requirements are purely on the amount of resources that need to go in, not physical limitations. Yes, some specific suggestions would require materials that look impossible. For example, an inflexible single piece ringworld is likely to be impossible (the tensile strength among other requirements make it implausible). But many megascale structures aren't in that category.
But let me guess, you believe the aliens use magical particles like tachyons and gravitons to communicate and we're just too stupid to figure it out but when we do we'll be invited to the galactic fraternity, right?
No. Absolutely not. First note that tachyons and gravitons aren't "magical" there's a massive difference between theoretical particles consistent with the laws of physics. It is likely that tachyons do not exist, since they'd either allow causality violations (unlikely) or they'd not allow communication. Similarly, thinking that one could use something like gravitons to communicate is just silly since they'd be incredibly weak. I don't have any belief in some galactic fraternity, but your attempt to pigeon hole rather than read what people write is interesting. Concerns about the Great Filter arise specifically from there being no evidence of anything remotely like that. If there were any reason to think that was at all likely, we could breath a lot easier.
For the record I think that there is life everywhere in the universe because the laws of physics will be the same.
So, we're in complete agreement here. But the problem is what this leads to: it means that out of the civilizations, none of them are trying anything on a large scale, not even the few more ambitious ones. This suggests that once life gets sufficiently advanced, it gets wiped out somehow. The Great Filter is a serious problem: Nick Bostrom and his colleagues at the Future of Humanity Institute for example have given this a lot of thought. See for example http://www.nickbostrom.com/extraterrestrial.pdf. And this is very much the sort of problem where if it exists, pretending it doesn't won't make it go away.
Doesn't work. It isn't just a lack of Dyson spheres. It is a complete lack of any signs of artificial structure, or of use of the vast amounts of energy available from stars. As far as we can tell, everything looks natural.
This is pretty scary. One of the major unsolved problems right now is the Fermi problem- why we don't see any signs of civilizations other than our own, not just no radio transmissions but no Dyson spheres (and yes, we've looked http://home.fnal.gov/~carrigan/infrared_astronomy/Fermilab_search.htm, stellar uplifting, ringworlds or the like. Whatever is blocking this is the so-called Great Filter https://en.wikipedia.org/wiki/Great_Filter. Now, some of the Filter could be in our past. It may be tough for life to arise or for multicellular life to arise, etc. However, the more disturbing possibility is that it exists in our future: maybe civilizations before they can spread out manage to wipe themselves out with their technologies, such as through nuclear war, bad nanotech, engineered bioweapons, resource depletion, environmental damage, or something we haven't even thought about before.
Over the last few years, more and more evidence has suggested that a lot of the obvious filtration events in the past aren't serious filters. For example, we've found that planets are common. This is not only an example of more such evidence, but it suggests that if life got started it would have had billions years more to evolve, meaning that evolutionarily based filters will be substantially less effective. Worse, it undermines one of the easier ways to try and get around a filter, to suggest that the conditions for complex life didn't arise until recently. There are serious problems with that idea already (especially the fact that life on Earth spent hundreds of millions of years in near stasis), and this makes those problems even more severe. If this checks out, it will be strong evidence that a substantial portion of the filter is in the future. If so, it is likely that the Filter is something that is going to happen to us within the next few hundred years, since it gets harder to wipe out a civilization once they spread beyond their initial planet, and most obvious things that would do so are also more noticeable.
One of the strangest things about the hexagon is that other gas giants don't see to have anything like it. And it rotates with the same period as Saturn's natural radio emissions, which is not the period of rotation of Saturn itself. See http://www.sciencemag.org/content/247/4947/1206. Also, relevant SMBC: http://www.smbc-comics.com/?id=1930.
So, aside from the issues already pointed out (you weren't running a 600 hp car), it is worth noting that actually a lot of older cars really were terribly unsafe to the point where we'd likely find them unacceptable for large-scale modern use. The technology has been steadily improving. The likelyhood that you will die car in accident in the US has been going down since the late 1960s, and that's even as the amount of driving per a person has gone up. See http://en.wikipedia.org/wiki/List_of_motor_vehicle_deaths_in_U.S._by_year for example.
Well, let's see, Warren Buffet and Bill Gates have both been heavily involved in massive charity to the developing world, especially in regards to malaria. Apparently some billionaires are more than willing to do so without having guns pointed at them. And then there's the Giving Pledge http://givingpledge.org/ where a group of wealthy philanthropists have committed to giving most of their wealth to charity. That motivation is clearly partially out of peer pressure. So apparently peer pessure and empathy both work to get billionaires to listen, which is just like how normal people work. Imagine that. Of course, none of this is at all relevant to the issue at an, since neither assisted suicide laws nor the vast majority of our other laws are decided on by billionaires.
At this point, we have a pretty good understanding of using genetics to estimate roughly when two populations diverged. If we find such life, we can first test if it at all resembles Earth life. If it does (in the sense that it uses most of the same amino acids, and uses similar machinery for DNA and replicating DNA), then we should be able to get a rough estimate of when it separated from Earth life based on how genetically different it is. There will be some difficulty with this sort of technique, since the life on alien worlds may be subject to extreme selection pressures, but that should be something we can roughly account for.
On the contrary, if you talk to the people who are doing this, many of them acknowledge that something might not work, and they are eager for that because it would be a glimpse of new physics. At this point, we know that the Standard Model isn't all there is, but we don't know exactly where it breaks down. If we can set up what should be fully functioning quantum computers and then they don't do what we want, that will be Nobel Prize level discoveries by itself. As to your last bit, I don't know what you mean by "failing to take into account the effects of the outside world"- if anything quantum mechanical demonstrations generally require very careful consideration of external effects, because superposition breaks down very easily when contact with outside objects occurs. As to the claim that there's any sort of "cloak" or "thick armor of complexity"-most of the math involved doesn't require anything beyond linear algebra, but it is worth considering that somethings in life have complicated math because they are genuinely complicated.
Actually, this does not follow either. Right now it is open if BQP (the set of decision problems solveable by a quantum computer in polynomial time http://en.wikipedia.org/wiki/BQP) lives in the polynomial hierarchy http://en.wikipedia.org/wiki/PH_(complexity). Most complexity classes we care about live between P and NP, but it turns out that PH (a class believed to be much larger than even NP) will also collapse to P if P=NP, so there are larger complexity classes that also collapse if P=NP. However, it is open as to whether BQP lives in PH. So it is consistent with what we know now for it to be true that P=NP but BQP != P. That would be a weird situation, but possible.
But we cannot depend on success any more than buying a lottery ticket to feed a family.
No one is saying that we should "depend" on it. And there are serious physicists and mathematicians who do doubt that these systems will ever work, but most of that concern is practical: that the fundamental difficulties involved are just too big to ever scale to practical sizes.
Because my career isn't in theoretical physics, I can get away with making controversial statements that at least should be considered.
That you can "get away" with something isn't a reason to do it. And if your career isn't in theoretical physics, computer science, math, or particle physics, then that's all the more reason you shouldn't throw out controversial statements as gospel when they likely are wrong. There's a massive difference between "We should consider if maybe X is true" and "X is true."
So, the result for encryption may not be that large, but that's by far not the only thing that people want to use quantum computers for. They can be used to optimize a number of problems that show up in real world conditions, and do quantum simulations for chemistry where actually observing the reactions in detail would be too difficult.
The underpinning of quantum computing is the idea that a qubit has the ability to be in more than one state simultaneously. This is simply illogical. Don't shrug it off and say "things work counter-intuitively at the subatomic level"; that's a philosophical cop out and is not science.
Actually, if anything, this is a biological/psychological statement. You are confusing logic with intuition. Humans evolved on the medium scale, where things aren't very large or very small, not very hot and not very cold, etc. So we have good physical intuition there. You shouldn't expect your intuition to be more than a rough guide outside that range. When math and empirical experiments contradict intuition, the thing that needs to be adjusted is almost invariably intuition, not math.
Quantum superposition is a useful statistical tool and that is all
So, whether or not some deep weird thing is happening, if you agree that these statistics do describe accurately what results to get, then you should expect a quantum computer work. But it may be worth noting that this is a common response to things people don't like. When the Copernican system arose, people tried to argue that it should be seen as only a calculational tool, rather than an actual description of the solar system, and that got extended even to Kepler's system. Similarly, in the 19th century, people suggested that one should view atoms as a convenient fiction. In general, arguing that some state of nature implied by a model is fictitious even while you think that the model gives near perfect descriptions has a bad track record. The only times this turns out to be the case is when it turns out something is genuinely wrong with the model itself, such as the plum-pudding model of the atom. But in fact this is part of why physicists are interested in quantum computers- they provide a novel way of testing how quantum mechanics functions. If in fact it turns out that they don't do what we expect them to do, then that will mean basic aspects of physics as we understand them are wrong, and so we'll learn from that.
Er, "strongly conjectured to occur" should be "strongly conjectured to *not occur*. Need to proofread more when using preview. Also, as long as I'm replying to myself, note that the set of problems which can be solved easily by a quantum computer is BQP http://en.wikipedia.org/wiki/BQP, but it is likely that for many practical applications, one will want the set of problems where a quantum computer can quickly convince a classical computer that it really has a solution, and this set, ZBQP, is likely much much smaller https://complexityzoo.uwaterloo.ca/Complexity_Zoo:Z#zbqp. Factoring lives in this smaller set because the classical computer can check the quantum computer's work essentially by just multiplying together the factors given by the quantum machine.