Solar thermal doesn't have as extreme intermittency problems as panels but it still has them. You see a power drop off as the night progresses, and cold spells with clouds can still lead to dips. This is why a lot of solar thermal actually includes direct heating elements being heated by burning fossil fuels http://www.volker-quaschning.de/articles/fundamentals2/index_e.php. So if one of your goals is to get rid of fossil fuel use, then you cannot use solar thermal unless you are willing to have a substantial dip. It is true that solar thermal does extend until late at night, and the latest hours in any given area people aren't using much power at all. But it then takes time to get really functioning quickly in the early morning. Worse, if one was to use this to power much of Asia then one wouldn't even have the advantage that the time when it is less functioning is when there's less power use.
And yes, HVDC is better than long-distance AC. That doesn't make transmission a solved problem. Far from it. It is more efficient, but there are still substantial energy losses. Moreover, HVDC has lower availability, due to more complicated equipment (although it is getting better and should be close to parity soon). They require specialized HVDC converter stations https://en.wikipedia.org/wiki/HVDC_converter_station which cause additional losses, Power flow control is also more difficult.
One big disadvantage of solar power is that it only works some of the time. The intermittent nature of both solar and wind is a serious problem. There's some amount that they help each other out, because in many locations the wind is strongest at night. Because of the intermittent nature of solar power, one cannot have large scale grids be completely solar without a lot of improvements in storage technology. Right now, battery technology is improving but it isn't where it needs to be. The best storage for most purposes right now is pumped hydroelectric https://en.wikipedia.org/wiki/Pumped-storage_hydroelectricity where one pumps water high up to a reserve when there is excess and then recovers it using a hydroelectric plant. This is more efficient than batteries. However, it requires specific geology to work well.
The other big issue with this plan is an issue is efficient transmission. If you are putting a large fraction of the entire world's power in one area, you are going to need to have massive transmission lines. Transmission is a major loss of power already. There have been small scale projects to use superconductors for transmission lines which need to be kept very cold but have very high efficiency. Holbrook Substation in Long Island for example has a 600 meter long superconducting line https://en.wikipedia.org/wiki/Holbrook_Superconductor_Project but this is literally multiple orders of magnitude smaller than the distances needed for the proposal,some of which would likely need to go underwater, and there has never been a serious superconducting line run underwater.
There's a lot wrong with this. First of all, you cannot use entanglement to transmit information. This is a theorem https://en.wikipedia.org/wiki/No-communication_theorem and this is closely related to this xkcd https://xkcd.com/1591/. Moreover, even if you timetravel, you don't automatically learn everything. In fact we know that closed-time-like curves make classical and quantum computing essentially equivalent http://www.scottaaronson.com/papers/ctc.pdf and you can then perform PSPACE computations in polynomial time, which is a hell of a lot, but that's not everything. You can't for example for a given Go position determine who will win efficiently (assuming you are playing with the generalized ko rule).
We are at least 50 years off from strong AI as in human level common sense about the world.
How certain of that are you? Are you willing to bet all of humanity on that? Experts disagree a lot about when we will have strong AI https://intelligence.org/2013/05/15/when-will-ai-be-created/. If it turns out to be sooner then this isn't a good situation.
Energy density is not all that matters, and even energy density is *complicated.* One can have high energy density if one looks at maximum energy per mass, or per volume, and depending on the application and how different they are one or the other can matter, which is why tables generally include both https://en.wikipedia.org/wiki/Energy_density#Energy_densities_of_common_energy_storage_materials . But even aside from energy density one has other issues, like recharge time and lifespan. It doesn't matter if you can make a battery with very high energy density but with a very short lifespan. In general, I'm skeptical of claims of massive improvement in batteries. As with new solar systems, if every single in-lab claimed battery improvement all were genuine and implementable we'd have solves all the world's energy problems years ago.
They don't mean blind in the sense of giving the detector so many photons that it is blinded but rather by cleverly adding a small number of extra photons they can make the detectors think everything is ok.
It depends how long term your outlook is. Nothing here will be practical for at least a decade and very likely more. But once quantum computers become a practical thing, there are going to be a lot of uses (e.g. factoring large numbers using Shor's algorithm https://en.wikipedia.org/wiki/Shor's_algorithm, and detailed molecular simulation). Note that one thing we don't expect to see is extreme speedup of generic NP-complete problems, although the popular press often says otherwise. Also, as with any computer technology, once the technology becomes more common, people will have more of an incentive to find uses for it. GPUs are a fun example of that: made for a very narrow purpose, but once they were made, people quickly started realizing they could do other things with them. Quantum computers will likely be in a similar boat.
So they claim it isn't the whole story, which seems fair. North Carolina in general has been very good about solar, and they've installed a massive amount in the state (to the point where they are running into problems with lack of storage during peak sunlight). However, the primary backlash was not so directed at the town as much as that one had many different people in the town saying really stupid things. Let's not forget that one of them was a retired science teacher. From the original article that started it all: http://www.roanoke-chowannewsherald.com/2015/12/08/woodland-rejects-solar-farm/:
Jane Mann said she is a local native and is concerned about the plants that make the community beautiful.
She is a retired Northampton science teacher and is concerned that photosynthesis, which depends upon sunlight, would not happen and would keep the plants from growing. She said she has observed areas near solar panels where the plants are brown and dead because they did not get enough sunlight.
She also questioned the high number of cancer deaths in the area, saying no one could tell her that solar panels didn’t cause cancer."
It sounds to me like this backlash is mainly pretty deserved. Even if they had legitimate reasons to say no to this new solar, it is clear that those were not the reasons articulated by the people in question.
It is even stupider than that because Musk is a major proponent of alternative energy and getting rid of the internal combustion engine (hence Tesla) precisely because he's concerned about global warming. So even if this did make sense (and it doesn't for the reasons you correctly identified) they'd still have the wrong billionaire.
This doesn't really deal with the real issue, the fact that the vast majority of what D-Wave is doing is complete hype with a very tiny chance of having any practical impacts. It isn't even clear that the type of problems D-Wave's machines can handle are problems where we should expect any substantial speedup from quantum computers. D-Wave's latest attempt at claiming that their computers show noticeable speedup is less lacking than some of their previous claims, but still not at all impressive. See Scott Aaronson's blog post http://www.scottaaronson.com/blog/?p=2535 where he notes that the D-Wave machine both doesn't give any apparent asymptotic speedup and is beaten by the best classical computers. The real question isn't security but why NASA is wasting money on this instead of more promising quantum computing research.
I agree that the total cost from MAW is relatively small. I'm not sure your metric is necessarily the bestf one looks not at all cancer funding but cancer research in children, one gets a much larger fraction. About 5% of all funding is for children's cancer (http://www.stbaldricks.org/filling-the-funding-gap/ says 4%) so this would be about 20% of funding for children's cancer. That may not be the best metric, because much cancer research applies to cancers at a broad age range, so I think I'd agree that the total amount is relatively small. According to Makke a Wish's own description they make one wish on average every 37 minutes http://wish.org/about-us which means they are making wishes for about 20,000 kids a year. In contrast, as the above link to St. Baldrick's notes, even for just St. B they came up about 8 million dollars short of funding all of the grant proposals that got considered to be outstanding. And they are very much not the only example of this sort of thing.
On the other hand, there's a serious problem in at least allied fields where people claim that their basic research is cancer related so they can more easily get grant money. In my own field, math, one has people doing all sorts of abstract stats or imaging work or differential equation modeling which people claim is cancer related, and it generally is related in the sense that one specific application might be some sort of cancer research. So that suggests that in some respects funding is actually over-saturated in which case Make A Wish isn't doing that much direct harm.
One of the big apparent complaints is Gates focus on infectious rather than chronic diseases. From the article:
The same is true when it comes to the foundation’s work in public health. As McGoey briefly acknowledges, the foundation’s investment of more than $15 billion in this field “has done considerable good.” That seems an understatement. Thanks in part to the Gateses’ strong investment in vaccines for infectious diseases, deaths from measles in Africa have dropped by 90 percent since 2000. Over the last quarter century, tuberculosis mortality worldwide has fallen by 45 percent, while over the last dozen years the number of new malaria cases has dropped by 30 percent. And polio, which in 1988 was endemic in 125 countries, is today endemic in only two. The foundation has also played an important part in fighting the spread of HIV and helping those infected with the virus to lead productive lives. For this, Bill and Melinda Gates deserve much credit.
So far so good.
The question is, has this been the best use of their money? As McGoey notes, chronic diseases, as opposed to communicable ones, exact a staggering toll worldwide, yet the foundation has invested less than 4 percent of its funding in research on them, and the global health community has largely followed suit. “The failure to combat obesity, cancer and heart disease epidemics in poor nations,” she observes, “has been one of the most glaring mistakes of global development efforts in recent years.” An equally serious shortcoming has been the neglect of primary-care facilities in the developing world. The initial problems that the nations of West Africa faced in combating the Ebola outbreak stemmed in part from the weaknesses in their overall health systems. Interestingly, in late September, the Gates Foundation, together with WHO and the World Bank, announced a joint partnership aimed at improving access to primary care in poor and middle-income countries — a dramatic (if tacit) acknowledgement that the emphasis on fighting individual diseases has been too narrow.
The primary reason it makes sense to focus on infectious diseases is that once they are gone, they are completely gone. Obesity and other problems don't go away permanently. In contrast if we wipe out malaria or polio, we won't have to deal with it again.
Note also that every single one of the other major criticisms acknowledges that it is something that the Gates have changed already. For example, the article discusses how a number of the Foundation's early attempts at education reform didn't work well. But they changed what they were doing. So they are already using effective evaluations and metrics to decide things.
I find it deeply unfortunate that someone spent an entire book criticizing the Gates Foundation when there are far more clear cut wastes of money out there. The Make a Wish Foundation is an example. They spent 58 million dollars last year http://www.charitynavigator.org/index.cfm?bay=search.programs&orgid=4038#.VljSXnsyH3U and millions more came from businesses in parts of wishes to help a tiny number of dying children, whereas if that money was spent effectively on cancer research, there would be fewer children dying. Instead we have an entire book focusing on one of the most effective and efficient charities in on the planet which complains that they aren't efficient enough.
The takeway I get is that Tesla's attempts to sell directly and avoid dealers makes complete sense because dealers have a clear conflict of interest here. Heck, it makes it seem like we should get rid of dealers altogether since they won't in general want to sell any cars that are very novel or that require substantially less maintenance.
Oil and coal were not from dinosaurs but rather from well before then. It isn't at all obvious that that sort of resource would exist a second time around, and especially given that it is unlikely that even in a snowball situation that all sea life will go away. Incidentally, I find it fascinating that people who would be horrified by a few hundred or a few thousand deaths somehow react with things like "Meh" when talking about every single life on the planet which should be far worse.
That you are going to need some waste heat does come out from pretty basic thermo. You should read the papers that the group searching for these K3 societies did. They outline why this doesn't require more than basic thermo and an extremely tiny amount of basic physics.
Kalai and Spielman are both very talented and have done a lot of work in many different branches of mathematics. Moreover, in this particular context they proved an equivalent version of the conjecture that was much closer to their own sort of work. The problem in question has many different equivalent formulations such as that described here http://arxiv.org/abs/math/0209078 is essentially a statement about vector spaces that anyone with some basic linear algebra background could understand. This is a very common tactic in mathematics if one has a tough problem: try to find equivalent problems that are in other subfields of math where their might be techniques to handle them.
I'm confused. What part do you think I said was false? The false claim is that it was of Chinese origin. Can you point to anything I said that was false?
Not really. Africa and South America both have very little in the way of high tech manufacturing and even if not many directly died there there would be substantial economic collapses. One could easily see the tech level going back much further to early 1800s or even earlier. The timespan that's a direct concern is getting technology from about 1850 levels to 1970s or so which is where we had all the bootstrapping of using fossil fuels and the like. There will be some advantages the second time around, such as the fact that many metals will have been minded and extracted and thus will be ready for reuse (e.g. a lot of aluminum and some titanium) so it isn't completely clear what would happen. The exact details might make a big difference.
I'm not sure what you think is wrong with the statement. The link you gave to debunks it as having a Chinese origin. Since I didn't assert that it did I'm not sure what your point is.
Proving the basic concept that one can have a rocket be completely reusable and land back where it started is a major step. Moreover, the long-term plan is not to stop with the current version but to later build scaled up systems which will be able to take both people and satellites to orbit.
Sure, we could be deeply wrong about things. In this case though, the primary issue is whether we are correct about basic thermodynamics. It is possible that we're wrong, but it isn't that likely. And yes, of course it isn't definitive: we've barely started looking into these things. But it should be deeply concerning.
Please read the article I linked to. One can detect a K3 civilization not just from the total power output but from the fact that the spectrum will look different. In particular, there will be a lot more infrared radiation from waste heat than there will be in a regular galaxy so the proportion of light at different wavelengths gives one good data. There are also other ways to detect aspects of K1 and K2 civilizations such as looking for megastructures.
Potentially yes, especially since there would have been very few targets in South America and Africa. Note that this is why I made an explicit point about losing technological civilization which one might not be able to regain.
Slashdot Mirror
Solar thermal doesn't have as extreme intermittency problems as panels but it still has them. You see a power drop off as the night progresses, and cold spells with clouds can still lead to dips. This is why a lot of solar thermal actually includes direct heating elements being heated by burning fossil fuels http://www.volker-quaschning.de/articles/fundamentals2/index_e.php. So if one of your goals is to get rid of fossil fuel use, then you cannot use solar thermal unless you are willing to have a substantial dip. It is true that solar thermal does extend until late at night, and the latest hours in any given area people aren't using much power at all. But it then takes time to get really functioning quickly in the early morning. Worse, if one was to use this to power much of Asia then one wouldn't even have the advantage that the time when it is less functioning is when there's less power use.
And yes, HVDC is better than long-distance AC. That doesn't make transmission a solved problem. Far from it. It is more efficient, but there are still substantial energy losses. Moreover, HVDC has lower availability, due to more complicated equipment (although it is getting better and should be close to parity soon). They require specialized HVDC converter stations https://en.wikipedia.org/wiki/HVDC_converter_station which cause additional losses, Power flow control is also more difficult.
One big disadvantage of solar power is that it only works some of the time. The intermittent nature of both solar and wind is a serious problem. There's some amount that they help each other out, because in many locations the wind is strongest at night. Because of the intermittent nature of solar power, one cannot have large scale grids be completely solar without a lot of improvements in storage technology. Right now, battery technology is improving but it isn't where it needs to be. The best storage for most purposes right now is pumped hydroelectric https://en.wikipedia.org/wiki/Pumped-storage_hydroelectricity where one pumps water high up to a reserve when there is excess and then recovers it using a hydroelectric plant. This is more efficient than batteries. However, it requires specific geology to work well.
The other big issue with this plan is an issue is efficient transmission. If you are putting a large fraction of the entire world's power in one area, you are going to need to have massive transmission lines. Transmission is a major loss of power already. There have been small scale projects to use superconductors for transmission lines which need to be kept very cold but have very high efficiency. Holbrook Substation in Long Island for example has a 600 meter long superconducting line https://en.wikipedia.org/wiki/Holbrook_Superconductor_Project but this is literally multiple orders of magnitude smaller than the distances needed for the proposal,some of which would likely need to go underwater, and there has never been a serious superconducting line run underwater.
There's a lot wrong with this. First of all, you cannot use entanglement to transmit information. This is a theorem https://en.wikipedia.org/wiki/No-communication_theorem and this is closely related to this xkcd https://xkcd.com/1591/. Moreover, even if you timetravel, you don't automatically learn everything. In fact we know that closed-time-like curves make classical and quantum computing essentially equivalent http://www.scottaaronson.com/papers/ctc.pdf and you can then perform PSPACE computations in polynomial time, which is a hell of a lot, but that's not everything. You can't for example for a given Go position determine who will win efficiently (assuming you are playing with the generalized ko rule).
We are at least 50 years off from strong AI as in human level common sense about the world.
How certain of that are you? Are you willing to bet all of humanity on that? Experts disagree a lot about when we will have strong AI https://intelligence.org/2013/05/15/when-will-ai-be-created/. If it turns out to be sooner then this isn't a good situation.
Energy density is not all that matters, and even energy density is *complicated.* One can have high energy density if one looks at maximum energy per mass, or per volume, and depending on the application and how different they are one or the other can matter, which is why tables generally include both https://en.wikipedia.org/wiki/Energy_density#Energy_densities_of_common_energy_storage_materials . But even aside from energy density one has other issues, like recharge time and lifespan. It doesn't matter if you can make a battery with very high energy density but with a very short lifespan. In general, I'm skeptical of claims of massive improvement in batteries. As with new solar systems, if every single in-lab claimed battery improvement all were genuine and implementable we'd have solves all the world's energy problems years ago.
They don't mean blind in the sense of giving the detector so many photons that it is blinded but rather by cleverly adding a small number of extra photons they can make the detectors think everything is ok.
It depends how long term your outlook is. Nothing here will be practical for at least a decade and very likely more. But once quantum computers become a practical thing, there are going to be a lot of uses (e.g. factoring large numbers using Shor's algorithm https://en.wikipedia.org/wiki/Shor's_algorithm, and detailed molecular simulation). Note that one thing we don't expect to see is extreme speedup of generic NP-complete problems, although the popular press often says otherwise. Also, as with any computer technology, once the technology becomes more common, people will have more of an incentive to find uses for it. GPUs are a fun example of that: made for a very narrow purpose, but once they were made, people quickly started realizing they could do other things with them. Quantum computers will likely be in a similar boat.
Jane Mann said she is a local native and is concerned about the plants that make the community beautiful. She is a retired Northampton science teacher and is concerned that photosynthesis, which depends upon sunlight, would not happen and would keep the plants from growing. She said she has observed areas near solar panels where the plants are brown and dead because they did not get enough sunlight. She also questioned the high number of cancer deaths in the area, saying no one could tell her that solar panels didn’t cause cancer."
It sounds to me like this backlash is mainly pretty deserved. Even if they had legitimate reasons to say no to this new solar, it is clear that those were not the reasons articulated by the people in question.
It is even stupider than that because Musk is a major proponent of alternative energy and getting rid of the internal combustion engine (hence Tesla) precisely because he's concerned about global warming. So even if this did make sense (and it doesn't for the reasons you correctly identified) they'd still have the wrong billionaire.
Ugh, linked to the wrong one of Scott's posts. The correct one is http://www.scottaaronson.com/blog/?p=2555.
This doesn't really deal with the real issue, the fact that the vast majority of what D-Wave is doing is complete hype with a very tiny chance of having any practical impacts. It isn't even clear that the type of problems D-Wave's machines can handle are problems where we should expect any substantial speedup from quantum computers. D-Wave's latest attempt at claiming that their computers show noticeable speedup is less lacking than some of their previous claims, but still not at all impressive. See Scott Aaronson's blog post http://www.scottaaronson.com/blog/?p=2535 where he notes that the D-Wave machine both doesn't give any apparent asymptotic speedup and is beaten by the best classical computers. The real question isn't security but why NASA is wasting money on this instead of more promising quantum computing research.
I agree that the total cost from MAW is relatively small. I'm not sure your metric is necessarily the bestf one looks not at all cancer funding but cancer research in children, one gets a much larger fraction. About 5% of all funding is for children's cancer (http://www.stbaldricks.org/filling-the-funding-gap/ says 4%) so this would be about 20% of funding for children's cancer. That may not be the best metric, because much cancer research applies to cancers at a broad age range, so I think I'd agree that the total amount is relatively small. According to Makke a Wish's own description they make one wish on average every 37 minutes http://wish.org/about-us which means they are making wishes for about 20,000 kids a year. In contrast, as the above link to St. Baldrick's notes, even for just St. B they came up about 8 million dollars short of funding all of the grant proposals that got considered to be outstanding. And they are very much not the only example of this sort of thing.
On the other hand, there's a serious problem in at least allied fields where people claim that their basic research is cancer related so they can more easily get grant money. In my own field, math, one has people doing all sorts of abstract stats or imaging work or differential equation modeling which people claim is cancer related, and it generally is related in the sense that one specific application might be some sort of cancer research. So that suggests that in some respects funding is actually over-saturated in which case Make A Wish isn't doing that much direct harm.
The same is true when it comes to the foundation’s work in public health. As McGoey briefly acknowledges, the foundation’s investment of more than $15 billion in this field “has done considerable good.” That seems an understatement. Thanks in part to the Gateses’ strong investment in vaccines for infectious diseases, deaths from measles in Africa have dropped by 90 percent since 2000. Over the last quarter century, tuberculosis mortality worldwide has fallen by 45 percent, while over the last dozen years the number of new malaria cases has dropped by 30 percent. And polio, which in 1988 was endemic in 125 countries, is today endemic in only two. The foundation has also played an important part in fighting the spread of HIV and helping those infected with the virus to lead productive lives. For this, Bill and Melinda Gates deserve much credit.
So far so good.
The question is, has this been the best use of their money? As McGoey notes, chronic diseases, as opposed to communicable ones, exact a staggering toll worldwide, yet the foundation has invested less than 4 percent of its funding in research on them, and the global health community has largely followed suit. “The failure to combat obesity, cancer and heart disease epidemics in poor nations,” she observes, “has been one of the most glaring mistakes of global development efforts in recent years.” An equally serious shortcoming has been the neglect of primary-care facilities in the developing world. The initial problems that the nations of West Africa faced in combating the Ebola outbreak stemmed in part from the weaknesses in their overall health systems. Interestingly, in late September, the Gates Foundation, together with WHO and the World Bank, announced a joint partnership aimed at improving access to primary care in poor and middle-income countries — a dramatic (if tacit) acknowledgement that the emphasis on fighting individual diseases has been too narrow.
The primary reason it makes sense to focus on infectious diseases is that once they are gone, they are completely gone. Obesity and other problems don't go away permanently. In contrast if we wipe out malaria or polio, we won't have to deal with it again.
Note also that every single one of the other major criticisms acknowledges that it is something that the Gates have changed already. For example, the article discusses how a number of the Foundation's early attempts at education reform didn't work well. But they changed what they were doing. So they are already using effective evaluations and metrics to decide things.
I find it deeply unfortunate that someone spent an entire book criticizing the Gates Foundation when there are far more clear cut wastes of money out there. The Make a Wish Foundation is an example. They spent 58 million dollars last year http://www.charitynavigator.org/index.cfm?bay=search.programs&orgid=4038#.VljSXnsyH3U and millions more came from businesses in parts of wishes to help a tiny number of dying children, whereas if that money was spent effectively on cancer research, there would be fewer children dying. Instead we have an entire book focusing on one of the most effective and efficient charities in on the planet which complains that they aren't efficient enough.
The takeway I get is that Tesla's attempts to sell directly and avoid dealers makes complete sense because dealers have a clear conflict of interest here. Heck, it makes it seem like we should get rid of dealers altogether since they won't in general want to sell any cars that are very novel or that require substantially less maintenance.
Oil and coal were not from dinosaurs but rather from well before then. It isn't at all obvious that that sort of resource would exist a second time around, and especially given that it is unlikely that even in a snowball situation that all sea life will go away. Incidentally, I find it fascinating that people who would be horrified by a few hundred or a few thousand deaths somehow react with things like "Meh" when talking about every single life on the planet which should be far worse.
That you are going to need some waste heat does come out from pretty basic thermo. You should read the papers that the group searching for these K3 societies did. They outline why this doesn't require more than basic thermo and an extremely tiny amount of basic physics.
Kalai and Spielman are both very talented and have done a lot of work in many different branches of mathematics. Moreover, in this particular context they proved an equivalent version of the conjecture that was much closer to their own sort of work. The problem in question has many different equivalent formulations such as that described here http://arxiv.org/abs/math/0209078 is essentially a statement about vector spaces that anyone with some basic linear algebra background could understand. This is a very common tactic in mathematics if one has a tough problem: try to find equivalent problems that are in other subfields of math where their might be techniques to handle them.
That doesn't really work. Even if you use things efficiently, you have to dump waste heat.
I'm confused. What part do you think I said was false? The false claim is that it was of Chinese origin. Can you point to anything I said that was false?
Not really. Africa and South America both have very little in the way of high tech manufacturing and even if not many directly died there there would be substantial economic collapses. One could easily see the tech level going back much further to early 1800s or even earlier. The timespan that's a direct concern is getting technology from about 1850 levels to 1970s or so which is where we had all the bootstrapping of using fossil fuels and the like. There will be some advantages the second time around, such as the fact that many metals will have been minded and extracted and thus will be ready for reuse (e.g. a lot of aluminum and some titanium) so it isn't completely clear what would happen. The exact details might make a big difference.
I'm not sure what you think is wrong with the statement. The link you gave to debunks it as having a Chinese origin. Since I didn't assert that it did I'm not sure what your point is.
Proving the basic concept that one can have a rocket be completely reusable and land back where it started is a major step. Moreover, the long-term plan is not to stop with the current version but to later build scaled up systems which will be able to take both people and satellites to orbit.
Sure, we could be deeply wrong about things. In this case though, the primary issue is whether we are correct about basic thermodynamics. It is possible that we're wrong, but it isn't that likely. And yes, of course it isn't definitive: we've barely started looking into these things. But it should be deeply concerning.
Please read the article I linked to. One can detect a K3 civilization not just from the total power output but from the fact that the spectrum will look different. In particular, there will be a lot more infrared radiation from waste heat than there will be in a regular galaxy so the proportion of light at different wavelengths gives one good data. There are also other ways to detect aspects of K1 and K2 civilizations such as looking for megastructures.
Potentially yes, especially since there would have been very few targets in South America and Africa. Note that this is why I made an explicit point about losing technological civilization which one might not be able to regain.