Firstly, it's an assumption that bronze mirrors were the best available to Archimedes. Since well before Archimedes, people have been making mirrors out of polished metal. Yes, usually bronze, but other metals were available. Notably silver, which is very nearly as reflective as aluminum (and is notably _more_ reflective in infrared ranges). The obstacle for silver was obviously the cost, but, although modern silver plating did not exist, silver leaf did. While applied silver leaf would not be an ideal surface for a mirror intended for admiring ones reflection, it could potentially work quite well in one merely intended to reflect sunlight. Then of course there are other materials that were available such as pewter that could have been used for an improved mirror surface.

Of course, even if only bronze was available, there is still room for improvement in the shaping of the mirror so that it can focus the light to more of a point at the appropriate range. Bear in mind that I am not saying that Archimedes did any of these things. There is simply no evidence that he could not have. Suitable materials existed and were known at the time, even if they were not commonly used in vanity mirrors of the time. Not to mention that historical discoveries keep showing us that many inventions that we think of as modern have actually been invented in the past, then vanished into the mists of history: flushing toilets, steam engines, electric batteries, clockwork, etc.

Ironic for you to accuse me of a failure to understand when you clearly either have a serious reading comprehension problem or you do not understand the difference between lift and thrust. To clarify, I wrote: "...a dragon with certain characteristics would not be able to generate downward thrust equal to its body weight." Note please that I said "thrust". You replied with "Of course a dragon has to generate lift equal to its weight to remain airborne". This sentence is technically true, but does not relate to my sentence about thrust. Thrust and lift are different concepts in aerodynamics. Thrust can be used to generate lift, but most heavier than air flying machines and animals use significantly less thrust than their own body weight to stay aloft because aerodynamics allows them to generate lift greater than their body weight. That you go on to say " that is just Newton's second law, that an object with a net force applied accelerates in the direction of the force (in this case, downwards)." suggests that this was not mostly a reading comprehension fail, you just really do not understand aerodynamics. Or, at least you do not understand the role of thrust in aerodynamics.

So, my point stands, the author in the magazine in question was incorrectly assuming that a flying thing needs thrust equal to its weight to stay aloft. Your explanation about gliding entirely misses the point that gliding works without any thrust. A gliding object is capable of falling slower than acceleration due to gravity would demand because lift is countering that acceleration, not thrust. Now, gliding is not flying, but it is part way there. By also applying thrust to a gliding object, you can turn a gliding object into a flying object that can stay in level flight indefinitely (at least until the thrust runs out). The cost in thrust to do that is, under normal circumstances, less than the force of gravity that applies to the object and is generally approximately equal to the difference between the lift it gets as a glider and the force of gravity. Sure, that's a simplification. Once again, the main point still stands: you do not need thrust to equal or exceed weight in order to make something fly!

I'm not sure where you got your nonsense analysis of what I wrote. You seem to have made the error of thinking that I am trying to defend the idea that a dragon would be able to fly. That's missing the point entirely on your part. My point was that the argument they made for why a dragon would not be able to fly was nonsense. It was back of the envelope stuff by someone who was not considering the physical realities, just their little math problem.

You see this kind of stuff all the time. People claiming that, according to the math, bumblebees can't fly or kangaroos or sturgeon use more energy than they consume as food. All based on flawed models of aerodynamics or hydrodynamics or, in the case of kangaroos, ignoring that bounding is elastic and most of the energy from a jump is recycled in the next jump. Other fun examples are those people who insisted that large sauropods would have had to spend their entire lives in ponds because there's no way an animal that size could walk around without its leg bones fracturing. The ironic counterpoint to that ridiculous argument was that sauropods could not have stayed submerged because the pressure would have crushed their windpipes. That also ridiculous argument used a comparison between a sauropods neck and a garden hose, ignoring the fact that the garden hose is very, very thin and a sauropods neck would have been very, very thick and made of bone and very solid muscle.

So, that's the problem I have with so many Mythbusters episodes and other people who think that they have "disproven" things with simplistic methods and math. The problem is that they are not generally disproving the thing itself, they are disproving a model. If the model is wrong, then their proof is meaningless. That does not mean that the thing they are trying to disprove is actually real, it just means that they need to work harder to convincingly disprove it.

What you're saying may be true, but it's not really relevant. We made the solar power plant solar thermal in this example, but it could have just as easily been photovoltaic, or wind power (ultimately driven by the sun). The point was that if you bypass traditional imaging optics as the method, you absolutely can concentrate temperature to a higher level than the source over a lesser area. The fact that some or even most of the energy is dissipated has absolutely no bearing on that. You obviously can, 100% with no doubt, use the EM radiation coming from the sun and, through various methods, concentrate that energy to produce temperatures far in excess of the temperature of the sun. Sure, there are situations where you can't when you apply arbitrary restrictions like the very specific technologies you're allowed to use but, in the general case, you absolutely can. It is unquestionably true.

Mythbusters, while a neat show, had a tendency to jump to conclusions based on insufficient data. One of their biggest problems was testing skills that might take a decade to master after about a day of training and concluding that they were impossible. One episode I remember, they wanted to test to see if it would be possible for someone to catch a sword between their hands like in a kung fu movie. So they built a hand clapping machine that clapped two flappy hands made of ballistic gel together and tried to catch a sword with it. Substituting something that was supposed to be a carefully coordinated set of highly-trained, careful movements with an extremely crude, unwieldy machine. Naturally the result was myth busted. That's not to say that catching a sword blade would in any way be a practical combat move, but it's at least blatantly obvious that someone attempting to do it would try to match the motion of their hands to the motion of the sword blade, which their device obviously did not do.
The same applies to their two episodes on the death ray. They "busted" it once, then tried again due to deficiencies in their original experiment. For the second one they had a whole classroom of students helping them aim mirror shields and they developed a technique for aiming. Still though, those students ultimately only had a few hours of training. Not to mention that the mirror shields they used did not go through any process of refinement to make them better suited to the purpose.
For an actual military weapon, soldiers would have drilled day after day, week after week until they could pick up their shields and aim at a common target almost perfectly in a few seconds. The shields would have been refined to best concentrate the light at the appropriate range. There might have even been different selections of mirror shields for different ranges, or different techniques developed for getting better concentration of light at arbitrary range. The Mythbusters episodes did none of that.
You pointed out that it might be better to fire stuff out of a catapult or from an archer's bow rather than use such a system, but that ignores the fact that decent archers or catapult operators get lots of practice. Have you ever seen anyone try to use a bow on their first day? Sure, some people might have an instant talent for it, but if you just grab a bunch of school kids and hand them bows and arrows, you will not get good results. If you used the same methods the Mythbusters used to "bust" the death ray, you would have to conclude that it was a "busted myth" that archery was ever used effectively in warfare after watching them try to fire hundreds of arrows and fail to hit or even reach a ship 200 meters offshore.
I am reminded of a piece in some educational magazine I had in class as a child that "explained" why dragons would not be able to fly. It used a wing surface area argument and pointed out that a dragon with certain characteristics would not be able to generate downward thrust equal to its body weight. At the time, it seemed very wrong to me. For one thing there was the whole chain of assumptions about weight, material strength, muscle strength, etc. but also, even though I did not know much about aerodynamics at the time, it was intuitively obvious that thrust doesn't need to exceed weight in order to fly. It seemed obvious from seeing things glide. If no thrust was required to glide, then staying aloft should just require the difference between gliding and level flight, not full thrust. So, it was clear that they had just contrived a set of parameters and rules that would lead to their conclusion rather than carefully considering their model. That's not to say that I believed in flying dragons, it was just obvious that their model was garbage.
All that said, it does not mean that the solar death ray would have been a practical weapon, or that it even ever really existed. It's just to say that the "proof" offered by Mythbusters was insufficient.

That seems wrong. As was pointed out, the restriction only applies when using imaging optics to achieve the goal. Plenty of other methods of doing it will achieve the goal of "concentrating temperature to a higher level than the source over a lesser area"
Consider as a thought experiment a solar power plant hooked up to a Z-machine. A z-machine generates temperatures far in excess of the sun. We'll make the solar power plant in question a thermal solar power plant too, just to avoid confusing the discussion with a digression into light energy vs. thermal energy.
The largest solar thermal plant I can find is Mohammed bin Rashid Al Maktoum Solar Park Phase IV which apparently covers 30 sq miles and produces 700 MW. There's no reason (aside from cost, which doesn't matter because this is a thought experiment) you couldn't make it a thousand times the size and produce 700 GW. That's enough power to easily run a z-machine or any number of devices that take electrical energy and generate temperatures hotter than the sun. It's been done in labs so many times in so many different ways by now that it's just routine and, for most of those devices, the input is just electricity.
So, clearly you can take EM energy coming from the sun and concentrate it to generate temperatures far, far in excess of the sun by "concentrating temperature to a higher level than the source over a lesser area". To do it, you apparently can't use pure imaging optics, but, as this thought experiment shows, there are clearly other arrangements of opticis plus other mechanisms you can use to achieve the required end result.

Have you considered therapy? Medication? Just, whatever you do, don't show up at a pizza restaurant with a fully automatic weapon to "save" the children in the non-existent basement. Generally speaking, people on the left are, in fact, very much concerned about the plight of exploited children in all sorts of situations. However, since their understanding of the issues is grounded in reality rather than adolescent power fantasies, their solutions tend to be a bit more grounded. More grounded solutions tend to be much less dramatic. Things like easing poverty and providing social safety nets, counseling, providing safe harbors, etc. Dramatic solutions work best in fiction.

Meanwhile I would say that life itself is a fire that's been burning for billions of years. Respiration, whether aerobic or anaerobic is just a form of combustion so, from a certain perspective, all living things are basically a complicated hearth that keeps a fire going. Sure, there's a lot else going on there, but we're basically all a continuation of a billions of years old fire.

What I wonder is, if the robots need a stable, cool temperature to operate properly (plenty of electronics fail more rapidly in hot environments and it's usually pretty easy to demonstrate statistically) or if they need temporary stops during the day for maintenance tasks like battery swapping, greasing, whatever, or maintenance periods where they are offline for days or weeks, how will Amazon act? Will they provide air conditioning where they would not provide it for humans? Breaks that they would not provide for humans, etc.?

It is a legitimate issue. Which is why it's a pity to see it trivialized by nonsense, unrealistic movies that chiefly exist to glamorize the personal narrative of someone who seems to actually be a pretty creepy person. In its way, it's not that different from some of Steven Seagal's heavily fictionalized supposedly autobiographical movies.

The position you're taking on this movie is absurd. It's like you're accusing me of throwing awareness of terrorism under the bus for calling, for example, True Lies just a movie. Or airplane hijackings and Passenger 57. Or Taken and sex trafficking. People who get their ideas about how any of this stuff works in the real world from these movies end up with an extremely warped understanding of the world. I mean, seriously, I like Batman as much as the next nerd, but I'm also fully aware that, in the real world, Batman is a ridiculous concept that would never work. He would spend a few years hanging around on rooftops waiting for a crime to happen in view, then give up after realizing that it's actually really hard to just happen to be around when crime happens. That or kill himself jumping off something. The fact that you seem to believe that you've experienced something deep and that you're somehow part of the solution because you _watched a movie_ is just disturbing and sad.

Plenty of societies have attempted to cull the parts of their population in ways that only leave the intelligent, healthy, morally sound, etc., etc. It always seems to turn out, in hindsight, or from an outside perspective, that they just acted on their biases, racism, xenophobia, etc. and just murdered a bunch of people they didn't like. It makes sense. It's a fundamentally evil plan, so the people who implement plans like that are normally either evil or stupid and they're the ones who end up deciding who to kill (or sterilize). Basically, any attempt to follow such a plan, as good as the people doing it may believe their intentions to be, will result in people who are functionally evil and incompetent choosing who to label as not good enough to live. So, no thank you to that idea.

Part of the problem boils down to the fact that, fundamentally, Malthus was not wrong. There is a limit to how many people any system can support, and it is possible to far exceed that limit for a time, but it will catch up to you. So that part of the equation, that resources are not infinite and continuous population growth will hit hard limits at some point, all else being equal, is not wrong. However it is also necessary to understand that all else is not always equal. The hard limits on resources may actually be soft limits, completely changed by some new development that gets more out of less, and actually evaluating that is difficult and very much situationally dependent.

Our civilization is an example of this. We are very, very clearly living in a manner that's beyond what our environment can support. That's obvious because we are systematically destroying our environment. Earth can't support our current population living the way we do. However, that's not an absolute declaration that Earth can't support our population. It very well might be able to if we can change the way we live. So, the question becomes if we can change the way we live and in what way. To be well understood, don't take this as advocating going back to live like cavemen. Exactly the opposite really. Earth can't support a population the size of ours living as hunter/gatherers. In the long run what we need to do is make pretty much all human activity more self-contained. Basic principles like reduce. reuse, recycle are a bit trite, but they pretty well cover what we need to do. In general, we need to keep moving towards a scenario where all our waste is part of a cycle that eventually gets re-used somehow. We need to make everything we do as efficient as we can make it and we need to recognize where we are being pointlessly wasteful and also recognize where we are not counting the real costs of things that we do.

Absolutely. There are features produced by evolution in lots of species that seem to have a cost with no benefit. Or at least, the benefits only exist in the context of evolution in the first place. For example, developing some sort of crest as a sexual display where only individuals with a big crest get to mate and a feedback loop just keeps driving that every generation. Of course, even there, pointless display features are a result of having the extra metabolic budget to support those features in the first place. So, those features also advertise success at gathering food, general health, etc. making them not so pointless after all, even if they can seem arbitrary.

The simple fact is though that features like sneezing are very effective at aerosolizing pathogens and spreading infection to other animals, especially members of our own species that we live in close quarters with. That sort of thing leads to death, so a simple concept of survival of the fittest suggests that anything that would tend to spread pathogens and increase mortality would be filtered out over millions of years by evolution. A more nuanced view recognizes that evolution does not favor invincibility. There's a reason that nature does not railroad predators into invincible super-predators, for example. They would quickly kill everything and starve to death. In the same way, things like sneezing have to be seen in the context of the actual battle against pathogens. In the context of how social animals actually live, traditionally, a fast spread of a lethal pathogen within small groups actually means a slowed spread across the broader population.

The problem is, that does not apply so well in the modern world. A fast spread means a fast spread across basically the whole population. Still not an evolutionary dead end of course. There will be those resistant to just about any lethal pathogen. Plus, of course, some small part of the population who just remain isolated and get passed over. However, we tend to find mass death to be tragic. Not to mention that our modern civilization is so interconnected that enough people dying can seriously affect our civilization.

So, given that conditions are different now, we can't assume that the solutions of the past will work today. So we can't just say that if a pathogen managed to be locked up in an icy tomb in the first place, it can't be that dangerous. We also have to recognize that the "solutions" of the past are often not actually that desirable. It's easy to say that plagues and outbreaks of the past are not that big a deal because the human race got through them. It's easy to be blasé about say half the human race dying when it happened far, far in the past. When it happens in this day and age though, then it hits a bit harder.

Oh I get it, but that's a clear problem with, to repeat myself, using "for-profit health insurance as a substitute for a proper medical safety net." The parts of health insurance that make sense for a medical safety net are the risk pooling aspects. People have different medical requirements over time, but everyone eventually needs medical care. No-one should need to game the system in the first place. It should be set up not to require gaming.

I don't think anyone on the left has an issue with the movie itself. It's just another crappy movie. The problem is with the qanon types who think that the movie is actually salient to the real world in any way.

Does history support that though? Time and time again through history, as long as the modern patent regime has been a thing, we've seen technology stifled and forced to wait twenty years due to patents. Consider aviation, for example. The Wright brothers patent suppressed aviation right up to WWI, at which point military aviation ignored the patents. Oil companies used patents for decades to suppress solar power. Phillip Morris used patents to suppress filtered cigarettes initially because safety features for cigarettes might make people think they were unsafe. There are many, many more examples. Again and again, the patent system seems to translate in the real world into delays in advances that could help the world actually reaching the public.

Except that, in the MCU, after eliminating half the universe, Thanos destroys the infinity stones so they can never be used again, so he was definitely treating it like a one and done solution. Consider that, even if he's a Deviant, Thanos is one of the Eternals. To them, the lives of most beings in the universe are fleeting. Consider that the Earth''s human population has doubled in just the last 50 years. Chances are, after a cataclysm like that, it could potentially repopulate even faster. To an Eternal, that would be a blink of an eye. The movies don't give a precise timeline, but it can be inferred that Thanos has been trying to achieve the death of half the beings in the universe for longer than the results of that quest would actually last. If you want to look at real-world examples, look at the culling of any animal considered a pest. Those are not one and done events. They are culled, then they repopulate again, really fast to fill the niche left behind by the culling.

So the problem was not that it wasn't a sane plan. Thanos is supposed to be insane, after all. The problem was that it was an unintelligent plan and Thanos is supposed to be intelligent. The original comic book motivation was insane and required no logic. Kill half the universe to romantically impress Death

That was my point. Why would your body sneeze it out when you could swallow it? Any contagion that you could expel by sneezing it out would have to be so localized that it would not be a deadly contagion. For communal animals living in tight spaces however, a sneeze is an almost perfect method of spreading contagion. So it does seem like the sort of thing that should be selected against unless rapidly spreading contagion actually turned out to be a net evolutionary advantage.