All of Areva's renewables investments combined are less than 10% of their business. And they're performing far better than their core nuclear business. I find it amazing that you argue that they shouldn't have invested in the few projects they're involved in that are actually paying off.
It's not just neutron bombardment either. Your fuel is producing almost every element in the periodic table, anisotropically and varying across time. It's pretty much the worst situation one could come up with from a containment standpoint inside the fuel even before you factor in neutron bombardment.
Then there's the nature of nuclear disasters: they're disasters in slow motion. The upside is that few people usually die from them because there's usually plenty of time to get away. The downside is that they take bloody forever and a king's ransom to clean up, where it's even possible. Picture, for example, an accident at Indian Point that would increase NYC residents' rate of cancer over the next 10 years by two to three orders of magnitude. You could evacuate over days to weeks and it'd have little impact on public health. But you'd be having to pay for the loss and cleanup of New York City. That is, of course, an extreme case, but it's an illustration of the financial challenge faced by an industry that deals with large amounts of chemicals that are incredibly toxic even in the minutest quantities. Screwups can turn out to be REALLY BIG screwups.
Judging from our sample size of one on what sort of conditions life can thrive in, and a couple datapoints on where it doesn't seem to, I think we haven't the foggiest of clues where we're actually likely to find life. There seems to be this presumption among many that "where we find liquid water we should find life, and where we don't find liquid water we shouldn't". I think that's totally logically indefensible. We have no bloody clue whether water-based life is a common or rare occurrence, nor whether non-water-based life is a common or rare occurrence. We have way, way to little data to be drawing these kind of conclusions.
Life can be defined empirically and that's a good enough of a description. The problem is people debating over what that definition should be. The problem with gravity is not describing it, but figuring out why it exists as it does. They're very different situations.
Most people agree on the basics of life - something that can self replicate and evolve - but it's the details that pose the thorny issues. For example, how particular is it about its environment? Viruses leave most of the work of their reproduction to outside sources, so there are many people who don't want to call them life. But there's a continuous slope between that and something that can survive on nothing more than sunlight, water, CO2 and trace minerals; you don't say that a cat isn't alive because it can't make taurine and has to rely on external entities to do so, for example. And at an even more basic level, how picky must one be about what constitutes "replication"? What if you have imperfect replicators that create entities "similar" to themselves, which may have varying degrees (perhaps frequently "zero") of ability to replicate themselves? Certainly such a thing has the potential to at least lead to life. But is it life? If not then what's the cutoff point in terms of replicative accuracy when you start to call it life and the inaccuracies in its reproduction "evolution"?
I don't think this is at all special. There have been tons of space-matter-abiogenesis experiments that have been done, with similar results. For example, it's been shown that Titan's atmosphere can produce at least 16 amino acids and all five nucleotide bases, and we've already detected organic molecules over 10000 daltons there.
Nature likes to produce rather complex mixtures of organic chemicals without any help from life, nobody should doubt this any more, there's been way too much evidence that it happens. Nature is more than happy to continously rain down vast amounts of varied, complex organics given the right situation, providing both potential organic catalysts to develop into early life and "food" that they can scavenge. The question that needs to be answered next is, from a random diverse mix of organics, how does a hypercycle get started, wherein some chemicals / mixtures of chemicals / families of chemicals begin to encourage the creation of more chemicals "like" them, increasing the odds that there will be more produced of whatever is needed to keep the cycle going. Once you get to that point, you have the potential for evolution to take hold - first by a simple race to produce the most exact copies of the most efficiently-catalyzing chemicals and the poisoning of competing chemicals, up to the development of membranes to provide defense/hoarde resources/survive adverse situations/etc (the first "ur-cells").
Right. Having the government cover all of your major liabilities, getting to write off massive debts, pass all of your cost overruns onto local consumers without them having a say in the manner, and so on, that's all "paying their own way", right? In nuclear power, the gains have always been privatized while the costs and risks socialized. And it's *still* been very difficult to find investors. Nuclear has always been more popular on K-Street than Wall Street.
Here's a paper going into the various massive ways nuclear has been subsidies. And they still can't bloody manage to stay afloat. It's one of the few industries with a negative growth curve - where technology gets more expensive with time, not cheaper.
Wow, way to not link to a study, but rather a Smithsonian blog talking about a Wordpress blog talking about a study. You clearly love your primary sources!
FYI, the study is just one of many. The study itself cites others, including:
20,000 birds/yr (Sovacool, 2012) 10,000–40,000 birds/yr (Erickson et al., 2001 and Manville, 2005) 20,000–40,000 birds/yr (Erickson et al., 2005) 440,000 (Manville, 2009) 573,000 (Smallwood, 2013).
The latter two include lattice towers, which are largely being decommissioned as unsafe to birds.
But hey, having varied numbers clearly means that if you can find a blog linking to another blog linking to a study that shows high numbers (among many different studies), then clearly the GP is "plain wrong", right?
And yes, even if we go with your choice study's mean of 234,012 annual bird deaths, that's still orders of magnitude less than many other types of human activities.
The number of grammatical cases is irrelevant. Question: What's the difference between a grammatical case without stem changes and a postposition (opposite of a preposition? Answer: A space.
That which is challenging, apart from stem changes, is the same thing that is challenging with helper words in general: when to use what with what. Picture a person learning English and trying to remember what to use with what. "I was scolding her.... over it? for it? about it? to it? around it?" "We were unhappy.... over it? for it? about it? to it? around it?" "She was dedicated.... over it? for it? about it? to it? around it?" And so forth. It's the same for people trying to learn which declension case to use in which context. But if the declensions are just suffixes without stem changes, then they're no different from postpositions. And often stem changes where they occur follow pretty predictable rules, often for pronunciation reasons.
I'm sorry, but I agree with that. If you on the UK want us to dam up our rivers and build roads out to geothermal areas and tap into our resources, and raise our local power prices in the process, all for the benefit of the UK, our government better damn well profit as much as possible from it and reduce our taxes / improve our services in exchange for that.
Better negotiate the contract during a Sjálfstæðisflokkurinn / Framsóknarflokkurinn (conservative) government. Samfylkingin would approve it under the condition that the Icelandic government's share of the sales are so high that you would barely save any money on the imported power, and Vinstri Grænir would outright reject it no matter what you offered. But Sjálfstæðisflokkurinn and Framsóknarflokkurinn would let you dam up whatever rivers you want and take gigawatts of power in exchange for a handful of shiny trinkets and a couple magic beans.
What sort of claim is that? Since when do oxygen masks need 20kPa to function? And secondly, if there's "problematic loading on the capsules" from too much pressure on the pressure-compromised capsule, then your pressure is also way too high inside. Which means that you've repressurized the tube way too much. So the solution is: Don't do that!
Branching at full speed is probably not possible with the Hyperloop as designed; the skis are curved to match the diameter of the tube, with a ~1mm clearance with the tube surface, so there is no passive tube design that could accommodate a "switch". In order to continue from Section A to either Section B or Section C, you'd have to make an intermediate length of tube several hundred meters long that could be physically moved at one end from B to C, with sub-millimeter precision
Wait, meaning that while it's technically possible, but it'd be really tricky to accomplish? Gee, I wish I had written something like "Branching would be really tricky, but there's no physical barriers" at the top of my post;)
The reason is threefold: drag continues to increase at higher speeds regardless of the speed of sound
Drag is reduced in the first place by using hydrogen even at a given pressure. And you can use 1/4th the pressure and still maintain lift because you're moving four times as fast. And given how few reboosts are needed from LA to SF in the base case, a few more per unit distance hardly seems limiting.
If you consider that the steel Hyperloop pipe draped across 30m-spaced pylons will approximate a vertical sine wave, then at 700mph the allowable sag is only about 5cm
Irrelevant because earthquakes impose far more deflection that you have to be able to counter (and that the proposal calls for countering) than a craft moving past.
Mechanical braking from 1500mph in the event of an emergency is also a non-starter
What, you're picturing drum brakes or something? You're moving at high speeds in a giant steel tube. Magnetic braking couldn't possibly be easier.
a 700mph capsule will incur about 2g's of aerobraking deceleration
Where are you getting this from? Even if the tube was instantly full pressure (which it wouldn't be), a streamlined shape will not experience 2Gs at 700mph, any more than a passenger jet losing full engine power does. And anyway, 10g horizontal is not fatal even if that was the case. The average untrained individual, properly restrained, can tolerate 10g for a minute without even loss of cognitive function.
Not only that, but if your craft is travelling four times as fast, you're sweeping through four times as much gas per unit time to compress under the skis.
Hydrogen has all sorts of advantages. And the very low pressures prevent most of the negatives. The only one that I don't know about and would require testing would be what sort of reaction would one see as a craft moves past, with any residual oxygen. If I had to guess, I'd guess that you will get some combustion, but the craft moves past so fast and the mixture will decompress so fast, I would think the rate would be quite limited.
First off, if servicing that requires full de/repressurization is some sort of frequent event, then the whole concept is doomed for reasons entirely unrelated to anything in this discussion. Secondly, 1/5 ton of hydrogen at industrial rates is about $200. Whoop-di-doodle-doo. And the advantage is being able to travel at mach freaking 4, not about the reduction of drag at a given speed (which is, FYI, true also).
As someone else already mentioned, it uses low pressure air because the "trains" are ground-effect aircraft, not maglev. They need air.
Secondly, the pumping budget to overcome leaks is so small, both in terms of capital and ongoing costs, that you could increase them by an order of magnitude and not have any sort of practical effect on the budget. Whatever factor you increase over the baseline increases the factor you can replace air by. You don't need 100%.
You think keeping hundreds of miles of tubing is really going to be cheap? Go look at a highway budget sometime.
Because Hyperloop is a highway? The closest analogy is a pipeline. Except that the environmental hurdles for building an oil pipeline raise the cost dramatically. Yet Musk's budget in Hyperloop Alpha is well higher than that of an equivalent diameter per mile.
Then consider... Then consider... Then consider... Then consider...
And when you're done with that, then consider that every last thing you mention here was analyzed in detail in the Hyperloop Alpha proposal, which you apparently never read.
Slashdot Mirror
All of Areva's renewables investments combined are less than 10% of their business. And they're performing far better than their core nuclear business. I find it amazing that you argue that they shouldn't have invested in the few projects they're involved in that are actually paying off.
It's not just neutron bombardment either. Your fuel is producing almost every element in the periodic table, anisotropically and varying across time. It's pretty much the worst situation one could come up with from a containment standpoint inside the fuel even before you factor in neutron bombardment.
Then there's the nature of nuclear disasters: they're disasters in slow motion. The upside is that few people usually die from them because there's usually plenty of time to get away. The downside is that they take bloody forever and a king's ransom to clean up, where it's even possible. Picture, for example, an accident at Indian Point that would increase NYC residents' rate of cancer over the next 10 years by two to three orders of magnitude. You could evacuate over days to weeks and it'd have little impact on public health. But you'd be having to pay for the loss and cleanup of New York City. That is, of course, an extreme case, but it's an illustration of the financial challenge faced by an industry that deals with large amounts of chemicals that are incredibly toxic even in the minutest quantities. Screwups can turn out to be REALLY BIG screwups.
Judging from our sample size of one on what sort of conditions life can thrive in, and a couple datapoints on where it doesn't seem to, I think we haven't the foggiest of clues where we're actually likely to find life. There seems to be this presumption among many that "where we find liquid water we should find life, and where we don't find liquid water we shouldn't". I think that's totally logically indefensible. We have no bloody clue whether water-based life is a common or rare occurrence, nor whether non-water-based life is a common or rare occurrence. We have way, way to little data to be drawing these kind of conclusions.
Life can be defined empirically and that's a good enough of a description. The problem is people debating over what that definition should be. The problem with gravity is not describing it, but figuring out why it exists as it does. They're very different situations.
Most people agree on the basics of life - something that can self replicate and evolve - but it's the details that pose the thorny issues. For example, how particular is it about its environment? Viruses leave most of the work of their reproduction to outside sources, so there are many people who don't want to call them life. But there's a continuous slope between that and something that can survive on nothing more than sunlight, water, CO2 and trace minerals; you don't say that a cat isn't alive because it can't make taurine and has to rely on external entities to do so, for example. And at an even more basic level, how picky must one be about what constitutes "replication"? What if you have imperfect replicators that create entities "similar" to themselves, which may have varying degrees (perhaps frequently "zero") of ability to replicate themselves? Certainly such a thing has the potential to at least lead to life. But is it life? If not then what's the cutoff point in terms of replicative accuracy when you start to call it life and the inaccuracies in its reproduction "evolution"?
I don't think this is at all special. There have been tons of space-matter-abiogenesis experiments that have been done, with similar results. For example, it's been shown that Titan's atmosphere can produce at least 16 amino acids and all five nucleotide bases, and we've already detected organic molecules over 10000 daltons there.
Nature likes to produce rather complex mixtures of organic chemicals without any help from life, nobody should doubt this any more, there's been way too much evidence that it happens. Nature is more than happy to continously rain down vast amounts of varied, complex organics given the right situation, providing both potential organic catalysts to develop into early life and "food" that they can scavenge. The question that needs to be answered next is, from a random diverse mix of organics, how does a hypercycle get started, wherein some chemicals / mixtures of chemicals / families of chemicals begin to encourage the creation of more chemicals "like" them, increasing the odds that there will be more produced of whatever is needed to keep the cycle going. Once you get to that point, you have the potential for evolution to take hold - first by a simple race to produce the most exact copies of the most efficiently-catalyzing chemicals and the poisoning of competing chemicals, up to the development of membranes to provide defense/hoarde resources/survive adverse situations/etc (the first "ur-cells").
True, we know that there is nowhere in the universe that His noodly appendages doesn't grace.
Right. Having the government cover all of your major liabilities, getting to write off massive debts, pass all of your cost overruns onto local consumers without them having a say in the manner, and so on, that's all "paying their own way", right? In nuclear power, the gains have always been privatized while the costs and risks socialized. And it's *still* been very difficult to find investors. Nuclear has always been more popular on K-Street than Wall Street.
Here's a paper going into the various massive ways nuclear has been subsidies. And they still can't bloody manage to stay afloat. It's one of the few industries with a negative growth curve - where technology gets more expensive with time, not cheaper.
Wow, way to not link to a study, but rather a Smithsonian blog talking about a Wordpress blog talking about a study. You clearly love your primary sources!
FYI, the study is just one of many. The study itself cites others, including:
20,000 birds/yr (Sovacool, 2012)
10,000–40,000 birds/yr (Erickson et al., 2001 and Manville, 2005)
20,000–40,000 birds/yr (Erickson et al., 2005)
440,000 (Manville, 2009)
573,000 (Smallwood, 2013).
The latter two include lattice towers, which are largely being decommissioned as unsafe to birds.
But hey, having varied numbers clearly means that if you can find a blog linking to another blog linking to a study that shows high numbers (among many different studies), then clearly the GP is "plain wrong", right?
And yes, even if we go with your choice study's mean of 234,012 annual bird deaths, that's still orders of magnitude less than many other types of human activities.
I have serious fears that we're facing an unduly high risk of a major wind spill here. :(
The number of grammatical cases is irrelevant. Question: What's the difference between a grammatical case without stem changes and a postposition (opposite of a preposition? Answer: A space.
That which is challenging, apart from stem changes, is the same thing that is challenging with helper words in general: when to use what with what. Picture a person learning English and trying to remember what to use with what. "I was scolding her.... over it? for it? about it? to it? around it?" "We were unhappy.... over it? for it? about it? to it? around it?" "She was dedicated.... over it? for it? about it? to it? around it?" And so forth. It's the same for people trying to learn which declension case to use in which context. But if the declensions are just suffixes without stem changes, then they're no different from postpositions. And often stem changes where they occur follow pretty predictable rules, often for pronunciation reasons.
I'm sorry, but I agree with that. If you on the UK want us to dam up our rivers and build roads out to geothermal areas and tap into our resources, and raise our local power prices in the process, all for the benefit of the UK, our government better damn well profit as much as possible from it and reduce our taxes / improve our services in exchange for that.
Unfortunately, xB and xD do not agree.
Readily replaceable intakes?
You could find fans for a plan like that...
Better negotiate the contract during a Sjálfstæðisflokkurinn / Framsóknarflokkurinn (conservative) government. Samfylkingin would approve it under the condition that the Icelandic government's share of the sales are so high that you would barely save any money on the imported power, and Vinstri Grænir would outright reject it no matter what you offered. But Sjálfstæðisflokkurinn and Framsóknarflokkurinn would let you dam up whatever rivers you want and take gigawatts of power in exchange for a handful of shiny trinkets and a couple magic beans.
And how do we know that the real benefit doesn't come from hitting yourself with birch branches?
zblockquote>See: Cabin_Pressurization [wikipedia.org]
A person needs at least 20kPa *from the mask to breathe*. Not 20kPa *ambient pressure*. Please learn to read.
Aerodynamic loading = pressure. If you have high loadings, you have high pressures. Period.
Are you talking about what I was talking about? I was talking about an electric motor, not a fuel-driven one.
What sort of claim is that? Since when do oxygen masks need 20kPa to function? And secondly, if there's "problematic loading on the capsules" from too much pressure on the pressure-compromised capsule, then your pressure is also way too high inside. Which means that you've repressurized the tube way too much. So the solution is: Don't do that!
Wait, meaning that while it's technically possible, but it'd be really tricky to accomplish? Gee, I wish I had written something like "Branching would be really tricky, but there's no physical barriers" at the top of my post ;)
Drag is reduced in the first place by using hydrogen even at a given pressure. And you can use 1/4th the pressure and still maintain lift because you're moving four times as fast. And given how few reboosts are needed from LA to SF in the base case, a few more per unit distance hardly seems limiting.
Irrelevant because earthquakes impose far more deflection that you have to be able to counter (and that the proposal calls for countering) than a craft moving past.
What, you're picturing drum brakes or something? You're moving at high speeds in a giant steel tube. Magnetic braking couldn't possibly be easier.
Where are you getting this from? Even if the tube was instantly full pressure (which it wouldn't be), a streamlined shape will not experience 2Gs at 700mph, any more than a passenger jet losing full engine power does. And anyway, 10g horizontal is not fatal even if that was the case. The average untrained individual, properly restrained, can tolerate 10g for a minute without even loss of cognitive function.
Not only that, but if your craft is travelling four times as fast, you're sweeping through four times as much gas per unit time to compress under the skis.
Hydrogen has all sorts of advantages. And the very low pressures prevent most of the negatives. The only one that I don't know about and would require testing would be what sort of reaction would one see as a craft moves past, with any residual oxygen. If I had to guess, I'd guess that you will get some combustion, but the craft moves past so fast and the mixture will decompress so fast, I would think the rate would be quite limited.
First off, if servicing that requires full de/repressurization is some sort of frequent event, then the whole concept is doomed for reasons entirely unrelated to anything in this discussion. Secondly, 1/5 ton of hydrogen at industrial rates is about $200. Whoop-di-doodle-doo. And the advantage is being able to travel at mach freaking 4, not about the reduction of drag at a given speed (which is, FYI, true also).
As someone else already mentioned, it uses low pressure air because the "trains" are ground-effect aircraft, not maglev. They need air.
Secondly, the pumping budget to overcome leaks is so small, both in terms of capital and ongoing costs, that you could increase them by an order of magnitude and not have any sort of practical effect on the budget. Whatever factor you increase over the baseline increases the factor you can replace air by. You don't need 100%.
It does - gravity high enough to deform it into a sphere.
And if Jupiter was large enough to be a brown dwarf? Yes, of course.