What do people mean when they say "make America great again"? My understanding is that they want a USA which is making new innovative industries, employing lots of people in the USA with high paying jobs, and making profit in the process (the more the better.) Elon Musk is the poster child for doing all of those things - yet many people crying "Make America great again" are trying to tear him down. The kindest explanation is that they are so blinded by ideology that they can't think straight.
Actually 91.75 km/h. (I think, but not sure, that includes night time.) But these vehicles aren't terribly practical, and wherever you live probably gets less sun than the Australian outback.
"This would give SpaceX three landing pads and the ability to bring back all three Falcon Heavy boosters to land while also retaining the option to land one or two on drone ships in the Atlantic Ocean."
I can imagine scenarios where you'd want to land zero, one or three boosters on drone ships. I can't imagine any scenario where it makes sense to land two boosters on drone ships. One way would be to have the center booster and one side booster landing at sea - but if one side booster can return to landing site, so can the other (and landing on land is both cheaper and safer if you can do it.) The other way is to land both side boosters at sea but return the center booster to land - but the center booster is always going to be much harder to return to land, as it burns longer and so is higher velocity and further down range when it has finished boosting.
The team was able to compress small flakes of graphene using a combination of heat and pressure. This process produced a strong, stable structure whose form resembles that of some corals and microscopic creatures called diatoms. These shapes, which have an enormous surface area in proportion to their volume, proved to be remarkably strong. “Once we created these 3-D structures, we wanted to see what’s the limit — what’s the strongest possible material we can produce,” says Qin. To do that, they created a variety of 3-D models and then subjected them to various tests. In computational simulations, which mimic the loading conditions in the tensile and compression tests performed in a tensile loading machine, “one of our samples has 5 percent the density of steel, but 10 times the strength,” Qin says.
The video is about testing 3D plastic models. Exactly what they have achieved is unclear to me. Do they have plastic in a configuration 10 times the strength of steel? Did they 3D print in steel, but didn't show it in the video? Did they extrapolate from a plastic model to say that if they'd made it of steel it would be 10 times the strength of steel? Did they use a computer model to say that if they could make the optimal graphine configuration it would be 10 times strength of steel?
They then began loading cold helium. Had the oxygen stayed liquid, it would have squeezed out (expected behavior). Rather, the oxygen wasn't able to seep out fast enough, and the increasing pressure caused some of it to solidify, blocking the escape of oxygen from the CF.
So if I understand the logic of these tanks correctly: The He tank necessarily is at high pressure relative to the LOX tank, as it will be pressurizing the much larger LOX tank as it empties. CF is strong enough to hold the tank together against this pressure, but can't prevent seepage through it. The aluminium layer prevents gas escape, but contributes little to the structural strength of the tank - hence when filled, it expands like a balloon until the CF prevents further expansion, which necessarily compresses the CF. (Because LOX will seep through the CF to contact the inner layer, the inner layer has to be something which plays nicely with LOX, and aluminium does so, but this is probably a happy coincidence rather than a reason why aluminium was chosen.)
An alternative fix would be add an outer aluminium layer (which could be very thin) to prevent LOX getting into the CF. However, the integrity of this outer layer would be critical - if it leaked a little LOX in, it would impede its exit when the tank pressurized, which would likely cause explosive failure.
If you are a web advertising company, why should you ever allow advertising clients to include arbitrary Javascript in their ads? Could you not provide a Javascript library of your own to do the legitimate things ad Javascript might do, and only allow advertising clients to use simple calls into your library?
I'm not knowledgeable about Javascript or web advertising - these are genuine questions, not rhetorical ones.
Yep, get rid of those political insiders who are so terrible because they are beholden to big money special interests. Let's replace them with, hmm, direct representatives of those big money special interests.
The connection I see is that you can use it to deorbit satellites at end of life, provided the satellite was was equipped with a deployable tether. Once the tether is deployed, the deorbiting process is completely passive and automatic. This doesn't help at all with the junk that is already present however. Perhaps you could attach tethers to large existing space junk but matching orbits with them to do this would be expensive.
I thought of a similar plan some years ago: make a balloon out of some very thin light material, such that when inflated, it is very much larger than the satellite. When the satellite is at end of life, inflate the balloon (takes very little gas, as we're in a vacuum.) This greatly increases the drag against the very thin outer atmosphere of the earth. (The balloon will get punctured eventually by other space junk. Without testing, I don't know if it would deflate to smaller cross-section if this occurred. If it would deflate, we'd need countermeasures, perhaps a balloon material which hardens on UV exposure, or spraying some adhesive into the freshly inflated balloon, either way so that it has structural strength to hold shape without gas pressure.)
This is similar to the Japanese plan in that it is a lightweight device you attach to your satellite, which deploys and end of life to speed up deorbiting. In both cases you could put the deorbit device on a dead man's switch, so that it will autodeploy should the satellite fail. I don't know which device would be more effective, except that my device is much more altitude sensitive than the Japanese tether, and that these people are smart enough to think of my balloon but chose to develop the tether.
Reading between the lines, defamation law still applies. It is only extra clauses in the sales contract banning/punishing bad reviews which are now not allowed.
If I write that I bought a new Rolls Royce, but when it arrived it was made of cardboard, and when I sat in it it collapsed and then caught fire, I can still be sued for libel, and if RR can show I was lying, I'll lose. Conversely if RR habitually sues people who post honest opinions which criticize them, then they're open to a SLAPP countersuit. This looks like a good balance to me.
Note, I am not a lawyer, and have no information beyond reading TFA. Corrections and elaborations from actual lawyers are welcome.
Glow-in-the-dark watch dials are almost always phosphorescent paint, not radioluminescent paint. If after a long time in darkness your watch dial no longer glows, but it glows brightly after exposure to light, it is phosphorescent. If it glows with the same brightness regardless of light exposure history, it is radioluminescent. Personally I have never to my knowledge been in the presence of a radioluminescent anything.
Even if it is radioluminescent, if made in the last 50 years it probably isn't radium, but rather promethium-147 or tritium.
It could be that the headline is correct, but the first sentence of the summary is wrong. Finland might pass a law forbidding coal power while Canada simply stops using it.
I expect there are island nations which have never used coal power stations - they aren't a good size fit for an atoll. New Zealand might well be coal-electricity free by 2022, judging by the plans for its only significant coal powered plant. (I'm not sure if insignificant power plants exist.) There are probably more examples I am unaware of.
I've just read the Wikipedia page on Faraday Future. I can't make sense of this from a business point of view. It is a Californian company funded by Chinese capital.
From Wikipedia: "In July 2015, Motor Trend ran an article that provided a few specifications for Faraday Future’s proposed electric vehicle: it will have 15 percent higher specific energy than a Tesla Model S, it utilizes a multi cell solution where both individual cells and groups of cells can be replaced, and it will have a modular design for improved mass-production methods."
OK, this is good - they have a point of difference, some things they think they can do better than Tesla or Nissan. But successfully starting a new car company requires either a niche you can exploit and then expand from, or huge amounts of money. Tesla used the niche method, but I can't see that this will work again, at least in markets where Tesla, Nissan etc have a presence. Both this story and other evidence (Wikipedia article) suggest they are short of capital, so the other method doesn't work either.
In any case, whatever their business plan, why would they think the USA is the place to do it? They have better connections, cheaper labour, a bigger and probably less competitive market in China. A thought that occurred to me is that this is a feint, they're really just getting a bunch of American engineers to do some designing, then they'll fold up and take the designs back to China. However, this also doesn't really hold up - I don't see that Chinese engineers wouldn't be up to the task, and even if they weren't, it would be much cheaper to offer $500,000 salaries to American engineers.
We know how to design and operate nuclear power plants safely, the problem is that we won't.... They needed only to build the walls higher.
Build walls higher, put generators above flood level, and make allowance for safely venting hydrogen, so that things don't progress from bad to total disaster.
According to one source I read, the USA realized the risk of hydrogen explosion and retrofitted all their stations to allow for safe venting. The Japanese chose not to retrofit. (Warning - the source was a USA nuclear engineer, but I read it years ago, and my memory is fallible.)
This is slight progress. In strongly Democrat districts, Republicans can still exert influence to try to elect the less objectionable of two Democrats. (Although less common, I'd also expect some districts to give a choice of two Republicans.)
Its not just the first past the post system which is holding back third parties in America
Perhaps not - but dismantling the legal/procedural barriers is a vital first step.
If one party believes that the electoral college works in their favour, it will be much harder to abolish it.
Of the two recent elections where the electoral college and the popular vote did not agree, a Democrat won the popular vote and lost the college. However, if I toss a coin twice and both times it comes up heads, this isn't strong evidence that my coin is biased.
Is the electoral college system biased? If it is, is it a bias that is likely to persist in the long term?
They should eradicate the electoral college, but there is another fix I'd sooner see.
Plurality voting (whichever candidate gets the most votes wins) gives a very strong push towards two party elections. In any contest, if your favourite candidate is not one of the top two, you're better off voting for whichever of the top two is best (or least evil), because a vote for your favourite will be wasted. Even if a candidate is the favourite of 60% of the electorate, if they are perceived by the electorate as not being one of the top two, they'll receive few votes.
With preferential voting, you rank the candidates. You can rank your favourite first, and if it still comes down to the two major party candidates, your ranking between those two will carry just as much weight as party faithful who put one of the major candidates at #1.
This allows compromise/centrist candidates to win, and allows for new coalitions of interests. For example, in the USA currently the evangelical Christians and those favouring small government have found a home in the Republican party, but these two interests have no essential alignment. (That many believe both or oppose both is partly an artefact of the current two party system - if you turn up to Republican rallies because you're evangelical, you'll get bombarded with small government arguments, and you'll want to feel part of the group.) Currently an evangelical who wants to increase social services spending has no chance of election (neither major party will take them as a candidate), but with preferential voting they do.
The partisan divide in the USA has become toxic. Preferential voting can erode that divide.
For electing a single candidate, I suggest using a Condorcet method. For multi member constituencies, the single transferable vote works well. In either case, it may be useful to have a prior round of primary voting to keep the number of candidates in the preferential voting round manageable.
Major parties could chose to put up multiple candidates. Imagine a Trump/Cruz/Rubio/Clinton/Sanders election. I believe such an election would have had a different outcome, and that the electorate would be happier with the outcome.
So yes, fueling the rocket with people aboard is dangerous but boarding an already fueled rocket would be even more dangerous.
The people who are actually rocket engineers, quoted in TFA, say you are wrong. Boarding an already fuelled rocket is how (nearly?) every manned flight up until now has been done.
Slashdot Mirror
What do people mean when they say "make America great again"? My understanding is that they want a USA which is making new innovative industries, employing lots of people in the USA with high paying jobs, and making profit in the process (the more the better.) Elon Musk is the poster child for doing all of those things - yet many people crying "Make America great again" are trying to tear him down. The kindest explanation is that they are so blinded by ideology that they can't think straight.
Can't wait to see three boosters land at once
You won't. All going well, at some point you'll see two landing at once, and a third a few minutes later.
Correction: Driving time is 8am to 5pm, with a little leeway for finding a good place to stop for the night. It does not include night driving.
Actually 91.75 km/h. (I think, but not sure, that includes night time.) But these vehicles aren't terribly practical, and wherever you live probably gets less sun than the Australian outback.
"This would give SpaceX three landing pads and the ability to bring back all three Falcon Heavy boosters to land while also retaining the option to land one or two on drone ships in the Atlantic Ocean."
I can imagine scenarios where you'd want to land zero, one or three boosters on drone ships. I can't imagine any scenario where it makes sense to land two boosters on drone ships. One way would be to have the center booster and one side booster landing at sea - but if one side booster can return to landing site, so can the other (and landing on land is both cheaper and safer if you can do it.) The other way is to land both side boosters at sea but return the center booster to land - but the center booster is always going to be much harder to return to land, as it burns longer and so is higher velocity and further down range when it has finished boosting.
Here's the most relevant bit:
The team was able to compress small flakes of graphene using a combination of heat and pressure. This process produced a strong, stable structure whose form resembles that of some corals and microscopic creatures called diatoms. These shapes, which have an enormous surface area in proportion to their volume, proved to be remarkably strong. “Once we created these 3-D structures, we wanted to see what’s the limit — what’s the strongest possible material we can produce,” says Qin. To do that, they created a variety of 3-D models and then subjected them to various tests. In computational simulations, which mimic the loading conditions in the tensile and compression tests performed in a tensile loading machine, “one of our samples has 5 percent the density of steel, but 10 times the strength,” Qin says.
The video is about testing 3D plastic models. Exactly what they have achieved is unclear to me. Do they have plastic in a configuration 10 times the strength of steel? Did they 3D print in steel, but didn't show it in the video? Did they extrapolate from a plastic model to say that if they'd made it of steel it would be 10 times the strength of steel? Did they use a computer model to say that if they could make the optimal graphine configuration it would be 10 times strength of steel?
They then began loading cold helium. Had the oxygen stayed liquid, it would have squeezed out (expected behavior). Rather, the oxygen wasn't able to seep out fast enough, and the increasing pressure caused some of it to solidify, blocking the escape of oxygen from the CF.
So if I understand the logic of these tanks correctly: The He tank necessarily is at high pressure relative to the LOX tank, as it will be pressurizing the much larger LOX tank as it empties. CF is strong enough to hold the tank together against this pressure, but can't prevent seepage through it. The aluminium layer prevents gas escape, but contributes little to the structural strength of the tank - hence when filled, it expands like a balloon until the CF prevents further expansion, which necessarily compresses the CF. (Because LOX will seep through the CF to contact the inner layer, the inner layer has to be something which plays nicely with LOX, and aluminium does so, but this is probably a happy coincidence rather than a reason why aluminium was chosen.)
An alternative fix would be add an outer aluminium layer (which could be very thin) to prevent LOX getting into the CF. However, the integrity of this outer layer would be critical - if it leaked a little LOX in, it would impede its exit when the tank pressurized, which would likely cause explosive failure.
If you are a web advertising company, why should you ever allow advertising clients to include arbitrary Javascript in their ads? Could you not provide a Javascript library of your own to do the legitimate things ad Javascript might do, and only allow advertising clients to use simple calls into your library?
I'm not knowledgeable about Javascript or web advertising - these are genuine questions, not rhetorical ones.
Yep, get rid of those political insiders who are so terrible because they are beholden to big money special interests. Let's replace them with, hmm, direct representatives of those big money special interests.
I don't see what your problem is with this. Uber employees are able to throw customers under the feet of information so that it falls over.
I didn't envision the balloon to be stretchy. Think weather balloon or hot air balloon.
The connection I see is that you can use it to deorbit satellites at end of life, provided the satellite was was equipped with a deployable tether. Once the tether is deployed, the deorbiting process is completely passive and automatic. This doesn't help at all with the junk that is already present however. Perhaps you could attach tethers to large existing space junk but matching orbits with them to do this would be expensive.
I thought of a similar plan some years ago: make a balloon out of some very thin light material, such that when inflated, it is very much larger than the satellite. When the satellite is at end of life, inflate the balloon (takes very little gas, as we're in a vacuum.) This greatly increases the drag against the very thin outer atmosphere of the earth. (The balloon will get punctured eventually by other space junk. Without testing, I don't know if it would deflate to smaller cross-section if this occurred. If it would deflate, we'd need countermeasures, perhaps a balloon material which hardens on UV exposure, or spraying some adhesive into the freshly inflated balloon, either way so that it has structural strength to hold shape without gas pressure.)
This is similar to the Japanese plan in that it is a lightweight device you attach to your satellite, which deploys and end of life to speed up deorbiting. In both cases you could put the deorbit device on a dead man's switch, so that it will autodeploy should the satellite fail. I don't know which device would be more effective, except that my device is much more altitude sensitive than the Japanese tether, and that these people are smart enough to think of my balloon but chose to develop the tether.
Reading between the lines, defamation law still applies. It is only extra clauses in the sales contract banning/punishing bad reviews which are now not allowed.
If I write that I bought a new Rolls Royce, but when it arrived it was made of cardboard, and when I sat in it it collapsed and then caught fire, I can still be sued for libel, and if RR can show I was lying, I'll lose. Conversely if RR habitually sues people who post honest opinions which criticize them, then they're open to a SLAPP countersuit. This looks like a good balance to me.
Note, I am not a lawyer, and have no information beyond reading TFA. Corrections and elaborations from actual lawyers are welcome.
Almost certainly not.
https://en.wikipedia.org/wiki/...
Glow-in-the-dark watch dials are almost always phosphorescent paint, not radioluminescent paint. If after a long time in darkness your watch dial no longer glows, but it glows brightly after exposure to light, it is phosphorescent. If it glows with the same brightness regardless of light exposure history, it is radioluminescent. Personally I have never to my knowledge been in the presence of a radioluminescent anything.
Even if it is radioluminescent, if made in the last 50 years it probably isn't radium, but rather promethium-147 or tritium.
But the Chinese backers have no compelling reason to choose USA as their first market.
It could be that the headline is correct, but the first sentence of the summary is wrong. Finland might pass a law forbidding coal power while Canada simply stops using it.
I expect there are island nations which have never used coal power stations - they aren't a good size fit for an atoll. New Zealand might well be coal-electricity free by 2022, judging by the plans for its only significant coal powered plant. (I'm not sure if insignificant power plants exist.) There are probably more examples I am unaware of.
I've just read the Wikipedia page on Faraday Future. I can't make sense of this from a business point of view. It is a Californian company funded by Chinese capital.
From Wikipedia:
"In July 2015, Motor Trend ran an article that provided a few specifications for Faraday Future’s proposed electric vehicle: it will have 15 percent higher specific energy than a Tesla Model S, it utilizes a multi cell solution where both individual cells and groups of cells can be replaced, and it will have a modular design for improved mass-production methods."
OK, this is good - they have a point of difference, some things they think they can do better than Tesla or Nissan. But successfully starting a new car company requires either a niche you can exploit and then expand from, or huge amounts of money. Tesla used the niche method, but I can't see that this will work again, at least in markets where Tesla, Nissan etc have a presence. Both this story and other evidence (Wikipedia article) suggest they are short of capital, so the other method doesn't work either.
In any case, whatever their business plan, why would they think the USA is the place to do it? They have better connections, cheaper labour, a bigger and probably less competitive market in China. A thought that occurred to me is that this is a feint, they're really just getting a bunch of American engineers to do some designing, then they'll fold up and take the designs back to China. However, this also doesn't really hold up - I don't see that Chinese engineers wouldn't be up to the task, and even if they weren't, it would be much cheaper to offer $500,000 salaries to American engineers.
Can anyone make sense of this?
If it works it violates conservation of momentum, which is just as big a deal as violating conservation of energy.
Although to be fair, taking that tractor trailer volume of nuclear waste and putting it all into the volume of a tractor trailer would be a Bad Idea.
We know how to design and operate nuclear power plants safely, the problem is that we won't. ... They needed only to build the walls higher.
Build walls higher, put generators above flood level, and make allowance for safely venting hydrogen, so that things don't progress from bad to total disaster.
According to one source I read, the USA realized the risk of hydrogen explosion and retrofitted all their stations to allow for safe venting. The Japanese chose not to retrofit. (Warning - the source was a USA nuclear engineer, but I read it years ago, and my memory is fallible.)
This is slight progress. In strongly Democrat districts, Republicans can still exert influence to try to elect the less objectionable of two Democrats. (Although less common, I'd also expect some districts to give a choice of two Republicans.)
Its not just the first past the post system which is holding back third parties in America
Perhaps not - but dismantling the legal/procedural barriers is a vital first step.
If one party believes that the electoral college works in their favour, it will be much harder to abolish it.
Of the two recent elections where the electoral college and the popular vote did not agree, a Democrat won the popular vote and lost the college. However, if I toss a coin twice and both times it comes up heads, this isn't strong evidence that my coin is biased.
Is the electoral college system biased? If it is, is it a bias that is likely to persist in the long term?
They should eradicate the electoral college, but there is another fix I'd sooner see.
Plurality voting (whichever candidate gets the most votes wins) gives a very strong push towards two party elections. In any contest, if your favourite candidate is not one of the top two, you're better off voting for whichever of the top two is best (or least evil), because a vote for your favourite will be wasted. Even if a candidate is the favourite of 60% of the electorate, if they are perceived by the electorate as not being one of the top two, they'll receive few votes.
With preferential voting, you rank the candidates. You can rank your favourite first, and if it still comes down to the two major party candidates, your ranking between those two will carry just as much weight as party faithful who put one of the major candidates at #1.
This allows compromise/centrist candidates to win, and allows for new coalitions of interests. For example, in the USA currently the evangelical Christians and those favouring small government have found a home in the Republican party, but these two interests have no essential alignment. (That many believe both or oppose both is partly an artefact of the current two party system - if you turn up to Republican rallies because you're evangelical, you'll get bombarded with small government arguments, and you'll want to feel part of the group.) Currently an evangelical who wants to increase social services spending has no chance of election (neither major party will take them as a candidate), but with preferential voting they do.
The partisan divide in the USA has become toxic. Preferential voting can erode that divide.
For electing a single candidate, I suggest using a Condorcet method. For multi member constituencies, the single transferable vote works well. In either case, it may be useful to have a prior round of primary voting to keep the number of candidates in the preferential voting round manageable.
Major parties could chose to put up multiple candidates. Imagine a Trump/Cruz/Rubio/Clinton/Sanders election. I believe such an election would have had a different outcome, and that the electorate would be happier with the outcome.
So yes, fueling the rocket with people aboard is dangerous but boarding an already fueled rocket would be even more dangerous.
The people who are actually rocket engineers, quoted in TFA, say you are wrong. Boarding an already fuelled rocket is how (nearly?) every manned flight up until now has been done.