The Nazis didn't outsource the creation of Enigma to the Americans. They brought it from the Poles (who had already broken it and given the keys to the British). Or something like that.
Speaking as someone who has spent years doing gas analyses in the oil industry (i.e. I have spent a lot of time thinking "that's a lot of flammable material ; if we handle this wrong, I may die."), and who recently had to shave his beard off (5 years of lovely growth) due to poison gas concerns on a well I was drilling offshore (nowhere to run to, nowhere to hide)...
I'm not particularly happy about "Joe Sixpack, Car Mechanic" working with hydrogen, because it is a bastard for leaks. A thorough-going bastard.
And I'm not terribly ecstatic about a fairly nasty gas like ammonia sitting around by the ton in tanks maintained by Joe Sixpack's brother. (I once broke a carbouy of 880 ammonia solution in water - and had spend hours cleaning the laboratory out ; that is nasty stuff. But it's nowhere near the lethality of my beard-sacrificing gas, H2S.).
And I'm fully aware of the hazards of hydrocarbon fuels too - I get paid to find the damned things.
On balance, if the conversion efficiency were adequate, I suspect an ammonia storage with local (i.e. within the engine block, where Joe Sixpack uses his best tools and concentrates, with the manual in hand) formation of hydrogen for use, either in an IC engine or in a fuel cell, could well be the lowest risk outcome. It certainly bears looking at.
It took me 30 seconds searching to find a couple of dozen papers in this general field of research, by someone called "McElrath". I know that it may seem heretical to you near-7 digiters, but some people use their real names (or in my case, profession) here, and have done for approaching two decades now.
If photons with a frequency in the visible spectrum don't react with "dark matter" than why would photons with a frequency in the x-ray spectrum?
For the same reason that if photons in the red end of the visible spectrum don't interact with this red-transmitting filter, then why would photons at the X-ray end of the visible part of the spectrum?
Wavelength matters to absorption spectra. That's rather what makes them spectra.
Every couple of years when I get my hearing test, the frequency response plot stops at 20kHz and the actual test signals stop at 18hKz. Because people can't hear higher than that.
At something in excess of 80% of the volume of the planet (though I've not calculated the mass ratio recently), I rather think we'll run out of crust first. And since most of that isn't really worth much for anything, I just don't see running out of mantle as being a problem much this side of the Sun turning red giant.
Besides, there's no real shortage of chondrite, just a lack of application in getting to it. While short of drilling a MoHole (which was never actually done, despite hype), we don't have many ways of getting at the mantle.
I suspect that "banned" isn't quite the right word. The issue is that the range of refractive index available in lgass is smaller than the range available in optical polymers. So, if a particular lens manufacturer makes a design decision that they'll produce lens blanks up to %DIAMETER%, and %THICKNESS%, and %WEIGHT%, that then constrains the maximum optical change that can be achieved within those parameters. Above a certain dioptre strength, lenses in glass (as opposed to polymer) cease to be available.
Personally, I refuse to use plastic lenses, because I've had bad experiences in the past with their ease of scratching. I'm told that the compositions have improved ; "fine", I'll let someone else find out. I'm told that I'll find it so much less uncomfortable with the much lighter plastic lenses, and I say "I'm not uncomfortable with them at the moment." I'm told that they're much more stylish and that plastic lenses will make my dick bigger, but my dick is already stretching the wife and I don't give a shit about my appearence. But even so, as my prescription changes through the years, I'm coming close to the limit of what I can get in glass lenses and will probably have to start ot take plastic in the near future - within one or two sets of lenses.
You may have more choices in America, but since I'm already using German lens suppliers (in standard size blanks, fitted by a local optician), with a 300-odd million market, I doubt you'll have much more choice.
I wonder if I can get a glass outer surface (for scratch resistance) bonded to an inner of optical plastic?
Xest thinks, upthread, that it's around 9% of people, which would be around 6 million weapons. I suspect your figure is more likely to be accurate- in the several hundred people I've known, I include a couple of poachers (probably long dead) and a couple of gamekeepers (also poachers, at different times), for whom a shotgun was a working tool. And a couple of people who did target shooting at uni (but only one of them still has a gun, because she's still shooting). Which would make around 2-3% of people, closer to your figure than Xest's.
To be honest, if Ihad my way on gun licensing laws, people like Derek Bird wouldn't be getting guns either. Nobody else would either, without a really, really good reason. Which is the only real point on which we differ.
Simply put, EVERYWHERE in north America you a not allowed to park by a fire hydrant the same way you can't park on a sidewalk.
Other correspondants are saying that rules vary between areas - and therefore one assumes that the "driver's manual" also varies form state to state. Unless you're a professional driving instructor, I don't think I'd accept your assurance thaqt its the same in all parts of the country. In the unlikely event that I found myself in America, and even more unlikely that I chose to drive, I suspect that I'd have to find the "driver's manual" for that state, city, jurisdiction, or road, and memorise that.
We have no need to make parking rules about fire hydrants - and I've never seen any calls for such rules - despite having fires that follow the same laws of physics. So I wonder why America even needs such rules? They're clearly not an international norm, or dictated by the laws of nature.
That reminds me to get some practice with US-style fire hose couplings - my current vessel uses US-style couplings, despite having been built in China and Rotterdam and operating in Africa.
Why not just find a big enough cave or a system of caves which all you would need to do is seal the entrance with a steel door so the cave can be pressurized and oxygen to be flooded in.
You are assuming, quite incorrectly, that the walls, roof and floor of the putative cave will be impermeable. You'd need to at the least seal over the "fracture porosity" (I was discussing an oil well I drilled a few years ago with extensive fracture porosity with an evaluation engineer earlier today, on the off-chance that we have to use such evaluation techniques on the project we're currently employed on ; it's tedious detail, and not even a particularly rare situation). Which could mean grouting a crack in the wall every metre or so with some gas-tight relative of plaster-of-Paris. Or it could mean that you essentially have to coat the whole inner surface with a 500 micron thickness of an appropriate plastic, and then look for the remaining leaks.
It's not as easy as "sealing the entrance". But it would still be a whole lot easier than building out on the plain surface. And, essentially for free, you get all the radiation shielding you want, just by choosing a deep enough cave system.
I would recommend that you take a long trip down a terrestrial "lava tube cave" ; they're common enough that you shouldn't experience any difficulty in finding one. There you can examine in the walls the detailed structure of the lava beds which the tubes laid down as they were constructing themselves. That's if you don't want to take the advice of a geologist (points finger at myself) who is also a speleologist (different finger, same self), and who has gone on day-trips down such caves as part of a volcanology holiday (different finger, same self), and spent several hours discussing this exact point with a professor of volcanology (the holiday leader) while getting nose to the rocks to examine the evidence.
It may not be your idea of fun, but it is mine. And the wife quite enjoyed the scenery and the walking too.
Using lava tube caves as a base for accommodation in/ on Mars is a real prospect for establishing a research base there (I dismiss terraforming Mars ; by the time we have the technologies for that, we simply won't need them). The biggest hindrance would be in finding suitable caves (they are known, but they are also rare) and surveying their geotechnical (areotechnical?) competence, particularly in the roof. Even on Earth, our ability to remotely detect caverns is severely limited to those within a few metres of the rock surface, and those are likely to be the mechanically weakest and most poorly suitable ones. Robotic surveyors are a workable tool kit for doing this sort of work.
TL;DR version : It's not that easy, but it's certainly not impossible.
TFA isn't talking about picking up echoes from the trails, but about actual emission from the trails, which is a different kettle of fish. Or even a different plasma of electrons, if you like your analogies mixed. As you say, people have been "bouncing" radio signals off meteor trails for decades. People have also been using omni-directional antennae hooked to fairly basic wide-band radio receivers as a too for detecting meteors in flight for a number of decades too. It's one of the easiest ways of getting a count of the actual rate of meteor arrival during a meteor shower, as it doesn't involve spending hours sitting out watching the sky, and the frailties to which the human observer is prone. Unsurprisingly, it correlates well with the ZHR records kept by experienced human observers, to the point that it's a valuable research tool.
So the fact that meteors produce Rf noise is hardly new ; being able to show that some of the RF meteor trails trails is fairly big news though. I still remember with a degree of awe the sight of the 100-odd degree long tail of Comet Hyakutake streaking across the sky in late 1996 (or was it 1997 and I'm getting confused with Hale-Bopp? Two good comets almost exactly a year apart. Was Slashdot even in existence then?)
I don't awe easily ; that was an incredible sight. To know that there are (broadly) similar events gracing the skies of our new, RF-seeing Overlords makes me feel happy for them and I extend my heartiest welcome to them.
The counter argument is that maybe all of the inner planets have the same ratios of oxygen isotopes as one another, and it was an inner planet that struck Earth and basically everything involved was made of the same stuff so the differences are small.
As T.E.D says down thread, you're glossing over, or unaware of, the evidence form Mars. We have in situ measurements of the properties of Mars' atmosphere which allows us to unambiguously [*] flag certain (I think a couple of dozen, but the number is increasing steadily) meteorites as having interacted with the Martian atmosphere for a very long time (millions to billions of years) ; the oxygen isotope ratios of the minerals in those rocks are distinct from the comparable ratios in terrestrial rocks.
It would be very interesting to get comparable rocks from Venus and Mercury. But the energy cost of getting a sample back form Mercury to Earth is very substantial, which would make such a mission expensive. Sending a sufficiently accurate measuring device would also be an expensive mission. Getting something through to the surface of Venus is also going to be very difficult -there's a lot of atmosphere in the way. Not impossible, but difficult and expensive.
[*] At least, I've heard no convincing counter-arguments, and since it takes more than 4 syllables to even describe the question, I don't expect any from even the most rabid lunatic fringe of the Creationists.
Yet pop the ["the pop", surely?] astronomy books that I read my children are full of moons being captured. I've never gotten that.
The people writing the pop astronomy books haven't actually studied the subject in sufficient depth. They're just parroting something they got from a popular astronomy book in the 1950s.
Just ask your phone company, most of them have plans to move to exclusively smart phones in the foreseeable future.
That'll be fine then when my non-smart phone (and the three other non-smart phone that I have laying in drawers having picked them up for comms on various remote worksites) dies. I reckon that'll be some time in the mid-2020s.
That makes the price of a one-time "how to use a map" training course, a basic compass, and a map for the city/ country that you're going to look positively good value. Of course, that also requires a little forethought and planning, plus the common sense to pick up a map when you arrive at your destination (if you're travelling on an emergency call out), but these are still low-priced commodities. Apart from the common sense.
I do plenty of walking in the country, just not in England - which may be "my country" in terms of birth address, but one which I only visit for the purposes of visiting family. I choose to live in Scotland, and do it to go into the mountains not potter around on farmland.
You may be right that there are lots of people in the country who have guns. But it would have to be pretty much EVERY person who lives in the countryside, and with "countryside" defined as towns of under 10,000 (approx., the size of London in the Middle Ages) for you to approach your claimed figure of about 6 million guns. (I actually grew up in a village of 3000 people, but with overspill from London escapees had grown to nearly 10,000 by the time I left to move to Scotland.)
That thing about "cadet hall staff"... are you implying that people are allowed near kids with guns, and not being employed by the armed forces. Well, I can see that lasting about 30 seconds after the "someone think of the children" brigade hearing about it. Adults with guns and an interest in kids? Yeah, that's not going to last. Good thing too.
Slashdot Mirror
The Nazis didn't outsource the creation of Enigma to the Americans. They brought it from the Poles (who had already broken it and given the keys to the British). Or something like that.
I'm not particularly happy about "Joe Sixpack, Car Mechanic" working with hydrogen, because it is a bastard for leaks. A thorough-going bastard.
And I'm not terribly ecstatic about a fairly nasty gas like ammonia sitting around by the ton in tanks maintained by Joe Sixpack's brother. (I once broke a carbouy of 880 ammonia solution in water - and had spend hours cleaning the laboratory out ; that is nasty stuff. But it's nowhere near the lethality of my beard-sacrificing gas, H2S.).
And I'm fully aware of the hazards of hydrocarbon fuels too - I get paid to find the damned things.
On balance, if the conversion efficiency were adequate, I suspect an ammonia storage with local (i.e. within the engine block, where Joe Sixpack uses his best tools and concentrates, with the manual in hand) formation of hydrogen for use, either in an IC engine or in a fuel cell, could well be the lowest risk outcome. It certainly bears looking at.
It took me 30 seconds searching to find a couple of dozen papers in this general field of research, by someone called "McElrath". I know that it may seem heretical to you near-7 digiters, but some people use their real names (or in my case, profession) here, and have done for approaching two decades now.
For the same reason that if photons in the red end of the visible spectrum don't interact with this red-transmitting filter, then why would photons at the X-ray end of the visible part of the spectrum?
Wavelength matters to absorption spectra. That's rather what makes them spectra.
I think Bugs Bunny must have been round your post. Eating all the carets.
Ah user ter DREAM of walking through water ice snow. For us it were wading through methane slush, all day every day.
Every couple of years when I get my hearing test, the frequency response plot stops at 20kHz and the actual test signals stop at 18hKz. Because people can't hear higher than that.
Besides, there's no real shortage of chondrite, just a lack of application in getting to it. While short of drilling a MoHole (which was never actually done, despite hype), we don't have many ways of getting at the mantle.
There's oxygen in carbon dioxide. Use that!
You'll probably die of suffocation from the (multiple, at least one per lung) air embolisms before you get around to noticing the bends.
Personally, I refuse to use plastic lenses, because I've had bad experiences in the past with their ease of scratching. I'm told that the compositions have improved ; "fine", I'll let someone else find out. I'm told that I'll find it so much less uncomfortable with the much lighter plastic lenses, and I say "I'm not uncomfortable with them at the moment." I'm told that they're much more stylish and that plastic lenses will make my dick bigger, but my dick is already stretching the wife and I don't give a shit about my appearence. But even so, as my prescription changes through the years, I'm coming close to the limit of what I can get in glass lenses and will probably have to start ot take plastic in the near future - within one or two sets of lenses.
You may have more choices in America, but since I'm already using German lens suppliers (in standard size blanks, fitted by a local optician), with a 300-odd million market, I doubt you'll have much more choice.
I wonder if I can get a glass outer surface (for scratch resistance) bonded to an inner of optical plastic?
Don';t they have things like Credit Unions etc in your home country? And not all banks are mega-conglomerates in any case.
Xest thinks, upthread, that it's around 9% of people, which would be around 6 million weapons. I suspect your figure is more likely to be accurate- in the several hundred people I've known, I include a couple of poachers (probably long dead) and a couple of gamekeepers (also poachers, at different times), for whom a shotgun was a working tool. And a couple of people who did target shooting at uni (but only one of them still has a gun, because she's still shooting). Which would make around 2-3% of people, closer to your figure than Xest's.
To be honest, if Ihad my way on gun licensing laws, people like Derek Bird wouldn't be getting guns either. Nobody else would either, without a really, really good reason. Which is the only real point on which we differ.
Other correspondants are saying that rules vary between areas - and therefore one assumes that the "driver's manual" also varies form state to state. Unless you're a professional driving instructor, I don't think I'd accept your assurance thaqt its the same in all parts of the country. In the unlikely event that I found myself in America, and even more unlikely that I chose to drive, I suspect that I'd have to find the "driver's manual" for that state, city, jurisdiction, or road, and memorise that.
We have no need to make parking rules about fire hydrants - and I've never seen any calls for such rules - despite having fires that follow the same laws of physics. So I wonder why America even needs such rules? They're clearly not an international norm, or dictated by the laws of nature.
That reminds me to get some practice with US-style fire hose couplings - my current vessel uses US-style couplings, despite having been built in China and Rotterdam and operating in Africa.
Snowden - 1
CIA . . . . - 0
KGB . . . - ~0.7
You are assuming, quite incorrectly, that the walls, roof and floor of the putative cave will be impermeable. You'd need to at the least seal over the "fracture porosity" (I was discussing an oil well I drilled a few years ago with extensive fracture porosity with an evaluation engineer earlier today, on the off-chance that we have to use such evaluation techniques on the project we're currently employed on ; it's tedious detail, and not even a particularly rare situation). Which could mean grouting a crack in the wall every metre or so with some gas-tight relative of plaster-of-Paris. Or it could mean that you essentially have to coat the whole inner surface with a 500 micron thickness of an appropriate plastic, and then look for the remaining leaks.
It's not as easy as "sealing the entrance". But it would still be a whole lot easier than building out on the plain surface. And, essentially for free, you get all the radiation shielding you want, just by choosing a deep enough cave system.
I would recommend that you take a long trip down a terrestrial "lava tube cave" ; they're common enough that you shouldn't experience any difficulty in finding one. There you can examine in the walls the detailed structure of the lava beds which the tubes laid down as they were constructing themselves. That's if you don't want to take the advice of a geologist (points finger at myself) who is also a speleologist (different finger, same self), and who has gone on day-trips down such caves as part of a volcanology holiday (different finger, same self), and spent several hours discussing this exact point with a professor of volcanology (the holiday leader) while getting nose to the rocks to examine the evidence.
It may not be your idea of fun, but it is mine. And the wife quite enjoyed the scenery and the walking too.
Using lava tube caves as a base for accommodation in/ on Mars is a real prospect for establishing a research base there (I dismiss terraforming Mars ; by the time we have the technologies for that, we simply won't need them). The biggest hindrance would be in finding suitable caves (they are known, but they are also rare) and surveying their geotechnical (areotechnical?) competence, particularly in the roof. Even on Earth, our ability to remotely detect caverns is severely limited to those within a few metres of the rock surface, and those are likely to be the mechanically weakest and most poorly suitable ones. Robotic surveyors are a workable tool kit for doing this sort of work.
TL;DR version : It's not that easy, but it's certainly not impossible.
So the fact that meteors produce Rf noise is hardly new ; being able to show that some of the RF meteor trails trails is fairly big news though. I still remember with a degree of awe the sight of the 100-odd degree long tail of Comet Hyakutake streaking across the sky in late 1996 (or was it 1997 and I'm getting confused with Hale-Bopp? Two good comets almost exactly a year apart. Was Slashdot even in existence then?)
I don't awe easily ; that was an incredible sight. To know that there are (broadly) similar events gracing the skies of our new, RF-seeing Overlords makes me feel happy for them and I extend my heartiest welcome to them.
Beef with jet A1 fuel? That sounds peculairly revolting.
Hang on ; we're talking about Texas. That makes sense then.
As T.E.D says down thread, you're glossing over, or unaware of, the evidence form Mars. We have in situ measurements of the properties of Mars' atmosphere which allows us to unambiguously [*] flag certain (I think a couple of dozen, but the number is increasing steadily) meteorites as having interacted with the Martian atmosphere for a very long time (millions to billions of years) ; the oxygen isotope ratios of the minerals in those rocks are distinct from the comparable ratios in terrestrial rocks.
It would be very interesting to get comparable rocks from Venus and Mercury. But the energy cost of getting a sample back form Mercury to Earth is very substantial, which would make such a mission expensive. Sending a sufficiently accurate measuring device would also be an expensive mission. Getting something through to the surface of Venus is also going to be very difficult -there's a lot of atmosphere in the way. Not impossible, but difficult and expensive.
[*] At least, I've heard no convincing counter-arguments, and since it takes more than 4 syllables to even describe the question, I don't expect any from even the most rabid lunatic fringe of the Creationists.
The people writing the pop astronomy books haven't actually studied the subject in sufficient depth. They're just parroting something they got from a popular astronomy book in the 1950s.
Though in this case, I suspect that the more appropriate word is "hoped", as in "hoped they wouldn't notice or find out."
That'll be fine then when my non-smart phone (and the three other non-smart phone that I have laying in drawers having picked them up for comms on various remote worksites) dies. I reckon that'll be some time in the mid-2020s.
That makes the price of a one-time "how to use a map" training course, a basic compass, and a map for the city/ country that you're going to look positively good value. Of course, that also requires a little forethought and planning, plus the common sense to pick up a map when you arrive at your destination (if you're travelling on an emergency call out), but these are still low-priced commodities. Apart from the common sense.
You may be right that there are lots of people in the country who have guns. But it would have to be pretty much EVERY person who lives in the countryside, and with "countryside" defined as towns of under 10,000 (approx., the size of London in the Middle Ages) for you to approach your claimed figure of about 6 million guns. (I actually grew up in a village of 3000 people, but with overspill from London escapees had grown to nearly 10,000 by the time I left to move to Scotland.)
That thing about "cadet hall staff" ... are you implying that people are allowed near kids with guns, and not being employed by the armed forces. Well, I can see that lasting about 30 seconds after the "someone think of the children" brigade hearing about it. Adults with guns and an interest in kids? Yeah, that's not going to last. Good thing too.