Some of the models call for a liquid water layer inside Pluto (if that's even a requirement). It has a young surface, younger than Mars; resurfacing** means energy and transport of chemicals between layers. And it's covered in tholins, meaning long-chain organics.
I'm not saying that there's life on (or rather, in) Pluto. Personally, I expect life to be pretty rare in the cosmos. But ruling it out just because it's far from the sun seems quite unreasonable. Look at all of the people oggling the finding of "water" on Mars (a more accurate headline would have been "Scientists find mildly damp rocket fuel on Mars"). Pluto could potentially have a subsurface ocean with organics actively cycling into it.
** - Heck, the best guess right now for what Sputnik Planum is is that it's a giant convecting nitrogen-ice "sea", like having the mantle exposed to the surface. If it truly is convecting then it's dragging down any heavier materials at the edges of its convection cells down into Pluto's (warmer) depths.
The New Horizons team refers to it as a planet. New Horizons head Alan Stern is one of the leading advocates for the reversal of the IAU decision. Pluto and other large KBOs have been referred to many times as planets in peer-reviewed literature since the IAU decision. One of the NASA links in this article itself refers to Pluto as a planet ("At half the diameter of Pluto, Charon is the largest satellite relative to its planet in the solar system."). Large numbers of people in the field - I'd wager a solid majority of planetary scientists (who make up only a small minority of the IAU's membership but really should be the ones making these decisions) - think the IAU seriously screwed up here. There are literally dozens of reasons why it was a screwup - need I go into them?
Indeed. Teaching basic coding (and let's roll in markup languages while we're at it) isn't like teaching someone to become an expert auto mechanic; it's like teaching them to change a flat tire, check their oil, jumpstart a car, etc. Interacting with computers is something that virtually everyone has to do these days. The ability to be able to write a simple script or even just have a basic understanding of *what* your computer is doing is not the same as having a 4-year CS degree. I think it would be good if kids were taught to change a flat tire and check their oil. And I think it's good that they learn the fundamentals of programming. Just like it's good for them to learn the fundamentals of mathematics, and chemistry, and biology, and so on down the line.
Your science analogy is spot on, but in more ways than you mention. It's not at all rare these days for mathematicians and scientists to have to do computer programming as part of their work. A mathematician is much more likely to need to know what a for loop is than what a scalene triangle is. A physicist is much more likely to need to know what a function call is than which element comes after cerium on the periodic table.
This is going to be an unpopular post. But the premise of the article - that the accident itself caused/will cause no deaths, only overreaction - is simply not true. And their "proof by ghost reference" doesn't help things any.
Radiation risks from Fukushima were more enhanced near the plant, while the evacuation measures were crucial for its reduction. According to our estimations, 730–1700 excess cancer incidents are expected of which around 65% may be fatal, which are very close to what has been already published (see references therein).
Estimates not good enough? Let's try actual measurements of thyroid cancer in children:
Assuming two years for duration on detectable level of cytology until clinical level, incidence rate ratio was 26.98 (95% confidence interval, 14.12-48.61) in the nearest area, and in Fukushima city, it was 19.41 (95% confidence interval,?9.62-37.31), compared with the Japanese mean annual incidence among those aged 15-19 years from 1975 to 2008 (i.e., 5 per 1,000,000).
They do note that there's a risk of screening effects, but given the correlation between rates and distance from the plant, they believe that the outbreak is real and needs further study
What did I mean earlier by "proof by ghost reference"? Their first two links just go to NYT search pages that aren't fruitful in backing up anything they claim. The third link takes some work but you can dig out the actual report in question. The NYT article describes it thusly:
Even among Fukushima workers, the number of additional cancer cases in coming years is expected to be so low as to be undetectable, a blip impossible to discern against the statistical background noise.
The actual report says:
The latency time for late radiation health effects can be decades, and therefore it is not possible to discount the potential occurrence of such effects among an exposed population by observations a few years after exposure... Among the group of workers who received effective doses of 100 mSv or more, UNSCEAR concluded that “an increased risk of cancer would be expected in the future. However, any increased incidence of cancer in this group is expected to be indiscernible because of the difficulty of confirming such a small incidence against the normal statistical fluctuations in cancer incidence.”
Okay, so we do expect more cancer in them - the sample size however is low enough (174 people) that it's hard to prove statistical significance. But wait, this too is an indirect reference - what does its source say? Just a second, but first let's cite one more thing from the IAEA report the NYT article cites (a WHO study):
For leukaemia, the lifetime risks are predicted to increase by up to around 7% over baseline cancer rates in males exposed as infants; for breast cancer, the estimated lifetime risks increase by up to around 6% over baseline rates in females exposed as infants; for all solid cancers, the estimated lifetime risks increase by up to around 4% over baseline rates in females exposed as infants; and for thyroid cancer, the estimated lifetime risk increases by up to around 70% over baseline rates in females exposed as infants. These percentages represent estimated relative increases over the baseline rates and are not estimated absolute risks for developing such cancers”
But back to the UNSCEAR report: here's its section on cancer risks that the IAEA claim cited by the Times was based on:
40. For adults in Fukushima Prefecture, the Committee estimates average life
There's a difference between a substance being bad (which has been empirically demonstrated) and it being dangerous at the concentrations being suggested.
Just like there's a difference between knowing the fact that the health impacts of the NOx emitted at various emissions standards has been quite studied in the peer-reviewed literature, including cost benefits analyses, versus posting about the topic while simply assuming that there hasn't been any study on the topic.
To be more specific: N2 + O2 is thermodynamically favorable at lower temperatures and pressures, while NOx is more favorable at higher temperatures and pressures. Combustion of fuel is also more efficient at higher temperatures and pressures. So pretty much whatever you do to get more power and efficiency out of your fuel, also tends to give you more NOx. Now, there's a wide range of things you can do to try to reduce the NOx; the ones with few drawbacks are pretty much universally done, while the others (such as urea injection) come at a cost. But the easiest way to reduce NOx for emissions tests is simply to burn cooler, at lower pressures, for shorter periods of time - aka, hurt your power and fuel economy.
To be fair, the "proper engineering" fixes available all are some combination of reducing performance and increasing cost. Which is what their competitors had to do to meet the standards. Volkswagen's cheating gave them a leg up, allowing them to offer more powerful, cheaper vehicles at a given emissions level.
So yes, the cheating was a financial decision, but it wasn't out of laziness - it was out of a well known tangible benefit for doing so.
And as a result, they've killed people. I know it's not as visible or dramatic as a car going out of control or the like, but the connection between NOx and premature death is well established, both in high-NOx and low-NOx areas. NOx is what makes Beijing air that lovely brownish color. Volkswagen willingly killed people to steal sales from its competitors.
I don't know about you, but my car, despite having had its engine design refined for over a hundred years and benefitting from massive amounts of investment and testing, cannot operate for years nonstop without maintenance.
I guess if you've got a gas mask pressures down to below half an atmosphere are fine. 56km is an atmospheric pressure similar to that at the top of Denali. But, since you'll be breathing through a mask anyway, I guess you might as well choose whatever temperature is the most comfortable, so long as the pressure isn't so low that the it starts dehydrating your skin:)
Solar power is way more powerful than at Mars. There's little attenuation overhead (the main cloud deck is below), the solar constant is 4,4x higher than on Mars, and you can get nearly as much power from the underside of your panels as from above due to reflection from the cloud deck. And there are no global storms of electrostatic dust to dirty up your cells.
Indeed, if you used propulsion (propellers) you could track the same spot, although you'd need to maintain a very high velocity (~100m/s) near the equator to do that (less and less the closer you get to the poles, to near zero - although there are weird twin-eyed cyclones that reside there, with peak winds of 35-50m/s). Venus is what's called a "superrotator", in that the atmosphere circles the planet much faster than the planet rotates. If you just drift you spend two Earth days in the sun and two days in the dark.
While the wind speeds are high, that shouldn't be confused with turbulence. Nowhere that's been observed shows any significant turbulence at 52,5km altitude... but again, we have so little data, it's hard to say with confidence that there never is any. Also note that the ideal altitude may vary depending on where on Venus you are. Near the poles there are areas of upwelling and downwelling which can give you warmer or cooler temperatures than normal at a given altitude and pressure.
So, from what we know, there shouldn't be any problems with having a colony floating in Venus's "habitable zone". But we really need to have a robotic exploration mission spend several years drifting or motoring around the planet to make sure of that.
52,5km is Denver air pressures with ~37C/100F air temperatures, which seems a nice balance. Plus, it's a "dry heat";)
The SOx isn't actually as concentrated as most people picture, it's a diffuse mist... more like a bad smog. Yes, it's corrosive to some materials, but not to everything. Most plastics, for example, are indifferent to it. So are many metals (at practical Venusian concentrations, most metals are probably fine, even steels). And on the upside, you don't have the dust problems as found on Mars, have far less radiation exposure, and far more constant temperatures.
There are of course a couple disadvantages to being at altitude while exploring the surface. One of the most notable is that the winds are far faster at those altitudes than at the surface, so you'd have to play "catchup" with your surface-exploring probes. One way to do that is to have the probes float up even higher than the base on return from a surface trip, into even faster winds. There are also some concerns about turbulence and lightning, although we think these are confined to lower altitudes. Unfortunately, we've explored Venus so little that it's hard to make definitive statements.:P
Another common misconception is that there's "no water" on Venus. Actually, Venus's atmosphere has almost as much water vapor as Earth's atmosphere - it's just mixed in with a *lot* of other stuff, mainly CO2, which is why the percentage is so low. The percentage is however notably higher at "typical floating colony" altitudes than at near the surface. In addition to carbon, hydrogen, oxygen and sulfur in the atmosphere, at those levels Venus's atmosphere also contains a number of other useful chemicals - lots of nitrogen (as N2); moderately low amounts of argon, low amounts of helium and neon; very low amounts of chlorine (as HCl) and phosphorus (as H3PO4 - it's more commonly found lower); and trace amounts of hydrofluoric acid and what appears to be volcanic ash/dust (the Venera probes identified small amounts of probable iron and silica on detectors during descent). Thankfully there are notably different properties between the atmospheric constituents - for example, a chilling stage would first draw out a mixture of acids (containing the water and dusts), then the bulk CO2 would freeze out, leaving the N2 and noble gases. Further steps would depend on what the goal was. So if one wants to look at the long term view, there's a lot of potential to produce a wide range of plastics and plant macronutrients just from the atmosphere - although metals and many of the lesser plant nutrients would probably have to come from the surface (such as the tailings from the rocks being studied (nearer term) or mined (longer term)) unless one is highly effective at capturing ash/dust.
A Venusian cloud city isn't as "romantic", as you never get to physically walk on the surface... but it is indeed easier (very easy entry, much better radiation protection, earthlike gravity, more frequent launch windows, much easier EVAs, no landing site restrictions, much more sunlight (and nearly doubled due to reflection from below), etc) as well as being more useful. Latency doesn't matter much when operating Mars probes remotely, but on Venus, when any atmosphere-diving surface explorer probe is going to have a very limited period of time at the surface before it overheats, command latency is critical; also, maintenance needs on your surface probes are probably higher, which also calls for humans. Plus, any good Venus exploring program would have power generation/recharging, cooling, and sample analysis done at altitude in a centralized aerial station rather than hauling down (and back up) a lot of sensitive equipment that you have to protect from the heat - which makes it easier to just declare that central station a manned laboratory. You can explore the whole planet rather than just the area immediately around your landing site. And lastly, we've explored Mars way better than we've explored Venus - there's far bigger outstanding scientific questions about Venus than about Mars.
It'd also be a lot more comfortable to live on Venus. Buoyancy = space. People will have a lot of room to move around in. Or grow plants or whatever else. And could potentially walk outside on the surface of the craft in as little as an oxygen mask and eye protection (the CO and SOx levels are too high for the eyes but might be tolerable to the skin). Some SOx-hardy plants might even be able to grow on the exterior of the craft if properly watered and nourished.
I daresay that Venus also has more potential to be profitable than Mars in the distant future. There's a lot of potential for precipitating out exotic compounds in the high pressure / high temperature environment, the Venera probes found some types of lava flows often associated with rare mineral deposits, and there's good evidence to suggest large carbonatite flows which are often associated with even rarer deposits.
Re:Worse than the space station? No.
on
Let's Not Go To Mars
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· Score: 5, Informative
The people who reduce Mars resource extraction to simple "We'll simply do this, then that" statements have clearly never had to work building or maintaining mining, ore processing, and refining equipment on Earth, let alone on Mars;) We've never done any sort of actual mining on other worlds (no, using a RAT or taking tiny dust samples is not "mining"), and most of the stuff one might consider even close to "refining" we've done in space has proved to be a maintenance nightmare. Seriously, how often has the ISS lost things like its oxygen generators, its urine reprocessor, etc? And all of these are quite toward the easy end of "refining" tasks. Heck, the oxygen generator literally just dumps its hydrogen overboard and they never attempt to tank the oxygen. I remember that one of the reasons that the oxygen generators were failing at one point was that the water they were feeding it was "slightly too acidic". I mean, seriously, and you want to use dug-up muddy Mars ice with who knows what in it as your feedstock? And that's when the system's not trying to kill you - they've had corrosive chemical leaks, near-fire situations, etc.
Everyone who says "We'll just dig up X for resource Y" as if it's just that simple needs a serious reality check. These systems can take decades to refine to the point where you can rely on them being dependable enough for the long periods of time involved in a Mars mission to have peoples' lives hinge upon them. And they're anything but "simple", even for the simplest tasks like water production and oxygen generation.
To reduce risk, reasonable mission profiles for Mars that involve in-situ actually call for a long "prep phase". In such a phase, one tries to produce everything robotically and then store it, with the idea of having everything present on-site and ready when people arrive. That way, if the system fails, or produces resources that for some reason or another are not usable, people don't die. But it also means long delays before you can launch people, even after you get the mission there.
One example is with MOXIE. They're considering including it on the Mars 2020 rover (although somewhat controversially - I wouldn't be too shocked if it got cut). It takes CO2 from the atmosphere and makes O2 and CO - both just released to the atmosphere, no attempt to store it. The idea being that the atmosphere should be a more consistent and reliable source of raw materials than mined water ice. If it works right and lasts, then the idea is to make a 100x bigger system with its own dedicated high power RTG (read: expensive), as well as tankage, compressors, etc and send that to Mars, leave it running for 5-10 years, and if it completes storing up enough O2, then use that for a human mission. So this would mean:
1) Hope that MOXIE doesn't get cut before launch 2) Hope that Mars 2020 makes it into the 2020 launch window 3) Arrive at Mars after a long cruise phase. Hope that there's no accidents in launch, transit or on landing. 4) Spend enough time with MOXIE operating to prove that it actually works in a Mars environment (dust storms, radiation, temperature swings, etc). Hope it actually works. 5) Take proposals for the expensive oxygen generation mission... competing with a wide range of other scientific proposals for mission money. Hope it gets approved. 6) Hope that people are willing to go ahead and lock future manned missions into a particular site chosen that long in advance, before the mission hardware is even designed. 7) Spend years building the refinery-craft, hope for no cutbacks or cancellations. 8) Launch the refinery craft, hope for no accidents. 9) Wait through cruise phase (hope for no accidents) and landing phase (again, hope) 10) Hope that the new system actually works as desired for many years on end (which means keeping breakage-prone things like compressors running for long periods of time). 11) Hope that a manned Mars mission actually gets funding -
Never said cyclists don't use less energy. They use less energy, but they use it terribly inefficiently. And no, nobody burns "excess calories that they would have already eaten". The reason you get hungry after exercise is because you're burning calories. If you start burning an excess of calories and never eat more to compensate, you will starve to death. There's a small amount of exception to that rule, in as you lose weight, your baseline metabolism drops. But it doesn't drop anywhere near the amount that a person cycling an hour or so a day burns. You simply cannot add an extra ~750 calories a day to your routine and not eat any more. You will literally die if you do so.
Human energy doesn't come from magic. It comes from food.
And this thread was about a cyclist dying in an accident. A comment whose main purpose was about the dangers of cycling is fully on topic. The environmental aspect was just a related followup that people are choosing to obsess over.
And of course it's risk of death per mile that matters, not per time or per number of trips. Are you going to quit your job and pick a job closer to your home when you switch to the bike too? You have the same destination as in the car, just a different mode of transportation. You have to do the same number of miles.
The average Briton cycles 53 miles a year. The average number of car miles is 8200 - 155 times more mileage. Looking at the same year's accident statistics, 801 people died in cars and 8232 were seriously injured. 110 cyclists died, 3222 seriously injured. That's 7,3 times more deaths and 2,6 times more serious injuries for cars... which go 155 times further. Even if you factor in 100% of pedestrian deaths to cars (and hey, are we forgetting that we still need goods hauled around?), they're only about half of the car casualties, so it doesn't even bring the numbers close too each other.
Sorry, bike nuts. Your mode of transportation is horrible for the environment and horribly dangerous per mile. So stop trying to make us all take part in your stupid hobby.
Because, all energy sources are equally efficient, right? Because I didn't just write "Which is very inefficient in terms of energy in (oil, natural gas, etc) per unit energy of muscle power released from burning said food", right? 58 calories of beef per mile is about 600 grams of CO2 per mile. Which is a terrible rate of CO2 emissions per mile.
See this post for a breakdown. Yes, there's a lot of fail, but it's in your post.
Food is an incredibly inefficient source of energy. A kilogram of beef, for example, causes the emission of a couple dozen kilograms of CO2 and contains 2140 kcal. A typical man cycling will burn on the order of 60 calories per mile at 14mph, or 840 calories per hour. Driving should be about 100 (comparing to other activities), so 740 excess kcal, aka 346 grams of beef, aka about 8 kilograms of CO2 for 14 miles, aka about 600 grams per mile. A prius emits 135 grams per mile. A Hummer H2 emits about 660, depending on the version - most large SUVs well less
Before you go off on a rant and call people "dumbass", do the damn math.
And before you start saying "people don't eat just beef" - no, they don't! But a lot of other things they eat are even worse. For example, vegetables - healthy for you, but an utterly terrible ratio of calories per unit CO2 emitted (because they don't contain a lot of calories). Other meats are also very bad - some even worse than beef. Lots of fruits and nuts, while containing relevant amounts of calories are bad because they take so much energy to harvest, process, or ship. Only some relatively narrow categories allow a cyclist to beat a car in terms of CO2 emissions. But food doesn't just have CO2 emissions as its negative consequences, as mentioned, but also others which are sometimes even worse, such as habitat consumption, water consumption, and fertilizer and pesticide pollution.
But it raises an important point. Per mile travelled, cyclists are far more likely to be injured or die where cars are present than car drivers/passengers, and even where you only look at bike accidents classified as cars not being involved, cyclists are still more likely to die or be injured per mile. People who do "training of their bike handling skills" may be better off than the average cyclist, but - on a per-mile basis - bike travel is more dangerous than car travel.
I live in a place where the city keeps trying all sorts of ridiculous ways to force people out of cars and onto bikes, such as spending small fortunes to shrink down roads and doing nothing particular with the space on the sides, putting up all sorts of obstacles in the road (such as constant turn lanes, alternating between left and right) to turn 3-4 lane roads into effective 2-lane roads, building new buildings without any parking, tearing down existing parking, etc. And among their reasons for trying to force people off of cars is "safety for cyclists". But even if they succeed at making their goal of forcing a dozen or two percent of the population to switch from cars to bikes, they're only going to increase the total number of transport deaths.
They also give environmental reasons as an excuse, which is also ridiculous. Cycling burns calories. Calories don't come from thin air - they come from food production. Which is very inefficient in terms of energy in (oil, natural gas, etc) per unit energy of muscle power released from burning said food. Now, there's a big difference between types of foods - for example, locally-grown grains and starchy plant-based foods can render a cyclist's net environmental picture better than a single driver in a Prius (although not better than people carpooling in a Prius). But few cyclists eat a diet of locally grown grains and starchy plants (especially where I live!). Meat has a huge environmental footprint per calorie, as do vegetables. A person who gets half their calories from a meat like beef increases their caloric load by biking wherever they go instead of driving; they'd be better for the environment driving a large SUV without any passengers. And of course, that's only the energy picture - that doesn't even consider the habitat consumed for agriculture, the water consumption, the effects of pesticides and herbicides, etc.
Andy Weir may be a computer programmer and not a scientist, but he did his homework for the book.
*double snicker*
For me, the experience of reading it was the scientific equivalent of MST3K - at least one hilariously bad science error per page when stuff is actually happening. Sometimes numerous. Protagonist not noticing that the hydrogen levels are Mickey Mouse-voice high and the oxygen levels unconsciousness-levels low? Check! 2-3 orders of magnitude too little light to grow crops? Check! Not even understanding how photosynthesis works? Check! Fraction-of-a-percent-as-dense-as-Earth atmosphere wreaking havoc in a windstorm? Check! Page after page of the same confusion between moles of a substance and liters of it? Check! Giant rant full of superlatives about how dangerous the radiation of 238-Pu is? Check! And a thousand more checks, just over and over again. If I wrote up a book describing all of the science errors in The Martian, it'd be longer than The Martian.
I guess the book is more enjoyable to people who this stuff doesn't jump out of - to me it was like the author kept interrupting the book to hold up a sign reading "I Got A D Average In My High School Science Classes". Then again, even if the science hadn't been so terrible, the author's writing probably would have ruined it for me anyway. All of the characters have the same "voice", which comes across like that of a teenage boy. In the case of our protagonist, that of a "botanist" who hardly ever uses a single scientific term but is obsessed with his butt. And with all of the scientific equipment given old school pulp sci-fi names like "oxygenator" and such.
I'm hoping for just the opposite. I read as much of the book as I could stomach. The plot idea was excellent, but the writing was terrible, like an 15-year-old boy wrote it, and the level of understanding of science about equal to that of your average 15-year-old. Almost every page made me want to hit my head into a wall.
However, I'm hoping that the movie will be better, and there's some signs that maybe it will be. For example, compared to the laughably absurd way in which the potatoes were grown in the book, in the trailer for The Martian one can see a grow tent with light coming in from the skylights. Anyone who knows anything about plants can still see that there's still way too little space and energy input to produce enough to keep a person alive, but at least it's not the 2-3 orders of magnitude off like in the book (among literally dozens of other reasons that plot point alone as presented in the book wouldn't have worked, among dozens of other plot-points that were head-wall-bangingly bad). I'm hopeful that they've gone through and fixed most of the plot holes and bad science, and will be left with an at least somewhat plausible movie based on the (quite good) "castaway on Mars" premise.
At the same time, this march of Muslims should speak out against Islamic terrorism and the sort of extremism that their religious brethren in the ISIL areas, and the Boko Haram practice in the Middle East, and Africa. Burning folks alive in cages, auctioning off 12 year old girls for sex slavery . . . this is what Islam is all about.
Slashdot Mirror
Says who?
Some of the models call for a liquid water layer inside Pluto (if that's even a requirement). It has a young surface, younger than Mars; resurfacing** means energy and transport of chemicals between layers. And it's covered in tholins, meaning long-chain organics.
I'm not saying that there's life on (or rather, in) Pluto. Personally, I expect life to be pretty rare in the cosmos. But ruling it out just because it's far from the sun seems quite unreasonable. Look at all of the people oggling the finding of "water" on Mars (a more accurate headline would have been "Scientists find mildly damp rocket fuel on Mars"). Pluto could potentially have a subsurface ocean with organics actively cycling into it.
** - Heck, the best guess right now for what Sputnik Planum is is that it's a giant convecting nitrogen-ice "sea", like having the mantle exposed to the surface. If it truly is convecting then it's dragging down any heavier materials at the edges of its convection cells down into Pluto's (warmer) depths.
The New Horizons team refers to it as a planet. New Horizons head Alan Stern is one of the leading advocates for the reversal of the IAU decision. Pluto and other large KBOs have been referred to many times as planets in peer-reviewed literature since the IAU decision. One of the NASA links in this article itself refers to Pluto as a planet ("At half the diameter of Pluto, Charon is the largest satellite relative to its planet in the solar system."). Large numbers of people in the field - I'd wager a solid majority of planetary scientists (who make up only a small minority of the IAU's membership but really should be the ones making these decisions) - think the IAU seriously screwed up here. There are literally dozens of reasons why it was a screwup - need I go into them?
Indeed. Teaching basic coding (and let's roll in markup languages while we're at it) isn't like teaching someone to become an expert auto mechanic; it's like teaching them to change a flat tire, check their oil, jumpstart a car, etc. Interacting with computers is something that virtually everyone has to do these days. The ability to be able to write a simple script or even just have a basic understanding of *what* your computer is doing is not the same as having a 4-year CS degree. I think it would be good if kids were taught to change a flat tire and check their oil. And I think it's good that they learn the fundamentals of programming. Just like it's good for them to learn the fundamentals of mathematics, and chemistry, and biology, and so on down the line.
Your science analogy is spot on, but in more ways than you mention. It's not at all rare these days for mathematicians and scientists to have to do computer programming as part of their work. A mathematician is much more likely to need to know what a for loop is than what a scalene triangle is. A physicist is much more likely to need to know what a function call is than which element comes after cerium on the periodic table.
This is going to be an unpopular post. But the premise of the article - that the accident itself caused/will cause no deaths, only overreaction - is simply not true. And their "proof by ghost reference" doesn't help things any.
Here's proof by actual reference.
Estimates not good enough? Let's try actual measurements of thyroid cancer in children:
They do note that there's a risk of screening effects, but given the correlation between rates and distance from the plant, they believe that the outbreak is real and needs further study
What did I mean earlier by "proof by ghost reference"? Their first two links just go to NYT search pages that aren't fruitful in backing up anything they claim. The third link takes some work but you can dig out the actual report in question. The NYT article describes it thusly:
The actual report says:
Okay, so we do expect more cancer in them - the sample size however is low enough (174 people) that it's hard to prove statistical significance. But wait, this too is an indirect reference - what does its source say? Just a second, but first let's cite one more thing from the IAEA report the NYT article cites (a WHO study):
But back to the UNSCEAR report: here's its section on cancer risks that the IAEA claim cited by the Times was based on:
Just like there's a difference between knowing the fact that the health impacts of the NOx emitted at various emissions standards has been quite studied in the peer-reviewed literature, including cost benefits analyses, versus posting about the topic while simply assuming that there hasn't been any study on the topic.
Right. Peer reviewed research is "laughable" and giant car manufacturers cheating on emissions tests and lying about is is "ethics". Gotcha.
To be more specific: N2 + O2 is thermodynamically favorable at lower temperatures and pressures, while NOx is more favorable at higher temperatures and pressures. Combustion of fuel is also more efficient at higher temperatures and pressures. So pretty much whatever you do to get more power and efficiency out of your fuel, also tends to give you more NOx. Now, there's a wide range of things you can do to try to reduce the NOx; the ones with few drawbacks are pretty much universally done, while the others (such as urea injection) come at a cost. But the easiest way to reduce NOx for emissions tests is simply to burn cooler, at lower pressures, for shorter periods of time - aka, hurt your power and fuel economy.
To be fair, the "proper engineering" fixes available all are some combination of reducing performance and increasing cost. Which is what their competitors had to do to meet the standards. Volkswagen's cheating gave them a leg up, allowing them to offer more powerful, cheaper vehicles at a given emissions level.
So yes, the cheating was a financial decision, but it wasn't out of laziness - it was out of a well known tangible benefit for doing so.
And as a result, they've killed people. I know it's not as visible or dramatic as a car going out of control or the like, but the connection between NOx and premature death is well established, both in high-NOx and low-NOx areas. NOx is what makes Beijing air that lovely brownish color. Volkswagen willingly killed people to steal sales from its competitors.
I don't know about you, but my car, despite having had its engine design refined for over a hundred years and benefitting from massive amounts of investment and testing, cannot operate for years nonstop without maintenance.
I guess if you've got a gas mask pressures down to below half an atmosphere are fine. 56km is an atmospheric pressure similar to that at the top of Denali. But, since you'll be breathing through a mask anyway, I guess you might as well choose whatever temperature is the most comfortable, so long as the pressure isn't so low that the it starts dehydrating your skin :)
Solar power is way more powerful than at Mars. There's little attenuation overhead (the main cloud deck is below), the solar constant is 4,4x higher than on Mars, and you can get nearly as much power from the underside of your panels as from above due to reflection from the cloud deck. And there are no global storms of electrostatic dust to dirty up your cells.
Indeed, if you used propulsion (propellers) you could track the same spot, although you'd need to maintain a very high velocity (~100m/s) near the equator to do that (less and less the closer you get to the poles, to near zero - although there are weird twin-eyed cyclones that reside there, with peak winds of 35-50m/s). Venus is what's called a "superrotator", in that the atmosphere circles the planet much faster than the planet rotates. If you just drift you spend two Earth days in the sun and two days in the dark.
While the wind speeds are high, that shouldn't be confused with turbulence. Nowhere that's been observed shows any significant turbulence at 52,5km altitude... but again, we have so little data, it's hard to say with confidence that there never is any. Also note that the ideal altitude may vary depending on where on Venus you are. Near the poles there are areas of upwelling and downwelling which can give you warmer or cooler temperatures than normal at a given altitude and pressure.
So, from what we know, there shouldn't be any problems with having a colony floating in Venus's "habitable zone". But we really need to have a robotic exploration mission spend several years drifting or motoring around the planet to make sure of that.
52,5km is Denver air pressures with ~37C/100F air temperatures, which seems a nice balance. Plus, it's a "dry heat" ;)
The SOx isn't actually as concentrated as most people picture, it's a diffuse mist... more like a bad smog. Yes, it's corrosive to some materials, but not to everything. Most plastics, for example, are indifferent to it. So are many metals (at practical Venusian concentrations, most metals are probably fine, even steels). And on the upside, you don't have the dust problems as found on Mars, have far less radiation exposure, and far more constant temperatures.
There are of course a couple disadvantages to being at altitude while exploring the surface. One of the most notable is that the winds are far faster at those altitudes than at the surface, so you'd have to play "catchup" with your surface-exploring probes. One way to do that is to have the probes float up even higher than the base on return from a surface trip, into even faster winds. There are also some concerns about turbulence and lightning, although we think these are confined to lower altitudes. Unfortunately, we've explored Venus so little that it's hard to make definitive statements. :P
Another common misconception is that there's "no water" on Venus. Actually, Venus's atmosphere has almost as much water vapor as Earth's atmosphere - it's just mixed in with a *lot* of other stuff, mainly CO2, which is why the percentage is so low. The percentage is however notably higher at "typical floating colony" altitudes than at near the surface. In addition to carbon, hydrogen, oxygen and sulfur in the atmosphere, at those levels Venus's atmosphere also contains a number of other useful chemicals - lots of nitrogen (as N2); moderately low amounts of argon, low amounts of helium and neon; very low amounts of chlorine (as HCl) and phosphorus (as H3PO4 - it's more commonly found lower); and trace amounts of hydrofluoric acid and what appears to be volcanic ash/dust (the Venera probes identified small amounts of probable iron and silica on detectors during descent). Thankfully there are notably different properties between the atmospheric constituents - for example, a chilling stage would first draw out a mixture of acids (containing the water and dusts), then the bulk CO2 would freeze out, leaving the N2 and noble gases. Further steps would depend on what the goal was. So if one wants to look at the long term view, there's a lot of potential to produce a wide range of plastics and plant macronutrients just from the atmosphere - although metals and many of the lesser plant nutrients would probably have to come from the surface (such as the tailings from the rocks being studied (nearer term) or mined (longer term)) unless one is highly effective at capturing ash/dust.
A Venusian cloud city isn't as "romantic", as you never get to physically walk on the surface... but it is indeed easier (very easy entry, much better radiation protection, earthlike gravity, more frequent launch windows, much easier EVAs, no landing site restrictions, much more sunlight (and nearly doubled due to reflection from below), etc) as well as being more useful. Latency doesn't matter much when operating Mars probes remotely, but on Venus, when any atmosphere-diving surface explorer probe is going to have a very limited period of time at the surface before it overheats, command latency is critical; also, maintenance needs on your surface probes are probably higher, which also calls for humans. Plus, any good Venus exploring program would have power generation/recharging, cooling, and sample analysis done at altitude in a centralized aerial station rather than hauling down (and back up) a lot of sensitive equipment that you have to protect from the heat - which makes it easier to just declare that central station a manned laboratory. You can explore the whole planet rather than just the area immediately around your landing site. And lastly, we've explored Mars way better than we've explored Venus - there's far bigger outstanding scientific questions about Venus than about Mars.
It'd also be a lot more comfortable to live on Venus. Buoyancy = space. People will have a lot of room to move around in. Or grow plants or whatever else. And could potentially walk outside on the surface of the craft in as little as an oxygen mask and eye protection (the CO and SOx levels are too high for the eyes but might be tolerable to the skin). Some SOx-hardy plants might even be able to grow on the exterior of the craft if properly watered and nourished.
I daresay that Venus also has more potential to be profitable than Mars in the distant future. There's a lot of potential for precipitating out exotic compounds in the high pressure / high temperature environment, the Venera probes found some types of lava flows often associated with rare mineral deposits, and there's good evidence to suggest large carbonatite flows which are often associated with even rarer deposits.
The people who reduce Mars resource extraction to simple "We'll simply do this, then that" statements have clearly never had to work building or maintaining mining, ore processing, and refining equipment on Earth, let alone on Mars ;) We've never done any sort of actual mining on other worlds (no, using a RAT or taking tiny dust samples is not "mining"), and most of the stuff one might consider even close to "refining" we've done in space has proved to be a maintenance nightmare. Seriously, how often has the ISS lost things like its oxygen generators, its urine reprocessor, etc? And all of these are quite toward the easy end of "refining" tasks. Heck, the oxygen generator literally just dumps its hydrogen overboard and they never attempt to tank the oxygen. I remember that one of the reasons that the oxygen generators were failing at one point was that the water they were feeding it was "slightly too acidic". I mean, seriously, and you want to use dug-up muddy Mars ice with who knows what in it as your feedstock? And that's when the system's not trying to kill you - they've had corrosive chemical leaks, near-fire situations, etc.
Everyone who says "We'll just dig up X for resource Y" as if it's just that simple needs a serious reality check. These systems can take decades to refine to the point where you can rely on them being dependable enough for the long periods of time involved in a Mars mission to have peoples' lives hinge upon them. And they're anything but "simple", even for the simplest tasks like water production and oxygen generation.
To reduce risk, reasonable mission profiles for Mars that involve in-situ actually call for a long "prep phase". In such a phase, one tries to produce everything robotically and then store it, with the idea of having everything present on-site and ready when people arrive. That way, if the system fails, or produces resources that for some reason or another are not usable, people don't die. But it also means long delays before you can launch people, even after you get the mission there.
One example is with MOXIE. They're considering including it on the Mars 2020 rover (although somewhat controversially - I wouldn't be too shocked if it got cut). It takes CO2 from the atmosphere and makes O2 and CO - both just released to the atmosphere, no attempt to store it. The idea being that the atmosphere should be a more consistent and reliable source of raw materials than mined water ice. If it works right and lasts, then the idea is to make a 100x bigger system with its own dedicated high power RTG (read: expensive), as well as tankage, compressors, etc and send that to Mars, leave it running for 5-10 years, and if it completes storing up enough O2, then use that for a human mission. So this would mean:
1) Hope that MOXIE doesn't get cut before launch ... competing with a wide range of other scientific proposals for mission money. Hope it gets approved.
2) Hope that Mars 2020 makes it into the 2020 launch window
3) Arrive at Mars after a long cruise phase. Hope that there's no accidents in launch, transit or on landing.
4) Spend enough time with MOXIE operating to prove that it actually works in a Mars environment (dust storms, radiation, temperature swings, etc). Hope it actually works.
5) Take proposals for the expensive oxygen generation mission
6) Hope that people are willing to go ahead and lock future manned missions into a particular site chosen that long in advance, before the mission hardware is even designed.
7) Spend years building the refinery-craft, hope for no cutbacks or cancellations.
8) Launch the refinery craft, hope for no accidents.
9) Wait through cruise phase (hope for no accidents) and landing phase (again, hope)
10) Hope that the new system actually works as desired for many years on end (which means keeping breakage-prone things like compressors running for long periods of time).
11) Hope that a manned Mars mission actually gets funding -
And most people don't go to gyms, so this is an irrelevant point.
Adding exercise where there was none is adding caloric consumption where there was none.
Never said cyclists don't use less energy. They use less energy, but they use it terribly inefficiently. And no, nobody burns "excess calories that they would have already eaten". The reason you get hungry after exercise is because you're burning calories. If you start burning an excess of calories and never eat more to compensate, you will starve to death. There's a small amount of exception to that rule, in as you lose weight, your baseline metabolism drops. But it doesn't drop anywhere near the amount that a person cycling an hour or so a day burns. You simply cannot add an extra ~750 calories a day to your routine and not eat any more. You will literally die if you do so.
Human energy doesn't come from magic. It comes from food.
And this thread was about a cyclist dying in an accident. A comment whose main purpose was about the dangers of cycling is fully on topic. The environmental aspect was just a related followup that people are choosing to obsess over.
And of course it's risk of death per mile that matters, not per time or per number of trips. Are you going to quit your job and pick a job closer to your home when you switch to the bike too? You have the same destination as in the car, just a different mode of transportation. You have to do the same number of miles.
The average Briton cycles 53 miles a year. The average number of car miles is 8200 - 155 times more mileage. Looking at the same year's accident statistics, 801 people died in cars and 8232 were seriously injured. 110 cyclists died, 3222 seriously injured. That's 7,3 times more deaths and 2,6 times more serious injuries for cars... which go 155 times further. Even if you factor in 100% of pedestrian deaths to cars (and hey, are we forgetting that we still need goods hauled around?), they're only about half of the car casualties, so it doesn't even bring the numbers close too each other.
Sorry, bike nuts. Your mode of transportation is horrible for the environment and horribly dangerous per mile. So stop trying to make us all take part in your stupid hobby.
Because, all energy sources are equally efficient, right? Because I didn't just write "Which is very inefficient in terms of energy in (oil, natural gas, etc) per unit energy of muscle power released from burning said food", right? 58 calories of beef per mile is about 600 grams of CO2 per mile. Which is a terrible rate of CO2 emissions per mile.
See this post for a breakdown. Yes, there's a lot of fail, but it's in your post.
*Which is accounted for in the above.
Food is an incredibly inefficient source of energy. A kilogram of beef, for example, causes the emission of a couple dozen kilograms of CO2 and contains 2140 kcal. A typical man cycling will burn on the order of 60 calories per mile at 14mph, or 840 calories per hour. Driving should be about 100 (comparing to other activities), so 740 excess kcal, aka 346 grams of beef, aka about 8 kilograms of CO2 for 14 miles, aka about 600 grams per mile. A prius emits 135 grams per mile. A Hummer H2 emits about 660, depending on the version - most large SUVs well less
Before you go off on a rant and call people "dumbass", do the damn math.
And before you start saying "people don't eat just beef" - no, they don't! But a lot of other things they eat are even worse. For example, vegetables - healthy for you, but an utterly terrible ratio of calories per unit CO2 emitted (because they don't contain a lot of calories). Other meats are also very bad - some even worse than beef. Lots of fruits and nuts, while containing relevant amounts of calories are bad because they take so much energy to harvest, process, or ship. Only some relatively narrow categories allow a cyclist to beat a car in terms of CO2 emissions. But food doesn't just have CO2 emissions as its negative consequences, as mentioned, but also others which are sometimes even worse, such as habitat consumption, water consumption, and fertilizer and pesticide pollution.
But it raises an important point. Per mile travelled, cyclists are far more likely to be injured or die where cars are present than car drivers/passengers, and even where you only look at bike accidents classified as cars not being involved, cyclists are still more likely to die or be injured per mile. People who do "training of their bike handling skills" may be better off than the average cyclist, but - on a per-mile basis - bike travel is more dangerous than car travel.
I live in a place where the city keeps trying all sorts of ridiculous ways to force people out of cars and onto bikes, such as spending small fortunes to shrink down roads and doing nothing particular with the space on the sides, putting up all sorts of obstacles in the road (such as constant turn lanes, alternating between left and right) to turn 3-4 lane roads into effective 2-lane roads, building new buildings without any parking, tearing down existing parking, etc. And among their reasons for trying to force people off of cars is "safety for cyclists". But even if they succeed at making their goal of forcing a dozen or two percent of the population to switch from cars to bikes, they're only going to increase the total number of transport deaths.
They also give environmental reasons as an excuse, which is also ridiculous. Cycling burns calories. Calories don't come from thin air - they come from food production. Which is very inefficient in terms of energy in (oil, natural gas, etc) per unit energy of muscle power released from burning said food. Now, there's a big difference between types of foods - for example, locally-grown grains and starchy plant-based foods can render a cyclist's net environmental picture better than a single driver in a Prius (although not better than people carpooling in a Prius). But few cyclists eat a diet of locally grown grains and starchy plants (especially where I live!). Meat has a huge environmental footprint per calorie, as do vegetables. A person who gets half their calories from a meat like beef increases their caloric load by biking wherever they go instead of driving; they'd be better for the environment driving a large SUV without any passengers. And of course, that's only the energy picture - that doesn't even consider the habitat consumed for agriculture, the water consumption, the effects of pesticides and herbicides, etc.
I'm sorry, by telling this story were you under the mistaken impression that the story puts you in a good light?
Doesn't crash me either. google-chrome 43.0.2357.134, Fedora 22.
*double snicker*
For me, the experience of reading it was the scientific equivalent of MST3K - at least one hilariously bad science error per page when stuff is actually happening. Sometimes numerous. Protagonist not noticing that the hydrogen levels are Mickey Mouse-voice high and the oxygen levels unconsciousness-levels low? Check! 2-3 orders of magnitude too little light to grow crops? Check! Not even understanding how photosynthesis works? Check! Fraction-of-a-percent-as-dense-as-Earth atmosphere wreaking havoc in a windstorm? Check! Page after page of the same confusion between moles of a substance and liters of it? Check! Giant rant full of superlatives about how dangerous the radiation of 238-Pu is? Check! And a thousand more checks, just over and over again. If I wrote up a book describing all of the science errors in The Martian, it'd be longer than The Martian.
I guess the book is more enjoyable to people who this stuff doesn't jump out of - to me it was like the author kept interrupting the book to hold up a sign reading "I Got A D Average In My High School Science Classes". Then again, even if the science hadn't been so terrible, the author's writing probably would have ruined it for me anyway. All of the characters have the same "voice", which comes across like that of a teenage boy. In the case of our protagonist, that of a "botanist" who hardly ever uses a single scientific term but is obsessed with his butt. And with all of the scientific equipment given old school pulp sci-fi names like "oxygenator" and such.
*snicker*
In the same way The Flintstones was written by a paleontologist.
I'm hoping for just the opposite. I read as much of the book as I could stomach. The plot idea was excellent, but the writing was terrible, like an 15-year-old boy wrote it, and the level of understanding of science about equal to that of your average 15-year-old. Almost every page made me want to hit my head into a wall.
However, I'm hoping that the movie will be better, and there's some signs that maybe it will be. For example, compared to the laughably absurd way in which the potatoes were grown in the book, in the trailer for The Martian one can see a grow tent with light coming in from the skylights. Anyone who knows anything about plants can still see that there's still way too little space and energy input to produce enough to keep a person alive, but at least it's not the 2-3 orders of magnitude off like in the book (among literally dozens of other reasons that plot point alone as presented in the book wouldn't have worked, among dozens of other plot-points that were head-wall-bangingly bad). I'm hopeful that they've gone through and fixed most of the plot holes and bad science, and will be left with an at least somewhat plausible movie based on the (quite good) "castaway on Mars" premise.
Funny, then, that Daesh is more popular in Europe than it is in the Middle East.