Or unless you're manufacturing the devices somewhere where energy is very cheap and using them somewhere where it's expensive.
You'd think it should be strictly true (and it probably is), and yet nonetheless you constantly see claims like "solar panels cost more energy to manufacture than they produce in their lifetime".
Incidentally, it costs about a thousand gallons of gas worth of energy to build a new Prius. Depending on the mpg of your gas guzzler, it can take as little as 25,000 miles to pay off the energy cost of building the Prius.
You should try listening to people talk about clean energy, then. It's one of the most common canards out there.
As for how much energy goes into making a solar panel, you can search for it yourself. Google is easy to use. Hint: in general, energy recapture time (amount of time before the energy the device produces is greater than the energy used to produce the device) is shorter than payback time (amount of time before the value of the energy it produces is greater than the cost of the device).
It would be useful to me, as my state (New York) bullies online retailers into collecting sales taxes and then insists that taxpayers fill in a nonzero value for unpaid use tax (being so "helpful" as to provide an unpaid use tax estimation table based on income).
Not surprisingly, there's no line item on the federal return for a state tax.
If you read your state tax regulations (even the simplified ones), they'll explain how use tax works. There are forms to fill out with the other state to get your sales tax paid there back (or never pay it in the first place).
In practice, for most items, it's totally pointless to bother dealing with it. It'd be worthwhile for expensive items if people bothered actually paying use tax. (It's probably advisable for forms of purchases that are recorded, like buying an out-of-state car.)
Not that Zuckerberg is destitute, but he doesn't have $50 billion. What he has, besides some money, is partial ownership (and not majority ownership) of a business (Facebook) that has been valued at $50 billion. But Facebook isn't a publicly-traded company, so properly assigning value to his share of it isn't nearly as straightforward or accurate as if he had shares in a publicly-traded company. It also means that his share of the company has limited liquidity (you can't just sell it easily on the open market) and liquidating any reasonable fraction of it could substantially change its value (as people might decide Facebook is less valuable if Zuckerberg is cashing out).
His net worth, incidentally, which includes his partial ownership of Facebook, is $13.5 billion.
Feynman's idea of "understanding" quantum mechanics is a much higher bar than implied by TFS. After all, he often claimed that if you could not explain a concept to a layman, you didn't truly understand it.
Failure of primary containment is bad, but nowhere near as bad as explosive failure, which is what you got at, say, Chernobyl.
Atmospheric dispersal is much worse than oceanic. There's a lot of water in the ocean, and water mixes relatively well. (There's already an enormous quantity of naturally-occurring uranium in the ocean, for example.) Atmospheric dispersal from a fire is relatively localized and deposits large quantities of radioactive ash over a relatively large area of land, contaminating the whole area. It's much more hazardous to human health.
Radiation monitors designed for people working at a site that has chronic exposure risk, maybe. Personal radiation monitors for acute exposure can handle well above 100 mSv/hr. Radiation monitors in general can measure above 100 Sv/hr, 3 orders of magnitude higher than what they're talking about. It's not that the levels of radiation are "immeasurable", as the article incorrectly states. It's just that they apparently don't have equipment on hand sufficient to measure it.
Overall this situation is redefining 'worst-case'. It may have been simpler to have a couple of core melts and just pour concrete and sand over the whole damned thing. Now we've gotten broken containment, multiple vectors, and inadequate resources. Oh, and the Japanese way of self-reliance to the point of failure. Works for the residents and their migration, doesn't work for engineering problems./quote.
No, there's still quite a ways to go before you get near "worst case". One bad scenario is failing to cool the fuel to the point that it combusts, putting ash heavy with radioactive material into the air. (Also bad is an explosive failure of the primary containment, but that's very unlikely these days.) Uncontained radioactive materials at the reactor site and in the ocean is one thing. Radioactive materials in the ground water is worse. Radioactive materials in the atmosphere in large quantities is very bad.
It's not "likely", it's "measurably likely". As in, there is a small but measurable increase in the probability that you will one day get cancer.
100 mSv/hr is not a trivial amount of radiation. It's not Godzilla or Chernobyl, but it's substantial. As you point out, a few hours at 100 mSv/hr will cause radiation poisoning, and a few more hours will kill you.
It's also tricky to figure out all the physics and finer engineering points (how much to use, etc.) the first time. After that it's not nearly as difficult.
But yes, the engineering behind obtaining enriched uranium is enormously more complex than building the bomb itself.
Electricity's a very important abstraction layer. It's a form of energy that we can (not necessarily do, but can) use to run almost any device that needs energy, and there's already a distribution system and enormous demand. Any developments in producing electricity necessarily improve every device that uses electricity.
Fission is always taking place in nuclear fuel and spent fuel, as long as there are unstable isotopes present. It's just not very much fission.
You can certainly have materials with a half-life of "days" two weeks after fission is "stopped". If the half-life is one day, then there's 1/2^14th as much as there used to be. While one part in 16 thousand or so is not very much, the detection threshold for radioisotopes is very low. How much they detected matters quite a lot.
We're having a hard time controlling insurgency in two smaller countries using all of that technology. It'd be a lot harder doing the same at home, where the soldiers have friends and family that live in the places they're trying to occupy.
Slashdot Mirror
Or unless you're manufacturing the devices somewhere where energy is very cheap and using them somewhere where it's expensive.
You'd think it should be strictly true (and it probably is), and yet nonetheless you constantly see claims like "solar panels cost more energy to manufacture than they produce in their lifetime".
Incidentally, it costs about a thousand gallons of gas worth of energy to build a new Prius. Depending on the mpg of your gas guzzler, it can take as little as 25,000 miles to pay off the energy cost of building the Prius.
You should try listening to people talk about clean energy, then. It's one of the most common canards out there.
As for how much energy goes into making a solar panel, you can search for it yourself. Google is easy to use. Hint: in general, energy recapture time (amount of time before the energy the device produces is greater than the energy used to produce the device) is shorter than payback time (amount of time before the value of the energy it produces is greater than the cost of the device).
This assumes, of course, that you're buying a brand-new Prius and that buying a brand-new car and keeping your current car are equally-viable options.
The choice of "average" is pedantically correct but not useful. Uploads are by no means distributed evenly at all.
Air is also not electrically conductive and seeps between things much more efficiently than oil.
I already pay sales tax on anything from Amazon, and it's still cheaper than brick and mortar stores for most products.
It would be useful to me, as my state (New York) bullies online retailers into collecting sales taxes and then insists that taxpayers fill in a nonzero value for unpaid use tax (being so "helpful" as to provide an unpaid use tax estimation table based on income).
Not surprisingly, there's no line item on the federal return for a state tax.
If you read your state tax regulations (even the simplified ones), they'll explain how use tax works. There are forms to fill out with the other state to get your sales tax paid there back (or never pay it in the first place).
In practice, for most items, it's totally pointless to bother dealing with it. It'd be worthwhile for expensive items if people bothered actually paying use tax. (It's probably advisable for forms of purchases that are recorded, like buying an out-of-state car.)
Not that Zuckerberg is destitute, but he doesn't have $50 billion. What he has, besides some money, is partial ownership (and not majority ownership) of a business (Facebook) that has been valued at $50 billion. But Facebook isn't a publicly-traded company, so properly assigning value to his share of it isn't nearly as straightforward or accurate as if he had shares in a publicly-traded company. It also means that his share of the company has limited liquidity (you can't just sell it easily on the open market) and liquidating any reasonable fraction of it could substantially change its value (as people might decide Facebook is less valuable if Zuckerberg is cashing out).
His net worth, incidentally, which includes his partial ownership of Facebook, is $13.5 billion.
It's not a crime, it's a civil offense. He wouldn't be imprisoned.
Border searches include your checked luggage. You're thinking of airport security screenings, perhaps, which are entirely different.
Feynman's idea of "understanding" quantum mechanics is a much higher bar than implied by TFS. After all, he often claimed that if you could not explain a concept to a layman, you didn't truly understand it.
Actually, it's equivocation, which is a logical fallacy.
Failure of primary containment is bad, but nowhere near as bad as explosive failure, which is what you got at, say, Chernobyl.
Atmospheric dispersal is much worse than oceanic. There's a lot of water in the ocean, and water mixes relatively well. (There's already an enormous quantity of naturally-occurring uranium in the ocean, for example.) Atmospheric dispersal from a fire is relatively localized and deposits large quantities of radioactive ash over a relatively large area of land, contaminating the whole area. It's much more hazardous to human health.
Radiation monitors designed for people working at a site that has chronic exposure risk, maybe. Personal radiation monitors for acute exposure can handle well above 100 mSv/hr. Radiation monitors in general can measure above 100 Sv/hr, 3 orders of magnitude higher than what they're talking about. It's not that the levels of radiation are "immeasurable", as the article incorrectly states. It's just that they apparently don't have equipment on hand sufficient to measure it.
Overall this situation is redefining 'worst-case'. It may have been simpler to have a couple of core melts and just pour concrete and sand over the whole damned thing. Now we've gotten broken containment, multiple vectors, and inadequate resources. Oh, and the Japanese way of self-reliance to the point of failure. Works for the residents and their migration, doesn't work for engineering problems./quote.
No, there's still quite a ways to go before you get near "worst case". One bad scenario is failing to cool the fuel to the point that it combusts, putting ash heavy with radioactive material into the air. (Also bad is an explosive failure of the primary containment, but that's very unlikely these days.) Uncontained radioactive materials at the reactor site and in the ocean is one thing. Radioactive materials in the ground water is worse. Radioactive materials in the atmosphere in large quantities is very bad.
It's not "likely", it's "measurably likely". As in, there is a small but measurable increase in the probability that you will one day get cancer.
100 mSv/hr is not a trivial amount of radiation. It's not Godzilla or Chernobyl, but it's substantial. As you point out, a few hours at 100 mSv/hr will cause radiation poisoning, and a few more hours will kill you.
Or about a factor of a thousand less than Chernobyl 2-3 weeks after its meltdown.
Inverse square law, no?
It's also tricky to figure out all the physics and finer engineering points (how much to use, etc.) the first time. After that it's not nearly as difficult.
But yes, the engineering behind obtaining enriched uranium is enormously more complex than building the bomb itself.
Electricity's a very important abstraction layer. It's a form of energy that we can (not necessarily do, but can) use to run almost any device that needs energy, and there's already a distribution system and enormous demand. Any developments in producing electricity necessarily improve every device that uses electricity.
Protons are ions. :p
Fission is always taking place in nuclear fuel and spent fuel, as long as there are unstable isotopes present. It's just not very much fission.
You can certainly have materials with a half-life of "days" two weeks after fission is "stopped". If the half-life is one day, then there's 1/2^14th as much as there used to be. While one part in 16 thousand or so is not very much, the detection threshold for radioisotopes is very low. How much they detected matters quite a lot.
We're having a hard time controlling insurgency in two smaller countries using all of that technology. It'd be a lot harder doing the same at home, where the soldiers have friends and family that live in the places they're trying to occupy.