>>Third dumb question: How do KiloVolts relate to Ozone production? Shouldn't current also be a part of this?
This one at least is a dumb question, or at least one I can answer. It's the voltage that creates ionisation and thus ozone, current is irrelevant:
high voltage = strong electric field strong electric field => electrons get stripped off atoms and molecules ('ionisation') oxygen ions react with O2 => ozone production.
Creation of ions does result in an electric current (since electrons and positive ions are flowing in the electric field), but it's a consequence and not a cause of ionisation. Since ozone production is a consequence of the same thing, the two quantities will be related, but both depend on the voltage rather than each other.
>>EM fields follow the inverse square law and HV lines hang quite high, so the amount of energy anyone around those lines absorbs wouldn't be very big.
Actually IIRC my e/m lectures, while the electric field of a point charge varies as an inverse square, the field of a line charge varies as a simple inverse (you have to add up the effect of all the charges along the wire). So the fall-off isn't nearly so far.
Then again I remember something about (point)dipoles falling off as fourth powers, and HV lines usually come in pairs at least - presumably one carrying the juice one way and the other carrying it back. So maybe overall a line dipole works out as inverse square...someone who still remembers his physics please do the maths!
Ahem, are you think about the European Convention on Human Rights and the European Court of Human Rights? Actually that's nothing to do with the European Union. The ECHR was written in 1947 by BRITISH lawyers with the backing of the BRITISH government to try and ensure that the human rights abuses seen in Europe in the run up to WWII would never be repeated. It was really trying to bring European standards of human rights up to British standards. Unfortunately it looks like since then British standards have slipped.
(If you're wondering about the Human Rights Act 1998, it's effect was just to let British citizens enforce the ECHR without having to go all the way to Strasbourg. It didn't give us more rights, just made it easier to claim them.)
>>Europe believes criminals deserve more rights than citizens.
No, the ECHR simply says that everyone has the same rights. It says everyone should have a fair trial and no-one should be executed or tortured. Apart from that, punishment is up to the member state.
>>Here comes some continental Europeans to mod me down for speaking the truth...
No, I'm British. I just happen to know what I'm talking about. (Not that I blame you for your ignorance. Most newspapers and politicians, whether they support the ECHR or not, make the same mistake.) Stop reading the Daily Mail and try looking up the actual treaties.
>>Every year I spend between $500-1000 on books, and all of that money (save one or two books locally) is spent on online booksellers. I'm not exaggerating when I say that I save a few hundred dollars on books every year just for waiting a few days for a shipment to show up. Bottom line: if you want to save money, buy online.
>>Since there allways will be people with opposing views it is unlikely that articles at wikipedia take sides.
In other words, Wikipedia is the ultimate post-modern reference source: truly, there is no such thing as objective truth (did I say truth? Sorry, must have been a slip of the tongue caused by my indoctrination as a mathematics graduate. I meant social construct.)
I guess it boils down to this. Do you want to read encyclopedia articles written by world-renowned experts who have devoted their lives to studying the topic, or would you rather trust the efforts of a few thousand people who have taken an introductory course on the subject in college, or have read a couple of books on it.
I love reading wikipedia. But I'm always seeing things and thinking, that's plain wrong. So I change them. But maybe someone else will change them back. And maybe I'm wrong. As the dude said, that's like, just your opinion, man. And that's what Wikipedia is - a distillation of the (geek) world's opinion.
>> If on the other hand every one starts to agree about something - humanity is bound to be doomed anyway then.
On the contrary, I'd say the number one threat to humanity the way politicians use a purported lack of agreement as an excuse to avoid action. Global warming springs to mind... a tiny minority of scientists funded by oil companies are used as an excuse to ignore the consensus of the overwhelming majority.
>>2. Once people realize there's a free encyclopedia out there that rivals expensive ones (I don't know Wikipedia well enough to know whether it lags, rivals, or surpasses, but I suspect that if it isn't already, it's only a matter of time until it's a serious contender), will they abandon the paid ones? If so, it'll be interesting to see the effects of abandoning our existing knowledge infrastructure.
In my experience, a lot of what's on wikipedia is copied out of other encyclopedias and reference sources. So if wikipedia does drive them out of business, it'll be shooting itself in the foot.
The problem with Wikipedia is not trolling. It's people who don't know as much as they think they do correcting other people's arguments. It's the majority view winning out over the correct one.
Don't get me wrong - I love wikipedia,it's fun to read and fun to contribute to. But never, ever confuse it being a reliable source, since by its nature it reflects the majority belief. Open sourcing code is one thing: if it works, it works. Open sourcing knowledge is riskier: it's not hard to imagine a world where most wikipedia users were creationists. Would you trust the evolution article then?
No, that is EXACTLY like glass. Glass is also elastic up to a point -- it's hard to see on a window pane but easy with narrow filaments, such as fibre-optic cables. Deform it slightly and it springs back into shape. Deform it further and it shatters.
This case is a simple matter of commercial rights and is pretty clear cut, simple stuff. There's really nothing for slashdotters to get outraged about. Imagine for a minute that it wasn't CDs but, say, Apple computers at stake. Say some company is buying Macs in the US (where they are far cheaper than the UK) and importing and selling them in the UK, undercutting Apple's own prices.
Now there's a good argument that this should be perfectly legal - after all, the computers were bought legit from Apple, why shouldn't you be able to take advantage of differential pricing? On the other hand, there's a good argument the other way: Apple is free to choose its own business strategy, and its brand is one of its main assets. People selling cut-price Macs on street corners, with foreign manuals (and probably without a locally valid warranty) would have an adverse impact on Apple's high-value brand.
So far in court, the second argument has won - basically the unofficial importer is potentially undermining the brand strength and goodwill of the supplier. But note that all the big cases so far have come from major "lifestyle" brands, such as Levis. I doubt that some Korean company shipping nameless PC grey boxes would get very far with it.
Besides the fact that music is probably THE lifestyle industry, BPI also has another strong point in its favour: it (or its members) own the UK rights to the music being sold by CD-WOW, and by selling in the UK without permission CD-WOW is infringing those rights. You might say, so what, the music was bought once so the copyright was paid for -- but copyrights are regional in nature. If I own the UK rights to a song and you own the US rights, then for someone to buy CDs from you in the US and sell them in the UK is depriving me of my income.
So overall, this is a no-story, unless you have an ideological problem with copyright and trademarks in th first place. Yes, in some ways it sucks for the consumer. But if you want cheap stuff from abroad, you're free to either go there or order it direct from stores in that country (but be ready to pay import taxes)
The constitutional argument is even more bullshit than that, because the Constitution is meant to control the power of the government, not . Individuals are perfectly free to give up their constitutional rights if they wish to do so on a private, contractual basis.
For example, I can sign an NDA with a company, which limits my right of free speech. I can agree with my employer not to carry a gun at work. Neither of these infringe the constitution and both would be upheld at law. Even the 13th amendment against slavery bans only involuntary servitude - I (and most sportsmen) are still free to enter into a contract of service under which I can be sold or traded (as happens in sport all the time)
Similarly, I can choose to use GPL'd software, or release my own software under the GPL, whether or not the Constitution makes the profit motive the reason behind copyright law. The constitution can't force me to make a profit.
When I buy a product new - any product - I have the legal right to expect it to be properly designed and manufactured.
I have the legal right to expect the manufacturer to take care of any problems that result from bad design and/or quality control, without having to buy an extended warranty, because such problems arise from the manufacturer's negligence.
Warranties are there to fix unexpected/unpredictable problems which can happen to even the best built products.
The Japanese develop it and are first to market (most Japanese gadgets made for the home market are several product development cycles ahead of European/US versions). The technology thrives because the Japanese are gadget-crazy.
A year or so later, the Europeans create a standard for the technology. The technology then thrives because Europeans can be confident their purchases will work.
The US decries the European approach as government interference and leaves it to the markets to choose a standard. US consumers do not buy into the technology because they don't know which standard will prevail (they learned that lesson with betamax!). Five years later, one standard eventually becomes dominant, but it's a different standard from that used anywhere else in the world. A year or two later, that standard becomes obsolete anyway because the Japanese introduced a newer technology.
Don't get me wrong. Insurance can be a good thing because it allows you to spread risk. I insure my home because even though it doesn't make statistical sense, I'm not rich enough to be able to take the small risk of it burning down. I insure my health because again, the potential liability for not insuring is enormous. =
But a laptop? Whatever goes wrong with it, I know I can afford to fix it or buy another. That's my peace of mind. (And if I really can't afford to fix/replace it when it breaks, I'll have bigger worries than my laptop.)
For me, it makes no sense to insure against a risk I can afford to run, because clearly if the insurance company can make a profit on my premium, they're charging more than the risk is worth.
Actually what the poster is describing is nothing whatsoever to do with a bose-einstein condensate.
BECs occur at low temperatures when atoms (or molecules) join together in a way that allows them to all enter the same quantum state. This means that every atom (or molecule) within the BEC is indistinguishable from every other, which gives rise to all sorts of wierd quantum effects, but within each atom/molecule all the constituent electrons, neutrons and protons are in the usual places. Far from being made of of atoms disentigrating into pieces, BECs result from atoms linking up in a wierd quantum way.
It's only at very HIGH temperatures that atoms break down into the "soup" you're describing - we're talking beginning-of-the-universe conditions.
If I bought a laptop whose hinge, keyboard, touchpad and CD drive were failing after 6 months, I'd be complaining to consumer standards. It's clearly not fit for its purpose.
In the UK, any product failure within 6 months is ASSUMED to be the manufacturer's fault unless they can prove otherwise. Even after 6 months they're not off the hook as all goods sold new have to be of "merchantable quality", which includes being reasonably durable and able to withstand normal wear and tear.
>> If you're the worrying kind, it's not a lot of money.
Actually, the problem is that extended warranties do cost a lot of money. They're mostly just cash cows for the manufacturers. Eg. for the cheapest $1000 iBook, AppleCare is $250 - that's 25% of the list price to extend the warranty from 1 to 3 years. By the end of the first year your $1000 laptop will only be worth around $500 anyway. So effectively you've spent $250 to insure something worth $500 at the time the insurance kicks in. And by the end of the third year the laptop will probably be worth less than $250.
Yes, if it breaks down in that time and you have the warranty, you'll be ahead. But think, how many consumer electronics are you going to buy over your lifetime? What proportion of those will break in the extended warranty period? Under 10%, I'd hope. But you're paying around 50% of the value of the item at the time the warranty kicks in. That's what I call a rip-off, not peace of mind.
Here's a suggestion. Every time you buy something new, instead of buying the extra warranty, put the same amount into savings. In a couple of years, you'll have saved enough to cover any repairs that might be needed. In 20 years you'll be able to retire.
The planet has reached a natural balance. The climate is stable. It's just very hot. The atmosphere is composed of heavier molecules than here on earth -- mostly CO2 -- so it can withstand much higher temperatures before being boiled off.
Why? Atmospheres "boil away" when the molecules in the atmosphere are moving faster than the escape velocity of the planet. But while particles in a hot gases move faster than those in cooler sample fo the same gas, gases made up of heavy and/or complex molecules will have lower particle speeds than gases made of light, simple molecules at the same temperature.
This is because temperature is related to energy: for two gases to have the same temperature means that the average energy of each particle is the same in the two gases. But heavy molecules reach the same kinetic energy at a lower speed (a molecule four times the weight reaches the same kinetic energy at only twice the speed). And just as importantly, complex molecules can store more energy in "internal modes" -- by spinning and vibrating. N2 and O2, the main constituents of earth's atmosphere, both have 1 vibrational and 2 rotational modes. CO2 is heavier, and has 3 vibrational and 3 rotational modes.
As a result, Venus's CO2-dominated atmosphere can be be much, much hotter before boiling off compared with earth's atmosphere. Probably the reason Venus's atmosphere is dominated by heavy elements and complex molecules is that the lighter stuff has already escaped.
The problem is you'd never know when it was coming. The gamma rays travel at the speed of light, so the first time you know the supernova has happened is the same time the radiation hits you.
The reason MD never took off is that record companies never released much music on MD, so you were obliged to rerecord from CD, plus it long predated the online revolution so users couldn't get music off the net. With a USB interface and online music stores, both problems are removed.
Slashdot Mirror
>>Third dumb question: How do KiloVolts relate to Ozone production? Shouldn't current also be a part of this?
This one at least is a dumb question, or at least one I can answer. It's the voltage that creates ionisation and thus ozone, current is irrelevant:
high voltage = strong electric field
strong electric field => electrons get stripped off atoms and molecules ('ionisation')
oxygen ions react with O2 => ozone production.
Creation of ions does result in an electric current (since electrons and positive ions are flowing in the electric field), but it's a consequence and not a cause of ionisation. Since ozone production is a consequence of the same thing, the two quantities will be related, but both depend on the voltage rather than each other.
>>EM fields follow the inverse square law and HV lines hang quite high, so the amount of energy anyone around those lines absorbs wouldn't be very big.
Actually IIRC my e/m lectures, while the electric field of a point charge varies as an inverse square, the field of a line charge varies as a simple inverse (you have to add up the effect of all the charges along the wire). So the fall-off isn't nearly so far.
Then again I remember something about (point)dipoles falling off as fourth powers, and HV lines usually come in pairs at least - presumably one carrying the juice one way and the other carrying it back. So maybe overall a line dipole works out as inverse square...someone who still remembers his physics please do the maths!
maybe so at some level, but usually cultural/artistic works are not described as products. Consider the following:
"did you see the Van Gogh exhibition?"
"sure, that sunflowers painting is a great product!"
"Sgt Pepper was the Beatles' best-selling product"
"Steel construction techniques made products such as the Empire State Building possible"
If these sentences sound natural to you, OK. But I'd guess you're in the minority, and that most people wouldn't call Jurassic Park a product either.
>>The Video Toaster ushered in the age of affordable desktop video in 1991 and was used in products such as Babylon 5 and Jurassic Park.
Jurassic Park a product? And there was me thinking it was a movie.
The operative words are 'defend themselves'. Last time I looked, shooting someone in the back as they were running away doesn't count as defence.
Ahem, are you think about the European Convention on Human Rights and the European Court of Human Rights? Actually that's nothing to do with the European Union. The ECHR was written in 1947 by BRITISH lawyers with the backing of the BRITISH government to try and ensure that the human rights abuses seen in Europe in the run up to WWII would never be repeated. It was really trying to bring European standards of human rights up to British standards. Unfortunately it looks like since then British standards have slipped.
(If you're wondering about the Human Rights Act 1998, it's effect was just to let British citizens enforce the ECHR without having to go all the way to Strasbourg. It didn't give us more rights, just made it easier to claim them.)
>>Europe believes criminals deserve more rights than citizens.
No, the ECHR simply says that everyone has the same rights. It says everyone should have a fair trial and no-one should be executed or tortured. Apart from that, punishment is up to the member state.
>>Here comes some continental Europeans to mod me down for speaking the truth...
No, I'm British. I just happen to know what I'm talking about. (Not that I blame you for your ignorance. Most newspapers and politicians, whether they support the ECHR or not, make the same mistake.) Stop reading the Daily Mail and try looking up the actual treaties.
>>Every year I spend between $500-1000 on books, and all of that money (save one or two books locally) is spent on online booksellers. I'm not exaggerating when I say that I save a few hundred dollars on books every year just for waiting a few days for a shipment to show up. Bottom line: if you want to save money, buy online.
Alternatively, join a library and save even more.
>>Since there allways will be people with opposing views it is unlikely that articles at wikipedia take sides.
In other words, Wikipedia is the ultimate post-modern reference source: truly, there is no such thing as objective truth (did I say truth? Sorry, must have been a slip of the tongue caused by my indoctrination as a mathematics graduate. I meant social construct.)
I guess it boils down to this. Do you want to read encyclopedia articles written by world-renowned experts who have devoted their lives to studying the topic, or would you rather trust the efforts of a few thousand people who have taken an introductory course on the subject in college, or have read a couple of books on it.
I love reading wikipedia. But I'm always seeing things and thinking, that's plain wrong. So I change them. But maybe someone else will change them back. And maybe I'm wrong. As the dude said, that's like, just your opinion, man. And that's what Wikipedia is - a distillation of the (geek) world's opinion.
>> If on the other hand every one starts to agree about something - humanity is bound to be doomed anyway then.
On the contrary, I'd say the number one threat to humanity the way politicians use a purported lack of agreement as an excuse to avoid action. Global warming springs to mind... a tiny minority of scientists funded by oil companies are used as an excuse to ignore the consensus of the overwhelming majority.
>>2. Once people realize there's a free encyclopedia out there that rivals expensive ones (I don't know Wikipedia well enough to know whether it lags, rivals, or surpasses, but I suspect that if it isn't already, it's only a matter of time until it's a serious contender), will they abandon the paid ones? If so, it'll be interesting to see the effects of abandoning our existing knowledge infrastructure.
In my experience, a lot of what's on wikipedia is copied out of other encyclopedias and reference sources. So if wikipedia does drive them out of business, it'll be shooting itself in the foot.
The problem with Wikipedia is not trolling. It's people who don't know as much as they think they do correcting other people's arguments. It's the majority view winning out over the correct one.
Don't get me wrong - I love wikipedia,it's fun to read and fun to contribute to. But never, ever confuse it being a reliable source, since by its nature it reflects the majority belief. Open sourcing code is one thing: if it works, it works. Open sourcing knowledge is riskier: it's not hard to imagine a world where most wikipedia users were creationists. Would you trust the evolution article then?
No, that is EXACTLY like glass. Glass is also elastic up to a point -- it's hard to see on a window pane but easy with narrow filaments, such as fibre-optic cables. Deform it slightly and it springs back into shape. Deform it further and it shatters.
>> What's wrong with "VARPTR"? Are you on drugs? Is this Variable Pointer? Veterans Affairs Reporter? VARP Tree (whatever a VARP is)?
That's what comments are for.
This case is a simple matter of commercial rights and is pretty clear cut, simple stuff. There's really nothing for slashdotters to get outraged about. Imagine for a minute that it wasn't CDs but, say, Apple computers at stake. Say some company is buying Macs in the US (where they are far cheaper than the UK) and importing and selling them in the UK, undercutting Apple's own prices.
Now there's a good argument that this should be perfectly legal - after all, the computers were bought legit from Apple, why shouldn't you be able to take advantage of differential pricing? On the other hand, there's a good argument the other way: Apple is free to choose its own business strategy, and its brand is one of its main assets. People selling cut-price Macs on street corners, with foreign manuals (and probably without a locally valid warranty) would have an adverse impact on Apple's high-value brand.
So far in court, the second argument has won - basically the unofficial importer is potentially undermining the brand strength and goodwill of the supplier. But note that all the big cases so far have come from major "lifestyle" brands, such as Levis. I doubt that some Korean company shipping nameless PC grey boxes would get very far with it.
Besides the fact that music is probably THE lifestyle industry, BPI also has another strong point in its favour: it (or its members) own the UK rights to the music being sold by CD-WOW, and by selling in the UK without permission CD-WOW is infringing those rights. You might say, so what, the music was bought once so the copyright was paid for -- but copyrights are regional in nature. If I own the UK rights to a song and you own the US rights, then for someone to buy CDs from you in the US and sell them in the UK is depriving me of my income.
So overall, this is a no-story, unless you have an ideological problem with copyright and trademarks in th first place. Yes, in some ways it sucks for the consumer. But if you want cheap stuff from abroad, you're free to either go there or order it direct from stores in that country (but be ready to pay import taxes)
The constitutional argument is even more bullshit than that, because the Constitution is meant to control the power of the government, not . Individuals are perfectly free to give up their constitutional rights if they wish to do so on a private, contractual basis.
For example, I can sign an NDA with a company, which limits my right of free speech. I can agree with my employer not to carry a gun at work. Neither of these infringe the constitution and both would be upheld at law. Even the 13th amendment against slavery bans only involuntary servitude - I (and most sportsmen) are still free to enter into a contract of service under which I can be sold or traded (as happens in sport all the time)
Similarly, I can choose to use GPL'd software, or release my own software under the GPL, whether or not the Constitution makes the profit motive the reason behind copyright law. The constitution can't force me to make a profit.
>> this unique property...
As set out in the quote itself, there's nothing very unique about shattering -- it's just like glass.
When I buy a product new - any product - I have the legal right to expect it to be properly designed and manufactured.
I have the legal right to expect the manufacturer to take care of any problems that result from bad design and/or quality control, without having to buy an extended warranty, because such problems arise from the manufacturer's negligence.
Warranties are there to fix unexpected/unpredictable problems which can happen to even the best built products.
Contract law is there to fix the rest.
My view would be more like:
Someone (often British) invents the technology.
The Japanese develop it and are first to market (most Japanese gadgets made for the home market are several product development cycles ahead of European/US versions). The technology thrives because the Japanese are gadget-crazy.
A year or so later, the Europeans create a standard for the technology. The technology then thrives because Europeans can be confident their purchases will work.
The US decries the European approach as government interference and leaves it to the markets to choose a standard. US consumers do not buy into the technology because they don't know which standard will prevail (they learned that lesson with betamax!). Five years later, one standard eventually becomes dominant, but it's a different standard from that used anywhere else in the world. A year or two later, that standard becomes obsolete anyway because the Japanese introduced a newer technology.
Don't get me wrong. Insurance can be a good thing because it allows you to spread risk. I insure my home because even though it doesn't make statistical sense, I'm not rich enough to be able to take the small risk of it burning down. I insure my health because again, the potential liability for not insuring is enormous. = But a laptop? Whatever goes wrong with it, I know I can afford to fix it or buy another. That's my peace of mind. (And if I really can't afford to fix/replace it when it breaks, I'll have bigger worries than my laptop.) For me, it makes no sense to insure against a risk I can afford to run, because clearly if the insurance company can make a profit on my premium, they're charging more than the risk is worth.
Actually what the poster is describing is nothing whatsoever to do with a bose-einstein condensate.
BECs occur at low temperatures when atoms (or molecules) join together in a way that allows them to all enter the same quantum state. This means that every atom (or molecule) within the BEC is indistinguishable from every other, which gives rise to all sorts of wierd quantum effects, but within each atom/molecule all the constituent electrons, neutrons and protons are in the usual places. Far from being made of of atoms disentigrating into pieces, BECs result from atoms linking up in a wierd quantum way.
It's only at very HIGH temperatures that atoms break down into the "soup" you're describing - we're talking beginning-of-the-universe conditions.
Surely if you stirred a spoon in a superfluid soup it would not swirl at all, because there's no friction for the spoon to set up a vortex.
If I bought a laptop whose hinge, keyboard, touchpad and CD drive were failing after 6 months, I'd be complaining to consumer standards. It's clearly not fit for its purpose.
In the UK, any product failure within 6 months is ASSUMED to be the manufacturer's fault unless they can prove otherwise. Even after 6 months they're not off the hook as all goods sold new have to be of "merchantable quality", which includes being reasonably durable and able to withstand normal wear and tear.
>> If you're the worrying kind, it's not a lot of money.
Actually, the problem is that extended warranties do cost a lot of money. They're mostly just cash cows for the manufacturers. Eg. for the cheapest $1000 iBook, AppleCare is $250 - that's 25% of the list price to extend the warranty from 1 to 3 years. By the end of the first year your $1000 laptop will only be worth around $500 anyway. So effectively you've spent $250 to insure something worth $500 at the time the insurance kicks in. And by the end of the third year the laptop will probably be worth less than $250.
Yes, if it breaks down in that time and you have the warranty, you'll be ahead. But think, how many consumer electronics are you going to buy over your lifetime? What proportion of those will break in the extended warranty period? Under 10%, I'd hope. But you're paying around 50% of the value of the item at the time the warranty kicks in. That's what I call a rip-off, not peace of mind.
Here's a suggestion. Every time you buy something new, instead of buying the extra warranty, put the same amount into savings. In a couple of years, you'll have saved enough to cover any repairs that might be needed. In 20 years you'll be able to retire.
The planet has reached a natural balance. The climate is stable. It's just very hot. The atmosphere is composed of heavier molecules than here on earth -- mostly CO2 -- so it can withstand much higher temperatures before being boiled off.
Why? Atmospheres "boil away" when the molecules in the atmosphere are moving faster than the escape velocity of the planet. But while particles in a hot gases move faster than those in cooler sample fo the same gas, gases made up of heavy and/or complex molecules will have lower particle speeds than gases made of light, simple molecules at the same temperature.
This is because temperature is related to energy: for two gases to have the same temperature means that the average energy of each particle is the same in the two gases. But heavy molecules reach the same kinetic energy at a lower speed (a molecule four times the weight reaches the same kinetic energy at only twice the speed). And just as importantly, complex molecules can store more energy in "internal modes" -- by spinning and vibrating. N2 and O2, the main constituents of earth's atmosphere, both have 1 vibrational and 2 rotational modes. CO2 is heavier, and has 3 vibrational and 3 rotational modes.
As a result, Venus's CO2-dominated atmosphere can be be much, much hotter before boiling off compared with earth's atmosphere. Probably the reason Venus's atmosphere is dominated by heavy elements and complex molecules is that the lighter stuff has already escaped.
The problem is you'd never know when it was coming. The gamma rays travel at the speed of light, so the first time you know the supernova has happened is the same time the radiation hits you.
The reason MD never took off is that record companies never released much music on MD, so you were obliged to rerecord from CD, plus it long predated the online revolution so users couldn't get music off the net. With a USB interface and online music stores, both problems are removed.