I'll concede my calculations are in error. As stated in my post, I was curious to get ballpark figures for whether this made sense or not. This was all done in 5 minutes, using Window's calculator app and the first figures available from a google search - really, it would have been a miracle if it wasn't crap! On reflection, I see I have used the specific energy for petrol, not the energy per litre. In calculating daily energy my error is in vascillating on whether to work in kJ or not, which made me put the wrong unit to the wrong quantity which was then erroneously carried over into later calculations.
It's not my best work, I'll grant, but you do me an injustice by characterising it as 'fantasy'. It's quite possible to make earnest errors without being delusional. I'm not partisan; I'm simply tired of people saying "Won't work! Will too! Won't work! Will too!", without putting numbers to it. Digging out some figures with citations - even hastily googled figures - can at least put the discussion on the civil path of providing some evidence for positions, as you have done. I appreciate your rigour in following up on it.
Ok, I'm skeptical too. Let's check it out! I apologise in advance for large numbers.
From this website I've got a figure of just over 4 million sq. kilometers of arable land in the United States. This website gives daily cross-year average sunlight falling on a square meter of ground as about 160 W. That's 640 x 10^12 W-days of power falling on the land, per day. Wikipedia cites that plants have a metabolic conversion efficiency of six per cent. This website cites a biomass-to-energy conversion efficiency of 20 per cent. So, if we assume that only 1 per cent of arable land was actually covered with plant, and then turned into electricity, total daily production would be 77 x10^9 W-days of power. This sounds like a lot; obviously there will be some more production and transport inefficiencies in there.
For comparison, the US consumes 1.39 x10^9 litres of fuel per day. According to Wikipedia, the energy density of petrol is 49.2 x 10^6 J/L, so that's 684 x10^12 J of energy per day... or, expressed in Watt-days (86400 seconds in a day), that's 7.91 x10^9 W-days of energy.
There are a lot of real world factors not being included in these estimates, but the 10-to-1 ratio here indicates to me that the energies involved are of a comparable scale; if we devoted 10 per cent of arable land to agriculture, we could (with highly efficient processes), conceivably put a sizable dent in our energy usage.
I have been with my partner for eight years - going on 9 years in August. We met and dated through the internet, and lived close enough that transport was never a problem. We've lived together, car-free in three cities (and two countries) thus far, without drama. We generally get supplies and groceries delivered and catch the ferry when we care to go out on the town. He is an artist, and I am an engineering professor, so our daily routines complement each other well. Living with a car is an expensive convenience, tha,t when you realise the options available to do without it, is less essential than most people think.
I don't have a car. I can certainly afford one, but I did the maths and it's more cost effective to pay $100 more in rent per week to live walking distance to work, than to pay the amortised cost of car purchase, maintenance, fuel and parking. Plus, I get more exercise!
The strange paradox is that people don't seem to accept that opting out is a valid choice.
For example, I refuse to buy PC games or programs that use online activation - I disagree with the philosophy of allowing other people to dictate when I may use something I have bought. I would not accept it for a car, I would not accept it for a toaster. Why should I accept it for software? That it greatly reduces my choices in the market place is besides the point - I vote with my feet and will continue doing so. And yet, my friends think I'm nuts because - omg - I'm not up to date with whatever hot title just came out. How can I live?? Really, I don't feel like entertainment is worth compromising my principles for
Likewise, if you really prefer your printer from the 1990s, spend the money it's worth to you to get it fixed or retrofitted to keep operating with modern ink, or be prepared to do without. Don't accept substandard. Don't accept exploitative business practices. But the increasingly common refrain is that "One person won't change anything", much like saying that voting for a third party is wasting your vote. If people were prepared to stand up for their principles instead of falling over for the shiney gadget, we would all be better off.
I mean "reasonable" in the sense that it can be done (and is, occasionally). It's just that it isn't customary. While pi is a very fine factor for radians, it isn't a base per se. I can see a use for talking about megaradians, but it's harder to imagine why you would talk about pi^n radians as a practical unit.
You should come visit Australia - it's metric all the way down! Of course, with the possible exception of things standardised by international convention (like aircraft altitude in feet) but even then, we also provide the same units in metric just to be sure.
The coherent angular unit is called the Radian. It is perfectly reasonable (but generally not done) to talk in metric kilo- and milli- radians. Angular degrees are generally used because of the nice trigonometric properties of triangle (from which we get the trig- of trigonometry), and allow for rational expressions of angles in convenient ratios. However, angular degrees are not coherent and serious engineering often necessitates using radian measurements - an example is helicopter design (my field), in which the tip velocity of a rotor blade is the length of the blade times its rotational velocity in radians per second.
We have already had the first fatality from a civilian UAV: a man was killed by debris when a Yamaha R-Max crashed (admittedly, under remote manual control). Prior to that, several people have been killed while operating remote controled hobby aircraft.
If this turns out to be true, every MOTHERFUCKER who's ever called someone fat or blamed them for their weight is going to have the shit beat out of them by a mob of angry newly-skinny people with incredible core body strength.
Well, let's see... what have science majors (ie. science) done for black people? Hmmm... there's medicine (vaccinations, ER, GPs, surgery, pallative, rehabilitative, etc), agriculture (cheaper food, better selection, more nutritious produce), public infrastructure (transport, power, utilities), high tech industry supported by secondary industry supported by service industries, then there's the internet (publically accessible via libraries if not in homes), access to education (via the internet), access to a more diverse job market (via education).
Oh wait, I see now - because science and technology is developed by science majors, that means that nobody but science majors can enjoy the benefits. No... wait... actually, that's complete bullshit. Black people have benefited as much as the rest of us.
Research been showing more problems than prevention from vaccines
I'm going to use my annecdotal dataset of one. Let's see, people I know who've had vaccines. Hmm... all of them. Number of those people who have had negative side-effects.... none whatsoever. So, if there are more problems than prevention from vaccines, I'm not seeing it in my little slice of the world.
In fact, given that vaccination rates run at something from 70-90% in industrialised countries and we aren't seeing 70-90% of people suffering more than they might expect from polio, measles, influenza, etc. I'd say that claiming that vaccines do more harm than good is complete bullshit.
That -is- an interesting question. And one I would like to know the answer to. Things done on astronomical scales tend to be prohibitively expensive, but Earth's magnetic field is pretty weak as it is. Maybe it's plausible enough to look into.
Me, I'm planning for the high-def video streaming service that will be offered over 802.11ad - the so-called "ad-HD" format. Supports lightning-fast channel switching.
For similar reasons, I often find myself about to post my views on something and then hesitate: "Does the internet really need to hear my opinion on this? Is it worth the emotional backlash if my thoughts set off a troll?" More often than not recently I've answered "No". And before anyone leaps out and cries "But you shouldn't be so emotionally invested in what you post!" I'll assure you that it's impossible to express a considered opinion and not invest some part of yourself in it. Everyone should be able to state their point of view without being wished bodily harm as the parent was.
I like how the Hackaday forum has cleaned up its act by permabanning trolls and flamers and holding people more accountable. Yes, it's whackamole with fake accounts but if trolls don't get any traction in your forum eventually they go away. Trolls are a lot like schoolyard bullies and have similar motivations. By removing the enabling mechanism (anonimity) or removing the payoff mechanism (flame response), I expect such bad behaviour can be diminished.
people who've never lived in anything other than a wonderland of privilege
Oh, how I wish academia was like that. It's 8 pm and I'm still at work. When I go home in half an hour, I will keep on working until I can't work anymore. If I'm lucky, I might get to see my family on the weekend. If I don't work this hard, I won't get tenure and I won't have a job. Academia is no wonderland of privilage and it hasn't been since the 18th century, when the only people who had time to think about things were the idle nobility. Anybody in academia today has worked hard to get there and continues to work hard to stay there. Why do we want to stay there? Because it's the only way we can study things we're really passionate about, rather than what people force us to. But at 8 pm after a long day of teaching, I wonder if I really do want to be here afterall...
Slashdot Mirror
I'll concede my calculations are in error. As stated in my post, I was curious to get ballpark figures for whether this made sense or not. This was all done in 5 minutes, using Window's calculator app and the first figures available from a google search - really, it would have been a miracle if it wasn't crap! On reflection, I see I have used the specific energy for petrol, not the energy per litre. In calculating daily energy my error is in vascillating on whether to work in kJ or not, which made me put the wrong unit to the wrong quantity which was then erroneously carried over into later calculations.
It's not my best work, I'll grant, but you do me an injustice by characterising it as 'fantasy'. It's quite possible to make earnest errors without being delusional. I'm not partisan; I'm simply tired of people saying "Won't work! Will too! Won't work! Will too!", without putting numbers to it. Digging out some figures with citations - even hastily googled figures - can at least put the discussion on the civil path of providing some evidence for positions, as you have done. I appreciate your rigour in following up on it.
Ok, I'm skeptical too. Let's check it out! I apologise in advance for large numbers.
From this website I've got a figure of just over 4 million sq. kilometers of arable land in the United States. This website gives daily cross-year average sunlight falling on a square meter of ground as about 160 W. That's 640 x 10^12 W-days of power falling on the land, per day. Wikipedia cites that plants have a metabolic conversion efficiency of six per cent. This website cites a biomass-to-energy conversion efficiency of 20 per cent. So, if we assume that only 1 per cent of arable land was actually covered with plant, and then turned into electricity, total daily production would be 77 x10^9 W-days of power. This sounds like a lot; obviously there will be some more production and transport inefficiencies in there.
For comparison, the US consumes 1.39 x10^9 litres of fuel per day. According to Wikipedia, the energy density of petrol is 49.2 x 10^6 J/L, so that's 684 x10^12 J of energy per day... or, expressed in Watt-days (86400 seconds in a day), that's 7.91 x10^9 W-days of energy.
There are a lot of real world factors not being included in these estimates, but the 10-to-1 ratio here indicates to me that the energies involved are of a comparable scale; if we devoted 10 per cent of arable land to agriculture, we could (with highly efficient processes), conceivably put a sizable dent in our energy usage.
I have been with my partner for eight years - going on 9 years in August. We met and dated through the internet, and lived close enough that transport was never a problem. We've lived together, car-free in three cities (and two countries) thus far, without drama. We generally get supplies and groceries delivered and catch the ferry when we care to go out on the town. He is an artist, and I am an engineering professor, so our daily routines complement each other well. Living with a car is an expensive convenience, tha,t when you realise the options available to do without it, is less essential than most people think.
;)
Of course, ask me again once we have kids.
I don't have a car. I can certainly afford one, but I did the maths and it's more cost effective to pay $100 more in rent per week to live walking distance to work, than to pay the amortised cost of car purchase, maintenance, fuel and parking. Plus, I get more exercise!
The strange paradox is that people don't seem to accept that opting out is a valid choice.
/rant
For example, I refuse to buy PC games or programs that use online activation - I disagree with the philosophy of allowing other people to dictate when I may use something I have bought. I would not accept it for a car, I would not accept it for a toaster. Why should I accept it for software? That it greatly reduces my choices in the market place is besides the point - I vote with my feet and will continue doing so. And yet, my friends think I'm nuts because - omg - I'm not up to date with whatever hot title just came out. How can I live?? Really, I don't feel like entertainment is worth compromising my principles for
Likewise, if you really prefer your printer from the 1990s, spend the money it's worth to you to get it fixed or retrofitted to keep operating with modern ink, or be prepared to do without. Don't accept substandard. Don't accept exploitative business practices. But the increasingly common refrain is that "One person won't change anything", much like saying that voting for a third party is wasting your vote. If people were prepared to stand up for their principles instead of falling over for the shiney gadget, we would all be better off.
Because it only takes 20 or more launches to make a $1B space gun competitive with a $50M rocket.
Excellent idea. Exactly what is the value of Avogadro's number, again? Unfortunately, it's not quite so simple.
I mean "reasonable" in the sense that it can be done (and is, occasionally). It's just that it isn't customary. While pi is a very fine factor for radians, it isn't a base per se. I can see a use for talking about megaradians, but it's harder to imagine why you would talk about pi^n radians as a practical unit.
Well, they're metric turtles, y'see?
You should come visit Australia - it's metric all the way down! Of course, with the possible exception of things standardised by international convention (like aircraft altitude in feet) but even then, we also provide the same units in metric just to be sure.
He only changes them infrequently.
The coherent angular unit is called the Radian. It is perfectly reasonable (but generally not done) to talk in metric kilo- and milli- radians. Angular degrees are generally used because of the nice trigonometric properties of triangle (from which we get the trig- of trigonometry), and allow for rational expressions of angles in convenient ratios. However, angular degrees are not coherent and serious engineering often necessitates using radian measurements - an example is helicopter design (my field), in which the tip velocity of a rotor blade is the length of the blade times its rotational velocity in radians per second.
See also Gradian
We have already had the first fatality from a civilian UAV: a man was killed by debris when a Yamaha R-Max crashed (admittedly, under remote manual control). Prior to that, several people have been killed while operating remote controled hobby aircraft.
If this turns out to be true, every MOTHERFUCKER who's ever called someone fat or blamed them for their weight is going to have the shit beat out of them by a mob of angry newly-skinny people with incredible core body strength.
FTFY.
I'm sure glad the editor thought to clarify which Bradley Manning it is we're talking about. I was so confused!
there are few sights that can beat watching a flock of pigs fly over the capitol building and getting shot down by a flight of F-22s.
Like that will ever happen - they'll never work out the problems with the F-22s!
Good question!
Well, let's see... what have science majors (ie. science) done for black people? Hmmm... there's medicine (vaccinations, ER, GPs, surgery, pallative, rehabilitative, etc), agriculture (cheaper food, better selection, more nutritious produce), public infrastructure (transport, power, utilities), high tech industry supported by secondary industry supported by service industries, then there's the internet (publically accessible via libraries if not in homes), access to education (via the internet), access to a more diverse job market (via education).
Oh wait, I see now - because science and technology is developed by science majors, that means that nobody but science majors can enjoy the benefits. No... wait... actually, that's complete bullshit. Black people have benefited as much as the rest of us.
That's what the hovercraft is for.
Research been showing more problems than prevention from vaccines
I'm going to use my annecdotal dataset of one. Let's see, people I know who've had vaccines. Hmm... all of them. Number of those people who have had negative side-effects.... none whatsoever. So, if there are more problems than prevention from vaccines, I'm not seeing it in my little slice of the world.
In fact, given that vaccination rates run at something from 70-90% in industrialised countries and we aren't seeing 70-90% of people suffering more than they might expect from polio, measles, influenza, etc. I'd say that claiming that vaccines do more harm than good is complete bullshit.
I think that is what the GP is talking about.
That -is- an interesting question. And one I would like to know the answer to. Things done on astronomical scales tend to be prohibitively expensive, but Earth's magnetic field is pretty weak as it is. Maybe it's plausible enough to look into.
Me, I'm planning for the high-def video streaming service that will be offered over 802.11ad - the so-called "ad-HD" format. Supports lightning-fast channel switching.
After tenure? Eternal vacation! :D
For similar reasons, I often find myself about to post my views on something and then hesitate: "Does the internet really need to hear my opinion on this? Is it worth the emotional backlash if my thoughts set off a troll?" More often than not recently I've answered "No". And before anyone leaps out and cries "But you shouldn't be so emotionally invested in what you post!" I'll assure you that it's impossible to express a considered opinion and not invest some part of yourself in it. Everyone should be able to state their point of view without being wished bodily harm as the parent was.
I like how the Hackaday forum has cleaned up its act by permabanning trolls and flamers and holding people more accountable. Yes, it's whackamole with fake accounts but if trolls don't get any traction in your forum eventually they go away. Trolls are a lot like schoolyard bullies and have similar motivations. By removing the enabling mechanism (anonimity) or removing the payoff mechanism (flame response), I expect such bad behaviour can be diminished.
people who've never lived in anything other than a wonderland of privilege
Oh, how I wish academia was like that. It's 8 pm and I'm still at work. When I go home in half an hour, I will keep on working until I can't work anymore. If I'm lucky, I might get to see my family on the weekend. If I don't work this hard, I won't get tenure and I won't have a job. Academia is no wonderland of privilage and it hasn't been since the 18th century, when the only people who had time to think about things were the idle nobility. Anybody in academia today has worked hard to get there and continues to work hard to stay there. Why do we want to stay there? Because it's the only way we can study things we're really passionate about, rather than what people force us to. But at 8 pm after a long day of teaching, I wonder if I really do want to be here afterall...