I came up with a general number -- 1.5 kilowatts, this is about the amount of energy you would need to propel a small car (like a volkswagon beetle, old variety).
Even small older cars like the VW beetle have engines that put out between 20 and 40kW. That much isn't needed to cruise, only a minimal part of the engine's power is needed to overcome air and tire friction at the speeds such cars typically go, but the engine needs to be able to accelerate the car from standstill in a reasonable amount of time.
That's the idea behind hybrid cars: they have smaller engines that couldn't accelerate the car alone, but they charge up batteries that are able to provide temporary power surges for accelerations. Smaller engines == smaller gas consumption.
Can't you use fresnel along with photvoltaic to improve the power of the photovoltaics? Maybe not this size of fresnel, but smaller, cheaper ones to get a boost on your cells.
If you pair a photovoltaic panel to the same size fresnel lens, no because you'll just have concentrated the same amount of light on a tiny bit of the photovoltaic panel instead of having the same power spread on the entire surface. You can however increase the power to a smaller panel, because then you concentrate on this smaller surface the power gathered by the larger lens.
There's a limit to how much you can concentrate the solar light onto the solar panel before destroying the panel though. For this to work, you'd probably have to keep the solar panel out of the lens' focal point, and if your lens is really big, cool the panel with water or something (their efficiency is higher when they're cool).
I wish I knew the math to this, but damn, if it could provide even a small fraction of the power I use during the daytime... (by this, I mean 5-10%)
- In bright summer daylight, at noon the sun provides 1200W/m2
- This fresnel lens is 80x100, so captures 1200 * 0.8 = 960W at best
- A good steam engine, with a condenser and exhaust reheater provides has an efficiency of about 30%, so it would give 960 * 0.3 = 288W in mechanical power
- A good alternator, going at its preferred RPM (not necessarily that of the steam engine's prefered RPM, but let's assume) has an efficiency of about 90%, so it would give 288 * 0.9 = 260W
So you'd get 260W in the best possible conditions, in the brightest of days, in summer, at midday. Throw some clouds and, assuming the entire thing doesn't stall and stays at its nominal efficiency (not likely, but let's assume), you get about 6 times less power, so about 43W
In short, you're better off with solar panels: perhaps a little less efficiency for the same price, but more surface and a lot less aggravation.
Chalk burns eh? Creative chemistry, more like it. Here's another fun thing you can do: drop your "burnt" chalk in a glass half-full of water, let it bubble, and put your finger in it. Let me know how it feels.
So do aluminum cans. They smell really bad.
Aluminium doesn't smell bad when it burns. I suspect whatever soda pop chemicals remaining in the can do.
It seems that normal concrete will start emitting plumes of smoke just before it pops
As would burning tar, or any other heavy petroleum derivate.
* Mike's car.
Well, not yet. But it's plastic, so it would go up in no time at all. Or maybe we could just shrink-wrap the body around the frame.
Try focusing the lens on the round plastic thing that smells funny, on the rear side of the car...
Seriously, this article is all about playing with a new destructive toy and not much about using the toy in question to do interesting science-related experiments.
Tanenbaum is being disingenious
on
More From Tanenbaum
·
· Score: 2, Insightful
In his email, Linus said that Brown never contacted him. No email, no phone call, no personal interview. Nothing. Considering the fact that Brown was writing an explosive book in which he accused Linus of not being the author of Linux, you would think a serious author would at least confront the subject with the accusation and give him a chance to respond. What kind of a reporter talks to people on the periphery of the subject but fails to talk to the main player?
Hmmm, duh!
How many "explosive" books on Diana were published without giving Diana a chance to respond in the book?
Dragging someone's name into the dirt in a book and not including an interview of that person in the book is the hallmark of a trashy book. But then, we all knew it, since it's a Microsoft PR ploy ultimately, so no surprise there.
Not so. IBM was called the benevolent dictator, and that since way before the 80s. I don't think I've ever seen Microsoft been called benevolent by any sane person...
People have said the same thing about the Dallas series, yet it kept going and going and going.
You have to realize it's not about justice, or what the fate of Linux will be, or putting the GPL to the test, or anything. The SCO affair has become a entertaining sitcom for Linux people, and a way for them to vent their (perceived) frustration by beating the dead horse again and again.
(and also a way for Slashdot to fill up on slow days).
Hayabusa, which is Japanese for "falcon", will act much like its namesake, descending to the asteroid's surface, capturing its prey and returning it to Earth.
Presumably it'll let go of it before coming back? otherwise it'll be the biggest space sample ever collected.
And you think that's bad? Look, my business partner in Nigeria, Mr. Adewale Johnson, read the above Slashdot article and got scared. I haven't heard a word from him since the article was posted. It's a bummer actually because I had just sent him $10K to pay for his lawyer's fees, and I was waiting for his confirmation that he wired me the $20M.
Personal message: Dr. Johnson, don't be scared by Slashdot, the article doesn't apply to you, only crooks. Please talk to me, I await your response eagerly. -- Your business partner!
the FBI told Congress on Thursday that it has 'identified over 100 significant spammers
That's very nice, but the fact remains that 90% of all spam originates from countries that are out of the FBI's jurisdiction. What are they going to do about it?
It nothing else, American spammers will just move their operations abroad. The FBI knows this very well, so I reckon they're just making noise and spewing hot air in an effort to look like they're on top of the problem, when really they're not.
The question I have is why did she fake it? I mean, the story says she went in the standard Chernobyl tourist ride with a helmet, in order to fake photos, so it was a deliberate, planned deception.
So why did she take the pain to do all this? I doubt it's the money, since she didn't sell her story AFAIK, and I doubt she wants to promote some form of radioactive tourism. So, unless she's completely mythomaniac and/or she really really wanted to delude herself that she had made the trip for real, I just don't get it...
Dillo is a fast, small footprint, neat little web browser.
I still use Moz mail for my mail though, but that's mainly because I have megabytes of old mail in hundreds of folders and I want to keep accessing them.
Traditional TLDs have passed into everyday english. When you phone someone and say "hey here's my email: xyz at something dot com". People on the other end kind of expect a "dot com" to end the email. They can tolerate a "dot net" or "dot org" because they're very common (less so for emails). National TLDs are common too, for the nationals concerned, and other people in the world who see them regularly.
But "john at cia dot info"? "robert at shackled dot mobi"? these extensions are so uncommon nobody wants them in their emails, or FQDNs, because almost invariably people go "uh?" hearing them. They just don't stick.
New TLDs are a catch-22 problem: people won't use them because they sound alien, and they sound alien because people don't use them.
Some of those kids' parents need to just slap those brats across the face!
Either that of lock them up in their rooms and tell them they can get out and have dinner only when they hit 10000 at Tetris. Who knows, the brats might get to like older games after several hours of it.
Not only computers may not give fair grades, but there's a deeper problem with grading using computers: to me, students working to get good grades from a computer conjures up images of sheeps going in the wool-extraction machine. While this may be fine for sheeps, how do you think the students feel about it?
When I was in school, I was glad to know whatever essay I was writing was being read by my teacher, whom I had real human student/teacher relationships with, and whom I could discuss whatever was or wasn't right in the essay after class. The schooling system already lacks humanity, why de-humanize it even more?
0.03 % performance increase with the new, latest, more expensive system.
Yes, but with any luck the new system won't need expensive warranty calls and won't make its designers look like retards.
More seriously though, if NASA was Microsoft, ESA would be the new Linux community : they're copying Hubble with Webb, and GPS with Galileo, more or less to say "Space isn't all Americano/Russian anymore". It's me-too technology, primarily. Not to say that it won't yield interesting results however...
Let me get this straight... I won't get hacked because I leave my computers open to hackers?
Perhaps he's hoping that real hackers (not crackers/pirates) will see him as the lame dipstick he is, take pity on him and leave him alone, to move on to more challenging hacking...
Re:Go view the salon day pass.. then read this
on
Safe and Insecure?
·
· Score: 2, Insightful
If it ever comes down to a lawsuit, who can be certain that I was the offender? And can the victim of hacking be held responsible for the hacker's crimes?
Yes you Honor, the police found a girl's dead body in the trunk of my car, but then, I leave the doors open and the key on the ignition all the time, so how can you be certain it was me?
Sad for Open Source primarily. Astroturfind is the sort of activity you expect from corporations like Microsoft, but I would much prefer F/OSS (and the industries it created) to flourish on its own merits, just to prove to the world that there is no need for dirty tricks when the software and development methods are good.
in which New York City is treated to a 10,000-year-long ski season
If this is to happen, I hope there's a massive earthquake crust movement to tilt the city a bit...
Clients are available for various varieties of Microsoft Windows, but none are listed for other OSes.
If I was to make a program that basically asks of people to give me something for free (in this case, CPU time, and a little aggravation to install the client), I'd make the Linux/*BSD client a priority, since those OSes have been made almost entirely by people on their own time for free.
At least I'd know I'd be likely to find a sympathetic hear to whatever cause my client serves in that community.
Slashdot Mirror
I came up with a general number -- 1.5 kilowatts, this is about the amount of energy you would need to propel a small car (like a volkswagon beetle, old variety).
:-)
Even small older cars like the VW beetle have engines that put out between 20 and 40kW. That much isn't needed to cruise, only a minimal part of the engine's power is needed to overcome air and tire friction at the speeds such cars typically go, but the engine needs to be able to accelerate the car from standstill in a reasonable amount of time.
That's the idea behind hybrid cars: they have smaller engines that couldn't accelerate the car alone, but they charge up batteries that are able to provide temporary power surges for accelerations. Smaller engines == smaller gas consumption.
Anyhow, that's not quite 1.5kW
Can't you use fresnel along with photvoltaic to improve the power of the photovoltaics? Maybe not this size of fresnel, but smaller, cheaper ones to get a boost on your cells.
If you pair a photovoltaic panel to the same size fresnel lens, no because you'll just have concentrated the same amount of light on a tiny bit of the photovoltaic panel instead of having the same power spread on the entire surface. You can however increase the power to a smaller panel, because then you concentrate on this smaller surface the power gathered by the larger lens.
There's a limit to how much you can concentrate the solar light onto the solar panel before destroying the panel though. For this to work, you'd probably have to keep the solar panel out of the lens' focal point, and if your lens is really big, cool the panel with water or something (their efficiency is higher when they're cool).
I wish I knew the math to this, but damn, if it could provide even a small fraction of the power I use during the daytime... (by this, I mean 5-10%)
- In bright summer daylight, at noon the sun provides 1200W/m2
- This fresnel lens is 80x100, so captures 1200 * 0.8 = 960W at best
- A good steam engine, with a condenser and exhaust reheater provides has an efficiency of about 30%, so it would give 960 * 0.3 = 288W in mechanical power
- A good alternator, going at its preferred RPM (not necessarily that of the steam engine's prefered RPM, but let's assume) has an efficiency of about 90%, so it would give 288 * 0.9 = 260W
So you'd get 260W in the best possible conditions, in the brightest of days, in summer, at midday. Throw some clouds and, assuming the entire thing doesn't stall and stays at its nominal efficiency (not likely, but let's assume), you get about 6 times less power, so about 43W
In short, you're better off with solar panels: perhaps a little less efficiency for the same price, but more surface and a lot less aggravation.
Chalk actually burns under this thing.
Chalk burns eh? Creative chemistry, more like it. Here's another fun thing you can do: drop your "burnt" chalk in a glass half-full of water, let it bubble, and put your finger in it. Let me know how it feels.
So do aluminum cans. They smell really bad.
Aluminium doesn't smell bad when it burns. I suspect whatever soda pop chemicals remaining in the can do.
It seems that normal concrete will start emitting plumes of smoke just before it pops
As would burning tar, or any other heavy petroleum derivate.
* Mike's car.
Well, not yet. But it's plastic, so it would go up in no time at all. Or maybe we could just shrink-wrap the body around the frame.
Try focusing the lens on the round plastic thing that smells funny, on the rear side of the car...
Seriously, this article is all about playing with a new destructive toy and not much about using the toy in question to do interesting science-related experiments.
In his email, Linus said that Brown never contacted him. No email, no phone call, no personal interview. Nothing. Considering the fact that Brown was writing an explosive book in which he accused Linus of not being the author of Linux, you would think a serious author would at least confront the subject with the accusation and give him a chance to respond. What kind of a reporter talks to people on the periphery of the subject but fails to talk to the main player?
Hmmm, duh!
How many "explosive" books on Diana were published without giving Diana a chance to respond in the book?
Dragging someone's name into the dirt in a book and not including an interview of that person in the book is the hallmark of a trashy book. But then, we all knew it, since it's a Microsoft PR ploy ultimately, so no surprise there.
IBM - effectively the Microsoft of the 80s
Not so. IBM was called the benevolent dictator, and that since way before the 80s. I don't think I've ever seen Microsoft been called benevolent by any sane person...
Seriously, who cares anymore?
People have said the same thing about the Dallas series, yet it kept going and going and going.
You have to realize it's not about justice, or what the fate of Linux will be, or putting the GPL to the test, or anything. The SCO affair has become a entertaining sitcom for Linux people, and a way for them to vent their (perceived) frustration by beating the dead horse again and again.
(and also a way for Slashdot to fill up on slow days).
Hayabusa, which is Japanese for "falcon", will act much like its namesake, descending to the asteroid's surface, capturing its prey and returning it to Earth.
Presumably it'll let go of it before coming back? otherwise it'll be the biggest space sample ever collected.
How will I get my p3n1s enlarged?
And you think that's bad? Look, my business partner in Nigeria, Mr. Adewale Johnson, read the above Slashdot article and got scared. I haven't heard a word from him since the article was posted. It's a bummer actually because I had just sent him $10K to pay for his lawyer's fees, and I was waiting for his confirmation that he wired me the $20M.
Personal message: Dr. Johnson, don't be scared by Slashdot, the article doesn't apply to you, only crooks. Please talk to me, I await your response eagerly. -- Your business partner!
the FBI told Congress on Thursday that it has 'identified over 100 significant spammers
That's very nice, but the fact remains that 90% of all spam originates from countries that are out of the FBI's jurisdiction. What are they going to do about it?
It nothing else, American spammers will just move their operations abroad. The FBI knows this very well, so I reckon they're just making noise and spewing hot air in an effort to look like they're on top of the problem, when really they're not.
I don't think so. As far as I know the Amazon patent covers only buying with one click
So if I tried to corrupt a congressman with this system, then I guess Bezos could sue the EFF.
The question I have is why did she fake it? I mean, the story says she went in the standard Chernobyl tourist ride with a helmet, in order to fake photos, so it was a deliberate, planned deception.
So why did she take the pain to do all this? I doubt it's the money, since she didn't sell her story AFAIK, and I doubt she wants to promote some form of radioactive tourism. So, unless she's completely mythomaniac and/or she really really wanted to delude herself that she had made the trip for real, I just don't get it...
lets Slashdot readers (and others) write to their Congresscritter with one click,
In other news: Amazon sues the EFF
Dillo is a fast, small footprint, neat little web browser.
I still use Moz mail for my mail though, but that's mainly because I have megabytes of old mail in hundreds of folders and I want to keep accessing them.
Traditional TLDs have passed into everyday english. When you phone someone and say "hey here's my email: xyz at something dot com". People on the other end kind of expect a "dot com" to end the email. They can tolerate a "dot net" or "dot org" because they're very common (less so for emails). National TLDs are common too, for the nationals concerned, and other people in the world who see them regularly.
But "john at cia dot info"? "robert at shackled dot mobi"? these extensions are so uncommon nobody wants them in their emails, or FQDNs, because almost invariably people go "uh?" hearing them. They just don't stick.
New TLDs are a catch-22 problem: people won't use them because they sound alien, and they sound alien because people don't use them.
Some of those kids' parents need to just slap those brats across the face!
Either that of lock them up in their rooms and tell them they can get out and have dinner only when they hit 10000 at Tetris. Who knows, the brats might get to like older games after several hours of it.
I mean look, their built their success on great game names like Mario and Zelda back in 1981, and since then, they've...
Nevermind...
Not only computers may not give fair grades, but there's a deeper problem with grading using computers: to me, students working to get good grades from a computer conjures up images of sheeps going in the wool-extraction machine. While this may be fine for sheeps, how do you think the students feel about it?
When I was in school, I was glad to know whatever essay I was writing was being read by my teacher, whom I had real human student/teacher relationships with, and whom I could discuss whatever was or wasn't right in the essay after class. The schooling system already lacks humanity, why de-humanize it even more?
0.03 % performance increase with the new, latest, more expensive system.
Yes, but with any luck the new system won't need expensive warranty calls and won't make its designers look like retards.
More seriously though, if NASA was Microsoft, ESA would be the new Linux community : they're copying Hubble with Webb, and GPS with Galileo, more or less to say "Space isn't all Americano/Russian anymore". It's me-too technology, primarily. Not to say that it won't yield interesting results however...
Let me get this straight...
I won't get hacked because I leave my computers open to hackers?
Perhaps he's hoping that real hackers (not crackers/pirates) will see him as the lame dipstick he is, take pity on him and leave him alone, to move on to more challenging hacking...
If it ever comes down to a lawsuit, who can be certain that I was the offender? And can the victim of hacking be held responsible for the hacker's crimes?
Yes you Honor, the police found a girl's dead body in the trunk of my car, but then, I leave the doors open and the key on the ignition all the time, so how can you be certain it was me?
Come on, this must be a joke...
Great, now EVERY blog out there that talks about Java is slashdotted...
How much do you bet they run on Java too?
This explains that...
Sad for Open Source primarily. Astroturfind is the sort of activity you expect from corporations like Microsoft, but I would much prefer F/OSS (and the industries it created) to flourish on its own merits, just to prove to the world that there is no need for dirty tricks when the software and development methods are good.
This is just sad. Shame on JBoss...
in which New York City is treated to a 10,000-year-long ski season If this is to happen, I hope there's a massive earthquake crust movement to tilt the city a bit...
Clients are available for various varieties of Microsoft Windows, but none are listed for other OSes.
If I was to make a program that basically asks of people to give me something for free (in this case, CPU time, and a little aggravation to install the client), I'd make the Linux/*BSD client a priority, since those OSes have been made almost entirely by people on their own time for free.
At least I'd know I'd be likely to find a sympathetic hear to whatever cause my client serves in that community.