Fact: Buttered bread always falls butter-side down. Fact: Cats always land on their feet.
Sythesis: By strapping buttered bread on the backs of millions of cats and dropping them, all cat-bread entities will stop short of landing on the ground and hover over the ground while spinning.
I propose a monorail to be constructed bridging New York and Los Angeles which is powered by these cat-bread systems.
That's right, I said don't rip the DVDs. While this solution would be slower and more difficult to setup, this is Slashdot. Geek factor counts.
Buy some LEGO blocks and an RCX set. Build a tower to hold the dvds and a crawler to traverse the rack, pick off the right dvd, open, close, load and unload the drive. Actual implementation is left as an exercise for the reader.
A wing profile is the cross-sectional area of the wing. You're probably thinking of the planform shape, which is the shape you see when looking straight down (or up) at the plane. The profile is the shape when looking at a section of the wing from the side.
Also, winglets don't contribute much to stability. They reduce the rate at which air flows from the bottom of the wing to the top at the edges. The difference in pressures, which causes the lift, can't simply jump from low to high... there must be a gradient. Winglets make the gradient sharper, and therefore the difference in pressures remains high over a greater portion of the wing area. Not only that, but it also decreases the magnitude of trailing vortices, which contribute significantly to overall drag. Typical trailing subsonic trailing vortices contribute to about 25% of the total drag.
-carambola5, your friendly neighborhood aeronautical engineer
There is nothing that says that this thing cannot fly ever. Sure, there are many calculations to perform, but the design isn't inherently unusable.
First of all, the main thing to notice is the lack of a tail. The main difficulty with the lack of a tail is that you need to balance both Cm (moment coefficient) and AOA (angle of attack) with the trailing edge of the same airfoil, namely the wings. While possible, it's not an easy thing to do. Essentially, for the vehicle to be stable, it needs to have a positive pitching moment at zero AOA (Cmo) and a negative derivative of the pitching moment with respect to AOA (Cmalpha). With a flying wing, the positive Cmo is not difficult to achieve, it's the negative Cmalpha that's difficult. Think of it this way, if the plane is disturbed such that the nose goes up (ie: updraft), the plane needs to have the nose tend down. Tails are really good for this, but without a tail, it's pretty difficult.
The simplest solution is to push back the aerodynamic center (AC) of the wing. Since most wing profiles have an AC at about 1/4 chord (25% from leading edge) for subsonic applications, a profile not used commonly must be used. Once again, this can be done... it's just not very common.
The winglets are a nice touch... helps decrease downwash and therefore overall lift. That, and I think winglets are sexy.
Gone are the times when the floppy is the only rescue tool for a b0rked computer. Bootable CDs and USB drives have fixed that. So why are they still around? For all intents and purposes, USB drives beat floppies in every respect: physical size, storage size, access time, mtbf.... the list goes on.
Please, can we stop calling it "nanotechnology" and start calling it what it really is?
CHEMISTRY!
I'm not trying to be funny. That new stain-defender stuff in pants? Apparently it's called nanotechnology. No! Chemistry! It's just chemistry! Stop subjecting your minds to buzzwords.
so if there's a temperature gradient at different depths
Check it out: http://lter.limnology.wisc.edu/slrecent.htm
That's for a Wisconsin Lake. As you can see, during the warm to semi-warm months, there is a definite drop in temperature between 10 and 15 meters in depth. And this is for a temperate lake... imagine the gradients in a tropical/sub-tropical ocean.
So the question is not if there's a temperature gradient, it's how big is the temperature gradient. And going by this data, 10 degC is plenty for these suckers.
Disclaimer: I didn't design the site. Though I did consider building one of these gliders once. And for much less than $60k. The overall cost for a hacked-together glider is around $200. Though the knowledge to do it efficiently could cost you nearly $60k in college tuition.
Haven't we learned that introducing a foreign species to rid a different species is usually a Bad Idea? I work with fish ecologists, and I have never heard them say, "You know, Bob, that introduction of carp to the lake cleaned out that pesky perch problem. AND, the carp are so clean!"
You forgot to multiply by the number of computers. I'm sure many slashdotters (myself included) have more than one computer. Granted, they probably won't all be 3GHz P4s, but still...
So, that's 48 km/s relative to what? If it's correct to assume the writer meant "relative to Jupiter," then that is ridiculously fast. IIRC, typical orbits around Earth manage only ~8-10km/s.
Yes, I realize Jupiter is larger than Earth, but still...
If you dig deep enough, it's ranked 2 for Nuclear Engineering. That makes 3/. articles today. Now, if only there was an article on the top party schools... IIRC, UW is 2nd place this year.
Just write an ebuild and submit it to www.breakmygentoo.net
Or, if you have enough of a following, have one of your Gentoo-using minions to write the ebuild for you. Packages that are on breakmygentoo.net have the best exposure you can get while the auditing process on your package over at bugs.gentoo.org makes sure it can be a viable addition to the standard portage tree.
Kids will always find ways to outsmart their parents. It's called progress!
First of all, we are forgetting the rule that kids are always smarter than their parents when it comes to computers. Always. Next, enter the fact that kids could construct their own nets and attach a tag somewhere underneath their parents' cars.
Can you say "proximity alert"? Works a helluva lot better with a range of 1 or 2 miles compared to hearing the garage door open.
She hopes to become a character designer for a video game company and is convinced that even more women would play video games if there were more characters geared toward them.
This is something that has bothered me...well, barely bothered me, but bothered nonetheless. Why is it that almost every female video game character is, in some way, a sex object? I'd be perfectly content with playing a game that had, as a main character, a female that didn't have a rack bigger than her head. Tomb Raider immediately comes to mind.
OK, maybe a sorceress in Diablo qualifies, but you hardly get a good view of the character... Blizzard can afford to make the character unattractive because she's too small to matter. Seriously, when was the last time you played a game that had a male main character that, in another situation (ie: not shooting at bad guys), would be a sex object?
-Hi, Malaysia? Is this Malaysia? -Yes sir. You have reached the tourist center for Malaysia. How may I help you? -I need 500 CDs burned fast! -Excuse me sir? -Like I said, I need 500 CDs burned and shipped before Saturday. I read about your country's amazing capabilities to do something like this on Slashdot and I figured I'd give it a shot. -I'm sorry sir, this is a tourist hotline. -Don't get smart with me, buddy. I know for a FACT that all you guys up in Malaysia are in the CD pirating business. Don't make me turn you in. -I'd be happy to refer you to our Business Bureau. -You don't get it! I don't want a bureau. I want some CDs. Legal CDs! Linux CDs! And you guys have to make them. -I'm sorry sir, but I just can't help you. -Sheesh. What do I need to do to get your country to make some CDs for me? Do I need to bribe you? -Sir, you'll have to contact someone else for your needs. I can't help you. -Sure you can. You're from Malaysia, and Malaysia makes CDs. Now what's it gonna take? Twenty dollars? A few shiny trinkets? You Malaysians go for that kind of stuff, right? -<click>
OK, I know there are many cynics out there about the competition itself... as well as the number of links in my post. So here are some explanations:
Links: So I put a few too many links in there. Jeez, sorry. But don't the mods think it's a bit overkill to mod up more than one post that mentions this?
"Why an Explorer?": The goal of the competition is not to make the most fuel efficient car/truck (it used to be a FutureCar contest in the '90s) possible. The goal is to make the most fuel efficient car/truck given a certain make and model. There are very good reasons for this. As most of you know, the number of SUVs sold in the US is around 50% of all vehicles sold. Seriously, what would be the point of the teams developing a one-seat solar car that requires the driver to lay down? The competition is in place to attempt to ease the general public into a more fuel- and environment-friendly vehicle. You can't simply stop people from driving SUVs. But you can get them to drive better SUVs.
"Ford sucks/doesn't care/etc": First of all, the competition switches between GM and Ford vehicles every two years. Because of that, Ford and GM donate one car to each of 15 teams every other year. In addition to that, Ford sent each team 15 advisors from their own engineering pool to visit the teams. Ford also held the 9-day competition at their proving grounds. And yes, they are trying to incorporate these modifications. Unfortunately, it takes time and money to introduce a new technology which is vital the operation of the vehicle. We, as a university team, may do some optimizations, but Ford would take them to a level we couldn't achieve.
"Ford should use students": They do. Many of the graduates from our team go on to work for Ford or GM. And the posts about firing engineers and using free student labor are stupid. We do this for the recognition of our school... and for our resumes. We won't work for free for our whole lives.
"How much would it cost?": Well, our (UW-Madison) truck, IIRC weighed in at over $500.000 since it was a prototype (probably a lot more). But our analysis shows that putting all of our modifications into a stock vehicle would increase the cost only about $5000-6000. Oh, and I use the term "weighed in" loosely. The actual weight, including electric motor, batteries and other mods was below stock weight.... For UW at least.
Slashdot Mirror
Fact: Buttered bread always falls butter-side down.
Fact: Cats always land on their feet.
Sythesis: By strapping buttered bread on the backs of millions of cats and dropping them, all cat-bread entities will stop short of landing on the ground and hover over the ground while spinning.
I propose a monorail to be constructed bridging New York and Los Angeles which is powered by these cat-bread systems.
That's right, I said don't rip the DVDs. While this solution would be slower and more difficult to setup, this is Slashdot. Geek factor counts.
Buy some LEGO blocks and an RCX set. Build a tower to hold the dvds and a crawler to traverse the rack, pick off the right dvd, open, close, load and unload the drive. Actual implementation is left as an exercise for the reader.
A wing profile is the cross-sectional area of the wing. You're probably thinking of the planform shape, which is the shape you see when looking straight down (or up) at the plane. The profile is the shape when looking at a section of the wing from the side.
Also, winglets don't contribute much to stability. They reduce the rate at which air flows from the bottom of the wing to the top at the edges. The difference in pressures, which causes the lift, can't simply jump from low to high... there must be a gradient. Winglets make the gradient sharper, and therefore the difference in pressures remains high over a greater portion of the wing area. Not only that, but it also decreases the magnitude of trailing vortices, which contribute significantly to overall drag. Typical trailing subsonic trailing vortices contribute to about 25% of the total drag.
-carambola5, your friendly neighborhood aeronautical engineer
Time to think out of the box. Where do you think the CG of a typical airliner craft is? And where are the wings?
Answers:
1) just short of halfway up the fuselage.
2) near the bottom of the fuselage.
Just because hangliders work that way doesn't mean all aircraft do.
There is nothing that says that this thing cannot fly ever. Sure, there are many calculations to perform, but the design isn't inherently unusable.
First of all, the main thing to notice is the lack of a tail. The main difficulty with the lack of a tail is that you need to balance both Cm (moment coefficient) and AOA (angle of attack) with the trailing edge of the same airfoil, namely the wings. While possible, it's not an easy thing to do. Essentially, for the vehicle to be stable, it needs to have a positive pitching moment at zero AOA (Cmo) and a negative derivative of the pitching moment with respect to AOA (Cmalpha). With a flying wing, the positive Cmo is not difficult to achieve, it's the negative Cmalpha that's difficult. Think of it this way, if the plane is disturbed such that the nose goes up (ie: updraft), the plane needs to have the nose tend down. Tails are really good for this, but without a tail, it's pretty difficult.
The simplest solution is to push back the aerodynamic center (AC) of the wing. Since most wing profiles have an AC at about 1/4 chord (25% from leading edge) for subsonic applications, a profile not used commonly must be used. Once again, this can be done... it's just not very common.
The winglets are a nice touch... helps decrease downwash and therefore overall lift. That, and I think winglets are sexy.
Yes, I'm an aeronautical geek. Deal.
Gone are the times when the floppy is the only rescue tool for a b0rked computer. Bootable CDs and USB drives have fixed that. So why are they still around? For all intents and purposes, USB drives beat floppies in every respect: physical size, storage size, access time, mtbf.... the list goes on.
Never underestimate the power of stupid people in large groups.
AIM, Yahoo! and MSN are here to stay, folks.
Try making Aerogel in Zero G under a 45 second time constraint. Now that takes talent.
Does anyone else get the feeling that these people are just saying "It's too hard. We give up" ?
Please, can we stop calling it "nanotechnology" and start calling it what it really is?
CHEMISTRY!
I'm not trying to be funny. That new stain-defender stuff in pants? Apparently it's called nanotechnology. No! Chemistry! It's just chemistry! Stop subjecting your minds to buzzwords.
Sorry, but speaking from purely a capitalist's point of view, the keyword here is few. As cool as the technology is, it'll never take off.
Check it out: http://lter.limnology.wisc.edu/slrecent.htm
That's for a Wisconsin Lake. As you can see, during the warm to semi-warm months, there is a definite drop in temperature between 10 and 15 meters in depth. And this is for a temperate lake... imagine the gradients in a tropical/sub-tropical ocean.
So the question is not if there's a temperature gradient, it's how big is the temperature gradient. And going by this data, 10 degC is plenty for these suckers.
Disclaimer: I didn't design the site. Though I did consider building one of these gliders once. And for much less than $60k. The overall cost for a hacked-together glider is around $200. Though the knowledge to do it efficiently could cost you nearly $60k in college tuition.
Haven't we learned that introducing a foreign species to rid a different species is usually a Bad Idea? I work with fish ecologists, and I have never heard them say, "You know, Bob, that introduction of carp to the lake cleaned out that pesky perch problem. AND, the carp are so clean!"
SCO sells software?
You forgot to multiply by the number of computers. I'm sure many slashdotters (myself included) have more than one computer. Granted, they probably won't all be 3GHz P4s, but still...
So, that's 48 km/s relative to what? If it's correct to assume the writer meant "relative to Jupiter," then that is ridiculously fast. IIRC, typical orbits around Earth manage only ~8-10km/s.
Yes, I realize Jupiter is larger than Earth, but still...
Big day for University of Wisconsin.
/. articles today. Now, if only there was an article on the top party schools... IIRC, UW is 2nd place this year.
If you dig deep enough, it's ranked 2 for Nuclear Engineering. That makes 3
At least we'll only get sued for using Linux, rather than Linux and XviD.
Just write an ebuild and submit it to www.breakmygentoo.net
Or, if you have enough of a following, have one of your Gentoo-using minions to write the ebuild for you. Packages that are on breakmygentoo.net have the best exposure you can get while the auditing process on your package over at bugs.gentoo.org makes sure it can be a viable addition to the standard portage tree.
First of all, we are forgetting the rule that kids are always smarter than their parents when it comes to computers. Always. Next, enter the fact that kids could construct their own nets and attach a tag somewhere underneath their parents' cars.
Can you say "proximity alert"? Works a helluva lot better with a range of 1 or 2 miles compared to hearing the garage door open.
from the defeating-the-original-purpose-of-actually-hearin
Brilliant, guys. Simply stellar.
This is something that has bothered me...well, barely bothered me, but bothered nonetheless. Why is it that almost every female video game character is, in some way, a sex object? I'd be perfectly content with playing a game that had, as a main character, a female that didn't have a rack bigger than her head. Tomb Raider immediately comes to mind.
OK, maybe a sorceress in Diablo qualifies, but you hardly get a good view of the character... Blizzard can afford to make the character unattractive because she's too small to matter. Seriously, when was the last time you played a game that had a male main character that, in another situation (ie: not shooting at bad guys), would be a sex object?
-Hi, Malaysia? Is this Malaysia?
-Yes sir. You have reached the tourist center for Malaysia. How may I help you?
-I need 500 CDs burned fast!
-Excuse me sir?
-Like I said, I need 500 CDs burned and shipped before Saturday. I read about your country's amazing capabilities to do something like this on Slashdot and I figured I'd give it a shot.
-I'm sorry sir, this is a tourist hotline.
-Don't get smart with me, buddy. I know for a FACT that all you guys up in Malaysia are in the CD pirating business. Don't make me turn you in.
-I'd be happy to refer you to our Business Bureau.
-You don't get it! I don't want a bureau. I want some CDs. Legal CDs! Linux CDs! And you guys have to make them.
-I'm sorry sir, but I just can't help you.
-Sheesh. What do I need to do to get your country to make some CDs for me? Do I need to bribe you?
-Sir, you'll have to contact someone else for your needs. I can't help you.
-Sure you can. You're from Malaysia, and Malaysia makes CDs. Now what's it gonna take? Twenty dollars? A few shiny trinkets? You Malaysians go for that kind of stuff, right?
-<click>
does anyone else think that the quotes should be around "clarifies" in the title rather than "violations?"
OK, I know there are many cynics out there about the competition itself... as well as the number of links in my post. So here are some explanations:
Links: So I put a few too many links in there. Jeez, sorry. But don't the mods think it's a bit overkill to mod up more than one post that mentions this?
"Why an Explorer?": The goal of the competition is not to make the most fuel efficient car/truck (it used to be a FutureCar contest in the '90s) possible. The goal is to make the most fuel efficient car/truck given a certain make and model. There are very good reasons for this. As most of you know, the number of SUVs sold in the US is around 50% of all vehicles sold. Seriously, what would be the point of the teams developing a one-seat solar car that requires the driver to lay down? The competition is in place to attempt to ease the general public into a more fuel- and environment-friendly vehicle. You can't simply stop people from driving SUVs. But you can get them to drive better SUVs.
"Ford sucks/doesn't care/etc": First of all, the competition switches between GM and Ford vehicles every two years. Because of that, Ford and GM donate one car to each of 15 teams every other year. In addition to that, Ford sent each team 15 advisors from their own engineering pool to visit the teams. Ford also held the 9-day competition at their proving grounds. And yes, they are trying to incorporate these modifications. Unfortunately, it takes time and money to introduce a new technology which is vital the operation of the vehicle. We, as a university team, may do some optimizations, but Ford would take them to a level we couldn't achieve.
"Ford should use students": They do. Many of the graduates from our team go on to work for Ford or GM. And the posts about firing engineers and using free student labor are stupid. We do this for the recognition of our school... and for our resumes. We won't work for free for our whole lives.
"How much would it cost?": Well, our (UW-Madison) truck, IIRC weighed in at over $500.000 since it was a prototype (probably a lot more). But our analysis shows that putting all of our modifications into a stock vehicle would increase the cost only about $5000-6000. Oh, and I use the term "weighed in" loosely. The actual weight, including electric motor, batteries and other mods was below stock weight.... For UW at least.