What's the difference between a normal jet engine and a scramjet?
Almost everything. Normal jet engines have lots of moving parts - turbines, compressors, etc. Ramjets and scramjets don't have any moving parts. They also require very high velocities to work properly, whereas a turbojet/turbofan is quite happy running all day long without moving.
That link is a quick overview of the Blackbird, including a bit of info about the engines. Ram air definitely plays a big part. Anyone know if those "ejector nozzles" are what I'd call an afterburner, or is the afterburner included in the "basic engine itself?" It sounds like they're the ramjet portion, but...
There's speculation that the donuts-on-a-rope photos that were in Aviation Leak a few years back were created by a Pulse Detonation Wave engine. The donuts imply distinct combustion pulses (like in an internal combustion engine, only much slower), as opposed to continuous combustion (turbine).
Another theory is that the donuts are some sort of weapon; the "rope" is the contrail left by the aircraft's engines, and the donuts are exhaust pulses from a gun or something.
What it comes down to is that like you said, nobody knows what created the phenomenon.
Aha! Modes sound good at first, but they're not necessarily the way to go; Jef Raskin does a far better job explaining why than I could in The Humane Interface. At first glance modes are great, but they quickly get in the way (Win2k's adaptive menus or whatever they're called, for example). Some people swear by them, but for the masses modes are just one more thing they have to learn/will get confused by.
FWIW Jef Raskin is one of the guys behind the original Macintosh interface. Perhaps more interestingly, he's also a cognitive psychologist - as a result, he has a very different point of view than most UI folk. The book is a bit dry at times, but nonetheless should be required reading for anyone even thinking about designing user interfaces.
Re:while we're at it, let's burn our Makefiles too
on
Subversion Hits Alpha
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· Score: 4, Interesting
...and there's always ant, from the folks over at jakarta.apache.org. It's aimed at java development, but can be used with other languages as well.
Ant has some pretty cool features (and a few misfeatures, sadly), but it's really caught on in Java-land.
Well, I guess we've each different experiences then. Of the several dozen gfx cards I've come in contact with over the years, only the NVidia cards have given me any shit. ATI's drivers have been butt-slow, but they worked.
Is there really anybody here that hasn't bought one? Personally I buy their cards because they're the best.
me
but then again, what do I know.
NVidia's cards might be the best, if you define "best" as "most FPS in Quake". They're not "best" if you care about things like accurate color, stable drivers (several of my cow-orkers have shiny new laptops with NVidia chipsets/drivers that bring the things down every hour or two), etc. ATI still has them beat there, as do other manufacturers.
And yes, money talks. If people like something but nobody buys it, that something is usually considered a failure. In this case, sending a friendly thank-you note to NVidia along with your order is probably a good course of action...
save your money and get a 7500/7600
on
Mac PVR Coming Soon
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· Score: 4, Insightful
I have a Powermac 7600, which shipped with built-in RCA audio + video inputs, as well as an S-Video input. The video quality is excellent (for a consumer device), and it does full-screen (640x480) playback without any of the ugliness I've seen from most USB capture devices. Granted, this new doodad seems to do MPEG-1 encoding on the device, but I'll take a raw stream over MPEG any day.
So that's the video input part, on a machine that's 6+ years old. The Tivo part can be done with a bit of script magic (Applescript, perl, whatever) or tools like BTV from bensoftware. You can encode to MPEG/cinepak/whatever on the fly, or later on. If you don't need the Tivo part, Apple's software does a good job of recording things.
Total cost is about $50 these days, and I'll bet the quality is better.
There's one more thing you need: JDOM. It's basically a wrapper for XML parsers that make manipulating XML in Java much less painful. It's good enough, in fact, that Sun has adopted it as a JSR (JSR 102, I think). I bumped into it a few months ago, and it's already made a huge difference in terms of productivity. With JDOM you spend less time worrying about all the oddities of the DOM or the limits of SAX - instead you mess with good ol' Java objects and JDOM does the rest.
What you refer to as stored procedures can be emulated with the greatest of ease in MySQL with a bit of Perl scripting and mod_perl.
That's nice, but most DBAs (that I've met, at least) don't speak Perl. They speak various dialects of SQL. Hell, a lot of engineers I know don't speak Perl. MySQuirreL needs real stored procedures, not workarounds. It's not "greatest of ease" if you have to learn a new language (esp. if that language is Perl!!)
If only MySQueeL supported stored procedures, subselects, etc
Yeah, I know there's support for subselects in the 4.1 dev tree, and I know there are workarounds for both SPs and subselects. I don't want workarounds, I want the damn feature!
Oh well, I guess I should be happy that they finally support transactions, sort of.
Don't worry about stability. Of course they've solved those problems. If people can make the X-29 fly, they can make the blended wing fly (let's gloss over the fact that flying wings have been around for 50+ years).
FWIW, the X-29 is a highly manoeuverable experimental aircraft. One of the reasons it's so agile is that it's instable - so much so that it requires a computer to fly it; people aren't capable of controlling it. Same goes for the F-117 (nickname: the wobbly goblin). Stability is an old problem; computers are usually pretty good at that type problem.
Dear sir,
That was one of the most informative posts I have seen on Slashdot in a long time, perhaps since the days of TheGloriousMeept! It truly captures the spirit of discussion.
Thank you again kind sir,
me
while the slowest take home little more than a dollar, still slightly higher than the pay of a local policeman
It's kind of hard to be exploiting someone if they're willingly doing the job - especially if you're paying them more than they would otherwise earn. This is why the so-called sweatshops in Southeast Asia are so popular among the workers there - they get paid a fortune compared to what they would otherwise earn (yes, mothers and fathers in Indonesia, etc. actually dream that someday their kids will make clothes for Nike!)
Aetna's not exploiting anyone, it's a mutually beneficial situation. Everyone wins, with the possible exception of the person in Oklahoma or wherever that would have been paid the $6/hr (they should work at Walmart anyway, better pay + benefits).
The problem is that broke their own rules when going from os9 to osX. Finder commands which have been constant since System 7 changed for no good reason: want to create a new folder? Command-N doesn't do it anymore, that opens a new Finder window - Shift-Command-N is your new keyboard shortcut now
Believe it or not, Apple had a really good reason for changing the "New Folder" shortcut. In virtually every other application, "Cmd-N" means "New Window." Apple decided that the Finder wasn't so special that it needed to break the standard, so they made Cmd-N behave just like every other application out there. Type Cmd-N anywhere, and you know what you get: a new window. Consistency is good, and Apple fixed a consistency problem by making Cmd-N open a new window instead of create a new folder. Sure it took 2 days to teach my fingers the difference, but they were right to make the change.
Re:standardized locations, etc.
on
Is RPM Doomed?
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· Score: 3, Informative
One of the problems you bump into with standard, one-size-fits-all packages is that APIs change, and bugs get fixed/introduced. Assume package A v1.2 was compiled against package B v3.6. Now package C comes along. Package C needs package B v4.0, so it upgrades package B. In the switch from v3.7 to v4.0, however, the API changed and a misfeature was corrected. Now assume package A relies on the old API and the presence/functionality of the misfeature. Now assume package A is no longer actively developed.
This situation (and ones like it) happen all the time. That's one reason why programs often get their own copy of a library, even though it sucks from an end-user standpoint.
Nevertheless, you're right....versioning needs to be better.
Arguably better than Cruise Control is Anthill, which is a continuous build tool that takes a different approach. Unlike CC, Anthill, doesn't require you to muck with your project's build script - it works with your existing scripts, which is a big plus for me.
Even more important is Anthill's support for multiple projects, complete with dependency graphs. Support for multiple projects is such a must-have feature (for me, anyway) that choosing Anthill over CC was a no-brainer. It's even open-source, so you can tweak it to your heart's content.
Funny you should bring up Xerox....rumor has it that color copiers have special circuitry to prevent counterfeiting money, and JJ Johnson (Nevada libertarian candidate for senate) seems to think that copiers print an invisible serial # on every copy you make, allowing the feds to trace it if necessary. The imprint goes there even if you're not copying anything illegal. I have no idea if any of this is true, but it wouldn't surprise me...
OSX supports software RAID, even at the consumer level. Put in 2 or more disks, and you can stripe/mirror all you want. The new servers have 4 independent IDE channels...it's a safe bet that you'll be able to set up a RAID. Maybe not RAID 5, but that's what you buy the forthcoming fiber channel storage device for. In any case, how is built-in RAID a rip-off?
You're not the target market for these servers. The target market is education, science (biotech), and creative professionals (video, audio, etc). They want these. Desperately.
As for Joe Consumer....there's what, 6 people who want a "rackmount for the rest of us"? For starters, you need a rack to put it in....
Slashdot Mirror
Almost everything. Normal jet engines have lots of moving parts - turbines, compressors, etc. Ramjets and scramjets don't have any moving parts. They also require very high velocities to work properly, whereas a turbojet/turbofan is quite happy running all day long without moving.
Yup - sort of.Studies have shown that less than 20 percent of the total thrust used to fly at Mach 3 is produced by the basic engine itself. The balance of the total thrust is produced by the unique design of the engine inlet and "moveable spike" system at the front of the engine nacelles and by the ejector nozzles at the exhaust which burn air compressed in the engine bypass system.
That link is a quick overview of the Blackbird, including a bit of info about the engines. Ram air definitely plays a big part. Anyone know if those "ejector nozzles" are what I'd call an afterburner, or is the afterburner included in the "basic engine itself?" It sounds like they're the ramjet portion, but...
Another theory is that the donuts are some sort of weapon; the "rope" is the contrail left by the aircraft's engines, and the donuts are exhaust pulses from a gun or something.
What it comes down to is that like you said, nobody knows what created the phenomenon.
This is hilarious, someone mod it up
FWIW Jef Raskin is one of the guys behind the original Macintosh interface. Perhaps more interestingly, he's also a cognitive psychologist - as a result, he has a very different point of view than most UI folk. The book is a bit dry at times, but nonetheless should be required reading for anyone even thinking about designing user interfaces.
Ant has some pretty cool features (and a few misfeatures, sadly), but it's really caught on in Java-land.
Well, I guess we've each different experiences then. Of the several dozen gfx cards I've come in contact with over the years, only the NVidia cards have given me any shit. ATI's drivers have been butt-slow, but they worked.
me
but then again, what do I know.
NVidia's cards might be the best, if you define "best" as "most FPS in Quake". They're not "best" if you care about things like accurate color, stable drivers (several of my cow-orkers have shiny new laptops with NVidia chipsets/drivers that bring the things down every hour or two), etc. ATI still has them beat there, as do other manufacturers.
And yes, money talks. If people like something but nobody buys it, that something is usually considered a failure. In this case, sending a friendly thank-you note to NVidia along with your order is probably a good course of action...
So that's the video input part, on a machine that's 6+ years old. The Tivo part can be done with a bit of script magic (Applescript, perl, whatever) or tools like BTV from bensoftware. You can encode to MPEG/cinepak/whatever on the fly, or later on. If you don't need the Tivo part, Apple's software does a good job of recording things.
Total cost is about $50 these days, and I'll bet the quality is better.
There's one more thing you need: JDOM. It's basically a wrapper for XML parsers that make manipulating XML in Java much less painful. It's good enough, in fact, that Sun has adopted it as a JSR (JSR 102, I think). I bumped into it a few months ago, and it's already made a huge difference in terms of productivity. With JDOM you spend less time worrying about all the oddities of the DOM or the limits of SAX - instead you mess with good ol' Java objects and JDOM does the rest.
That's nice, but most DBAs (that I've met, at least) don't speak Perl. They speak various dialects of SQL. Hell, a lot of engineers I know don't speak Perl. MySQuirreL needs real stored procedures, not workarounds. It's not "greatest of ease" if you have to learn a new language (esp. if that language is Perl!!)
Yeah, I know there's support for subselects in the 4.1 dev tree, and I know there are workarounds for both SPs and subselects. I don't want workarounds, I want the damn feature!
Oh well, I guess I should be happy that they finally support transactions, sort of.
FWIW, the X-29 is a highly manoeuverable experimental aircraft. One of the reasons it's so agile is that it's instable - so much so that it requires a computer to fly it; people aren't capable of controlling it. Same goes for the F-117 (nickname: the wobbly goblin). Stability is an old problem; computers are usually pretty good at that type problem.
Dear sir, That was one of the most informative posts I have seen on Slashdot in a long time, perhaps since the days of TheGloriousMeept! It truly captures the spirit of discussion. Thank you again kind sir, me
"Doctor, it hurts when I do this..."
while the slowest take home little more than a dollar, still slightly higher than the pay of a local policeman
It's kind of hard to be exploiting someone if they're willingly doing the job - especially if you're paying them more than they would otherwise earn. This is why the so-called sweatshops in Southeast Asia are so popular among the workers there - they get paid a fortune compared to what they would otherwise earn (yes, mothers and fathers in Indonesia, etc. actually dream that someday their kids will make clothes for Nike!)
Aetna's not exploiting anyone, it's a mutually beneficial situation. Everyone wins, with the possible exception of the person in Oklahoma or wherever that would have been paid the $6/hr (they should work at Walmart anyway, better pay + benefits).
Believe it or not, Apple had a really good reason for changing the "New Folder" shortcut. In virtually every other application, "Cmd-N" means "New Window." Apple decided that the Finder wasn't so special that it needed to break the standard, so they made Cmd-N behave just like every other application out there. Type Cmd-N anywhere, and you know what you get: a new window. Consistency is good, and Apple fixed a consistency problem by making Cmd-N open a new window instead of create a new folder. Sure it took 2 days to teach my fingers the difference, but they were right to make the change.
This situation (and ones like it) happen all the time. That's one reason why programs often get their own copy of a library, even though it sucks from an end-user standpoint.
Nevertheless, you're right....versioning needs to be better.
Thank you, Captain Obvious!
Even more important is Anthill's support for multiple projects, complete with dependency graphs. Support for multiple projects is such a must-have feature (for me, anyway) that choosing Anthill over CC was a no-brainer. It's even open-source, so you can tweak it to your heart's content.
Funny you should bring up Xerox....rumor has it that color copiers have special circuitry to prevent counterfeiting money, and JJ Johnson (Nevada libertarian candidate for senate) seems to think that copiers print an invisible serial # on every copy you make, allowing the feds to trace it if necessary. The imprint goes there even if you're not copying anything illegal. I have no idea if any of this is true, but it wouldn't surprise me...
And while you're at it, pick up a congressman or two
OSX supports software RAID, even at the consumer level. Put in 2 or more disks, and you can stripe/mirror all you want. The new servers have 4 independent IDE channels...it's a safe bet that you'll be able to set up a RAID. Maybe not RAID 5, but that's what you buy the forthcoming fiber channel storage device for. In any case, how is built-in RAID a rip-off?
As for Joe Consumer....there's what, 6 people who want a "rackmount for the rest of us"? For starters, you need a rack to put it in....
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