You're right! It's For Hhe Children! And The Children are so Holy that nothing done in Their Name could possibly be evil! Let's think of more things to do For The Children!
The surveillance cameras violate my presumption of innocence. If my face happens to match the description of somebody who robbed a bank across town, that record will be used to "prove" that I robbed the bank. I will then have to prove that I did not. This is unacceptable.
You've also probably seen dozens if not hundreds of American tourists getting along just fine with the people in the country they're visiting, because they aren't acting like "American tourists".
So how about you give the stereotype a break? There are assholes in every country. Sometimes they travel. Let's move along.
There will be no cheap, environmentally friendly fusion power in 2004, and we'll have another year without widespread deployment of hydrogen fueled vehicles.
We'll also not see the Moon stop rotating around the Earth, nor will we see ESR go to work for Microsoft.
Wow, this is like a total lack of news. It's the polar opposite of news. It feels like there should be a new word. Anti-news?
Geeks (like me) need to get over their inferiority complex (which I did). Intellectual pursuits are not more or less worthy than physical ones...they're just different.
The Bill of Rights is (mostly) a list of things the US Government is not allowed to do. Since the 10 Commandments are not written by the US Government, it is not possible for the 10 Commandments to "violate" the Constitution.
The ethics and morals of the 10 Commandments may be different from those that inform the Constitution, indeed. But the Constitution expressly forbids the Government from preventing me from adhering to the 10 Commandments.
There sure is. When you're going Mach 10, the coefficient of lift you need to carry a body is very, very small. The dominant force on the body at high speed is wave drag. The wave drag is going to be at least two orders of magnitude bigger than the lift force.
That 4x number comes from a talk I attended at school, and I don't have my notes handy.
Re:A Third of the Way There...
on
X43-A on to Mach 10
·
· Score: 2, Informative
OK, that was a little too flip. More details.
Consider a coordinate system fixed to the aircraft, with a Mach 10 flow passing around it.
A scramjet (supersonic combustion ramjet) uses a series of oblique shock waves to compress (and slow down) air in order to get it to combust. In a ramjet, the throat of the engine sets up a shockwave perpendicular (normal) to the free stream velocity. Any time you have a so-called "normal" shock wave, the downstream flow is always subsonic. With an oblique shockwave (oblique relative to the free stream velocity), you can have that shock wave compress and slow down the flow, but it will remain supersonic.
The problem with ramjets is that as they get closer to around Mach 5 or 6, their drag starts increasing in a non-linear fashion (meaning that going a little faster gets you a lot more drag), because the normal shock wave won't permit the downstream air to go a little bit faster (since it MUST be subsonic).
So, you have to figure out a way to allow the flow in the combustion chamber to remain supersonic. To do this, you arrange for the airframe and the engine intake to set up a series of oblique shock waves that compresses the flow, but allows it to remain supersonic. You then attempt to start a fire in that supersonic airflow (imagine trying to light your zippo while holding it out a car window and multiply that difficulty by about a million).
That's a scramjet. The drag comes from all those shockwaves (hence wave drag) and is related to the frontal area of the aircraft (which usually looks rather like a doorstop in profile, the entire frontal area is basically the ramp to the inlet of the engine). Wave drag is proportional to the square of frontal area. (never mind the skin friction drag, which will get worse and worse as you go faster and faster and eventually make your airframe go melty melty).
To make matters worse, consider what would happen if you're hurtling along at Mach 10, and you make a sudden correction in pitch. In all likelihood, you're going to upset the carefully orchestrated shock waves that are making the air play nice in your engine. If you're lucky, the aircraft just slows down (HARD) and resumes stable operation. If you're unlucky, one of the shockwaves will become a normal shock wave at the narrowest part of your engine, and it will be exactly like you hit a mountain. At Mach 10.
Does that clear things up? Honest, I don't mean to be patronizing. I'm far from an expert on this subject, but I do know more than your average Joe.
True enough. For powered travel, it's pretty inconsequential, but for orbits it is indeed a factor.
Engineering is the art of knowing what you can safely ignore. : )
Re:Naively, it should be x16.
on
X43-A on to Mach 10
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· Score: 2, Informative
Interesting. My heat transfer book calls it convection.
according to Google's definitions:
Advection: " The horizontal transfer of any property in the atmosphere by the movement of air. Examples include heat and moisture advection. "
Convection: " fluid circulation driven by large temperature gradients; the transfer of heat by this automatic circulation. "
In my aerodynamics classes, we talked exclusively about heat transfer via convection (mostly forced convection, with a moving airflow, as opposed to freee convection with a still airflow.)
Atmospheric flight (where you have to worry about speed of sound) is all continuum mechanics. Above a certain altitude (150,000 feet, give or take) you stop worrying about the atmosphere very much.
Slashdot Mirror
So marketshare only doesn't matter in markets where Apple has a dominant marketshare?
OK, that's cool. Just making sure I understand the double standard.
It doesn't.
Hence my point.
So you don't think that constant surveillance has a chilling effect on freedom?
I sure am glad you didn't write the Constitution.
Hmmm...I wonder if the movie producers were working on the slow motion bullet thing before the movie ever came out. What an astonishing thought.
What if they didn't have video of the bank robber, but they DID have video of you near the bank, matching the bank robber's description?
Any bad system can, occasionally, be used for "good" purposes. However, the ends do not justify the means.
You're right! It's For Hhe Children! And The Children are so Holy that nothing done in Their Name could possibly be evil! Let's think of more things to do For The Children!
The surveillance cameras violate my presumption of innocence. If my face happens to match the description of somebody who robbed a bank across town, that record will be used to "prove" that I robbed the bank. I will then have to prove that I did not. This is unacceptable.
Freedom.
And we Americans get offended when you assume that we are all like those assholes that shout at old ladies.
How many courteous American tourists have you seen? Probably not many, since they actually blend into the background pretty well.
You've also probably seen dozens if not hundreds of American tourists getting along just fine with the people in the country they're visiting, because they aren't acting like "American tourists".
So how about you give the stereotype a break? There are assholes in every country. Sometimes they travel. Let's move along.
So since I speak English and French, I'm cooler than other humans?
Whatever. Penis measuring contests are never interesting.
You're right. Nothing means anything, day is night, black is white, and communication is fruitless.
Oh wait, you're a loony. Never mind.
There will be no cheap, environmentally friendly fusion power in 2004, and we'll have another year without widespread deployment of hydrogen fueled vehicles.
We'll also not see the Moon stop rotating around the Earth, nor will we see ESR go to work for Microsoft.
Wow, this is like a total lack of news. It's the polar opposite of news. It feels like there should be a new word. Anti-news?
No.
If Stephen Hawking can do it, it's not a sport.
Geeks (like me) need to get over their inferiority complex (which I did). Intellectual pursuits are not more or less worthy than physical ones...they're just different.
GPS used to guide Iraqi missiles? I'd love to see that guy's source for that. I call bullshit.
Guy sounds like a crank to me.
You really misunderstand the Constitution.
The Bill of Rights is (mostly) a list of things the US Government is not allowed to do. Since the 10 Commandments are not written by the US Government, it is not possible for the 10 Commandments to "violate" the Constitution.
The ethics and morals of the 10 Commandments may be different from those that inform the Constitution, indeed. But the Constitution expressly forbids the Government from preventing me from adhering to the 10 Commandments.
See?
There sure is. When you're going Mach 10, the coefficient of lift you need to carry a body is very, very small. The dominant force on the body at high speed is wave drag. The wave drag is going to be at least two orders of magnitude bigger than the lift force.
That 4x number comes from a talk I attended at school, and I don't have my notes handy.
OK, that was a little too flip. More details.
Consider a coordinate system fixed to the aircraft, with a Mach 10 flow passing around it.
A scramjet (supersonic combustion ramjet) uses a series of oblique shock waves to compress (and slow down) air in order to get it to combust. In a ramjet, the throat of the engine sets up a shockwave perpendicular (normal) to the free stream velocity. Any time you have a so-called "normal" shock wave, the downstream flow is always subsonic. With an oblique shockwave (oblique relative to the free stream velocity), you can have that shock wave compress and slow down the flow, but it will remain supersonic.
The problem with ramjets is that as they get closer to around Mach 5 or 6, their drag starts increasing in a non-linear fashion (meaning that going a little faster gets you a lot more drag), because the normal shock wave won't permit the downstream air to go a little bit faster (since it MUST be subsonic).
So, you have to figure out a way to allow the flow in the combustion chamber to remain supersonic. To do this, you arrange for the airframe and the engine intake to set up a series of oblique shock waves that compresses the flow, but allows it to remain supersonic. You then attempt to start a fire in that supersonic airflow (imagine trying to light your zippo while holding it out a car window and multiply that difficulty by about a million).
That's a scramjet. The drag comes from all those shockwaves (hence wave drag) and is related to the frontal area of the aircraft (which usually looks rather like a doorstop in profile, the entire frontal area is basically the ramp to the inlet of the engine). Wave drag is proportional to the square of frontal area. (never mind the skin friction drag, which will get worse and worse as you go faster and faster and eventually make your airframe go melty melty).
To make matters worse, consider what would happen if you're hurtling along at Mach 10, and you make a sudden correction in pitch. In all likelihood, you're going to upset the carefully orchestrated shock waves that are making the air play nice in your engine. If you're lucky, the aircraft just slows down (HARD) and resumes stable operation. If you're unlucky, one of the shockwaves will become a normal shock wave at the narrowest part of your engine, and it will be exactly like you hit a mountain. At Mach 10.
Does that clear things up? Honest, I don't mean to be patronizing. I'm far from an expert on this subject, but I do know more than your average Joe.
Note my sig.
No, but being a Congresscritter means that you bend over and take it from your big money lobbyists.
Unfortunately, We the People don't have big money lobbyists.
Great article! Thanks!
True enough. For powered travel, it's pretty inconsequential, but for orbits it is indeed a factor.
Engineering is the art of knowing what you can safely ignore. : )
Interesting. My heat transfer book calls it convection.
according to Google's definitions:
Advection: " The horizontal transfer of any property in the atmosphere by the movement of air. Examples include heat and moisture advection. "
Convection: " fluid circulation driven by large temperature gradients; the transfer of heat by this automatic circulation. "
In my aerodynamics classes, we talked exclusively about heat transfer via convection (mostly forced convection, with a moving airflow, as opposed to freee convection with a still airflow.)
Um, in space? : )
Atmospheric flight (where you have to worry about speed of sound) is all continuum mechanics. Above a certain altitude (150,000 feet, give or take) you stop worrying about the atmosphere very much.
Make a bigger one.
No pressure==no interaction between molecules==no sound waves.