Also, why can't I buy just the cable channels that I want? I currently get about 70 stations on basic cable, but I would be happy to trim them down to the 15 that I ever actually want. And yes I know some channels are more expensive than others: if I want ESPN, I'm willing to pay more for that channel than for C-SPAN 2. (And don't tell me they can't do this--they have no problem working it for the "premium" channels (e.g. HBO), so surely they could do it for all the channels like that.)
Fine, let's work from the frame of reference of the ground. The shuttle is moving at Vs. Let's restrict ourselves to the single vertical dimension and make Vs a positive scalar. The foam is moving at Vf, a negative quantity. Their combined impact speed is |Vs|+|Vf|. So if drag lowers Vf, it's lowering the speed of impact.
But the best way of looking at it is from the frame of reference of the shuttle, since that's what the v in.5mv^2 is in terms of. Then the shuttle isn't moving at all, though the air happens to be moving past it at a certain velocity Vs, which has a downwards direction. Now from the air's perspective (sky being up), the foam has a certain downward velocity Vf due to gravity. Moving back to the shuttle's frame of reference, the air is moving Vs, which means the foam is moving Vs+Vf, and they're both in the same direction so it takes us right back to what we got in the last paragraph.
Because they were embarrassed enough to lose Challenger when they launched it in temperatures lower than those in which they were confident, and they don't want to bring up the possibility that it happened again with Columbia.
But the foam wasn't moving 500 mph relative to the orbiter. It had only fallen 30 ft (10 m). Given that the crew never experience more than 3 Gs of acceleration, the maximum acceleration of the foam was 40 m/s^2 towards the wing. Assuming no drag on the foam, it took 1/sqrt(2)=0.7 seconds for it to travel, so it hit at a velocity of 28 m/s. This gives it at most 310 J of kinetic energy at time of impact. This is equivalent to a tenth of a gram of TNT according to your numbers for TNT energy.
A 100-W incandescent bulb uses that amount of energy in three seconds. This leads us to two conclusions: (a) don't use incandescent light, and (b) the shuttle can be damaged with relatively little energy.
I don't claim to be an expert PHP developer, but I have spent a fair amount of time with it. Here's what I've found works:
Every file includes base.inc.
base.inc includes a config file based on the hostname and port--this is to allow you to use the same code to run both testing and production servers. These config files are where you keep stuff like the directories in which to store files, the database config, and so on.
Use PEAR as much as you can. In particular, use PEAR::DB. Since you probably use the DB in every request, open it up in base.inc and store it in a global. Also, you never know when you'll switch to a different RDBMS, and if you have to modify every single call...
On that note, use PHP OO to abstract away the DB. Do it logically, not "one class per table". This way, when you change the database or even just the schema, only the library files need to change. If it's a big multi-user project, write regression tests.
If you're using the Zend Optimizer or a similar bytecode cache, go ahead and include all the library files from base.inc so you never have to worry about doing that.
Use CVS. Even if it's just you.
Use a good template system like Smarty. Just because PHP lets you mix code with HTML doesn't mean it's a good idea.
Write your own classes to handle any common task, even for something as simple as getCgiVar().
Keep the DB schema in one file so it's easy to read and modify.
Also, the EPA estimated fuel economy doesn't always reflect what you actually get. I believe most cars are designed to be the most fuel-efficient at a constant 55 mph. Oregon would lower the cost for me to go 70 mph instead.
Oh, I didn't mean it that way. I meant planes can save friendly lives by killing enemies that would attack friendlies. Not a very friendly business, war...
Sure, but if a piece of equipment will save a thousand lives in battle at the cost of a couple accidents in training, the military will take it. That's just the calculus of war. Why do we have planes? They put pilots in danger, after all. But they save more friendly lives than they take, so they're worth it.
Though I'm lucky enough to have never had this experience, I'm imagine that when people are shooting at you, a little bit of RF energy is the least of your worries.
Also, why not put the antenna on top of the helmet? The helmet than then incorporate a layer of RF shielding. (It's already got layers of protection against shrapnel.
Are you kidding? I played because of the poorly drawn animated dog!
Re:The possibilities are endless!
on
More Clones!
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· Score: 1
Two points:
Cows (as well as every domesticated animal) have already been extensively bred for all the desired characteristics.
An animal can't be "cloned dead". To grow, it has to be living. You could probably remove useless stuff like sex organs (unless you want the milk) or legs, but the cow would still be alive and eating until it grew large enough to be killed for food.
OK, I accept your point about being able to target only the cities.
But consider for example that the Tunguska blast colored the skies of the world for a month. If you wanted to use the rock method of war, you'd be multiplying the effect. All it takes is a month of night to kill plant life, and once that's gone...
Rocks do not produce radioactive fallout, so a destroyed area could be immediately claimed, without waiting thousands of years for the ground to stop glowing.
You could indeed claim and conquer the destroyed area. Have fun living in your giant abiotic craters. Oh, and all the dust you kicked up is blocking the sun all over the world, causing mass extinctions, and reducing the human population by 99%. What a useful weapon. </sarcasm>
Countries don't fight over land that has no value. They fight for land that has some use to them. That's why there are no wars over Antarctica, Greenland, or Shea. If you turn your enemy's land into a series of craters, what are you possibly going to do there? Perhaps mining, but who would want to live in a desolate wasteland like that?
or even fission, you don't really have a radiation problem
True, you could produce lots of thermal energy with a fission reactor, but how are you going to convert it to electricity? The way it's done on Earth is by piping cool water past the reaction. Then you pipe the resulting steam out and turn a traditional generator. The fission reactor itself might be small, but where are you going to get all that water on the moon?
Slashdot Mirror
Also, why can't I buy just the cable channels that I want? I currently get about 70 stations on basic cable, but I would be happy to trim them down to the 15 that I ever actually want. And yes I know some channels are more expensive than others: if I want ESPN, I'm willing to pay more for that channel than for C-SPAN 2. (And don't tell me they can't do this--they have no problem working it for the "premium" channels (e.g. HBO), so surely they could do it for all the channels like that.)
Just think how much more democracy we'd have if he had used a Perl script to check lots of sites and see whether they'd changed.
Not to mention it wants to open links with JavaScript just so it can make them appear in tiny windows on my huge monitor.
Fine, let's work from the frame of reference of the ground. The shuttle is moving at Vs. Let's restrict ourselves to the single vertical dimension and make Vs a positive scalar. The foam is moving at Vf, a negative quantity. Their combined impact speed is |Vs|+|Vf|. So if drag lowers Vf, it's lowering the speed of impact.
But the best way of looking at it is from the frame of reference of the shuttle, since that's what the v in .5mv^2 is in terms of. Then the shuttle isn't moving at all, though the air happens to be moving past it at a certain velocity Vs, which has a downwards direction. Now from the air's perspective (sky being up), the foam has a certain downward velocity Vf due to gravity. Moving back to the shuttle's frame of reference, the air is moving Vs, which means the foam is moving Vs+Vf, and they're both in the same direction so it takes us right back to what we got in the last paragraph.
Bullshit. In the 2002 election cycle, the RIAA gave more money to Republicans than to Democrats.
Of course not. And if there was drag, it would mean the foam was going even slower when it hit the wing, which means less kinetic energy.
Or just take a few months off and then the contract will disappear with the company.
Because they were embarrassed enough to lose Challenger when they launched it in temperatures lower than those in which they were confident, and they don't want to bring up the possibility that it happened again with Columbia.
All numbers I'm using are approximate.
But the foam wasn't moving 500 mph relative to the orbiter. It had only fallen 30 ft (10 m). Given that the crew never experience more than 3 Gs of acceleration, the maximum acceleration of the foam was 40 m/s^2 towards the wing. Assuming no drag on the foam, it took 1/sqrt(2)=0.7 seconds for it to travel, so it hit at a velocity of 28 m/s. This gives it at most 310 J of kinetic energy at time of impact. This is equivalent to a tenth of a gram of TNT according to your numbers for TNT energy.
A 100-W incandescent bulb uses that amount of energy in three seconds. This leads us to two conclusions: (a) don't use incandescent light, and (b) the shuttle can be damaged with relatively little energy.
Sure, or you could just redirect to a real 404. :)
I don't claim to be an expert PHP developer, but I have spent a fair amount of time with it. Here's what I've found works:
Unfortunately the Iraqis trained on GTA3, which is why the United States is having so much trouble occupying their country.
Also, the EPA estimated fuel economy doesn't always reflect what you actually get. I believe most cars are designed to be the most fuel-efficient at a constant 55 mph. Oregon would lower the cost for me to go 70 mph instead.
Oh, I didn't mean it that way. I meant planes can save friendly lives by killing enemies that would attack friendlies. Not a very friendly business, war...
Sure, but if a piece of equipment will save a thousand lives in battle at the cost of a couple accidents in training, the military will take it. That's just the calculus of war. Why do we have planes? They put pilots in danger, after all. But they save more friendly lives than they take, so they're worth it.
Though I'm lucky enough to have never had this experience, I'm imagine that when people are shooting at you, a little bit of RF energy is the least of your worries.
Also, why not put the antenna on top of the helmet? The helmet than then incorporate a layer of RF shielding. (It's already got layers of protection against shrapnel.
Who cares about fuel costs? What oil tanker is going to refuse to surrender their cargo to a friggin aircraft carrier?
Would you pay $400/mon to sleep in a bunk above 5 others? Thanks, but I'll keep paying rent to sleep in my dumpster.
Get your former CEO elected as Vice President of the United States.
Are you kidding? I played because of the poorly drawn animated dog!
OK, I accept your point about being able to target only the cities.
But consider for example that the Tunguska blast colored the skies of the world for a month. If you wanted to use the rock method of war, you'd be multiplying the effect. All it takes is a month of night to kill plant life, and once that's gone...
I gave entirely fake information and they let me in.
You could indeed claim and conquer the destroyed area. Have fun living in your giant abiotic craters. Oh, and all the dust you kicked up is blocking the sun all over the world, causing mass extinctions, and reducing the human population by 99%. What a useful weapon. </sarcasm>
Countries don't fight over land that has no value. They fight for land that has some use to them. That's why there are no wars over Antarctica, Greenland, or Shea. If you turn your enemy's land into a series of craters, what are you possibly going to do there? Perhaps mining, but who would want to live in a desolate wasteland like that?