Isn't the performance lack in the STL versus your version due to the fact that the STL are templates, with all of the "extra" stuff in the template definitions (which makes the compiler do some work to determine how you are using the template)? I'm actually a rocket scientist, so what do I know about programming? I am genuinely curious though, because I thought using the STL also meant that in some cases you had to accept that the compiler would generate more code than was absolutely necessary.
What I typed out above is what I heard first-hand from a fairly recent graduate coming to the US to do her graduate work. She said that it wasn't until college that she learned how to solve problems. Up until that time in her life, and even during college, her studies consisted of figuring out what a problem looks like and then how to go to the library or other resource to find the solution.
But if you look at Chinese students for example, they aren't taught problem solving skills until they go to college.
Up to that point it's learning about all of the solutions to a problem so that you can go look at the solution that's already done. It's in essence, rote memorization.
By law, we're supposed to protect anything that is personal info. At least in the DoD. I guess I figured wrong in thinking that other agencies would follow similar rules. Even though this stuff is supposed to apply government-wide to Freedom of Information Act-related materials: in other words, the general public is not supposed to ever see your SSN, clearance, job title, duty phone, and so on.
There are plenty of days when I wish that natural selection would get rid of the idiots in this world at a higher rate...
You got lots of neutrons in a fusion reactor? Do two things.
1) Say who cares about a bit of radioactive copper or stainless steel that has to be buried for a few decades. THAT's much better than the hundreds of thousands of years of most fission by products.
2) If you are really concerned about neutrons hitting the walls, flow some liquid lithium or sodium around the conductive shell of your reactor. Keep the liquid aligned on the container with the proper magnetic flux (you'd only need several centimeters of liquid lithium for example). Then use it in a thermal cycle to capture the nuetron heating of the copper or stainless steel shell and carry the heat away for extracting that much more energy.
You don't even need ignition to build a power plant. What you do need is a large enough supply of deuterium or helium. Don't think about tritium, it's way too dangerous. The only time you need tritium is in startup. And if it's a power plant, you'd only do that once.
In fact, the hardest part about generating power from a fusion reactor is a CONTINUOUS CYCLE. Bringing in a new plasma, mixing it into the current plasma for burning, and exhausting the old plasma are going to be difficult. You'd have to stage the exhaust so you could capture energy to slow the exhaust products using magnetic nozzles, as well as capture unburned fuels and redirect them to the inlet. You'd have to force current sheets to interact with each other inside the reactor (very hard to do). And you'd have to have enough reserves of fuel to continously pump fuel in.
1) Their experiment detected the "other" solutions to maxwell's equations - in other words, the advanced wave. It's counter-intuitive, but a viable mathematical solution to the equations.
2) Maybe the "backwards pulse" is a not-yet-understood result of a superluminal group velocity in the fiber materials studied. Superluminal group velocities happen quite often. And by definition the group velocity is the speed at which the modulation of the wave's amplitude travels through space, so it stands to reason that this "backwards pulse" is an artifact of a superluminal group velocity. It happens all the time in such things as the ionosphere with certain frequencies and certain plasma densities.;)
Note that in both cases you'd still only have information traveling at the speed of light.
to use open source software. The problem is partly with the fact that many people percieve MS Office products as the only office products worth using out there.
MS hasn't exactly been forthcoming with opening up their Office software documents' standards. And if you couple that fact to the fact that MS Office doesn't run well on anything except MS Windows or a Mac, you get the problem that we have today.
I am typing this from a machine with Win XP on it, and Office 2003.
I used to work for a private company that did some software for DoD programs. And we always went with open source programs when we could. We'd have to verify that the source did exactly what we wanted, and nothing else. And there's an initiative inside DoD and for companies that want to provide DoD with stuff to use open source software.
A ramjet slows the incoming air via a shock across the inlet (and the various reflections). A supersonic ramjet still has shocks, but they don't slow the incoming air enough to run the way a ramjet works (if they did, you'd lose a LOT of energy in the pressure drop across said shocks).
If done right, you get your mixing properly, then you use shock heating to ignite your mixture, and extract the momentum with a nozzle on the engine exhaust.
No. I can't provide a link to the numbers for two reasons: first, my source is one that I can't release, and the second is that the DoD hasn't had a good track record with their accounting of the "nation building" stuff in Iraq.
But, since the invasion ended, the US has put about 60-80 billion towards rebuilding efforts (this from skimming GAO reports). The military operations side of things is more expensive. You have a carrier group in the Persian gulf. You have bases operated and maintained all over Iraq. You have to equip your soldiers, and the Army and Marines have been severely lacking in this area. You have to move all your equipment to Iraq, all the parts for your equipment, all of your maintainers for the equipment, and consumables for your equipment. For example, the footprint for moving a C-17 requires a few other C-17s to transport all the stuff you need (people, supplies, parts).
Your food example missed the other costs associated with feeding the troops there: acquiring the food, loading it into transports of some sort, transporting it and insuring it, unloading it, distributing it, preparing it. Not all of the troops are eating MREs every day. That's just for the food. You have the same deal with water. Which isn't as bad during the winter, but troops are pretty much required to drink a couple quarts of water an hour if they're on the ground. Aircrews get by with less, but that's because they're flying and they can get cool air.
For fuel, you have to do the same things as with the food. All of those costs add up. It's not like you go over to the local gas station and fill up on JP-8. Or hit the local 7-11 and get a slurpy and some water.
But that's not really the entire picture. Supposedly Haliburton and company are providing the meals for the troops. Well, we all know that Haliburton has a special relationship with the executive branch. So, those numbers for the food? You can probably trhow them out or make them a magnitude larger; it's equally valid either way.
I know for a fact that many classified things are getting cut due precisely to the war effort. And I know for a fact that the Air Force has been scrambling to figure out how to come out okay with a several-billion dollar shortfall. (I think it's 6 billion, but I'm not exactly sure.)
Actually, fuel is one of the big costs. The next is food and water. After that it's salaries and small arms ammunition.
The nation-building stuff comes from a separate budget item that is approved by Congress. There will be some retirements out of the Air Force inventory in the near future due to budget reasons.
If you have a set amount of relocation money, remember that when you get your hands on that money, the IRS is going to tax the hell out of it. It sounds weird, but when your first paycheck is 4500 dollars, including the relocation money, the IRS looks at that and says, "wait a sec! this person is going to make a buttload of money this year!". It turns out that 45% of my relocation bonus went to taxes. I ended up slowly getting out of that debt (went to credit cards), and it was because I didn't stop to think about the whole deal and ask for more money for relocation.
The other thing to remember is that moving companies are pretty much hit or miss. Even the reputable ones that your friend used last month can screw you over. There's a reason that there are so many horror stories about people losing their stuff, or their stuff being held ransom, or the company not willing to make good on their promises if they have a clause to reimburse you for each day they're late. I ended up just getting a budget truck and a flatbed trailer for my car, and stuffed everything I owned in them. After finding out about the tax thing, I was glad I did it myself.
Remember that you will not have some income for a short period due to having to get a new place (rent + deposits, or mortgage stuff), and moving out of your old place (breaking the lease or last month's rent, or putting your home up for sale). You're paying on both ends of the move.
Many employers help out new hires when they are bringing them in from far away. I am fortunate enough to work for my current employer; they helped point me in the right direction for getting a new apartment and where to go for things in town.
The likely reason is the Air Force's multiple billion dollar budget shortfall. Blame that on El Presidente.
There's talk of cutting many classified programs due to money. All that jet fuel for the war effort and that ordnance are expensive. I have heard confirmation that government contractors will be cut from several bases; civilians and military are getting RIF'ed too.
Except that you have ends to those cables, and you also have long wire lengths. Coax is always the better solution, unless you are concerned with weight. Fiber is best, but when working with the huge bundles you can get on commercial aircraft, you better hope you don't break one of the fibers. Otherwise, you have to pull the entire bundle. And there are structural requirements for fiber beyond the turn radius requirement.
The point is that the "fixes" that people have suggested on here aren't simple for aircraft. Heck, even painting the darn things can throw the balance off and require re-ballasting. You also have tight spaces and require high confidence in your parts.
It's not just a GPS equipment / radio beacon / comm radio problem with cell phones. It's the fact that with all of the thousands of channels on long wires, and large number of possible interaction routes between the cell phone and the plethora of lines, that you can't test or plan for all conditions. Even how the wires are bundled and installed has an impact on what they can pick up.
When I look at a box and try to figure out how to get EMI into it, the first things I look at are the lines going in and out, their connections, and any open sockets (diplays too). Then you have to look at incident angles, reflections, and energy levels. A cell phone can provide all of these if the conditions are just right.
What if you're in the clouds and you have no visual on anything? You've never experienced flying by instruments when your ears are telling you your spinning or in a turn. I've flown into and taken off from many airports that had heavy clouds and no visibility. The pilots were totally on instruments on approach.
And I've been in clouds before with a pilot that decided to see if I could tell what was happening. He had me close my eyes, put the plane into some turns, and had me put the plane back on the same course we were on. The turn indicator said we weren't turning, but my ears were screaming to bank hard. Our compass said the same heading, and our altitude was the same. But it was very cloudy and you couldn't see anything.
The problem in large part is due to lack of common ground. You get image currents running in places that they shouldn't be.
It is a run-away problem. But it's also more of an issue with older aircraft. All of the avionics that I worked on had both hardware and software error-rejection routines and built-in-test routines. But the hardware makes things heavier, and the software can foul up at any time when you don't get the input you should. It doesn't have to be garbage input either; bit flips can cause different commands to be performed because the incoming data says "GPS Altitude is 5 km" when it should be "GPS Altitude is 4 km". That is a contrived example, but it illustrates the problems that the avionics are faced with.
I'm in directed energy now, and it's those kinds of things which makes life difficult for EMI and EMC enineers that you want to exploit with a directed energy weapon.
You've obviously never tried to shield electronics. It's a LOT harder than people think. You aren't on the ground, so there's no way to have a common ground. The plane might act like a faraday cage, but it also acts like an antenna. And there are several kilometers/miles of wires inside your average commercial aircraft.
Actually, the light wave-particle duality dilemma was one of the things that pointed people in the direction of quantum mechanics. And that started with Max Planck figuring out that energy is quantized into very specific amounts. Planck came to that realization while studying electromagenetic waves inside resonator cavities. Using the analogy of a string held at two ends, he noticed that the electromagnetic "string" inside a metal box could ONLY vibrate at specific frequencies. That meant that the metal box was limiting the amount of energy in the waves, and it was the simplest reasoning that the energy is limited because the size of the box determines what specific energy quanta can be put inside it.
It was also realized that atomic models developed in the late 19th and early 20th centuries just didn't predict how atoms behaved using Newton's laws and electromagnetism. Instead, it was realized that electrons only fit into certain "orbitals" around an atom. I think it was Neils Bohr that did the first work towards this, with input from Einstein, Heisenberg, Planck, Schrodinger, Dirac, Paulii, and Max Born (basically the world's smartest physicists at the time).
It was further discovered that the "orbitals" weren't orbits in the sense of the planets around the sun. Physicists came to realize that these "orbitals" are the regions around an atom where it is extremely likely that you'll find an electron that is associated with that atom.
The electromagnetic wave in a box ended up describing the wave-particle duality that has stumped many people since it was first thought up. The atomic model was the first step towards quantum mechanics. Heisenberg's Uncertainty princple (the fact that for very small things you can't measure both the position and momentum of a particle at the same time; it's one or the other), and the much later discovery of quantum entanglement round out the basics of quantum mechanics.
I learned quantum mechanics from the approach of statistical thermodynamics, which is a fancy way of saying understanding the probabilities of atoms and molecules to move or not move in certain directions and speeds. Quantum mechanics says that everything is broken up into discrete units, and it's combinations of these discrete units that gives rise to our world.
And from my college physics class...
It's always best to remember this statement when thinking of quantum mechanics: If you pushed against a wall, there is a very small chance that you could fall through to the other side according to quantum mechanics. (It's a phenomenon called quantum tunneling, and it has many applications.)
but before you draft any standards or anything crazy like that, try this:
take your programmers, pair them up, and ask them to write some code and explain with NO comments to the other programmer what is going on in the code. If they can get the person to understand the code on the first try, great! That explanation is what you use to comment your code. If you're talking about a routine, fine, just make sure the explanation is in the comments.
Then, take the same two programmers, switch roles, and repeat. You could even iterate over the process once or twice more and reassign the pairings. And heck, if it's an assigned task from management, like say, code a sorting algorithm, then that's even a bit easier.
The whole point is to get everyone onto the same page for what is necessary for comments without patronizing the other person.
Turbines are terribly inefficient at idle. And it's pointless to run them at greater than idle if you aren't using the power they are producing; that would generate excess heat and waste fuel.
The efficiency of a closed-cycle engine is limited by the temperatures of the heat source and heat sink. Ideally, you want something that's infinitely hot and something that's at absolute zero for 100% efficiency. This and the fact that you add weight are the reasons that you don't see manufacturers try to capture the waste heat from a radiator and until now from the exhaust system.
But real life isn't ideal. There are temperature limits for the engine due to the materials used. And there is a temperature limit to how cold your sink can be.
You do realize that there is a 5 or 10 year lead time for development of some of these things, right? You can't just go to Radio Shack, get parts, put them together, and expect them to have a 100% success rate. You're retarded for thinking that the US can just magically create a missile defense system after it's needed.
I would rather have something that is being worked on now to counter those future threats, than hear a sonic boom and look up only to see a bright flash and wonder where the missile defense was...
Why do some myths get tested without much thought?
on
Ask The Mythbusters
·
· Score: 1
I saw the episode where Mythbusters tested the myth of a jet engine being able to push a car around. Instead of pushing the car, the engine used burned parts of it and make it slide a bit.
My background is in fluid mechanics, and I was wondering why the myth was disproved without researching the kinds of jet engines that are available.
The engine used was not a high bypass turbofan. It was just a regular turbofan that you'd see on a small jet aircraft or perhaps a fighter. If some more research was done, you would have found that large planes usually use high bypass turbofans. The difference is in how much mass the engines push (which equals more thrust). I know a large airplane can push a car around, having witnessed such an event.
Slashdot Mirror
Isn't the performance lack in the STL versus your version due to the fact that the STL are templates, with all of the "extra" stuff in the template definitions (which makes the compiler do some work to determine how you are using the template)? I'm actually a rocket scientist, so what do I know about programming? I am genuinely curious though, because I thought using the STL also meant that in some cases you had to accept that the compiler would generate more code than was absolutely necessary.
What I typed out above is what I heard first-hand from a fairly recent graduate coming to the US to do her graduate work. She said that it wasn't until college that she learned how to solve problems. Up until that time in her life, and even during college, her studies consisted of figuring out what a problem looks like and then how to go to the library or other resource to find the solution.
But if you look at Chinese students for example, they aren't taught problem solving skills until they go to college.
Up to that point it's learning about all of the solutions to a problem so that you can go look at the solution that's already done. It's in essence, rote memorization.
Ever hear of liquid lithium as a coolant for these vessels?
By law, we're supposed to protect anything that is personal info. At least in the DoD. I guess I figured wrong in thinking that other agencies would follow similar rules. Even though this stuff is supposed to apply government-wide to Freedom of Information Act-related materials: in other words, the general public is not supposed to ever see your SSN, clearance, job title, duty phone, and so on.
There are plenty of days when I wish that natural selection would get rid of the idiots in this world at a higher rate...
If I recall correctly, it's something like 10 years and a 250,000 dollar fine. For each offense.
But they're not that big of a problem.
You got lots of neutrons in a fusion reactor? Do two things.
1) Say who cares about a bit of radioactive copper or stainless steel that has to be buried for a few decades. THAT's much better than the hundreds of thousands of years of most fission by products.
2) If you are really concerned about neutrons hitting the walls, flow some liquid lithium or sodium around the conductive shell of your reactor. Keep the liquid aligned on the container with the proper magnetic flux (you'd only need several centimeters of liquid lithium for example). Then use it in a thermal cycle to capture the nuetron heating of the copper or stainless steel shell and carry the heat away for extracting that much more energy.
You don't even need ignition to build a power plant. What you do need is a large enough supply of deuterium or helium. Don't think about tritium, it's way too dangerous. The only time you need tritium is in startup. And if it's a power plant, you'd only do that once.
In fact, the hardest part about generating power from a fusion reactor is a CONTINUOUS CYCLE. Bringing in a new plasma, mixing it into the current plasma for burning, and exhausting the old plasma are going to be difficult. You'd have to stage the exhaust so you could capture energy to slow the exhaust products using magnetic nozzles, as well as capture unburned fuels and redirect them to the inlet. You'd have to force current sheets to interact with each other inside the reactor (very hard to do). And you'd have to have enough reserves of fuel to continously pump fuel in.
There are also two other things to consider:
;)
1) Their experiment detected the "other" solutions to maxwell's equations - in other words, the advanced wave. It's counter-intuitive, but a viable mathematical solution to the equations.
2) Maybe the "backwards pulse" is a not-yet-understood result of a superluminal group velocity in the fiber materials studied. Superluminal group velocities happen quite often. And by definition the group velocity is the speed at which the modulation of the wave's amplitude travels through space, so it stands to reason that this "backwards pulse" is an artifact of a superluminal group velocity. It happens all the time in such things as the ionosphere with certain frequencies and certain plasma densities.
Note that in both cases you'd still only have information traveling at the speed of light.
to use open source software. The problem is partly with the fact that many people percieve MS Office products as the only office products worth using out there.
MS hasn't exactly been forthcoming with opening up their Office software documents' standards. And if you couple that fact to the fact that MS Office doesn't run well on anything except MS Windows or a Mac, you get the problem that we have today.
I am typing this from a machine with Win XP on it, and Office 2003.
I used to work for a private company that did some software for DoD programs. And we always went with open source programs when we could. We'd have to verify that the source did exactly what we wanted, and nothing else. And there's an initiative inside DoD and for companies that want to provide DoD with stuff to use open source software.
You can still get trichonosis or tapeworm from infected meat, like regular pork.
But if that's the case, you could market it as a weight-loss program too!
Actually, the big problem is mixing.
A ramjet slows the incoming air via a shock across the inlet (and the various reflections). A supersonic ramjet still has shocks, but they don't slow the incoming air enough to run the way a ramjet works (if they did, you'd lose a LOT of energy in the pressure drop across said shocks).
If done right, you get your mixing properly, then you use shock heating to ignite your mixture, and extract the momentum with a nozzle on the engine exhaust.
No. I can't provide a link to the numbers for two reasons: first, my source is one that I can't release, and the second is that the DoD hasn't had a good track record with their accounting of the "nation building" stuff in Iraq.
But, since the invasion ended, the US has put about 60-80 billion towards rebuilding efforts (this from skimming GAO reports). The military operations side of things is more expensive. You have a carrier group in the Persian gulf. You have bases operated and maintained all over Iraq. You have to equip your soldiers, and the Army and Marines have been severely lacking in this area. You have to move all your equipment to Iraq, all the parts for your equipment, all of your maintainers for the equipment, and consumables for your equipment. For example, the footprint for moving a C-17 requires a few other C-17s to transport all the stuff you need (people, supplies, parts).
Your food example missed the other costs associated with feeding the troops there: acquiring the food, loading it into transports of some sort, transporting it and insuring it, unloading it, distributing it, preparing it. Not all of the troops are eating MREs every day. That's just for the food. You have the same deal with water. Which isn't as bad during the winter, but troops are pretty much required to drink a couple quarts of water an hour if they're on the ground. Aircrews get by with less, but that's because they're flying and they can get cool air.
For fuel, you have to do the same things as with the food. All of those costs add up. It's not like you go over to the local gas station and fill up on JP-8. Or hit the local 7-11 and get a slurpy and some water.
But that's not really the entire picture. Supposedly Haliburton and company are providing the meals for the troops. Well, we all know that Haliburton has a special relationship with the executive branch. So, those numbers for the food? You can probably trhow them out or make them a magnitude larger; it's equally valid either way.
I know for a fact that many classified things are getting cut due precisely to the war effort. And I know for a fact that the Air Force has been scrambling to figure out how to come out okay with a several-billion dollar shortfall. (I think it's 6 billion, but I'm not exactly sure.)
Actually, fuel is one of the big costs. The next is food and water. After that it's salaries and small arms ammunition. The nation-building stuff comes from a separate budget item that is approved by Congress. There will be some retirements out of the Air Force inventory in the near future due to budget reasons.
And I found a couple of things:
If you have a set amount of relocation money, remember that when you get your hands on that money, the IRS is going to tax the hell out of it. It sounds weird, but when your first paycheck is 4500 dollars, including the relocation money, the IRS looks at that and says, "wait a sec! this person is going to make a buttload of money this year!". It turns out that 45% of my relocation bonus went to taxes. I ended up slowly getting out of that debt (went to credit cards), and it was because I didn't stop to think about the whole deal and ask for more money for relocation.
The other thing to remember is that moving companies are pretty much hit or miss. Even the reputable ones that your friend used last month can screw you over. There's a reason that there are so many horror stories about people losing their stuff, or their stuff being held ransom, or the company not willing to make good on their promises if they have a clause to reimburse you for each day they're late. I ended up just getting a budget truck and a flatbed trailer for my car, and stuffed everything I owned in them. After finding out about the tax thing, I was glad I did it myself.
Remember that you will not have some income for a short period due to having to get a new place (rent + deposits, or mortgage stuff), and moving out of your old place (breaking the lease or last month's rent, or putting your home up for sale). You're paying on both ends of the move.
Many employers help out new hires when they are bringing them in from far away. I am fortunate enough to work for my current employer; they helped point me in the right direction for getting a new apartment and where to go for things in town.
The likely reason is the Air Force's multiple billion dollar budget shortfall. Blame that on El Presidente.
There's talk of cutting many classified programs due to money. All that jet fuel for the war effort and that ordnance are expensive. I have heard confirmation that government contractors will be cut from several bases; civilians and military are getting RIF'ed too.
Except that you have ends to those cables, and you also have long wire lengths. Coax is always the better solution, unless you are concerned with weight. Fiber is best, but when working with the huge bundles you can get on commercial aircraft, you better hope you don't break one of the fibers. Otherwise, you have to pull the entire bundle. And there are structural requirements for fiber beyond the turn radius requirement.
The point is that the "fixes" that people have suggested on here aren't simple for aircraft. Heck, even painting the darn things can throw the balance off and require re-ballasting. You also have tight spaces and require high confidence in your parts.
It's not just a GPS equipment / radio beacon / comm radio problem with cell phones. It's the fact that with all of the thousands of channels on long wires, and large number of possible interaction routes between the cell phone and the plethora of lines, that you can't test or plan for all conditions. Even how the wires are bundled and installed has an impact on what they can pick up.
When I look at a box and try to figure out how to get EMI into it, the first things I look at are the lines going in and out, their connections, and any open sockets (diplays too). Then you have to look at incident angles, reflections, and energy levels. A cell phone can provide all of these if the conditions are just right.
What if you're in the clouds and you have no visual on anything? You've never experienced flying by instruments when your ears are telling you your spinning or in a turn. I've flown into and taken off from many airports that had heavy clouds and no visibility. The pilots were totally on instruments on approach.
And I've been in clouds before with a pilot that decided to see if I could tell what was happening. He had me close my eyes, put the plane into some turns, and had me put the plane back on the same course we were on. The turn indicator said we weren't turning, but my ears were screaming to bank hard. Our compass said the same heading, and our altitude was the same. But it was very cloudy and you couldn't see anything.
The problem in large part is due to lack of common ground. You get image currents running in places that they shouldn't be.
It is a run-away problem. But it's also more of an issue with older aircraft. All of the avionics that I worked on had both hardware and software error-rejection routines and built-in-test routines. But the hardware makes things heavier, and the software can foul up at any time when you don't get the input you should. It doesn't have to be garbage input either; bit flips can cause different commands to be performed because the incoming data says "GPS Altitude is 5 km" when it should be "GPS Altitude is 4 km". That is a contrived example, but it illustrates the problems that the avionics are faced with.
I'm in directed energy now, and it's those kinds of things which makes life difficult for EMI and EMC enineers that you want to exploit with a directed energy weapon.
You've obviously never tried to shield electronics. It's a LOT harder than people think. You aren't on the ground, so there's no way to have a common ground. The plane might act like a faraday cage, but it also acts like an antenna. And there are several kilometers/miles of wires inside your average commercial aircraft.
Actually, the light wave-particle duality dilemma was one of the things that pointed people in the direction of quantum mechanics. And that started with Max Planck figuring out that energy is quantized into very specific amounts. Planck came to that realization while studying electromagenetic waves inside resonator cavities. Using the analogy of a string held at two ends, he noticed that the electromagnetic "string" inside a metal box could ONLY vibrate at specific frequencies. That meant that the metal box was limiting the amount of energy in the waves, and it was the simplest reasoning that the energy is limited because the size of the box determines what specific energy quanta can be put inside it.
It was also realized that atomic models developed in the late 19th and early 20th centuries just didn't predict how atoms behaved using Newton's laws and electromagnetism. Instead, it was realized that electrons only fit into certain "orbitals" around an atom. I think it was Neils Bohr that did the first work towards this, with input from Einstein, Heisenberg, Planck, Schrodinger, Dirac, Paulii, and Max Born (basically the world's smartest physicists at the time).
It was further discovered that the "orbitals" weren't orbits in the sense of the planets around the sun. Physicists came to realize that these "orbitals" are the regions around an atom where it is extremely likely that you'll find an electron that is associated with that atom.
The electromagnetic wave in a box ended up describing the wave-particle duality that has stumped many people since it was first thought up. The atomic model was the first step towards quantum mechanics. Heisenberg's Uncertainty princple (the fact that for very small things you can't measure both the position and momentum of a particle at the same time; it's one or the other), and the much later discovery of quantum entanglement round out the basics of quantum mechanics.
I learned quantum mechanics from the approach of statistical thermodynamics, which is a fancy way of saying understanding the probabilities of atoms and molecules to move or not move in certain directions and speeds. Quantum mechanics says that everything is broken up into discrete units, and it's combinations of these discrete units that gives rise to our world.
And from my college physics class...
It's always best to remember this statement when thinking of quantum mechanics: If you pushed against a wall, there is a very small chance that you could fall through to the other side according to quantum mechanics. (It's a phenomenon called quantum tunneling, and it has many applications.)
but before you draft any standards or anything crazy like that, try this:
take your programmers, pair them up, and ask them to write some code and explain with NO comments to the other programmer what is going on in the code. If they can get the person to understand the code on the first try, great! That explanation is what you use to comment your code. If you're talking about a routine, fine, just make sure the explanation is in the comments.
Then, take the same two programmers, switch roles, and repeat. You could even iterate over the process once or twice more and reassign the pairings. And heck, if it's an assigned task from management, like say, code a sorting algorithm, then that's even a bit easier.
The whole point is to get everyone onto the same page for what is necessary for comments without patronizing the other person.
Turbines are terribly inefficient at idle. And it's pointless to run them at greater than idle if you aren't using the power they are producing; that would generate excess heat and waste fuel.
The efficiency of a closed-cycle engine is limited by the temperatures of the heat source and heat sink. Ideally, you want something that's infinitely hot and something that's at absolute zero for 100% efficiency. This and the fact that you add weight are the reasons that you don't see manufacturers try to capture the waste heat from a radiator and until now from the exhaust system.
But real life isn't ideal. There are temperature limits for the engine due to the materials used. And there is a temperature limit to how cold your sink can be.
You do realize that there is a 5 or 10 year lead time for development of some of these things, right? You can't just go to Radio Shack, get parts, put them together, and expect them to have a 100% success rate. You're retarded for thinking that the US can just magically create a missile defense system after it's needed.
I would rather have something that is being worked on now to counter those future threats, than hear a sonic boom and look up only to see a bright flash and wonder where the missile defense was...
I saw the episode where Mythbusters tested the myth of a jet engine being able to push a car around. Instead of pushing the car, the engine used burned parts of it and make it slide a bit.
My background is in fluid mechanics, and I was wondering why the myth was disproved without researching the kinds of jet engines that are available.
The engine used was not a high bypass turbofan. It was just a regular turbofan that you'd see on a small jet aircraft or perhaps a fighter. If some more research was done, you would have found that large planes usually use high bypass turbofans. The difference is in how much mass the engines push (which equals more thrust). I know a large airplane can push a car around, having witnessed such an event.
Several components will have to be developed before photos can replace electrons inside computers.