In addition SRBs have lower ISPs than liquid engines. This isn't nearly as important as the above disadvantages though. Even though you need more fuel mass, the whole system as a whole is still less expensive than an equivalent liquid system. If your solid rockets are boosters on your first stage than the downside to them being heavier than liquid engines would be is pretty minimal. Using solid propellant in later stages is a bigger deal though, because the second stage being a bit heavier, but cheaper, means that the first stage now has to be a lot heavier, and more expensive.
Yeah, he made several errors in calculating the distance to Japan. He took the most optimistic estimates of all the distances involved, didn't add any sort of safety buffer to account for the fact he was being optimistic, and then made a couple unit errors to complete the set.
The royal advisers who wanted to stop him didn't do so because they thought the world was flat, they did so because they knew the world was round, and they knew it was roughly 5 times larger than Columbus had calculated.
Columbus wasn't a genius, but he was the single luckiest person in the history of mankind. He stumbled across an entire goddamned continent right when he was about to run out of food.
Seems to me that we have actual data point directly comparing media money to the amount of money a space program takes.
Apollo 13 made $355 million at the box office (wikipedia), and according to imdb another $92 million in rentals. Lets call it an even $600 million after adding VHS and DvD sales, which I didn't find numbers for.
The entire Apollo program cost $25.4 billion dollars. Even if every mission had been as suspenseful and interesting as Apollo 13 and had spawned a movie just as profitable it wouldn't even have paid for half of the program.
Obviously this isn't entirely apples and oranges to advertising dollars, but I still think it's a useful benchmark.
Oh my gosh! It never occurred to me to look for another planet. This whole time I was so hung up on living in Mars that I didn't notice this planet right past Jupiter. 9.81 m/s^2 surface gravity, 20-30C temperature, 20% oxygen, 3% CO2, the rest Nitrogen. Not only that but there is plenty of water and tasty animals and plants to eat!
Oh that's right, that planet doesn't exist. Everyone is hung up on Mars because the constraints for finding another planet to live in currently implicitly includes "planet in this solar system" and Mars is pretty much the best one here. Since it is the best one here our time is better spent figuring out how to live on it rather than wishing we had a better choice.
That's a bad analogy because Sony's entire electronic gaming division has been hemorrhaging money ever since the PS3 hit the market. In their case the "sell hardware at a loss, make up for it in games" hasn't worked for them. Microsoft is a much better example, as the game division has made a profit on both the Xbox and Xbox 360, even though they started selling both consoles at a loss.
Assuming your ambient light isn't coming from a laser wouldn't you be able to get rid of the light by filtering out any non-polarized light? If there are lasers (say multiple people in a SWAT team are using this) as part of the ambient light maybe each could be using a slightly different wavelength of light in order to filter out the other devices as well.
You're not an idiot for thinking that people shouldn't post "jokes" like that. You would be an idiot if you took such statements literally when they were so obviously in jest.
Once you do take them literally, if you then don't actually investigate them, then not only are you misidentifying possible threats, but then you are refusing to act on threats you have identified.
And if you are worried about wasting department resources, all the more reason to not prosecute him for menacing speech.
And no, I just don't see it. There is no smiley, no funny picture, nothing. And I cannot see you winking when you write it, either. If I read it on twitter, written by someone I don't know much about, I'll take it literally.
Then you just might be an idiot. Have you thought about running for office?
Even if you were taking him seriously, the correct approach would be to use this "offense" to get a warrant to search his house. If you are right and this is an actual terrorist you should find more evidence there, which is excellent, because instead of fining him $1000 pounds you can actually put him away now.
Now if you don't find any more evidence there than you go on your way. Have you wasted your time? Yes, yes you have, but arresting him for hyperbole isn't going to make your time any less wasted.
The only reason to actually arrest him for tweeting that is if tweeting itself is an offense, and what is the harm in having people say random, kinda sorta maybe threatening things on twitter? Are you worried that all that noise may make it harder to spot the real terrorists that are publicly sending threatening tweets under their real names?
I was expecting you to be incorrect about alloys being stronger in compression than tension at these scales, but after working the numbers it looks like you are right. The components of engines aren't large enough to have buckling start to make tensile strength much cheaper (per mass) than compressive strength.
As far as a specific case involving steel, it looks like we'd have a total yield strength of 400-700 MPa. The buckling failure mode is more complicated, as it depends on the dimensions of the column. If we assume a Young's Modulus of 200 GPa, a length of.2 meters, and width and height of.02 and.03 meters (so I = 2E-8) then we get a critical force of just under a million Newtons. For comparison at 500 MPa that same bar of steel would fail at around a third that amount of tensile force. Titanium is even worse for that specific geometry. I chose.2 meters because it's on the long side as well, a shorter rod would be even better under compression (and identical under tension).
I chose a K of 1.0 rather than 2.0, because even though one end moves laterally, it's not free to move laterally, it is still bound to move in a specific orientation, so it's fixed, even though it's not motionless.
That's not the same thing though, because until 60 years ago every single bit of material we mined out of the Earth stayed here. Even today the vast majority of what we mine stays here, and the majority of mass that we've sent off of Earth is in LEO and will come back to Earth within a few decades.
Of course even if we had been shipping things off of Earth this whole time it wouldn't have made much of a dent. The earth has a radius of 6,371 km, and we mine--what--10 miles deep? 50? The crust is a lot less dense than the core too.
I just find it amusing that humans gazing up at the moon think, "Gee, I bet there's some shit up there I could strip mine and sell".
If there are advanced races in the universe, it would be completely understandable if they decided to just go ahead and destroy Earth.
Are those advanced races going to destroy Earth because they are repulsed by our obsession with material goods? Or are they going to destroy Earth because there is some shit here that they can strip mine and sell?
I'd feel much better about dumping nukewaste that we know will be harmless in a couple years, than dumping, say, heavy metals that we know will never, ever be harmless.
After the nuclear waste cools down won't it still be a heavy metal, similarly dangerous to the other heavy metals? Just because it's not radioactive anymore doesn't mean it still can't be dangerous.
The big difference between nuclear power and other generation methods isn't that nuclear waste is less dangerous, it's that it's more compact and easier to collect.
Not only does it disable the task manager, this (or a variant of it) disables Control Panel and ways to get to useful parts of the control panel without going through it (like running msconfig.exe directly). They also change your proxy settings on your web browsers so that you can't go online to attempt to trouble shoot the problem. At this point even an above-average computer user can be flummoxed as most of the basic tools are taken away from them.
Although after this point they kinda drop the ball. Once you go into safe mode and look at the start up tasks the offending processes have been random collections of letters. Seems odd that they don't name themselves "Microsoft Security Panel" or something else like that.
Just like there are lettuce farms, carrot farms, and potato farms, there are also tree farms. Believe it or not companies that sell lumber and a paper understand that if all the trees they log disappear then they will too.
"Environmentalists" have cultivated this idea that loggers clear cut forests and then never replace them, however that's just not the case. The trees that are felled today for lumber and paper were specifically grown for that purpose. If the demand for paper and lumber fell to zero, what would happen to these tree farms? Even if you assume that the land isn't sold and turned into shopping malls, if it was untended you'd just be left with a bunch of full-grown trees sequestering a minimum amount of carbon. Purely from a CO2 standpoint it's better to plant a tree, let it grow, and once the rate of growth (and CO2 sequestration) falls off then cut it down, build a deck, and plant another one.
The very real problem of jungle deforestation is mostly due to burning down jungle land so that people (often poor people) can use the land for farming and ranching. This actual problem is 100% divorced from lumber or paper industries.
I've always been skeptical of the use of recycled paper for this very reason. If you are recycling all of your paper then you are never taking any CO2 out of the atmosphere, while you are still doing cleaning and processing on it, so you are obviously using energy.
However if you make fresh paper, use it, then bury it in a landfill you are still partially sequestering that carbon. Of course it takes more energy to make fresh paper than recycled paper, so it's completely possible that the energy (and thus CO2 for most forms of energy generation) saved from recycling the paper makes up for the lack of sequestration. You also use less chemicals to redye recycled paper than when you make it from scratch.
It seems like a fairly complicated cost-benefit analysis actually, but I have never seen anyone talk about crunching those numbers. By far the biggest reason I have heard for recycling paper is to "save the trees" which is stupid. When was the last time someone told you to stop eating salad in order to "save the lettuce?"
They could have caught him cutting open his little sister for all I care.
The school claims the system was only used to locate stolen laptops. If the kid's laptop had indeed been reported as stolen to the school, all 'bad things' that it caught (like him masturbating) isn't the school's fault.
If it HADN'T been reported stolen, then they have no 'get out of jail free card' on seeing him cutting open his little sister. They're still guilty of illegal wire tapping and if they've done it once, it really should be up to them to prove, no-one has been using the system to spy on people.
Actually it seems like even if the laptop had been stolen spying on the thief would still be unconstitutional. They should have to report the theft to the police and tell them the laptop has that capability, the police would then get a warrant and use the camera. Of course using it in an actual theft scenario is far less immoral than how it was used here, and would still get you the laptop back, but it seems like the evidence gathered by school district with the laptop camera wouldn't be admissible in court.
Some of the newer Anti-theft measures from professional companies work like this, where the owners of the computer don't have the ability to do the computer traces, the police have to contact the company directly. That is how the program-maker's newer programs work, and they are patching this error out of the older program used by this school district.
For the car analogy, if your car with OnStar is stolen the police can contact OnStar and request that they kill the engine. The dealership that you bought the car from does not have the ability to kill the engine if you are late on your payments, or for any other reason.
If he doesn't feel qualified to pass judgment on the administrator of a school then he may be in the wrong line of work. Maybe he should make a list of all the people he's not qualified to judge on and he can be removed from any trials which involve them.
Of course if "Junior High School Administrator" is on that list it may be faster if he makes a list of the professions he is qualified to judge on.
"But, you could be completely wrong!" Yes. I suppose we could. But in that case, we could be wrong in an infinite number of ways. And an earth destroying black hole would require us to be wrong in a very specific way on par with, "Our knowledge of electricity could be wrong and some magical circuit with just the right components will end all of reality as we know it."
Isn't that exactly what they are arguing, that the LHC is the electrical circuit with just the right components to end all of reality as we know it?
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In addition SRBs have lower ISPs than liquid engines. This isn't nearly as important as the above disadvantages though. Even though you need more fuel mass, the whole system as a whole is still less expensive than an equivalent liquid system. If your solid rockets are boosters on your first stage than the downside to them being heavier than liquid engines would be is pretty minimal. Using solid propellant in later stages is a bigger deal though, because the second stage being a bit heavier, but cheaper, means that the first stage now has to be a lot heavier, and more expensive.
Yeah, he made several errors in calculating the distance to Japan. He took the most optimistic estimates of all the distances involved, didn't add any sort of safety buffer to account for the fact he was being optimistic, and then made a couple unit errors to complete the set.
The royal advisers who wanted to stop him didn't do so because they thought the world was flat, they did so because they knew the world was round, and they knew it was roughly 5 times larger than Columbus had calculated.
Columbus wasn't a genius, but he was the single luckiest person in the history of mankind. He stumbled across an entire goddamned continent right when he was about to run out of food.
Seems to me that we have actual data point directly comparing media money to the amount of money a space program takes.
Apollo 13 made $355 million at the box office (wikipedia), and according to imdb another $92 million in rentals. Lets call it an even $600 million after adding VHS and DvD sales, which I didn't find numbers for.
The entire Apollo program cost $25.4 billion dollars. Even if every mission had been as suspenseful and interesting as Apollo 13 and had spawned a movie just as profitable it wouldn't even have paid for half of the program.
Obviously this isn't entirely apples and oranges to advertising dollars, but I still think it's a useful benchmark.
We Earthlings would like to let you Martians know that if you provide evidence of your diseases and microbes you'd easily win the Nobel prize.
Oh my gosh! It never occurred to me to look for another planet. This whole time I was so hung up on living in Mars that I didn't notice this planet right past Jupiter. 9.81 m/s^2 surface gravity, 20-30C temperature, 20% oxygen, 3% CO2, the rest Nitrogen. Not only that but there is plenty of water and tasty animals and plants to eat!
Oh that's right, that planet doesn't exist. Everyone is hung up on Mars because the constraints for finding another planet to live in currently implicitly includes "planet in this solar system" and Mars is pretty much the best one here. Since it is the best one here our time is better spent figuring out how to live on it rather than wishing we had a better choice.
That's a bad analogy because Sony's entire electronic gaming division has been hemorrhaging money ever since the PS3 hit the market. In their case the "sell hardware at a loss, make up for it in games" hasn't worked for them. Microsoft is a much better example, as the game division has made a profit on both the Xbox and Xbox 360, even though they started selling both consoles at a loss.
Or you could put a bunch of adjectives before your name that you don't really want.
Assuming your ambient light isn't coming from a laser wouldn't you be able to get rid of the light by filtering out any non-polarized light? If there are lasers (say multiple people in a SWAT team are using this) as part of the ambient light maybe each could be using a slightly different wavelength of light in order to filter out the other devices as well.
You're not an idiot for thinking that people shouldn't post "jokes" like that. You would be an idiot if you took such statements literally when they were so obviously in jest.
Once you do take them literally, if you then don't actually investigate them, then not only are you misidentifying possible threats, but then you are refusing to act on threats you have identified.
And if you are worried about wasting department resources, all the more reason to not prosecute him for menacing speech.
And no, I just don't see it. There is no smiley, no funny picture, nothing. And I cannot see you winking when you write it, either. If I read it on twitter, written by someone I don't know much about, I'll take it literally.
Then you just might be an idiot. Have you thought about running for office?
Even if you were taking him seriously, the correct approach would be to use this "offense" to get a warrant to search his house. If you are right and this is an actual terrorist you should find more evidence there, which is excellent, because instead of fining him $1000 pounds you can actually put him away now.
Now if you don't find any more evidence there than you go on your way. Have you wasted your time? Yes, yes you have, but arresting him for hyperbole isn't going to make your time any less wasted.
The only reason to actually arrest him for tweeting that is if tweeting itself is an offense, and what is the harm in having people say random, kinda sorta maybe threatening things on twitter? Are you worried that all that noise may make it harder to spot the real terrorists that are publicly sending threatening tweets under their real names?
BOOM!
I was expecting you to be incorrect about alloys being stronger in compression than tension at these scales, but after working the numbers it looks like you are right. The components of engines aren't large enough to have buckling start to make tensile strength much cheaper (per mass) than compressive strength.
As far as a specific case involving steel, it looks like we'd have a total yield strength of 400-700 MPa. The buckling failure mode is more complicated, as it depends on the dimensions of the column. If we assume a Young's Modulus of 200 GPa, a length of .2 meters, and width and height of .02 and .03 meters (so I = 2E-8) then we get a critical force of just under a million Newtons. For comparison at 500 MPa that same bar of steel would fail at around a third that amount of tensile force. Titanium is even worse for that specific geometry. I chose .2 meters because it's on the long side as well, a shorter rod would be even better under compression (and identical under tension).
I chose a K of 1.0 rather than 2.0, because even though one end moves laterally, it's not free to move laterally, it is still bound to move in a specific orientation, so it's fixed, even though it's not motionless.
No, that's the Electoral College.
The Earth would appear to be straight up from some parts of the moon, but from others it would be very close to the horizon, and anywhere in between.
That's not the same thing though, because until 60 years ago every single bit of material we mined out of the Earth stayed here. Even today the vast majority of what we mine stays here, and the majority of mass that we've sent off of Earth is in LEO and will come back to Earth within a few decades.
Of course even if we had been shipping things off of Earth this whole time it wouldn't have made much of a dent. The earth has a radius of 6,371 km, and we mine--what--10 miles deep? 50? The crust is a lot less dense than the core too.
I just find it amusing that humans gazing up at the moon think, "Gee, I bet there's some shit up there I could strip mine and sell".
If there are advanced races in the universe, it would be completely understandable if they decided to just go ahead and destroy Earth.
Are those advanced races going to destroy Earth because they are repulsed by our obsession with material goods? Or are they going to destroy Earth because there is some shit here that they can strip mine and sell?
I'd feel much better about dumping nukewaste that we know will be harmless in a couple years, than dumping, say, heavy metals that we know will never, ever be harmless.
After the nuclear waste cools down won't it still be a heavy metal, similarly dangerous to the other heavy metals? Just because it's not radioactive anymore doesn't mean it still can't be dangerous. The big difference between nuclear power and other generation methods isn't that nuclear waste is less dangerous, it's that it's more compact and easier to collect.
Not only does it disable the task manager, this (or a variant of it) disables Control Panel and ways to get to useful parts of the control panel without going through it (like running msconfig.exe directly). They also change your proxy settings on your web browsers so that you can't go online to attempt to trouble shoot the problem. At this point even an above-average computer user can be flummoxed as most of the basic tools are taken away from them. Although after this point they kinda drop the ball. Once you go into safe mode and look at the start up tasks the offending processes have been random collections of letters. Seems odd that they don't name themselves "Microsoft Security Panel" or something else like that.
- Viagra ads for those who appear to have undersized genitals
So you are saying they should put this technology in airport X-Ray machines?
"If that topic is forbidden, then surly it's ok to ban this topic, too"
No it's not. And don't call me surly.
Just like there are lettuce farms, carrot farms, and potato farms, there are also tree farms. Believe it or not companies that sell lumber and a paper understand that if all the trees they log disappear then they will too.
"Environmentalists" have cultivated this idea that loggers clear cut forests and then never replace them, however that's just not the case. The trees that are felled today for lumber and paper were specifically grown for that purpose. If the demand for paper and lumber fell to zero, what would happen to these tree farms? Even if you assume that the land isn't sold and turned into shopping malls, if it was untended you'd just be left with a bunch of full-grown trees sequestering a minimum amount of carbon. Purely from a CO2 standpoint it's better to plant a tree, let it grow, and once the rate of growth (and CO2 sequestration) falls off then cut it down, build a deck, and plant another one.
The very real problem of jungle deforestation is mostly due to burning down jungle land so that people (often poor people) can use the land for farming and ranching. This actual problem is 100% divorced from lumber or paper industries.
I've always been skeptical of the use of recycled paper for this very reason. If you are recycling all of your paper then you are never taking any CO2 out of the atmosphere, while you are still doing cleaning and processing on it, so you are obviously using energy.
However if you make fresh paper, use it, then bury it in a landfill you are still partially sequestering that carbon. Of course it takes more energy to make fresh paper than recycled paper, so it's completely possible that the energy (and thus CO2 for most forms of energy generation) saved from recycling the paper makes up for the lack of sequestration. You also use less chemicals to redye recycled paper than when you make it from scratch.
It seems like a fairly complicated cost-benefit analysis actually, but I have never seen anyone talk about crunching those numbers. By far the biggest reason I have heard for recycling paper is to "save the trees" which is stupid. When was the last time someone told you to stop eating salad in order to "save the lettuce?"
They could have caught him cutting open his little sister for all I care.
The school claims the system was only used to locate stolen laptops. If the kid's laptop had indeed been reported as stolen to the school, all 'bad things' that it caught (like him masturbating) isn't the school's fault.
If it HADN'T been reported stolen, then they have no 'get out of jail free card' on seeing him cutting open his little sister. They're still guilty of illegal wire tapping and if they've done it once, it really should be up to them to prove, no-one has been using the system to spy on people.
Actually it seems like even if the laptop had been stolen spying on the thief would still be unconstitutional. They should have to report the theft to the police and tell them the laptop has that capability, the police would then get a warrant and use the camera. Of course using it in an actual theft scenario is far less immoral than how it was used here, and would still get you the laptop back, but it seems like the evidence gathered by school district with the laptop camera wouldn't be admissible in court.
Some of the newer Anti-theft measures from professional companies work like this, where the owners of the computer don't have the ability to do the computer traces, the police have to contact the company directly. That is how the program-maker's newer programs work, and they are patching this error out of the older program used by this school district.
For the car analogy, if your car with OnStar is stolen the police can contact OnStar and request that they kill the engine. The dealership that you bought the car from does not have the ability to kill the engine if you are late on your payments, or for any other reason.
If he doesn't feel qualified to pass judgment on the administrator of a school then he may be in the wrong line of work. Maybe he should make a list of all the people he's not qualified to judge on and he can be removed from any trials which involve them. Of course if "Junior High School Administrator" is on that list it may be faster if he makes a list of the professions he is qualified to judge on.
"But, you could be completely wrong!" Yes. I suppose we could. But in that case, we could be wrong in an infinite number of ways. And an earth destroying black hole would require us to be wrong in a very specific way on par with, "Our knowledge of electricity could be wrong and some magical circuit with just the right components will end all of reality as we know it."
Isn't that exactly what they are arguing, that the LHC is the electrical circuit with just the right components to end all of reality as we know it?