I would think that at the speeds they're going at, and at low altitude where this scenario takes place, an airbrake could apply more delta-V than a jettison motor.
It doesn't take much of a change in aerodynamics to apply a force of 10g to a supersonic aircraft, after all.
I never said that we should measure Y in dollars, and I *certainly* don't want corporate contractors making that decision.
What I'm saying is that if it's determined that spending $10 million has a 1% chance of saving the lives of a crew of ten over the lifetime of the craft, then you're at $1 million per death averted. Is that worth it?
That's a moral question, not a scientific question -- and also not one to be made by corporate accountants.
I don't think affirmative-action-gone-amok has anything to do with socialism, really. You can have one without the other -- affirmative action persists in areas of the economy that are very far from socialistic, and yet countries that are more socialist than the US don't have these sorts of problems.
It takes a modern computer far less than six days to computationally model the behavior of the large belt of asteroids between Mars and Jupiter using Newton's law of gravitation.
If you do that, you'll see large gaps ("Kirkwood gaps") develop at radii corresponding to orbital resonances with Jupiter. These gaps take far more than six thousand years to develop.
If you look at the asteroid belt, such gaps actually exist. If the Universe is six thousand years, how did they get there? (No credit for "The universe is young but God wanted it to look old".)
***
There are celestial bodies far in excess of six thousand light years away. Anyone building spacecraft surely ought to know about them.
Then there's the georadiological evidence that I'm not going to go into because it's less applicable to astronomy.
The Air Force doesn't seem to be making a moral judgment.
They're doing what any good scientist or engineer will do: "If you do this, this will happen. I'm not telling you what you *should* do, but simply what will happen if you do it."
Especially for a German. He designed the thing, wound up retiring from NASA, and teaching English in his German accent.
Guy had quite the sense of humor, along with a reputation for being hard as hell. I asked him in the halls one day how many people had dropped dead from his latest exam, and he said "Oh, all of them! I run a mortuary on the side; good way to get more business!"
I think rather we should look at the cost-benefit ratio of decreasing the risk by a given amount, i.e. if a design decision that costs $X will on average save the lives of Y astronauts over the course of the design, should it be made?
I'm not claiming to know what the correct values of X and Y are. But I believe we should take all reasonable precautions to decrease risk, and this is really the only way to quantify "reasonable". (Granted, "reasonable" might include a lot fewer things than Nasa's doing.)
Fortunately it seems like this is a problem that *could be corrected* fairly easily -- with, say, a propulsion mechanism on the escape capsule, just enough to give enough delta-V that it would clear the debris cloud in time to deploy the parachutes. It's even easier since you're flying through the air: perhaps you could deploy some sort of air brake or aerodynamic device to change the drag characteristics of the capsule enough to escape the cloud?
It doesn't have to survive the heat or provide a safe landing -- all it has to do is bump you out of the debris cloud, and you're good.
I worked at Marshall Space Flight Center -- the facility where the Ares is being developed -- for a while as part of an undergrad summer research project. While it may not be polite to say such things, AC's criticism of NASA's affirmative action policies is spot on.
My boss and his officemate were both affirmative action hires. My boss couldn't remember his computer password and called IT every time he crashed WinNT and needed to reboot. His officemate just put his on a stickynote on his monitor. When he got a new computer he had to get me (an undergrad) to make him a desktop shortcut to Solitaire. I have no idea what that guy did other than order office supplies.
My boss often skipped work to play golf, leaving me in charge of the lab. I wound up growing samples in a gas deposition chamber and giving them to him to catalog and characterize. At one point I asked him how the characterization was going, and he said that the Raman spectroscopy lab was buried under a backlog of debris from Columbia (which was earlier that year). At the end of the summer I had a chat with *his* boss, who told me that there was no such backlog... and then we found all the samples I had painstakingly grown and labelled lying jumbled in the bottom of a drawer of his.
While it makes me sad to say it, I've seen Marshall Space Flight Center incompetence with my own eyes. I'm from Huntsville, the city where MSFC is located. When I was growing up Real Science got done there -- my high school English teacher is the guy who built the Lunar Rover. But it's gone downhill.
I also know the guy who's in charge of systems integration for the Ares project. He's a young-earth creationist. I have little faith in the engineering acumen of anyone who can accomplish such a massive feat of ignoring experimental evidence.
Solid rocket motors, however, tend to "go to hell all of a sudden" in a rather spectacular way. "Sucks to be you" is really their only failure mode.
Re:Any recommendations for a digital point-n-shoot
on
Kodak Kills Kodachrome
·
· Score: 1
Sure can.
I've been using the Panasonic FZ line for a long time. The FZ50 is the best of the line -- very durable, with a super 12x zoom lens. Makes beautiful prints. They don't make them any more, but you can pick a used one up for $325 from keh.com. I bought mine used from them and it was in perfect condition -- they're a respectable outfit.
The FZ18 and FZ28 are good too (both have RAW), but don't perform quite as well in low light. They're smaller, though -- the FZ50 is a fairly bulky thing (but did I mention how good the images were)?
There aren't many manufacturers who do lens corrections these days on digital. Panasonic and Olympus do it on their "micro 4/3" cameras (a very new invention); Nikon does correction of chromatic aberration; and Olympus claims to do automatic shading correction but none of their lenses actually need it (by design of the 4/3 standard).
Digital images these days are subjected to far more scrutiny than film was. Simply holding "up" on the keyboard in Picasa gives you the equivalent of a 40x30 print two feet from your eyeballs, which is pretty ridiculous.
Lenses today are sometimes better than they used to be. Sigma has recently used new technology to make a 50mm f/1.4 that outperforms any of the old designs from Canon/Nikon/Pentax/etc. There's less demand for some of those insane telephotos now because improvements in coatings and so on mean that you can get by with a medium-tele and a teleconverter with nearly the same optical quality.
Zooms are of course a lot better than they used to be too. A cheap old prime lens is better than a modern cheap zoom lens, but some of the modern high-end zoom lenses are ridiculously good. Olympus makes a couple of f/2 zooms that are stunningly good.
I agree with you to a point on autofocus. I need it much of the time (birds, wildlife), plus my viewfinder is smallish for judging critical manual focus without some sort of split-prism.
On the other hand, autofocus isn't as bad as you imply. I have mine set to "center point only", and simply put the little dot over what I want to focus on, focus, reframe the shot how I want it to be, and shoot. It's pretty painless.
But I have a couple of (wonderful) old OM manual focus lenses, and those are a pain in the butt to use without a split prism.
Note that you CAN get these focus screens installed as an aftermarket thing -- the company that makes them is called Katz Eye, I think, and I've heard good things about them.
I can change most anything interesting on my $400 SLR without taking my eye away from the viewfinder. There's only one control wheel, but it's pretty simple: one button that's easy to find (right by the shutter) for exposure compensation, another easy-to-find button for ISO, and just turn the wheel by itself for aperture. Pushing a button for exposure compensation isn't a problem, since you push that button with the finger that rests on the shutter.
You can even set flash power without taking your eye off the viewfinder.
For more esoteric things, there's a switch for AF/MF on the lens, and another button that's not hard to find on the camera body for continuous-drive autofocus if you want to get esoteric.
You can even change white balance without taking your eye from the viewfinder -- push a button and turn the wheel (not hard to do), and you can pick a Kelvin temperature.
I used to use a camera with two wheels, and find the Olympus interface I have now about as easy to use.
Beyond a certain point, you don't get much better pictures from higher priced equipment. What you get is the ability to take pictures in situations where cheaper equipment would be unable to get a decent shot.
In the example you give, the f/4 lens is actually slightly optically better than the f/2.8. If you have enough light to feed it, it'll look fantastic. But the f/2.8 lens is a lifesaver if you actually need that last stop.
These are, of course, both Canon high-quality L lenses. I, as a graduate student, can't afford stuff like this and only have slow f/5.6 zooms like this. But once you stop it down to f/7 (or if you don't run it all the way out to 300mm), it's very nearly as good as the expensive stuff. At least in what I do (nature), most of the time you don't shoot wide open anyway because you want more DOF when you can get it, not less.
Having slow glass doesn't mean your pictures are worse; it means that in some situations you just can't get the picture, period. You have to give up (or push ISO higher than you want) when the people with fast glass can just open another stop.
(And you are completely right about IS. It is pretty darn amazing how much it improves the experience of using a long lens.)
Seconded. Right now my only remote timer for doing timelapse photography is an eeepc, and its battery only lasts 10 hours -- dying right before sunrise when I really needed it at one point.
I bought an Olympus E-510 for $400 along with two lenses, and paid another $220 for a 600mm equivalent supertelephoto lens to shoot birds with (a Circuit City closeout; normal new price is $300). You can be a lot cheaper than that by buying just the body and getting cheap (but good) old manual lenses and an adapter.
So this is not true, unless you mean "full-frame" by "full-size"... and you certainly don't need a full-frame DSLR to take great photos. Even a quarter-frame DSLR like the Olympus mentioned above has better low-light performance than film -- I have ISO 800 enlargements that look great.
For that matter, you can make great photos on much cheaper digital cameras. Before the Olympus I had a Panasonic FZ50 which I bought for $260 or so. I have 16x20" prints from it hanging on my walls that look stunning. It's not an SLR, so there are the headaches of an electronic viewfinder and so on... but it certainly makes great prints if you can stay at ISO 100.
You don't need to pay Canon $2k to make good digital pictures.
Fair point -- I have installed XP only, as Vista sucks too hard to mess with (any OS with built-in DRM is a non-option, not to mention that I don't need a 10GB+ OS lying around).
I imagine Vista is still more painful, since it likely needs sixteen reboots before the drivers all get installed? (And, likely, clicking through EULA's?)
Also, should we be surprised that it doesn't crash? The world has lots of Linux machines that people just forget about, shoved under desks and in closets, that sit there doing their jobs without people worrying about them crashing.
If MS can make an operating system that doesn't crash much... well, hooray. That's like making a car whose brakes work.
I use ubuntu on both my laptop and desktop. Both work just fine with very little hassle.
Ever tried installing Windows on a machine and then spending the next few hours updating drivers and security patches, and then downloading all the stuff you need (firefox/OpenOffice/trillian/winamp/whatever) to actually get your stuff done? THAT is a hassle.
Installing Ubuntu consists of:
1) stick thumbdrive in netbook 2) boot netbook 3) click "install" and decide how big you want the partition to be 4) notice that while you're doing that it has found your wireless network 5) run pidgin and talk to people while waiting a few minutes for the install 6) tell friends you're going down for reboot and will be right back 7) boot working system with tons of useful software
Slashdot Mirror
I would think that at the speeds they're going at, and at low altitude where this scenario takes place, an airbrake could apply more delta-V than a jettison motor.
It doesn't take much of a change in aerodynamics to apply a force of 10g to a supersonic aircraft, after all.
I never said that we should measure Y in dollars, and I *certainly* don't want corporate contractors making that decision.
What I'm saying is that if it's determined that spending $10 million has a 1% chance of saving the lives of a crew of ten over the lifetime of the craft, then you're at $1 million per death averted. Is that worth it?
That's a moral question, not a scientific question -- and also not one to be made by corporate accountants.
Why don't we just make the congresscritters test the SRB's for safety?
I don't think affirmative-action-gone-amok has anything to do with socialism, really. You can have one without the other -- affirmative action persists in areas of the economy that are very far from socialistic, and yet countries that are more socialist than the US don't have these sorts of problems.
Obvious troll is obvious.
It takes a modern computer far less than six days to computationally model the behavior of the large belt of asteroids between Mars and Jupiter using Newton's law of gravitation.
If you do that, you'll see large gaps ("Kirkwood gaps") develop at radii corresponding to orbital resonances with Jupiter. These gaps take far more than six thousand years to develop.
If you look at the asteroid belt, such gaps actually exist. If the Universe is six thousand years, how did they get there? (No credit for "The universe is young but God wanted it to look old".)
***
There are celestial bodies far in excess of six thousand light years away. Anyone building spacecraft surely ought to know about them.
Then there's the georadiological evidence that I'm not going to go into because it's less applicable to astronomy.
The Air Force doesn't seem to be making a moral judgment.
They're doing what any good scientist or engineer will do: "If you do this, this will happen. I'm not telling you what you *should* do, but simply what will happen if you do it."
Rather than investing more in escape systems, it might make more sense to spend the same amount of money making rockets that blow up less...
Especially for a German. He designed the thing, wound up retiring from NASA, and teaching English in his German accent.
Guy had quite the sense of humor, along with a reputation for being hard as hell. I asked him in the halls one day how many people had dropped dead from his latest exam, and he said "Oh, all of them! I run a mortuary on the side; good way to get more business!"
I think rather we should look at the cost-benefit ratio of decreasing the risk by a given amount, i.e. if a design decision that costs $X will on average save the lives of Y astronauts over the course of the design, should it be made?
I'm not claiming to know what the correct values of X and Y are. But I believe we should take all reasonable precautions to decrease risk, and this is really the only way to quantify "reasonable". (Granted, "reasonable" might include a lot fewer things than Nasa's doing.)
Fortunately it seems like this is a problem that *could be corrected* fairly easily -- with, say, a propulsion mechanism on the escape capsule, just enough to give enough delta-V that it would clear the debris cloud in time to deploy the parachutes. It's even easier since you're flying through the air: perhaps you could deploy some sort of air brake or aerodynamic device to change the drag characteristics of the capsule enough to escape the cloud?
It doesn't have to survive the heat or provide a safe landing -- all it has to do is bump you out of the debris cloud, and you're good.
I worked at Marshall Space Flight Center -- the facility where the Ares is being developed -- for a while as part of an undergrad summer research project. While it may not be polite to say such things, AC's criticism of NASA's affirmative action policies is spot on.
My boss and his officemate were both affirmative action hires. My boss couldn't remember his computer password and called IT every time he crashed WinNT and needed to reboot. His officemate just put his on a stickynote on his monitor. When he got a new computer he had to get me (an undergrad) to make him a desktop shortcut to Solitaire. I have no idea what that guy did other than order office supplies.
My boss often skipped work to play golf, leaving me in charge of the lab. I wound up growing samples in a gas deposition chamber and giving them to him to catalog and characterize. At one point I asked him how the characterization was going, and he said that the Raman spectroscopy lab was buried under a backlog of debris from Columbia (which was earlier that year). At the end of the summer I had a chat with *his* boss, who told me that there was no such backlog... and then we found all the samples I had painstakingly grown and labelled lying jumbled in the bottom of a drawer of his.
While it makes me sad to say it, I've seen Marshall Space Flight Center incompetence with my own eyes. I'm from Huntsville, the city where MSFC is located. When I was growing up Real Science got done there -- my high school English teacher is the guy who built the Lunar Rover. But it's gone downhill.
I also know the guy who's in charge of systems integration for the Ares project. He's a young-earth creationist. I have little faith in the engineering acumen of anyone who can accomplish such a massive feat of ignoring experimental evidence.
Solid rocket motors, however, tend to "go to hell all of a sudden" in a rather spectacular way. "Sucks to be you" is really their only failure mode.
Sure can.
I've been using the Panasonic FZ line for a long time. The FZ50 is the best of the line -- very durable, with a super 12x zoom lens. Makes beautiful prints. They don't make them any more, but you can pick a used one up for $325 from keh.com. I bought mine used from them and it was in perfect condition -- they're a respectable outfit.
The FZ18 and FZ28 are good too (both have RAW), but don't perform quite as well in low light. They're smaller, though -- the FZ50 is a fairly bulky thing (but did I mention how good the images were)?
So what do you call prints made from images captured by a CCD?
Was that Canon f/1 lens very sharp?
There aren't many manufacturers who do lens corrections these days on digital. Panasonic and Olympus do it on their "micro 4/3" cameras (a very new invention); Nikon does correction of chromatic aberration; and Olympus claims to do automatic shading correction but none of their lenses actually need it (by design of the 4/3 standard).
Digital images these days are subjected to far more scrutiny than film was. Simply holding "up" on the keyboard in Picasa gives you the equivalent of a 40x30 print two feet from your eyeballs, which is pretty ridiculous.
Lenses today are sometimes better than they used to be. Sigma has recently used new technology to make a 50mm f/1.4 that outperforms any of the old designs from Canon/Nikon/Pentax/etc. There's less demand for some of those insane telephotos now because improvements in coatings and so on mean that you can get by with a medium-tele and a teleconverter with nearly the same optical quality.
Zooms are of course a lot better than they used to be too. A cheap old prime lens is better than a modern cheap zoom lens, but some of the modern high-end zoom lenses are ridiculously good. Olympus makes a couple of f/2 zooms that are stunningly good.
I agree with you to a point on autofocus. I need it much of the time (birds, wildlife), plus my viewfinder is smallish for judging critical manual focus without some sort of split-prism.
On the other hand, autofocus isn't as bad as you imply. I have mine set to "center point only", and simply put the little dot over what I want to focus on, focus, reframe the shot how I want it to be, and shoot. It's pretty painless.
But I have a couple of (wonderful) old OM manual focus lenses, and those are a pain in the butt to use without a split prism.
Note that you CAN get these focus screens installed as an aftermarket thing -- the company that makes them is called Katz Eye, I think, and I've heard good things about them.
Wait, what?
I can change most anything interesting on my $400 SLR without taking my eye away from the viewfinder. There's only one control wheel, but it's pretty simple: one button that's easy to find (right by the shutter) for exposure compensation, another easy-to-find button for ISO, and just turn the wheel by itself for aperture. Pushing a button for exposure compensation isn't a problem, since you push that button with the finger that rests on the shutter.
You can even set flash power without taking your eye off the viewfinder.
For more esoteric things, there's a switch for AF/MF on the lens, and another button that's not hard to find on the camera body for continuous-drive autofocus if you want to get esoteric.
You can even change white balance without taking your eye from the viewfinder -- push a button and turn the wheel (not hard to do), and you can pick a Kelvin temperature.
I used to use a camera with two wheels, and find the Olympus interface I have now about as easy to use.
I have a minor quibble with this.
Beyond a certain point, you don't get much better pictures from higher priced equipment. What you get is the ability to take pictures in situations where cheaper equipment would be unable to get a decent shot.
In the example you give, the f/4 lens is actually slightly optically better than the f/2.8. If you have enough light to feed it, it'll look fantastic. But the f/2.8 lens is a lifesaver if you actually need that last stop.
These are, of course, both Canon high-quality L lenses. I, as a graduate student, can't afford stuff like this and only have slow f/5.6 zooms like this. But once you stop it down to f/7 (or if you don't run it all the way out to 300mm), it's very nearly as good as the expensive stuff. At least in what I do (nature), most of the time you don't shoot wide open anyway because you want more DOF when you can get it, not less.
Having slow glass doesn't mean your pictures are worse; it means that in some situations you just can't get the picture, period. You have to give up (or push ISO higher than you want) when the people with fast glass can just open another stop.
(And you are completely right about IS. It is pretty darn amazing how much it improves the experience of using a long lens.)
Seconded. Right now my only remote timer for doing timelapse photography is an eeepc, and its battery only lasts 10 hours -- dying right before sunrise when I really needed it at one point.
I bought an Olympus E-510 for $400 along with two lenses, and paid another $220 for a 600mm equivalent supertelephoto lens to shoot birds with (a Circuit City closeout; normal new price is $300). You can be a lot cheaper than that by buying just the body and getting cheap (but good) old manual lenses and an adapter.
So this is not true, unless you mean "full-frame" by "full-size"... and you certainly don't need a full-frame DSLR to take great photos. Even a quarter-frame DSLR like the Olympus mentioned above has better low-light performance than film -- I have ISO 800 enlargements that look great.
For that matter, you can make great photos on much cheaper digital cameras. Before the Olympus I had a Panasonic FZ50 which I bought for $260 or so. I have 16x20" prints from it hanging on my walls that look stunning. It's not an SLR, so there are the headaches of an electronic viewfinder and so on... but it certainly makes great prints if you can stay at ISO 100.
You don't need to pay Canon $2k to make good digital pictures.
Fair point -- I have installed XP only, as Vista sucks too hard to mess with (any OS with built-in DRM is a non-option, not to mention that I don't need a 10GB+ OS lying around).
I imagine Vista is still more painful, since it likely needs sixteen reboots before the drivers all get installed? (And, likely, clicking through EULA's?)
Uh, that youtube link is a fake. :)
[citation needed]
Seriously, how is it better than XP?
Also, should we be surprised that it doesn't crash? The world has lots of Linux machines that people just forget about, shoved under desks and in closets, that sit there doing their jobs without people worrying about them crashing.
If MS can make an operating system that doesn't crash much ... well, hooray. That's like making a car whose brakes work.
Sure it can.
I use ubuntu on both my laptop and desktop. Both work just fine with very little hassle.
Ever tried installing Windows on a machine and then spending the next few hours updating drivers and security patches, and then downloading all the stuff you need (firefox/OpenOffice/trillian/winamp/whatever) to actually get your stuff done? THAT is a hassle.
Installing Ubuntu consists of:
1) stick thumbdrive in netbook
2) boot netbook
3) click "install" and decide how big you want the partition to be
4) notice that while you're doing that it has found your wireless network
5) run pidgin and talk to people while waiting a few minutes for the install
6) tell friends you're going down for reboot and will be right back
7) boot working system with tons of useful software