One of my buddies is working on this project. He had this to say about how the optics work:
"The basic idea is that under Fourier optics, a wavefront with electric field E that hits a lens with focal length f will produce the Fourier transform of that field E at a distance f from the lens. This location is called the image plane. The location of the lens is called the pupil plane, and the idea is that if you block part of the light at the pupil plane (say with a piece of material in a particular shape, called a mask), it can change the shape of the Fourier transform at the image plane. If we consider the incoming light to be from a star and a planet, we can design the mask so that there is very little light from the star in certain regions of the image plane, and we can see the light from the planet in those regions.
For a more rigorous introduction, I might recommend this paper from our group, which covers the basics of shaped pupils and shows some of our more interesting mask designs. The real challenges in this area now are eliminating the effects of tiny errors in our optics--the best we can get physically is to reduce the error in flatness of the various mirrors in the telescope design to on the order of 0.01 wavelength. (TPF will work in visible light, so that's on the order of a nanometer.) We need 0.0001 wavelength, though, and so we're trying to use adaptive optics (mirrors that we can shape) to cancel these errors. Researchers in this area are very close to achieving the "10 billion times brighter" from the article, we just need to show we can deal with these errors. Very interesting stuff."
Re:By the sound of it, they will be using optics
on
Looking for Life in Light
·
· Score: 3, Informative
I am guessing that they are talking about optical observations, since it appears to be an extra-atmospheric telescope they are designing. However, at those distances, how can they discern the difference between the shine from a planet and the light given off by the star(s) near the planet? I would think that we observe the earthshine from small enough distances that we can see it in spite of the Sun. I am curious how this would work for distant bodies.
The project is called Terrestrial Planet Finder (TPF). I don't know a ton about the details, but I know some guys who were working on it. One of the technologies being investigated (I'm not sure how well this relates to TFA, but it addresses your question directly) is an optical trick called a coronograph. The basic game is to design fancy Fourier optics that put more emphasis on small variations in off-center light. Like I said, not sure of the details, but it actually kind of works.
Seems that they realize that this is but baby steps, and there needs to be much more work done.
Amen. I'm getting sick of people reading a/. summary of a summary of someone's legitimate results and deciding then and there that the original research (whose message is now 2x re-interpreted by the successive authors) is crap. These people do this for a living; many hold tenure positions at prestigious research institutions that are reserved for the brightest in their fields. Most of their really significant results appear in peer-reviewed publications. They're probably slightly more qualified to decide what is significant in their fields than you are.
Popular media tends to mangle the crap out of stories in an effort to make it accessible to a wide variety of people. This is necessary for the sharing of information and the generation of public interest in scientific progress. If you're semi-intelligent and a particular story catches your eye, you should know enough to read between the lines a little bit. If you want to make any claims regarding validity, you need to find the original publications and make a slightly better assessment than a half-page web story can provide you with.
We're all victims here, I think. From TFA: "Conceivably, if scientists can predict how the microbes will adapt to changes in their environment, they can develop antibiotics that won't be rapidly rendered ineffective by stronger, successive generations." That's probably the real goal, the message just gets mangled by some dumbassed reporter.
We've been working at predicting evolution and using evolutionary results to explain why animals have certain characteristics for quite some time. c.f. Evolutionary Game Theory, Behavioral Ecology, Adaptive Dynamics, etc. Of course these are mostly all theoretical results. The guys from TFA are doing experimental research that happens to verify the theories, which is in itself pretty cool - it's hard to do evolutionary experiments for obvious reasons. Using bacteria isn't a particularly new idea, but modern technology is enabling more sophisticated and precise experiments.
That environment is absolutely different to real life. Try at least to have different temperature zones with more food in the hotter ones, for example. Or repeat the experiment not two, but a thousand times, and see if the result is always the same. That will be a bit more similar to real life, and so have a bit more prediction value.
I'm afraid you're another victim of popular media reporting on real science. From TFA, "Conceivably, if scientists can predict how the microbes will adapt to changes in their environment, they can develop antibiotics that won't be rapidly rendered ineffective by stronger, successive generations." This is undoubtedly the real motivation, not to test Darwin's celebrated theories.
Anyways, Darwin's theory doesn't really make any quantitative predictions. These guys are doing the basic science experiments that we haven't been able to do (not with much precision) until now b/c of technological limitations.
Now, as for the article... They perform and experiment TWICE and said that was enough to produce this theory. Because out of 2 million possible mutations, the same 6 occurred both times in large numbers.
Uhh... Don't forget CHANCE you fools. Twice is not very conclusive.
Uhh... It appeared in large numbers twice. Once was actually probably sufficient, but repeatability is always good. The probability of the mutation happening just twice amongst individual bacteria is astronomically small. It's a little like DNA tests in court - they're actually only probabilistically accurate to within about 1 in 10 billion, something on the order of one in the population of the world. It's just pretty damn unlikely that you're genetic partial-clone was also in the right place at the right time. If they can place it several times then it's especially damning.
Nevertheless, the experiments should and probably will be repeated.
Seriously though, I disagree with your assessment. The car should be much simpler tor the very reason you state -fewer degrees of freedom in the movement. You only need to worry about lert/right and forward/back, not up/down and rotation (those are pretty well fixed for cars on a road).
It's not about the number of degrees of freedom, but what the difference is between the directions you'd like to go in and the directions you can actually send yourself in. The fact that the car can't go up or down is irrelevant because it doesn't need to go up or down. Compare the satellite to the car from the standpoint of trying to drive either one just in two dimensions: Try to parallel park a car, then try to parallel park a satellite. To park the satellite, just turn it 90deg, move forward, then turn it back 90deg. To park the car, move forward, then do some complicated combination of moving backwards and steering at the same time. Or, drive in a big circle and slowly reduce the turning angle so you spiral out to the right point. The satellite is fundamentally simpler. Moving it to 3 dimensions doesn't really present any added difficulties, because you have the same freedoms. Even computationally, it's just two more numbers to keep track of (one more translation and one more rotation direction).
The reason why the satellite is a bigger technical challenge has more to do with the practical issues of controlling thrusters vs tires, the lack of references to navigate by, etc. My point was just that, in a purely dynamics/mechanics way, the car presents a fundamental challenge. You get the same sorts of problems when you want to start limiting the number of thrusters you put on your satellite.
No, but seriously, this is sad. It takes us farther away from what I'd like to see in a car, namely a self-steering one. I'd prefer one that detects an oncoming truck as oncoming and tries to get out of the way.
In some ways, the car is more difficult. The satellite is free to move in any direction (including rotation), given that we have enough thrusters. The car is nonholonomic - there are only two control inputs (turning the wheels, moving forward/backward) - so for example, moving sideways and turning on a central axis are both impossible with the car but theoretically possible with the satellite (if we're willing to spend enough on thrusters).
This is of course a gross oversimplification. It also doesn't say why the ranging failed (I didn't read the article, but probably literally a flipped sign).
These simple old tricks come all the way from my grandmother, and i've used them often enough to know that they work (either that or it's the placebo effect in action).
Dude. How often is severe diarrhea a problem for you and your family? Maybe you should be seeing someone for that.
Anyways, eating uncooked flour or normal cooked rice is probably just absorbing excess fluids in your body and giving the diarrhea a little more consistency so it slows down. The reason why diarrhea is a serious issue isn't because it's gross and inconvenient, it's dehydration. It might not be an issue for you, with nice clean drinking water on tap, but when water is already scarce and your body is flushing it out faster than you can take it in, you could really benefit from anything that helps you absorb what little you can get more efficiently.
So, basically, what scientists have shown is that reverse light (darkness) is faster than light!
Who needs experiments? Logically, we equate light with good, and Dark Helmet's law says that good is dumb, which is to say, good is slow. So light is slow. Darkness must therefore be faster than light.
Currently we are saving
equations in image format and inserting them into the document.
Please tell me there is an easier way.
AFAIK this is the only way. Openoffice doesn't even handle that that well. I use a program called eqe to generate rendered pngs from latex, then you can drag and drop the image into oo, but oo continues to look for the image file in the/tmp folder - so I have to save the image from within oo. I know that there are similar tools for mac and windows (for office) that work well, and additionally store the latex source in the image attributes and are nicely integrated so that when you double click the image in your document, the editor pops up with your latex source. I'm not aware of an oo counterpart with the same functionality (eqe is close):-/
I use Latex for everything I can. Unfortunately not everyone else does, especially for presentations. Recently I've had to work on a presentation in a group that wanted to use powerpoint. I did my part in OO.o and embedded equations as rendered pngs of latex output, but this is a big pain in the arse when it comes to wanting to *edit* the equations. There are a nice packages in windows, osx, and *nix for putting latex equations into powerpoint/oo.o presentations (unhappily, the windows and osx ones are superior b/c they integrate nicely and allow you to edit the equations), but they are all different and aren't really compatible (other than that the rendered output is pretty universal, which is a good start).
Having said that, the equation editors in Office and OO.o are awful for compatibility.
'm no biochemist, but from my rudimentary understanding of medicinal functions in the human body....isn't this how most medicines function? By 'binding' onto rogue molecules, or enabling the white blood corpuscles to do the same?
IANA Biochemist either, but my basic understanding of the big benefit of the nano-structure approach is that you can *make* the nano-structures. The drug discovery process is VERY slow - it takes years and basically a lot of luck. If we can get some success manufacturing the right binding sites, etc, then we can short circuit the whole process.
It doesn't really matter if you leave work earlier or later, as long as you leave slightly different from the rest of the pack, the road will most likely be empty.
I've found this to be mostly true, but in some circumstances I've actually found rush hour to get me there as quickly or even more quickly than when the road is clear. It all depends on the nature of the traffic during rush for you. Despite having to stop or slow down at a few particularly congested points, I can zip along during rush hour at 75+ and not have to worry about getting pulled over because I'm far from the fastest person on the road. At mid-day or late at night I get the opposite effect; I can't drive as fast because the road is full of people who either don't know the road well or are just not in any particular hurry.
It's not leaving later that saves you time, it's not driving when everyone else is driving.
I concur. It works just as well to go before the rush as after. Sometimes before is better, even. After rush you start getting the residual business/tourist traffic. My wife and I have both found that we can save at least 20 minutes by leaving at 6:50 instead of 7:00, and more like 30-45 minutes by leaving at 6:50 instead of 7:30 or 8:00.
The goal is to maximize time with your friends, family, hobby, etc. Staying late to avoid rush hour is pointless if you have somewhere you want to get to.
Amen. Winning the traffic game is silly if the only one benefitting from it is your employer.
Read man's man page some time. the -k option is like the apropos command (another thing you should look into), it searches for the word you supply in the title and description of all the manual pages.... I'm not ragging you for this or anything, I'm just amazed at how few people actually read man's man page.
A great tip, thanks. But how do you know to read the man page for man if you don't have any reason to suspect man has that kind of functionality? Or that man even *has* a man page. It seems so clear once you know, but from the n00b perspective (in general) a lot of times it just seems overwhelming - there are so many pieces of software that all do slightly different things and how do you know which one to look into? It's always discouraging when "RTFM" for X means "RTFM for X, then RTFM for Y, Z, P, and Q to understand TFM for X, then RTFM for H I J K23 to understand TFM for Y", etc, etc.
The cost is not that big a deal, either. Fifteen or seventeen inch flat panel monitors are available for less than $250 each, and can be used on other systems if the multi-monitor setup is not needed all the time.
OK, I'll take a couple of your spares. You can pay off my student loans while you're at it, too.
Autocad - developed for PC's (late 1980's). Initially expensive eye-candy.....For many so-called "Windows" packages there are normally Linux/Unix equivalents. Some *nix applications may not have as much eye-candy as an equivalent Windows application but they are normally quite functonal.
Saying that there is an *nix equivalent for ACAD is like saying that Octave is an equivalent for Matlab. I have been a power user of both (ACAD/*nix CAD and Matlab/Octave), and its just not even close. Pro/E, SolidWorks, etc.. don't really substitute either for normal 2-D drafting (though they are great for solids modeling). Luckily there ARE Matlab distributions for *nix (not free, of course). *nix ACAD would be fabulous.
This thing walks in a circle and is connected to a boom - it can't walk freely. All the legs have to worry about is front/back balance, and not side to side. Of course, making that obvious in the headline or summary would make the article seem much less interesting, and we couldn't have that, now could we?
Accepted. But that wasn't really the point of the research. If you RTFA and RTFWP (white paper), these guys are more interested in neuroscience. So what they did was design a simple mechanical system and a simple controller that both mimic the actual physical/physiological function of human legs. Balancing has alot to do with the structure of the foot and our ability to shift weight and is more of a dynamics issue. What these guys did was gait generation, which sounds simple (one foot after the other), but when you sit down and start trying to work out the details, its not so easy.
A similar (theoretical) study which actually addresses balancing (this time for insects with six legs):
J.E. Seipel, P. Holmes and R.J. Full (2004) Biological Cybernetics 91, 76-90. Dynamics and stability of insect locomotion: a hexapedal model for horizontal plane motions.
Slashdot Mirror
lmao
mod parent up, that was exactly what my internal dialog said when i read the headline
One of my buddies is working on this project. He had this to say about how the optics work:
"The basic idea is that under Fourier optics, a wavefront with electric field E that hits a lens with focal length f will produce the Fourier transform of that field E at a distance f from the lens. This location is called the image plane. The location of the lens is called the pupil plane, and the idea is that if you block part of the light at the pupil plane (say with a piece of material in a particular shape, called a mask), it can change the shape of the Fourier transform at the image plane. If we consider the incoming light to be from a star and a planet, we can design the mask so that there is very little light from the star in certain regions of the image plane, and we can see the light from the planet in those regions.
For a more rigorous introduction, I might recommend this paper from our group, which covers the basics of shaped pupils and shows some of our more interesting mask designs. The real challenges in this area now are eliminating the effects of tiny errors in our optics--the best we can get physically is to reduce the error in flatness of the various mirrors in the telescope design to on the order of 0.01 wavelength. (TPF will work in visible light, so that's on the order of a nanometer.) We need 0.0001 wavelength, though, and so we're trying to use adaptive optics (mirrors that we can shape) to cancel these errors. Researchers in this area are very close to achieving the "10 billion times brighter" from the article, we just need to show we can deal with these errors. Very interesting stuff."
I am guessing that they are talking about optical observations, since it appears to be an extra-atmospheric telescope they are designing. However, at those distances, how can they discern the difference between the shine from a planet and the light given off by the star(s) near the planet? I would think that we observe the earthshine from small enough distances that we can see it in spite of the Sun. I am curious how this would work for distant bodies.
The project is called Terrestrial Planet Finder (TPF). I don't know a ton about the details, but I know some guys who were working on it. One of the technologies being investigated (I'm not sure how well this relates to TFA, but it addresses your question directly) is an optical trick called a coronograph. The basic game is to design fancy Fourier optics that put more emphasis on small variations in off-center light. Like I said, not sure of the details, but it actually kind of works.
Seems that they realize that this is but baby steps, and there needs to be much more work done.
/. summary of a summary of someone's legitimate results and deciding then and there that the original research (whose message is now 2x re-interpreted by the successive authors) is crap. These people do this for a living; many hold tenure positions at prestigious research institutions that are reserved for the brightest in their fields. Most of their really significant results appear in peer-reviewed publications. They're probably slightly more qualified to decide what is significant in their fields than you are.
Amen. I'm getting sick of people reading a
Popular media tends to mangle the crap out of stories in an effort to make it accessible to a wide variety of people. This is necessary for the sharing of information and the generation of public interest in scientific progress. If you're semi-intelligent and a particular story catches your eye, you should know enough to read between the lines a little bit. If you want to make any claims regarding validity, you need to find the original publications and make a slightly better assessment than a half-page web story can provide you with.
We're all victims here, I think. From TFA: "Conceivably, if scientists can predict how the microbes will adapt to changes in their environment, they can develop antibiotics that won't be rapidly rendered ineffective by stronger, successive generations." That's probably the real goal, the message just gets mangled by some dumbassed reporter.
We've been working at predicting evolution and using evolutionary results to explain why animals have certain characteristics for quite some time. c.f. Evolutionary Game Theory, Behavioral Ecology, Adaptive Dynamics, etc. Of course these are mostly all theoretical results. The guys from TFA are doing experimental research that happens to verify the theories, which is in itself pretty cool - it's hard to do evolutionary experiments for obvious reasons. Using bacteria isn't a particularly new idea, but modern technology is enabling more sophisticated and precise experiments.
That environment is absolutely different to real life. Try at least to have different temperature zones with more food in the hotter ones, for example. Or repeat the experiment not two, but a thousand times, and see if the result is always the same. That will be a bit more similar to real life, and so have a bit more prediction value.
Basic science. Controlled experiments. Tractable models. Baby steps.
We'll get to that.
I'm afraid you're another victim of popular media reporting on real science. From TFA, "Conceivably, if scientists can predict how the microbes will adapt to changes in their environment, they can develop antibiotics that won't be rapidly rendered ineffective by stronger, successive generations." This is undoubtedly the real motivation, not to test Darwin's celebrated theories.
Anyways, Darwin's theory doesn't really make any quantitative predictions. These guys are doing the basic science experiments that we haven't been able to do (not with much precision) until now b/c of technological limitations.
Now, as for the article... They perform and experiment TWICE and said that was enough to produce this theory. Because out of 2 million possible mutations, the same 6 occurred both times in large numbers.
Uhh... Don't forget CHANCE you fools. Twice is not very conclusive.
Uhh... It appeared in large numbers twice. Once was actually probably sufficient, but repeatability is always good. The probability of the mutation happening just twice amongst individual bacteria is astronomically small. It's a little like DNA tests in court - they're actually only probabilistically accurate to within about 1 in 10 billion, something on the order of one in the population of the world. It's just pretty damn unlikely that you're genetic partial-clone was also in the right place at the right time. If they can place it several times then it's especially damning.
Nevertheless, the experiments should and probably will be repeated.
"I'm Feeling Lucky"
Seriously though, I disagree with your assessment. The car should be much simpler tor the very reason you state -fewer degrees of freedom in the movement. You only need to worry about lert/right and forward/back, not up/down and rotation (those are pretty well fixed for cars on a road).
It's not about the number of degrees of freedom, but what the difference is between the directions you'd like to go in and the directions you can actually send yourself in. The fact that the car can't go up or down is irrelevant because it doesn't need to go up or down. Compare the satellite to the car from the standpoint of trying to drive either one just in two dimensions: Try to parallel park a car, then try to parallel park a satellite. To park the satellite, just turn it 90deg, move forward, then turn it back 90deg. To park the car, move forward, then do some complicated combination of moving backwards and steering at the same time. Or, drive in a big circle and slowly reduce the turning angle so you spiral out to the right point. The satellite is fundamentally simpler. Moving it to 3 dimensions doesn't really present any added difficulties, because you have the same freedoms. Even computationally, it's just two more numbers to keep track of (one more translation and one more rotation direction).
The reason why the satellite is a bigger technical challenge has more to do with the practical issues of controlling thrusters vs tires, the lack of references to navigate by, etc. My point was just that, in a purely dynamics/mechanics way, the car presents a fundamental challenge. You get the same sorts of problems when you want to start limiting the number of thrusters you put on your satellite.
The $110 million DART mission was meant to test whether robots can perform some of the tasks astronauts currently must do.
Well, we answered that question. Mission accomplished!
Yes, we really HIT THE MARK with that one.
No, but seriously, this is sad. It takes us farther away from what I'd like to see in a car, namely a self-steering one. I'd prefer one that detects an oncoming truck as oncoming and tries to get out of the way.
In some ways, the car is more difficult. The satellite is free to move in any direction (including rotation), given that we have enough thrusters. The car is nonholonomic - there are only two control inputs (turning the wheels, moving forward/backward) - so for example, moving sideways and turning on a central axis are both impossible with the car but theoretically possible with the satellite (if we're willing to spend enough on thrusters).
This is of course a gross oversimplification. It also doesn't say why the ranging failed (I didn't read the article, but probably literally a flipped sign).
These simple old tricks come all the way from my grandmother, and i've used them often enough to know that they work (either that or it's the placebo effect in action).
Dude. How often is severe diarrhea a problem for you and your family? Maybe you should be seeing someone for that.
Anyways, eating uncooked flour or normal cooked rice is probably just absorbing excess fluids in your body and giving the diarrhea a little more consistency so it slows down. The reason why diarrhea is a serious issue isn't because it's gross and inconvenient, it's dehydration. It might not be an issue for you, with nice clean drinking water on tap, but when water is already scarce and your body is flushing it out faster than you can take it in, you could really benefit from anything that helps you absorb what little you can get more efficiently.
Same scientist, not as good quote, but still a great one.
Doc: "Reach!"
Train Engineer: "Is this a holdup?"
Doc: "It's a science experiment!
So, basically, what scientists have shown is that reverse light (darkness) is faster than light!
Who needs experiments? Logically, we equate light with good, and Dark Helmet's law says that good is dumb, which is to say, good is slow. So light is slow. Darkness must therefore be faster than light.
Currently we are saving equations in image format and inserting them into the document. Please tell me there is an easier way. AFAIK this is the only way. Openoffice doesn't even handle that that well. I use a program called eqe to generate rendered pngs from latex, then you can drag and drop the image into oo, but oo continues to look for the image file in the /tmp folder - so I have to save the image from within oo. I know that there are similar tools for mac and windows (for office) that work well, and additionally store the latex source in the image attributes and are nicely integrated so that when you double click the image in your document, the editor pops up with your latex source. I'm not aware of an oo counterpart with the same functionality (eqe is close) :-/
I use Latex for everything I can. Unfortunately not everyone else does, especially for presentations. Recently I've had to work on a presentation in a group that wanted to use powerpoint. I did my part in OO.o and embedded equations as rendered pngs of latex output, but this is a big pain in the arse when it comes to wanting to *edit* the equations. There are a nice packages in windows, osx, and *nix for putting latex equations into powerpoint/oo.o presentations (unhappily, the windows and osx ones are superior b/c they integrate nicely and allow you to edit the equations), but they are all different and aren't really compatible (other than that the rendered output is pretty universal, which is a good start).
Having said that, the equation editors in Office and OO.o are awful for compatibility.
That's called an antibody.
Yes, a custom-made antibody - not a drug that takes years to develop (basically by chance). That's the point.
'm no biochemist, but from my rudimentary understanding of medicinal functions in the human body....isn't this how most medicines function? By 'binding' onto rogue molecules, or enabling the white blood corpuscles to do the same?
IANA Biochemist either, but my basic understanding of the big benefit of the nano-structure approach is that you can *make* the nano-structures. The drug discovery process is VERY slow - it takes years and basically a lot of luck. If we can get some success manufacturing the right binding sites, etc, then we can short circuit the whole process.
It doesn't really matter if you leave work earlier or later, as long as you leave slightly different from the rest of the pack, the road will most likely be empty.
I've found this to be mostly true, but in some circumstances I've actually found rush hour to get me there as quickly or even more quickly than when the road is clear. It all depends on the nature of the traffic during rush for you. Despite having to stop or slow down at a few particularly congested points, I can zip along during rush hour at 75+ and not have to worry about getting pulled over because I'm far from the fastest person on the road. At mid-day or late at night I get the opposite effect; I can't drive as fast because the road is full of people who either don't know the road well or are just not in any particular hurry.
It's not leaving later that saves you time, it's not driving when everyone else is driving.
I concur. It works just as well to go before the rush as after. Sometimes before is better, even. After rush you start getting the residual business/tourist traffic. My wife and I have both found that we can save at least 20 minutes by leaving at 6:50 instead of 7:00, and more like 30-45 minutes by leaving at 6:50 instead of 7:30 or 8:00.
The goal is to maximize time with your friends, family, hobby, etc. Staying late to avoid rush hour is pointless if you have somewhere you want to get to.
Amen. Winning the traffic game is silly if the only one benefitting from it is your employer.
Read man's man page some time. the -k option is like the apropos command (another thing you should look into), it searches for the word you supply in the title and description of all the manual pages.... I'm not ragging you for this or anything, I'm just amazed at how few people actually read man's man page.
A great tip, thanks. But how do you know to read the man page for man if you don't have any reason to suspect man has that kind of functionality? Or that man even *has* a man page. It seems so clear once you know, but from the n00b perspective (in general) a lot of times it just seems overwhelming - there are so many pieces of software that all do slightly different things and how do you know which one to look into? It's always discouraging when "RTFM" for X means "RTFM for X, then RTFM for Y, Z, P, and Q to understand TFM for X, then RTFM for H I J K23 to understand TFM for Y", etc, etc.
The cost is not that big a deal, either. Fifteen or seventeen inch flat panel monitors are available for less than $250 each, and can be used on other systems if the multi-monitor setup is not needed all the time.
OK, I'll take a couple of your spares. You can pay off my student loans while you're at it, too.
Autocad - developed for PC's (late 1980's). Initially expensive eye-candy.....For many so-called "Windows" packages there are normally Linux/Unix equivalents. Some *nix applications may not have as much eye-candy as an equivalent Windows application but they are normally quite functonal.
Saying that there is an *nix equivalent for ACAD is like saying that Octave is an equivalent for Matlab. I have been a power user of both (ACAD/*nix CAD and Matlab/Octave), and its just not even close. Pro/E, SolidWorks, etc.. don't really substitute either for normal 2-D drafting (though they are great for solids modeling). Luckily there ARE Matlab distributions for *nix (not free, of course). *nix ACAD would be fabulous.
This thing walks in a circle and is connected to a boom - it can't walk freely. All the legs have to worry about is front/back balance, and not side to side. Of course, making that obvious in the headline or summary would make the article seem much less interesting, and we couldn't have that, now could we?
Accepted. But that wasn't really the point of the research. If you RTFA and RTFWP (white paper), these guys are more interested in neuroscience. So what they did was design a simple mechanical system and a simple controller that both mimic the actual physical/physiological function of human legs. Balancing has alot to do with the structure of the foot and our ability to shift weight and is more of a dynamics issue. What these guys did was gait generation, which sounds simple (one foot after the other), but when you sit down and start trying to work out the details, its not so easy.
A similar (theoretical) study which actually addresses balancing (this time for insects with six legs):
J.E. Seipel, P. Holmes and R.J. Full (2004) Biological Cybernetics 91, 76-90. Dynamics and stability of insect locomotion: a hexapedal model for horizontal plane motions.