Rather than have robots made out of prefabricated cubes, why not prefabricate the entire robot. Then when a robot wants to reproduce it just has to say "make it so" and lo! and behold! there's another prefabricated robot sitting there. I don't see that this is any less reproduction than this example. Of course, if you use the log probability measure mentioned in the paper it doesn't score too well but that could be fixed by giving each robot an on/off switch that another robot can press.
I'm sure I've seen more bogus papers than usual go by recently.
On the contrary, Penrose, genius though he is, needs to be ignored on the subject of computability. Fortunately, he is. He doesn't have anything new to contribute and repeatedly misrepresents Godel's theorem.
Yes. I guess that if you got feedback it would feel pretty cool.
But many people already feel that they are at one with their tools. Similarly, people with prosthetic limbs can sometimes feel that they really are their limbs. There are many factors that go into defining your body image, getting feedback is just one of them. In some cases you can feel that your own limb isn't part of your body even though it clearly is (eg. see various books by Oliver Sacks). I've already had one (neurally unmodified) friend report that he sometimes feels like his body extends out to the car's when he drives.
A deity capable of creating entire universes has no need to be deceitful.
That doesn't follow at all. When I see ants running around the back yard I sometimes like to confuse them and test their reactions. For example it's interesting to wipe an area of ground they've been walking over to remove the scent trail they leave. Or if they've been walking over a sheet of paper move the paper so that the trail is somewhere else. But even in a computer simulation of ants that is my own creation I'd probably play and do similar things. I have no need to do these things, but it's fun and interesting. I don't know that a deity would be into fun, or care about interest value, but I'm no surer that they wouldn't be deceitful either.
I don't understand. In what sense would it be different from the current situation? At the moment, if I want to turn left, something happens in my brain, a signal gets sent to my arms, they turn the steering wheel, and the car turns. With a direct neural connection, if I want to turn left, something happens in my brain, a signal gets sent to the car, and the car turns. In what way do these experiences differ apart from the fact that in one case your arms move? Would you feel more like 'being' the car if your arms didn't move? Are your arms (and legs) the only thing preventing you from merging with the car? What if someone numbed your arms and legs in such a way that you could still move them but you couldn't feel them. Would that make you feel like you were 'being' the car?
This attempt to seem l33t 'n' all might impress the neighbors, but if you can't figure out how to install fvwm, mutt, slrn and vim under MacOSX then I suggest you take up a hobby like flower arranging instead.
I just want to add: I've ordered 2 servos and a laser module and I intend to build some hardware to do the card reading trick without any fancy mathematics (can't afford projector so servo mounted laser will have to do). I'll report back in a few weeks on whether it works!
Let me briefly address your point about ray tracing. In ray tracing
Maybe I didn't make my point clear. When I said this I was talking solely about Helmholtz reciprocity. It isn't anything new, it's something people in graphics have been taking so much for granted they don't even know there's a name for it.
then you don't know the direction of ray (2)
Hang on. You do know the direction of ray (2) for the case of direct illumination. Given any pixel in the camera's field of view you know the direction of the corresponding ray. Without making any assumption about whether the target geometry is planar you just look for the intersection of these rays (or a least a least squares approximation to such an intersection). I know this works, in fact I was discussing building a simple 3D laser scanner out of Lego along these principles two days ago. As I say - the catch is dealing with the fact that the illumination is sometimes indirect.
I'm confused by the comments from the card trick. Illuminate each pixel in the projector one at a time. Each time you do so record the average color reflected onto the book page. Use that color to illuminate the corresponding pixel in an image. Trivial. The real trick is to confuse your readers into thinking you've done something hard by saying "It seems impossible to determine the identity...".
Given any rendering algorithm (scan line rasterization, ray-tracing, photon mapping, whatever) there is a dual one that swaps lights and cameras (though in some cases the dual is the same algorithm). I hadn't thought about looking at image capture in the same way, and for that I think the paper is interesting.
It is what they are doing. First suppose that you rasterize from the projector one pixel at a time. Getting the scene geometry in this scenario is standard "off-the-shelf" computer vision. Think about the barcode example. You don't need a priori knowledge at all because you know (1) the ray along which the laser is pointing and (2) the ray along which you have seen the point. It's fairly trivial to reconstruct the geometry.
But there are two catches: (1) when you see a point in the scene it might not be along the ray you expect from the projector because it might be due to a reflection and (2) it's expensive to rasterize each point individually so instead you use a binary coding scheme to you only have to project log(N) images, where N is the number of pixels. Dealing with these issues successfully is very cool - but fundamentally the original poster is giving a 100% correct description. This talk of "Helmholtz Reciprocity" gives the misleading impression that something deeper is going on. "Helmholtz Reciprocity" is why ray-tracing works, ie. why you can send rays 'backwards' from the camera into the scene to generate a CG image, it's not some deep new principle.
Acting by the guy (whose name I refuse to learn) who plays Annakin: 0/10 Acting by by the grits woman: 1/10 Acting by Ewan MacGregor: 2/10 Overall story: 6/10 Nostalgia value as we see the things we recognise from Episode IV: 8/10 Effects: 8/10 Pleasure from hearing Princess Leia's theme again: 8/10 Enjoyment value for those with a fetish for hand amputation: 9/10 Intelligence of characters who don't notice how Padme became pregnant: 0/10 Entertainment value of Yoda's big fight: 6/10 Entertainment value Yoda's big fight would have had if we hadn't seen it before: 10/10 General Grievous's homage to Harryhausen's Kali: 9/10 Amount of sense General Grievous subplot made after editors removed vital explanations from movie: 3/10 Did I mention Annakin's acting?: 0/10 Quality compared to Episodes I and II: 10/10 Quality compared to Episodes IV and V: 5/10 Overall: 7/10
That's a valid point. But even in a classical universe with EM traveling at c we'd still have a 2.2 billion year delay.
Also, there are meaningful ways to talk about the same time at different locations, at least approximately. For example there is a natural inertial frame for points in the universe, the one in which the cosmic background radiation appears to be at rest. (See here.) It seems reasonable to base statements about when large scale events in the universe happened on this frame. In fact, this is what astronomers implicitly do all the time and few astronomers would hesitate to say that this recent burst happened 2.2 billion years ago, even though someone flying past us at high speed might suggest a different date.
The explanation he gave is given in every popular text on the subject. But it looks different to the formal arguments. In the version I studied, you investigate how the vacuum evolves near a black hole. All kinds of funky stuff happens because your spacetime is curved and but the long and the short of it is that a big chunk of your wavefunction can't be observed because it's inside the black hole. The bit you can talk about, which is a kind of "half wavefunction" because part of it is missing, looks like multiparticle states. It's not really about particle-antiparticle creation. For example here is a link that has more words than the formal treatment I studied. Maybe there is a way of looking at this stuff that involves pair creation, but even when I raised this topic on sci.physics.research many years ago no physicist responded with an explanation of the popular account.
I may have to change it. I think it might be possible for the creator of our universe not to be able to deceive people in it. For example, one day people might figure out how to create mini-universes in a particle accelerator without having any means of interacting with what goes on within them. On the other hand, in this case it might not be correct describe such creators as deities. Similarly it might be possible to create a simulation of a universe on a computer without having the software tools to actually scan the vast amount of data produced to check for the existence of lifelike phenomena.
You are attempting to describe Hawking radiation. The burst wasn't Hawking radiation.
Also, I studied black holes for a bit (quantum field theory in curved spacetime 'n' all that). At no point was I able to make a connection between what I studied and the pop science description you just attempted. I think it probably bears little relation to the real physics!
Slashdot Mirror
I'm sure I've seen more bogus papers than usual go by recently.
On the contrary, Penrose, genius though he is, needs to be ignored on the subject of computability. Fortunately, he is. He doesn't have anything new to contribute and repeatedly misrepresents Godel's theorem.
But many people already feel that they are at one with their tools. Similarly, people with prosthetic limbs can sometimes feel that they really are their limbs. There are many factors that go into defining your body image, getting feedback is just one of them. In some cases you can feel that your own limb isn't part of your body even though it clearly is (eg. see various books by Oliver Sacks). I've already had one (neurally unmodified) friend report that he sometimes feels like his body extends out to the car's when he drives.
Hey! I didn't know about the Richert story. Thanks for that tidbit! It ought to be better publicized.
If you spell it correctly, and then do a web search, you'll see that it isn't as obscure as you might have thought. It's also beautiful stuff.
I don't understand. In what sense would it be different from the current situation? At the moment, if I want to turn left, something happens in my brain, a signal gets sent to my arms, they turn the steering wheel, and the car turns. With a direct neural connection, if I want to turn left, something happens in my brain, a signal gets sent to the car, and the car turns. In what way do these experiences differ apart from the fact that in one case your arms move? Would you feel more like 'being' the car if your arms didn't move? Are your arms (and legs) the only thing preventing you from merging with the car? What if someone numbed your arms and legs in such a way that you could still move them but you couldn't feel them. Would that make you feel like you were 'being' the car?
...I'll sleep better. My brain's always hard at work trying to solve problems I really don't want to be working on at 3am.
This attempt to seem l33t 'n' all might impress the neighbors, but if you can't figure out how to install fvwm, mutt, slrn and vim under MacOSX then I suggest you take up a hobby like flower arranging instead.
I just want to add: I've ordered 2 servos and a laser module and I intend to build some hardware to do the card reading trick without any fancy mathematics (can't afford projector so servo mounted laser will have to do). I'll report back in a few weeks on whether it works!
I was trying to be funny. But even I don't think it was funny enough to get modded to 5.
I'm confused by the comments from the card trick. Illuminate each pixel in the projector one at a time. Each time you do so record the average color reflected onto the book page. Use that color to illuminate the corresponding pixel in an image. Trivial. The real trick is to confuse your readers into thinking you've done something hard by saying "It seems impossible to determine the identity...".
Given any rendering algorithm (scan line rasterization, ray-tracing, photon mapping, whatever) there is a dual one that swaps lights and cameras (though in some cases the dual is the same algorithm). I hadn't thought about looking at image capture in the same way, and for that I think the paper is interesting.
Because, as we all know, it's GWB's policies that have caused Wired to lower their standards.
But there are two catches: (1) when you see a point in the scene it might not be along the ray you expect from the projector because it might be due to a reflection and (2) it's expensive to rasterize each point individually so instead you use a binary coding scheme to you only have to project log(N) images, where N is the number of pixels. Dealing with these issues successfully is very cool - but fundamentally the original poster is giving a 100% correct description. This talk of "Helmholtz Reciprocity" gives the misleading impression that something deeper is going on. "Helmholtz Reciprocity" is why ray-tracing works, ie. why you can send rays 'backwards' from the camera into the scene to generate a CG image, it's not some deep new principle.
For a short period before 1977 a muse alighted on Lucas's shoulders. Then she left. I hate to see Lucas getting all the credit.
Acting by the guy (whose name I refuse to learn) who plays Annakin: 0/10
Acting by by the grits woman: 1/10
Acting by Ewan MacGregor: 2/10
Overall story: 6/10
Nostalgia value as we see the things we recognise from Episode IV: 8/10
Effects: 8/10
Pleasure from hearing Princess Leia's theme again: 8/10
Enjoyment value for those with a fetish for hand amputation: 9/10
Intelligence of characters who don't notice how Padme became pregnant: 0/10
Entertainment value of Yoda's big fight: 6/10
Entertainment value Yoda's big fight would have had if we hadn't seen it before: 10/10
General Grievous's homage to Harryhausen's Kali: 9/10
Amount of sense General Grievous subplot made after editors removed vital explanations from movie: 3/10
Did I mention Annakin's acting?: 0/10
Quality compared to Episodes I and II: 10/10
Quality compared to Episodes IV and V: 5/10
Overall: 7/10
Water flowing
More water flowing
Even more water flowing
Water still flowing
Water flowing
Water flowing
Still interesting?
I have low expectations of science writers :-)
Also, there are meaningful ways to talk about the same time at different locations, at least approximately. For example there is a natural inertial frame for points in the universe, the one in which the cosmic background radiation appears to be at rest. (See here.) It seems reasonable to base statements about when large scale events in the universe happened on this frame. In fact, this is what astronomers implicitly do all the time and few astronomers would hesitate to say that this recent burst happened 2.2 billion years ago, even though someone flying past us at high speed might suggest a different date.
The explanation he gave is given in every popular text on the subject. But it looks different to the formal arguments. In the version I studied, you investigate how the vacuum evolves near a black hole. All kinds of funky stuff happens because your spacetime is curved and but the long and the short of it is that a big chunk of your wavefunction can't be observed because it's inside the black hole. The bit you can talk about, which is a kind of "half wavefunction" because part of it is missing, looks like multiparticle states. It's not really about particle-antiparticle creation. For example here is a link that has more words than the formal treatment I studied. Maybe there is a way of looking at this stuff that involves pair creation, but even when I raised this topic on sci.physics.research many years ago no physicist responded with an explanation of the popular account.
I may have to change it. I think it might be possible for the creator of our universe not to be able to deceive people in it. For example, one day people might figure out how to create mini-universes in a particle accelerator without having any means of interacting with what goes on within them. On the other hand, in this case it might not be correct describe such creators as deities. Similarly it might be possible to create a simulation of a universe on a computer without having the software tools to actually scan the vast amount of data produced to check for the existence of lifelike phenomena.
And you believed her when she told you that?
Try reading the posts before you respond.
Also, I studied black holes for a bit (quantum field theory in curved spacetime 'n' all that). At no point was I able to make a connection between what I studied and the pop science description you just attempted. I think it probably bears little relation to the real physics!