It's the typical Cambridge (Mass) conceit that if it doesn't happened within 50 miles of Kendall Square (or Harvard Square, depending on your persuasion) it doesn't count, and if it does, you should know about it.
Unix is not Multics (thus the name) and that is really all you need to know about Multics (except that a generation of MIT hackers cut their teeth in figuring out how to hack it).
This reminds me of the problems with perceptrons (a early, linear, neural net), which caused AI scientists to loose interest in them, until neural nets came along.
In "eternal inflation," inflation is seen as something like the natural state of the universe, with little nodes from time to time budding off of the inflationary stream, and forming universes like our own, with inflation continuing elsewhere (from our standpoint, very very far away, much beyond any distance we could reach, even if we traveled at the speed of light). In such theories, the big bang is not the time of the birth of the universe, it is the time of the cession of inflation here, in our part of this bigger universe. This is one type of what Max Tegmark calls a Level I Multiverse (as there would be other "big bangs" elsewhere).
It may be that the recent detection of cosmic acceleration (aka "dark energy") indicates that our universe may (if the acceleration itself starts to accelerate into something like a "big rip") return to this natural state of inflation in due course, and that might be the typical fate of "normal" universes like ours.
...the only interaction they can conceivably have with normal matter is via a nuclear recoil.
No, not quite. These neutrinos also interact gravitationally with ordinary matter, which, of course, the author knows, but just doesn't think of. That introduces two possible means of detecting them, either gravitationally, or by using the Sun or other bodies to focus them on a detector, thereby greatly amplifying their signal.
This is really a problem of the "dark ages" - roughly, red shifts between 1400 and 14 (i.e., the period between just after the cosmic microwave background up to the earliest quasars and galaxies). At one end, there are no black holes, at the other, there are supermassive ones, what happens in between, we don't really know. My own personal guess is that this is a consequence of dark matter, and thus wouldn't require worm-holes but, if we can test the wormhole hypothesis, we should. We know so little about the dark ages that IMHO no possibility should be ignored.
I type this on my Linux laptop that I use for work, but outside of some gaming, mobile devices have taken the crown for personal use. Mostly, I browse on my smart phone. I schedule on my smart phone. I email on my smart phone. My "TV" is actually a Google TV Stick running android. I frequently take a tablet with me when I travel, just so I can plug the hotel room HDMI into it and watch what I want, rather than "what's on".
It's funny, but I dislike using my phone for basically all of those things, and so I don't. IMHO, typing on a smart phone is much like trying to assemble Christmas toys while drunk; not pleasurable, and noteworthy mainly for the occasional disaster it causes.
On the other hand, if you go to places like Mumbai or Beijing, everyone appears to have a cell phone, and appears to use it constantly, so I can believe the overall number (well, to within a factor of 2 or so for hype inflation).
Have you ever run a technical program? If you do so (and I have, a number of times), you frequently have to evaluate technical statements by subject matter experts in areas that are not directly your field. Remember that in physics claims from authority are meaningless, all that counts is the evidence and how it is presented, and you certainly should challenge claims and statements that do not appear to be supported by the evidence. I have said nothing here I wouldn't say to Mr. Alvarez in person, should I be charged with evaluating his work, or at a meeting where this was presented, except that if this was in person, I would expect a better response than a claim from authority.
I believe that the Nevada Flats facility is basically just "storage" in this context. However, if you read this, you will see that most of the material is in other forms, such as "Molten Salt Reactor (MSRE) traps, Oxide powders and Zero Power Reactor Plates," and that potentially critical material will be "downblended," "driving the U-233 concentration below criticality and security concerns. It is to be dissolved and then downblended with depleted uranium so it can be disposed safely."
In other words, it's not like that they will put bomb components into a landfill, but everything will be converted to some form where it would be fairly complicated to make a bomb out of it.
Well, I am a physicist, and I think that the article was badly written and intended to produce more heat than light. If the author has heard such complaints and believes they have been addressed, he sure didn't do a good job doing so.
Different isotopes. This is basically highly radioactive waste, unless you want to burn it in a thorium reactor (which we are not pursuing at present).
Note that the "United States produced, over the course of the Cold War, approximately 2 metric tons of uranium-233, in varying levels of chemical and isotopic purity" (from Wikipedia. As best as I can tell from the BAS article, the missing U-233 is from "the Oak Ridge National Laboratory, the Rocky Flats nuclear weapons facility, and the Idaho National Laboratory" - i.e., it was weapons production related U-233, not stuff from a thorium breeder program, and probably a problem of bad book-keeping, not an actual loss of material.
Note that U233 is going to be highly radioactive, due to unavoidable U232 impurities, and will be such a strong emitter of gamma rays that this "makes manual handling in a glove box with only light shielding (as commonly done with plutonium) too hazardous." That, plus a failure to ever produce a non-fizzle U233 bomb, means that this really isn't a good fission bomb source material.
All in all, I actually expect better from the Bulletin of the Atomic Scientists.
Well, duh, don't connect them to the Internet. Unplug them from the wall when they are not in use, and cover over camera lenses with tape. But you should do that already.
The question is not really whether some physical process is random, the question is whether someone could predict some of the bits, say if you immersed the camera in a light field pulsed at the ccd refresh rate. Or an electromagnetic field that saturates the A/D converters wiring. Or...
The thing is that such a design has to be fixed, and then released in the field, and then be subjected to attacks tailored to its individual design and implementation, and there really is no magic bullet. So, "Counting the number of photons gives a straightforward way of generating random numbers" : maybe, but we won't know for sure if they are really and always random until it's been attacked for a few years.
Conventional thinking suggests that stars closest to the center of a given star cluster should be the oldest and the youngest stars can be found around the edges.
Does anyone understand why this conventional wisdom took hold?
These are open clusters. Over time, stars will leave the region of their birth. That would suggest to me that the oldest stars would be on the edges, and the newest, in the center, which was exactly what was observed. So why, exactly, was the prior belief the opposite?
So you would have it choose to mow down the stationary infant in its stroller as opposed to tapping a parking pickup truck backing up at at 10 MPH?
The problem with his original question is that he assumes the self-driving car has knowledge of the type, mass, and vulnerability of things around it. This might be the test case for the three laws of robotics - do not ever choose to hit an unprotected human (probably includes motorcyclists, bicyclists, and pedestrians). If you know (by a beacon or whatever) that a vehicle is completely autonomous and does not contain humans and has comparable delta-V, give that preference. If hitting a vehicle likely containing a human is inevitable, choose the lowest speed impact.
Now, that actually sounds sensible and it works in Asimov's laws. Excellent.
Slashdot Mirror
Machine Aided Computation.
It's the typical Cambridge (Mass) conceit that if it doesn't happened within 50 miles of Kendall Square (or Harvard Square, depending on your persuasion) it doesn't count, and if it does, you should know about it.
Unix is not Multics (thus the name) and that is really all you need to know about Multics (except that a generation of MIT hackers cut their teeth in figuring out how to hack it).
This reminds me of the problems with perceptrons (a early, linear, neural net), which caused AI scientists to loose interest in them, until neural nets came along.
In "eternal inflation," inflation is seen as something like the natural state of the universe, with little nodes from time to time budding off of the inflationary stream, and forming universes like our own, with inflation continuing elsewhere (from our standpoint, very very far away, much beyond any distance we could reach, even if we traveled at the speed of light). In such theories, the big bang is not the time of the birth of the universe, it is the time of the cession of inflation here, in our part of this bigger universe. This is one type of what Max Tegmark calls a Level I Multiverse (as there would be other "big bangs" elsewhere).
It may be that the recent detection of cosmic acceleration (aka "dark energy") indicates that our universe may (if the acceleration itself starts to accelerate into something like a "big rip") return to this natural state of inflation in due course, and that might be the typical fate of "normal" universes like ours.
No, not quite. These neutrinos also interact gravitationally with ordinary matter, which, of course, the author knows, but just doesn't think of. That introduces two possible means of detecting them, either gravitationally, or by using the Sun or other bodies to focus them on a detector, thereby greatly amplifying their signal.
The depth of my lack of sympathy for the FBI on this issue would float a navy.
Mod this parent up. This there (IMHO) nothing left to say.
These are the cases we know about. I bet the detection ratio (captures / total attempts) is actually pretty small.
The military officers I have known have at least been coherent.
This is really a problem of the "dark ages" - roughly, red shifts between 1400 and 14 (i.e., the period between just after the cosmic microwave background up to the earliest quasars and galaxies). At one end, there are no black holes, at the other, there are supermassive ones, what happens in between, we don't really know. My own personal guess is that this is a consequence of dark matter, and thus wouldn't require worm-holes but, if we can test the wormhole hypothesis, we should. We know so little about the dark ages that IMHO no possibility should be ignored.
I am surprised they don't mention the Event Horizon Telescope, which could resolve this.
I type this on my Linux laptop that I use for work, but outside of some gaming, mobile devices have taken the crown for personal use. Mostly, I browse on my smart phone. I schedule on my smart phone. I email on my smart phone. My "TV" is actually a Google TV Stick running android. I frequently take a tablet with me when I travel, just so I can plug the hotel room HDMI into it and watch what I want, rather than "what's on".
It's funny, but I dislike using my phone for basically all of those things, and so I don't. IMHO, typing on a smart phone is much like trying to assemble Christmas toys while drunk; not pleasurable, and noteworthy mainly for the occasional disaster it causes.
On the other hand, if you go to places like Mumbai or Beijing, everyone appears to have a cell phone, and appears to use it constantly, so I can believe the overall number (well, to within a factor of 2 or so for hype inflation).
Have you ever run a technical program? If you do so (and I have, a number of times), you frequently have to evaluate technical statements by subject matter experts in areas that are not directly your field. Remember that in physics claims from authority are meaningless, all that counts is the evidence and how it is presented, and you certainly should challenge claims and statements that do not appear to be supported by the evidence. I have said nothing here I wouldn't say to Mr. Alvarez in person, should I be charged with evaluating his work, or at a meeting where this was presented, except that if this was in person, I would expect a better response than a claim from authority.
Yeah, and that was about as realistic as the rest of the "1999" plot lines.
I believe that the Nevada Flats facility is basically just "storage" in this context. However, if you read this, you will see that most of the material is in other forms, such as "Molten Salt Reactor (MSRE) traps, Oxide powders and Zero Power Reactor Plates," and that potentially critical material will be "downblended," "driving the U-233 concentration below criticality and security concerns. It is to be dissolved and then downblended with depleted uranium so it can be disposed safely."
In other words, it's not like that they will put bomb components into a landfill, but everything will be converted to some form where it would be fairly complicated to make a bomb out of it.
Well, I am a physicist, and I think that the article was badly written and intended to produce more heat than light. If the author has heard such complaints and believes they have been addressed, he sure didn't do a good job doing so.
Different isotopes. This is basically highly radioactive waste, unless you want to burn it in a thorium reactor (which we are not pursuing at present).
Thorium 232 + a neutron -> Uranium 233.
Note that the "United States produced, over the course of the Cold War, approximately 2 metric tons of uranium-233, in varying levels of chemical and isotopic purity" (from Wikipedia. As best as I can tell from the BAS article, the missing U-233 is from "the Oak Ridge National Laboratory, the Rocky Flats nuclear weapons facility, and the Idaho National Laboratory" - i.e., it was weapons production related U-233, not stuff from a thorium breeder program, and probably a problem of bad book-keeping, not an actual loss of material.
Note that U233 is going to be highly radioactive, due to unavoidable U232 impurities, and will be such a strong emitter of gamma rays that this "makes manual handling in a glove box with only light shielding (as commonly done with plutonium) too hazardous." That, plus a failure to ever produce a non-fizzle U233 bomb, means that this really isn't a good fission bomb source material.
All in all, I actually expect better from the Bulletin of the Atomic Scientists.
Well, duh, don't connect them to the Internet. Unplug them from the wall when they are not in use, and cover over camera lenses with tape. But you should do that already.
The downside is that it runs 100 times slower than C, but since it is the programmer's productivity your are talking about, you are very wrong.
You do realize that CPU limited problems are not uncommon in physics and engineering?
Yeah, I used to hear that argument a lot in 1978...
The question is not really whether some physical process is random, the question is whether someone could predict some of the bits, say if you immersed the camera in a light field pulsed at the ccd refresh rate. Or an electromagnetic field that saturates the A/D converters wiring. Or...
The thing is that such a design has to be fixed, and then released in the field, and then be subjected to attacks tailored to its individual design and implementation, and there really is no magic bullet. So, "Counting the number of photons gives a straightforward way of generating random numbers" : maybe, but we won't know for sure if they are really and always random until it's been attacked for a few years.
Can we have one science article that doesn't essentially say "everything we ever knew is wrong"...
Based on experience, no.
Does anyone understand why this conventional wisdom took hold?
These are open clusters. Over time, stars will leave the region of their birth. That would suggest to me that the oldest stars would be on the edges, and the newest, in the center, which was exactly what was observed. So why, exactly, was the prior belief the opposite?
So you would have it choose to mow down the stationary infant in its stroller as opposed to tapping a parking pickup truck backing up at at 10 MPH?
The problem with his original question is that he assumes the self-driving car has knowledge of the type, mass, and vulnerability of things around it. This might be the test case for the three laws of robotics - do not ever choose to hit an unprotected human (probably includes motorcyclists, bicyclists, and pedestrians). If you know (by a beacon or whatever) that a vehicle is completely autonomous and does not contain humans and has comparable delta-V, give that preference. If hitting a vehicle likely containing a human is inevitable, choose the lowest speed impact.
Now, that actually sounds sensible and it works in Asimov's laws. Excellent.