The effect cannot produce long distance communication. In the example given in the paper, for instance, the experimenters sub-select the appropriately entangled states based on the five-fold co-incidence (that is, they require a single photon in each channel.) This kind of sub-selection, which is what any communication of useful information via entanglement (as opposed to via teleportation) depends on, is only possible if information as to the triggered/untriggered state of each detector is communicated to the others by more-or-less conventional means.
This is significant, because the "collapse" of the quantum state is non-local, and any direct communication via entanglement would occur instantaneously, causing the wheels to fall off the universe.
As to "unbreakable" encryption, a line that cannot be eavesdropped on is usually considered a Good Thing with regard to unbreakablility, and the fact that the information required is distributed amongst multiple photons, with no one of them being sufficient to determine the overall state being teleported is also a Good Thing.
Long answer: sail-boats sail upwind by creating a composite force vector from wind on the sails and hydro-dynamic forces on the keel that has a net up-wind component.
There are two cases to consider for solar sails: transfer orbits, and free flight. For transfer orbits, which we'll use to get from Earth to Mars, say, the sail can be used to either increase or decrease the orbital angular momentum of the spacecraft.
If the sail is tilted at 45 degrees to the solar radius such that the reflected light is pointed in the direction of orbital motion, the spacecraft will lose orbital angular momentum and fall inward toward the sun. Tilt the sail in the opposite direction and the opposite will happen.
For a spacecraft not in a closed orbit, things are more complicated, and I don't think it has quite the same freedom of motion. I'd guess that you'd want an interstellar solar sail to spiral out from the sun until it achieved solar escape velocity, and then have it point straight back at the sun for as long as possible. At some point you'd want it to turn over and point at the target star, which, due to deterioration of the sail etc, you'd probably want to be a good deal brighter than the sun, unless you were just going to pass on by.
In practical terms, solar sails may be used to send (very small) instrument packages out to local stellar systems in our lifetimes. It's very unlikely they'll ever be used for human travel. Of course, in 1945 it was very unlikely anyone would build a rocket large enough to send people to the moon.
I think this reasoning is correct, and indeed from what we know of evolution it is also reasonable.
We know that life is not too hard to do: it came about _very_ early in the Earth's history, quite probably more than once. Likewise, there are strong suggestions of early life on Mars (and I'm still holding out hopes for Titan and Europa).
Likewise, various good tricks that life uses have evolved multiple times: wings, eyes, etc. are things that we have good evidence came about independently pretty much as soon as they possibly could.
Intelligence, on the other hand, is fantasically rare--at most one or two species in the entire history of life on Earth have managed it, and they have all been closely related. The fact that millions of other species that could have (in the sense that they had the same basic neural machinery that we have--a spinal chord, a brain, etc.) evolved intelligence but didn't strongly suggests that the evolutionary path to intelligence is very narrow, and depends on numerous low-probability events, or possibly one very low probability event.
Unlike flight, it appears that intelligence doesn't give the possessor much of an advantage until the capability is really well-developed. And it appears that the usefulness is strongly restricted to social animals to begin with, cutting down the number of potential intelligent species by a large fraction at the very start.
So I think as we venture out into the galaxy we will find life everywhere, and intelligence nowhere.
There's a novel by Donald Kingsbury, The Moon Goddess and the Son (IIRC) from the mid 80's that describes the construction of a DIY cruise missile. It was plausible then (albiet by renegade MIT students) and even moreso now.
The only curious thing is that no one has yet done it. The only reasonable conclusion is that everyone who can do it, except for this clown in New Zealand, has the good sense not to want to.
This is the difficulty: you are comparing an imaginary system to a real one.
No real electronic (or mechanical) voting system is or can be error-free, which is what you are claiming for your system. When you say that it would be an advantage to be able to say, "So-and-so GOT *exactly* 8192 votes" what you actually mean is, "THE SYSTEM COUNTED *exactly* 8192 votes, AND THERE IS NO WAY TO DO A RECOUNT." This is nothing but a false sense of accuracy.
The inability to repeat a measurement does not increase the accuracy of the measurement.
Furthermore, a paper ballot contains far more information than an electronic ballot. To compare real systems, suppose a paper ballot contains a questionable mark that may or may not indicate a vote. The scrutineers can examine it for evidence of voter intent, and ask questions like, "How firm is it? Is it at all X-like, or just a dot or a single stroke? Does it centre on a circle or is it off to the edge?" and so on.
The equivalent case in a touch-screen voting system is a voter whose sleeve brushes against the screen as they reach to make their vote. No one--not even the voter--will ever know that they didn't register the vote they intended.
Finally, marking an X in a cirle is not so much more complicated than using a touch screen (to many people it is in fact easier!) that we can expect a higher rate of voter error with paper ballots than electronic. Yet a voting machine is far more complicated than a paper ballot, and therefore will always be more subject to failure and fraud.
Ergo, anyone who cares about democracy should be opposed to electronic and mechanical voting systems as such, regardless of the relative merits of this or that machine. None of them will ever come close to the level of information and security that paper ballots provide.
I was up at dawn (more or less in the middle of the eastern time zone, so about 2 hours before the transit was complete) and just as the sun cleared the horizon the morning mist was thick enough that you could look directly at the (deep red, very dim) solar disk, and there was a tiny but clearly visible black dot, pretty much exactly in the location shown in the "ascii image", and about the same size relative to the sun.
The mist was thick enough that as the sun rose higher there was a lot of scattered light, so my helioscope didn't show anything but a blurred solar image, but it was actually cooler to be able to look at the transit directly with my bare eyeballs for a minute or so.
It's only a fair comparison if they now change sides several times. Alcibiades betrayed everyone. To do anything comparable, Rumsfeld and Cheney would have to defect to Iraq, then betray them and flee to Russia.
I'm a Canadian. I've lived on the West Coast, in Winnipeg, and in Eastern Ontario. I also spent a year in the U.S., living in L.A. (Pasadena), and have been close to several Americans over the past 15 years.
I've worked in the public sector (universities and health care as a medical physicist) and in the private sector (largish public software company, several smaller private firms.) I now own my own company (http://www.predictivepatterns.com).
In one of my previous positions the company was run by Americans but staffed by Canadians, and it made me acutely aware of the cultural differences between the two countries. The Americans wanted cheer and ethusiasm. The Canadians weren't having any. They produced solid results, but they just couldn't be all happy and excited about it, and they found the Americans' attitudes extremely wearing. The Canadians' attitudes drove the Americans nuts.
So an American coming to Canada shouldn't be fooled by the fact that most of us speak something like the same language and have some other similarities. Canadians are different. We are more small-c conservative and more small-l liberal. We are stupid and wasteful in less obvious ways than Americans. We own lots and lots of guns but hardly ever shoot anyone with them.
Our national govenment is the only one in the G8 that has its fiscal house properly in order--we have run a surplus for long enough that I can't remember offhand the last time we had a deficit (sometime in the mid-90's) and we are steadly paying down our national debt. Most provincial governments are in less good shape, but still take fiscal probity seriously.
As a business-person, I love it here. You can incorporate nationally on-line for a total of $220. The federal government is a world-leader in supplying services electronically. Labour laws are a lot tighter here than in the U.S., but the work-force is generally well-educated and even unions are a lot more reasonable than they were 20 years ago. Taxes are somewhat higher, but this is largely compensated for by not having to pay for private health insurance.
The per-capita cost of health care is significantly lower in Canada than the US. We have a three-tier health care system, in which basic service is paid for via taxes, small levels of enhanced service are available for relatively small fees, and the very rich have U.S. hospitals ready to serve them right across the border.
The basic level of care for a wide range of things is as good or better as the U.S. average, but it's widely recognized that the basic health-care system is increasingly broken. If how we dealt with the federal deficit is any indication, there will be a decade of sometimes quite nasty debate that will end in a fairly broad concensus on what to do, and we'll do it.
Americans sometimes see that we are polite, and think us weak. They see that we are calm, and think us passive. They see that we are content, and think us stupid. They are wrong on all counts.
Has anyone else noticed that the press release is virtually content free?
What it says is, "We had one successful test on a bigger, faster, higher target than before. Some other tests worked in the past, too."
What it doesn't say is:
1) How much bigger/faster/higher? 2) How many tests were unsuccessful? 3) Those past successful tests were what fraction of the total tests?
That's not even considering all the background information left out that is available elsewhere, like how big the laser system is, what its duty cycle is, etc.
What, in your view, constitutes irrefutable proof? Worldwide famine, skyrocketing cancer rates (oh wait, we already have that problem)?
From the article cited as evidence for "skyrocketing cancer rates":
The predicted sharp increase in new cases - from 10 million new cases globally in 2000, to 15 million in 2020 - will mainly be due to steadily ageing populations in both developed and developing countries
That is, cancer rates are predicted to go up primarily due to the fact that people are living longer than ever before. Cancer is a disease of age, and if you don't die of any of the things that kept the pre-industrial, pre-democratic world relatively cancer-free, you will eventually die of it (or heart-disease or stroke.)
The rest of the article focuses on the 1/3 or so of preventable cancers due to smoking, diet and other unhealthy activities that people engage in.
So much for the dire threat of "a problem we already have."
Anthropogenic global warming may (or may not) be a real phenomenon. Personally, when GCMs can deal correctly with the "early cool sun problem" I'll take them a lot more seriously.
Regardless, there are good reasons to begin moving away from fosil fuels so that over the next few generations we can become entirely dependent on renewable energy without giving up our extravagant lifestyles. But gratuitous citation of irrelevant articles does not aid the case for doing so one little bit.
Size, mass and interaction strength are unrelated. For example, imagine trying to detect clouds by throwing rocks at them. Clouds are big, but they only interact with rocks very weakly.
So, as other posters have asked, where are the neutrons? I've had the opportunity to as Fleishmann himself that question, and watched others ask it as well. He didn't have an answer, and didn't even understand import of the question.
It goes like this: if I give any light nucleus more than a few MeV in a metal lattice, it's going to knock neutrons loose left and right. It doesn't matter if it's a proton, a deuteron, tritium, 4He, whatever. And it doesn't matter if I give it that energy via fission or fusion or waving a magic wand. No matter what I do, such a particle will produce neutrons. This is as close to a certainy as anything in this life can be.
Hand-waving plausibility arguments regarding lattice recoil won't do. Either show me the neutrons, or show me a way of dumping 20-odd MeV into a light nucleus in a metal lattice and NOT producing neutrons. Cold fusion advocates have done neither.
"Copenhagen" is an excellent play. It makes what is to me a very convincing case that Heisenberg did not want to build a bomb, and does so in a way that is free from the various historical biases that have clouded the question.
IAANP, and have done the kind of calculations that Heisenberg didn't (although not, I hasten to add, for bomb-making purposes!)
Mount Ararat is named in the Bible as the resting place of the Ark.
What does the Bible have to do with this? It is a secondary source for the flood. The closest thing we have to a primary source, which predates the Old Testament by fair margin, is the flood story from Sumerian literature, which is known primarily from the fact that Gilgamesh went in search of Utnapishtim, the builder of the ark, to discover the secret of eternal life.
Scientists are also scholars, and should go to the primary literature, not secondary sources that don't even cite the original!
To give you an idea of the scale here, the energy per neutron in any fusion reaction is a few MeV. This scale is set by the fundamental physics and can't be altered. 1 MeV = 1/1.6E-13 J. To produce 1 W you would therefore need to produce ~1E13 neutrons/s on a continuous basis. They are producing ~1E6 neutrons/s in bursts.
Ergo, they need to scale up by about a factor of 1E7 to have a 1 W reactor, and 1E13 to have a 1 MW reactor (sufficiently powerful to supply the energy needs of a few thousand typcial North American homes.)
These are not small numbers. Offhand, I can't think of any technology that has successfully spanned this many decades from proof-of-concept to practical reality. Even going from an early Chinese gunpowder rocket to a Saturn V booster didn't involve such an impressive scaling up.
Any means of breaking quantum crypto would involve implicit relativistic violations (that is, being able to send messages via EPR correlations.) As such, it would be equivalent to the ability to send messages into the past. Thus, it is of a quite different order from finding the prime factors of large numbers, which is merely hard.
Where is the corresponding north pole? The one thing we can be fairly sure of is that however many poles the Earth's magnetic fiedd has, it'll be an even number. Although I guess it's possible for multiple poles to overlap, giving the appearance of an odd number.
Economist John Maynard Keynes said In the long run... we are all dead.
Which demonstrates that Keynes was better at rhetoric than logic. In the long run, the vast majority of us have children. That gives us a strong interest in the future even past the end of our own lives.
If the best you can do is speculate about the effects on a child regarding how it might feel about the mode of reproduction its parent(s) used, then having children by genetic replication (sometimes known as cloning) is neither better nor worse than any other method. Nor, genetic causation being the crap-shoot it is, does it give a much higher level of predictivity of lifespan or disease risk than ordinary reproduction does, so you can simply put that fantasy aside.
Note that even to grasp at those straws requires that you exclude a small but significant portion of the human race (identical twins). I've known a number of identical twins, and they don't seem to labour under any greater mental strain than the rest of us.
All and every "ethical" problem regarding clones and cloning can be trivially resolved by replacing the word "clone" with the word "child".
If in 20 years, my son knows the fundamentals of string theory in junior high, at the expense of having to use a calculator to be able to do simultanious equations, I'll consider that a *good* thing. Leave the mundane tasks to the machines, leave the ones that require actual thinking to the humans.
Unfortunately, it is extremely unlikely that anyone will ever understand "the fundamentals of string theory" without first learning a whole lot of "mundane" things. Having a cartoon picture of string theory is certainly possible at the high-school level, but I'd far rather see my children learning more foundational things, including history, languages, classical physics, chemistry, biology and math.
In general, having a bad understanding of more is not preferable to having a good understanding of less, particularly when the "less" can serve as an open road to the "more" later in life.
This is particularly true when the "added" knowledge is likely to be ephemeral, a category that applies to both string theory and computing technology.
Open sourcing a search engine would 100% guarantee absolute junk for results.
Nope. There are two components to any computational system: algorithms and state. A good search engine would use adaptive algorithms, in which the state (the result of past operations) is allowed to (at least implicitly) modify the algorithm itself.
This would still not quite be fully open, as the state information would have to be hidden or it would be possible to generate pages with bogusly high rankings on the fly, but it would help.
Coffee is made by boiling ground coffee beans in (surprise!) boiling water. Whether you boil it yourself the old fashioned way, or get it from the office's coffee machine, it _will_ be hot.
This is as fine an example of innumeracy as one is ever likely to see.
"Hot" is a term with a wide range of meanings. To be able to pass judgement on a given case, one needs to specify numerically what is meant by "hot". If I say, "Hot coffee" I could be referring to any temperature between barely warm and boiling hot.
An innumerate person, such as the poster above, will simply hear "hot" and never think to apply a numerical value to the term. A numerate person will be aware that "hot" has a wide range of possible meanings and insist that the meaning in the current case be numerically specified. When that is done, the justice of the case becomes much clearer.
Sadly, it appears that the poster's complaints about America being a nation of morons are all too justified.
Back in grad school (in the '80's) I realized that almost all the technology I was working with had either been invented during WWII or given a huge boost by WWII. Kinda depressing, although not totally surprising in nuclear physics, a field that went from zero to ground zero in three short years in the early '40's.
But there are notable exceptions. Hyper-pure materials have had a large impact on technology. It may not seem like a breakthrough because software has lagged so much, but chip performance today is many factors of ten better than chip performance ten or twenty years ago.
Lasers are another purely post-war technology whose uses we are still learning to exploit. When I was a kid they were exotic curiousities. Today they're in everything from CD/DVD players to supermarket scanners, and are still improving in their many roles in medicine. Getting your vision corrected by reshaping your eye-balls sounds like something of a "breakthrough" to me.
Cars that don't need tune-ups, tires that don't (or almost don't) ever go flat, phones you can carry around with you... You can argue that all of these are incremental improvements on existing technologies, but I think that would take the notion of "incremental" too far. They all solve problems that have been around forever, but do so in radically new ways.
It's a good article covering things that were once thought likely to become practical that have not yet done so. But there are also lots of things that were known by almost everyone to be impossible that have come to pass.
Three examples off the top of my head:
1) Imaging a single atom 2) Imaging the disk of a star other than the sun 3) Detecting extra-solar planets
There are many more examples, especially if you look at the economic predictions of biologists. For example, it was once widely believed that oil and base metals were going to become much more expensive in the last quarter of the 20th century.
Slashdot Mirror
The effect cannot produce long distance communication. In the example given in the paper, for instance, the experimenters sub-select the appropriately entangled states based on the five-fold co-incidence (that is, they require a single photon in each channel.) This kind of sub-selection, which is what any communication of useful information via entanglement (as opposed to via teleportation) depends on, is only possible if information as to the triggered/untriggered state of each detector is communicated to the others by more-or-less conventional means.
This is significant, because the "collapse" of the quantum state is non-local, and any direct communication via entanglement would occur instantaneously, causing the wheels to fall off the universe.
As to "unbreakable" encryption, a line that cannot be eavesdropped on is usually considered a Good Thing with regard to unbreakablility, and the fact that the information required is distributed amongst multiple photons, with no one of them being sufficient to determine the overall state being teleported is also a Good Thing.
--Tom
Short answer: gravity.
Long answer: sail-boats sail upwind by creating a composite force vector from wind on the sails and hydro-dynamic forces on the keel that has a net up-wind component.
There are two cases to consider for solar sails: transfer orbits, and free flight. For transfer orbits, which we'll use to get from Earth to Mars, say, the sail can be used to either increase or decrease the orbital angular momentum of the spacecraft.
If the sail is tilted at 45 degrees to the solar radius such that the reflected light is pointed in the direction of orbital motion, the spacecraft will lose orbital angular momentum and fall inward toward the sun. Tilt the sail in the opposite direction and the opposite will happen.
For a spacecraft not in a closed orbit, things are more complicated, and I don't think it has quite the same freedom of motion. I'd guess that you'd want an interstellar solar sail to spiral out from the sun until it achieved solar escape velocity, and then have it point straight back at the sun for as long as possible. At some point you'd want it to turn over and point at the target star, which, due to deterioration of the sail etc, you'd probably want to be a good deal brighter than the sun, unless you were just going to pass on by.
In practical terms, solar sails may be used to send (very small) instrument packages out to local stellar systems in our lifetimes. It's very unlikely they'll ever be used for human travel. Of course, in 1945 it was very unlikely anyone would build a rocket large enough to send people to the moon.
--Tom
I think this reasoning is correct, and indeed from what we know of evolution it is also reasonable.
We know that life is not too hard to do: it came about _very_ early in the Earth's history, quite probably more than once. Likewise, there are strong suggestions of early life on Mars (and I'm still holding out hopes for Titan and Europa).
Likewise, various good tricks that life uses have evolved multiple times: wings, eyes, etc. are things that we have good evidence came about independently pretty much as soon as they possibly could.
Intelligence, on the other hand, is fantasically rare--at most one or two species in the entire history of life on Earth have managed it, and they have all been closely related. The fact that millions of other species that could have (in the sense that they had the same basic neural machinery that we have--a spinal chord, a brain, etc.) evolved intelligence but didn't strongly suggests that the evolutionary path to intelligence is very narrow, and depends on numerous low-probability events, or possibly one very low probability event.
Unlike flight, it appears that intelligence doesn't give the possessor much of an advantage until the capability is really well-developed. And it appears that the usefulness is strongly restricted to social animals to begin with, cutting down the number of potential intelligent species by a large fraction at the very start.
So I think as we venture out into the galaxy we will find life everywhere, and intelligence nowhere.
--Tom
There's a novel by Donald Kingsbury, The Moon Goddess and the Son (IIRC) from the mid 80's that describes the construction of a DIY cruise missile. It was plausible then (albiet by renegade MIT students) and even moreso now.
The only curious thing is that no one has yet done it. The only reasonable conclusion is that everyone who can do it, except for this clown in New Zealand, has the good sense not to want to.
--Tom
This is the difficulty: you are comparing an imaginary system to a real one.
No real electronic (or mechanical) voting system is or can be error-free, which is what you are claiming for your system. When you say that it would be an advantage to be able to say, "So-and-so GOT *exactly* 8192 votes" what you actually mean is, "THE SYSTEM COUNTED *exactly* 8192 votes, AND THERE IS NO WAY TO DO A RECOUNT." This is nothing but a false sense of accuracy.
The inability to repeat a measurement does not increase the accuracy of the measurement.
Furthermore, a paper ballot contains far more information than an electronic ballot. To compare real systems, suppose a paper ballot contains a questionable mark that may or may not indicate a vote. The scrutineers can examine it for evidence of voter intent, and ask questions like, "How firm is it? Is it at all X-like, or just a dot or a single stroke? Does it centre on a circle or is it off to the edge?" and so on.
The equivalent case in a touch-screen voting system is a voter whose sleeve brushes against the screen as they reach to make their vote. No one--not even the voter--will ever know that they didn't register the vote they intended.
Finally, marking an X in a cirle is not so much more complicated than using a touch screen (to many people it is in fact easier!) that we can expect a higher rate of voter error with paper ballots than electronic. Yet a voting machine is far more complicated than a paper ballot, and therefore will always be more subject to failure and fraud.
Ergo, anyone who cares about democracy should be opposed to electronic and mechanical voting systems as such, regardless of the relative merits of this or that machine. None of them will ever come close to the level of information and security that paper ballots provide.
--Tom
Hey, that's exactly what it really looked like!
I was up at dawn (more or less in the middle of the eastern time zone, so about 2 hours before the transit was complete) and just as the sun cleared the horizon the morning mist was thick enough that you could look directly at the (deep red, very dim) solar disk, and there was a tiny but clearly visible black dot, pretty much exactly in the location shown in the "ascii image", and about the same size relative to the sun.
The mist was thick enough that as the sun rose higher there was a lot of scattered light, so my helioscope didn't show anything but a blurred solar image, but it was actually cooler to be able to look at the transit directly with my bare eyeballs for a minute or so.
--Tom
It's only a fair comparison if they now change sides several times. Alcibiades betrayed everyone. To do anything comparable, Rumsfeld and Cheney would have to defect to Iraq, then betray them and flee to Russia.
--Tom
I'm a Canadian. I've lived on the West Coast, in Winnipeg, and in Eastern Ontario. I also spent a year in the U.S., living in L.A. (Pasadena), and have been close to several Americans over the past 15 years.
I've worked in the public sector (universities and health care as a medical physicist) and in the private sector (largish public software company, several smaller private firms.) I now own my own company (http://www.predictivepatterns.com).
In one of my previous positions the company was run by Americans but staffed by Canadians, and it made me acutely aware of the cultural differences between the two countries. The Americans wanted cheer and ethusiasm. The Canadians weren't having any. They produced solid results, but they just couldn't be all happy and excited about it, and they found the Americans' attitudes extremely wearing. The Canadians' attitudes drove the Americans nuts.
So an American coming to Canada shouldn't be fooled by the fact that most of us speak something like the same language and have some other similarities. Canadians are different. We are more small-c conservative and more small-l liberal. We are stupid and wasteful in less obvious ways than Americans. We own lots and lots of guns but hardly ever shoot anyone with them.
Our national govenment is the only one in the G8 that has its fiscal house properly in order--we have run a surplus for long enough that I can't remember offhand the last time we had a deficit (sometime in the mid-90's) and we are steadly paying down our national debt. Most provincial governments are in less good shape, but still take fiscal probity seriously.
As a business-person, I love it here. You can incorporate nationally on-line for a total of $220. The federal government is a world-leader in supplying services electronically. Labour laws are a lot tighter here than in the U.S., but the work-force is generally well-educated and even unions are a lot more reasonable than they were 20 years ago. Taxes are somewhat higher, but this is largely compensated for by not having to pay for private health insurance.
The per-capita cost of health care is significantly lower in Canada than the US. We have a three-tier health care system, in which basic service is paid for via taxes, small levels of enhanced service are available for relatively small fees, and the very rich have U.S. hospitals ready to serve them right across the border.
The basic level of care for a wide range of things is as good or better as the U.S. average, but it's widely recognized that the basic health-care system is increasingly broken. If how we dealt with the federal deficit is any indication, there will be a decade of sometimes quite nasty debate that will end in a fairly broad concensus on what to do, and we'll do it.
Americans sometimes see that we are polite, and think us weak. They see that we are calm, and think us passive. They see that we are content, and think us stupid. They are wrong on all counts.
--Tom
Has anyone else noticed that the press release is virtually content free?
What it says is, "We had one successful test on a bigger, faster, higher target than before. Some other tests worked in the past, too."
What it doesn't say is:
1) How much bigger/faster/higher?
2) How many tests were unsuccessful?
3) Those past successful tests were what fraction of the total tests?
That's not even considering all the background information left out that is available elsewhere, like how big the laser system is, what its duty cycle is, etc.
--Tom
From the article cited as evidence for "skyrocketing cancer rates":
That is, cancer rates are predicted to go up primarily due to the fact that people are living longer than ever before. Cancer is a disease of age, and if you don't die of any of the things that kept the pre-industrial, pre-democratic world relatively cancer-free, you will eventually die of it (or heart-disease or stroke.)
The rest of the article focuses on the 1/3 or so of preventable cancers due to smoking, diet and other unhealthy activities that people engage in.
So much for the dire threat of "a problem we already have."
Anthropogenic global warming may (or may not) be a real phenomenon. Personally, when GCMs can deal correctly with the "early cool sun problem" I'll take them a lot more seriously.
Regardless, there are good reasons to begin moving away from fosil fuels so that over the next few generations we can become entirely dependent on renewable energy without giving up our extravagant lifestyles. But gratuitous citation of irrelevant articles does not aid the case for doing so one little bit.
--Tom
Size, mass and interaction strength are unrelated. For example, imagine trying to detect clouds by throwing rocks at them. Clouds are big, but they only interact with rocks very weakly.
--Tom
So, as other posters have asked, where are the neutrons? I've had the opportunity to as Fleishmann himself that question, and watched others ask it as well. He didn't have an answer, and didn't even understand import of the question.
It goes like this: if I give any light nucleus more than a few MeV in a metal lattice, it's going to knock neutrons loose left and right. It doesn't matter if it's a proton, a deuteron, tritium, 4He, whatever. And it doesn't matter if I give it that energy via fission or fusion or waving a magic wand. No matter what I do, such a particle will produce neutrons. This is as close to a certainy as anything in this life can be.
Hand-waving plausibility arguments regarding lattice recoil won't do. Either show me the neutrons, or show me a way of dumping 20-odd MeV into a light nucleus in a metal lattice and NOT producing neutrons. Cold fusion advocates have done neither.
--Tom
"Copenhagen" is an excellent play. It makes what is to me a very convincing case that Heisenberg did not want to build a bomb, and does so in a way that is free from the various historical biases that have clouded the question.
IAANP, and have done the kind of calculations that Heisenberg didn't (although not, I hasten to add, for bomb-making purposes!)
--Tom
What does the Bible have to do with this? It is a secondary source for the flood. The closest thing we have to a primary source, which predates the Old Testament by fair margin, is the flood story from Sumerian literature, which is known primarily from the fact that Gilgamesh went in search of Utnapishtim, the builder of the ark, to discover the secret of eternal life.
Scientists are also scholars, and should go to the primary literature, not secondary sources that don't even cite the original!
--Tom
To give you an idea of the scale here, the energy per neutron in any fusion reaction is a few MeV. This scale is set by the fundamental physics and can't be altered. 1 MeV = 1/1.6E-13 J. To produce 1 W you would therefore need to produce ~1E13 neutrons/s on a continuous basis. They are producing ~1E6 neutrons/s in bursts.
Ergo, they need to scale up by about a factor of 1E7 to have a 1 W reactor, and 1E13 to have a 1 MW reactor (sufficiently powerful to supply the energy needs of a few thousand typcial North American homes.)
These are not small numbers. Offhand, I can't think of any technology that has successfully spanned this many decades from proof-of-concept to practical reality. Even going from an early Chinese gunpowder rocket to a Saturn V booster didn't involve such an impressive scaling up.
--Tom
Any means of breaking quantum crypto would involve implicit relativistic violations (that is, being able to send messages via EPR correlations.) As such, it would be equivalent to the ability to send messages into the past. Thus, it is of a quite different order from finding the prime factors of large numbers, which is merely hard.
--Tom
Where is the corresponding north pole? The one thing we can be fairly sure of is that however many poles the Earth's magnetic fiedd has, it'll be an even number. Although I guess it's possible for multiple poles to overlap, giving the appearance of an odd number.
--Tom
--Tom
No, if cruise missiles are made illegal, only governments will have cruise missiles...
If the best you can do is speculate about the effects on a child regarding how it might feel about the mode of reproduction its parent(s) used, then having children by genetic replication (sometimes known as cloning) is neither better nor worse than any other method. Nor, genetic causation being the crap-shoot it is, does it give a much higher level of predictivity of lifespan or disease risk than ordinary reproduction does, so you can simply put that fantasy aside.
Note that even to grasp at those straws requires that you exclude a small but significant portion of the human race (identical twins). I've known a number of identical twins, and they don't seem to labour under any greater mental strain than the rest of us.
All and every "ethical" problem regarding clones and cloning can be trivially resolved by replacing the word "clone" with the word "child".
--Tom
Unfortunately, it is extremely unlikely that anyone will ever understand "the fundamentals of string theory" without first learning a whole lot of "mundane" things. Having a cartoon picture of string theory is certainly possible at the high-school level, but I'd far rather see my children learning more foundational things, including history, languages, classical physics, chemistry, biology and math.
In general, having a bad understanding of more is not preferable to having a good understanding of less, particularly when the "less" can serve as an open road to the "more" later in life.
This is particularly true when the "added" knowledge is likely to be ephemeral, a category that applies to both string theory and computing technology.
--Tom
Nope. There are two components to any computational system: algorithms and state. A good search engine would use adaptive algorithms, in which the state (the result of past operations) is allowed to (at least implicitly) modify the algorithm itself.
This would still not quite be fully open, as the state information would have to be hidden or it would be possible to generate pages with bogusly high rankings on the fly, but it would help.
--Tom
P.S. Does "bogusly" have one "s" or two?
This is as fine an example of innumeracy as one is ever likely to see.
"Hot" is a term with a wide range of meanings. To be able to pass judgement on a given case, one needs to specify numerically what is meant by "hot". If I say, "Hot coffee" I could be referring to any temperature between barely warm and boiling hot.
An innumerate person, such as the poster above, will simply hear "hot" and never think to apply a numerical value to the term. A numerate person will be aware that "hot" has a wide range of possible meanings and insist that the meaning in the current case be numerically specified. When that is done, the justice of the case becomes much clearer.
Sadly, it appears that the poster's complaints about America being a nation of morons are all too justified.
--Tom
Back in grad school (in the '80's) I realized that almost all the technology I was working with had either been invented during WWII or given a huge boost by WWII. Kinda depressing, although not totally surprising in nuclear physics, a field that went from zero to ground zero in three short years in the early '40's.
But there are notable exceptions. Hyper-pure materials have had a large impact on technology. It may not seem like a breakthrough because software has lagged so much, but chip performance today is many factors of ten better than chip performance ten or twenty years ago.
Lasers are another purely post-war technology whose uses we are still learning to exploit. When I was a kid they were exotic curiousities. Today they're in everything from CD/DVD players to supermarket scanners, and are still improving in their many roles in medicine. Getting your vision corrected by reshaping your eye-balls sounds like something of a "breakthrough" to me.
Cars that don't need tune-ups, tires that don't (or almost don't) ever go flat, phones you can carry around with you... You can argue that all of these are incremental improvements on existing technologies, but I think that would take the notion of "incremental" too far. They all solve problems that have been around forever, but do so in radically new ways.
--Tom
It's a good article covering things that were once thought likely to become practical that have not yet done so. But there are also lots of things that were known by almost everyone to be impossible that have come to pass.
Three examples off the top of my head:
1) Imaging a single atom
2) Imaging the disk of a star other than the sun
3) Detecting extra-solar planets
There are many more examples, especially if you look at the economic predictions of biologists. For example, it was once widely believed that oil and base metals were going to become much more expensive in the last quarter of the 20th century.
Instead, they fell to record low prices.
--Tom