I understand your point, that there is an unaccounted for environmental cost in current energy use, but making it more expensive (say with some kind of tax) is an unlikely fix. Any country or community that imposed such a tax would immediately be putting themselves at an economic disadvantage to their neighbors. Companies that could afford to would likely move where energy was cheap, little would be solved, and the local economy would suffer.
The only way to make such a plan succeed would be to impose it at the international level, which given the "success" of Kyoto seems an unlikely plan.
If you want people to truly pursue a solution you need one that corporations will go along with, which means not hurting the economy (or more correctly imposing less damage to the economy than doing nothing about global warming is doing). Alternative energy is a good example, because even the most aggresive polluter will acknowledge that oil supplies won't last forever.
While we can certainly solve the problems of CO2 emission by strictly limiting CO2, a solution that we can never get passed is no solution. A less tried but more socially acceptable alternative is to pursue technological and scientific solutions to these problems. I have faith that humanity is smart enough to overcome this bump in the road (though probably not before the consequences of global warming become obvious to even the most resolute opponent).
When one year is warm the surface of the ocean heats up and expands ever so slightly that you couldn't even notice. If the next year is a bit cooler then it shrinks a little and everything maintains a nice equilibrium. If instead that next year is also warm then the heat diffuses downward and everything expands a little more.
The oceans are such a large thermal reservoir that the heating of the last half century is only barely perceptible in the expansion of the ocean. The best available evidence is that temperatures globally have been incredibly flat over the last 10000 years (end of the last ice age) up till 1900 or so. The lack of significant long term changes in temperature has kept the ocean volume essentially constant during this time. The problem comes in if global average temperatures have a sustained increase.
If the temperatures jump even one degree Celsius and STAY that way, then the temperatures will gradually diffuse in the oceans over centuries until they reach a new equilibrium. A millenium from now when the entire ocean has warmed a fraction of a degree, the thermal expansion of the oceans will have raised sea levels 10-20 METERS.
Of course this assummes that we do nothing about global warming and simply bask in the warmth while the water rises. It starts at the surface, but if you keep things warm that warmth will saturate the ocean, it's just a matter of time.
Of course a 10% drop looks a lot less impressive when you realize that 2000 years ago was the strongest field intensity that the Earth has seen in the last 70,000 years. We still have to lose another 75% before we are in the regime that is generally associated with magnetic reversals.
Sooner or later the field will reverse again, but I don't expect to see it in my lifetime.
During the last 750 thousand years, the ice age cycle seems to last about 100,000 years with ~10-15% of that as warm interglacials (with 10-15 depending on how you define warm). We have been in an interglacial for about 8000 years, so empirically we are due for a switch in the next 5000 years or so, but we know that some interglacials have been shorter than 8000 years, so it's hard to say.
Incidently from 750k years ago to more than 2.5M years ago, the ice age cycle was ~41 thousand years long. The full fledged ice age cycle is generally explained as being forced by changes in the Earth's orbit (due to perturbations of other planets). Two of the most well known such perturbatins have 41 and 100 thousand year periods.
Of course he's not talking about an actual ice age, which would result in a global temperature dip ~15 F, but rather a locally important dip whose global impact would only be a degree or two. Such as the "Little Ice Age" that froze much of Europe circa 1700.
(Expected Probability of Dying from Impactor of mass M) = (Frequency of impactor of mass M)*(Percent of People expected to Die in Impact)*(Average Human Lifetime)
For major extinction events (like that which killed the dinosaurs), reasonable numbers are: 1/300,000,000yrs*100%*70yrs = 1/4,300,000.
So in some sense you have a 1 in 4.3 million chance of dying the way the dinosaurs did.
Of course that event was rare, but suppose you are a pessimist and think 60 million people (1%) will die from a rock of a size that hits Earth every 50,000 yrs, then this gives a 1 in 70,000 chance of dying in this sort of event.
The idea is to do a sum over the entire range of impactor sizes with some presumed frequency of impact and percentage of people killed, but because these quantities are highly uncertain, you can essentially claim values that will lead to virtually any result you want.
In any case, you should realize that the probability of dying by impact is mostly determined by the rate of major impacts, which given 2000 years of recorded history, are probably rare enough that one isn't going to jump on us even if it takes a century to figure what we would do about a asteroid on a collision course.
Qubits have a tendancy to degrade and lose their state. Researchers tend to be happy if you could get the right answer from a calculation 80-90% of the time. This just means you have to do the calculation multiple times to make sure they agree.
Given a 2*n digit number, it suffices to generate a palindrome if the sum of the i-th and (2n-i+1)-th digit is less than 10 for all i between 1 and n. It follows that at least (2n)/(2^n) numbers of length 2*n will immediately form palindromes. While less obvious, it is also true that if the sum of the i-th and (2n-i+1)-th digit is greater than 10 then the next iteration can only generate a palindrome if the sum of every digit and it's counterpart is greater than 10 (e.g. 9292 -> 12221). Not all numbers with this property will immediately form palindromes (e.g. 9393 -> 13332), but it is a requirement. This property holds for an additional (2n)/(2^n) numbers.
Hence the probability that a number of length 2*n will immediately form a palidrome is 1/(2^(n-1)) for each iteration.
On average, the number gains 0.5 digits per iteration of the algorithm. Consequently for a number with 2*n digits, after infinite iterations, you expect to have encountered a number of palindromes approximately equal to Sum(1/2^(n-1+k/2)), k=0 to infinity => ~6.8*2^(-n).
A straight forward density argument shows that there have to be some Lychrel numbers and that most numbers with a large number of digits are Lychrel numbers, but of course it doesn't tell you which particular numbers have this property.
Obviously I haven't been entirely rigorous, but afterall this is slashdot.
Re:Good idea for nuclear waste?
on
Going Up?
·
· Score: 2
No, I don't remember the name for the effect. Actually I think that I am off by a factor of 10^3 (grams and kilograms are the same thing, right?). 1 Million years, 1 Billion years, doesn't make a lot of difference to the point.
Re:Good idea for nuclear waste?
on
Going Up?
·
· Score: 2
Actually it's very easy to get something to crash into the sun. Just place it up there and leave it alone.
Photons carry momentum, relativistically there is non-zero angle (~v/c) between the apparent direction of motion of the photon and the line between the sun and the object. Absorbing photons consequently imparts momentum which has a component opposite to the direction of motion of the object about the sun, hence removes angular momentum.
Provided the surface area of the object is not really large compared to it's mass, ie, it's not solar sail, this effect dominates over light pressure and causes the orbit to decay. For small (~ 10 m) meteors at 1 AU in circular orbit the characteristic time before it collapses into the sun is about a million years.
The same principle would apply to canisters of waste placed in solar orbit, which is fine provided you don't mind waiting a million years for it to get to the sun.
If you are interested the characteristic time goes proportional to density*object size*(distance to sun)^2, and is roughly 10^16 years for something the size of the Earth (ie. it's not horribly relevant).
Re:Good idea for nuclear waste?
on
Going Up?
·
· Score: 2
You're wrong.
The end of the elevator will follow a circle which is inclined with respect to the ecliptic. Let us say that the z direction is perpendicular to the ecliptic plane, then the end of the space elevator has z = R*cos(w*t)*sin(phi), where R is the radius of it's orbit, w is an angular frequency, t is time and phi is the angle of inclination relative to the ecliptic plane. Therefore v_z, the velocity in the z direction, = -R*w*sin(w*t)sin(phi). Clearly there are times when v_z is 0, and the question then becomes are there any times when v_z = 0 and the rest of v is pointed opposite to the motion of the Earth.
I claim that both these conditions are satisfied at 12 noon on the summer and winter solstices. I could prove it, but that would take a lot more space, and I'm hoping you'll understand without my taking the effort.
Besides, it's all moot, since we aren't going to be throwing waste at the sun from some rope ten times the distance from here to the moon.
Re:Good idea for nuclear waste?
on
Going Up?
·
· Score: 2
Assumming a stiff space elevator that rotates at the same speed as the Earth (ie. once per 24 hours), then to kill the 30 km/s velocity of the Earth with respect to the sun, you'd have a space elevator that is 30km/s/(1/24hr) = 2.5e6 km. For comparison, the distance to the moon is only 3.8e5 km.
Since the length and mass distribution of a space elevator is highly constrained by the need to have it orbit once per 24 hours, I highly doubt that that anyone is contemplating building one more than a factor of 2 past the 3.5e4 km that defines geosynchronous orbit, and certainly not 7 times past the orbit of the moon.
Certainly getting it away from the earth is a big plus, but it isn't going to help much in getting it to go towards the sun.
Forgive me, I agree that global warming is no joking matter, but you could use a better argument.
Venice is a total red herring. The reason Venice is sinking is primarily caused by the depletion (mostly by the mainland) of the aquifer that extends out under the bay and the island. I don't recall whether water usage has changed since identifying the problem, but I do remember that a large portion of the depletion actually resulted from WW2 era industrialization.
Bangledesh flooding might in fact be related to global warming, but the direct cause is increased rainfall (e.g. more/stronger monsoons) in the local river basins.
In neither case is changing global sea levels the main source of their problems. I suspect that there might be some islands that have a bone to pick with sea level change, but at current I don't know of any locales where this is their primary environmental concern.
As for chemicals in drinking water or defective tires, of course there is always a small chance that these things are happening to me. What you probably meant to say was that it would be foolish to ignore it if there was some evidence to suggest it was true. While I've never seen anything particularly bad about my tap water, there certainly is at least some evidence to suggest global warming is happening and is potentially very bad.
Honestly though, I don't think it's "mad" for most people to ignore global warming, because in all reality most people are irrelevant to the debate. Few people have the scientific background to contribute meaningfully to the debate, and even fewer are in the position to make policy decisions that will matter. Sure, it's all well and good that you recycle and turn out the lights in empty rooms, but even if the whole world started doing that it's unlikely to matter as much to global warming as, for instance, if US politicians insisted on a 10% increase in car fuel efficiency.
Maybe you think advocacy matters in setting policy? But even if you and a million of your friends yelled about the dangers of global warming till blue in the face, politicians are only going to do enough to placate you or shut you up, unless you can present a well reasoned, solid, and scientific case to justify the huge expense of actually doing anything significant about global warming. Frankly, I wouldn't want my politicians to spend billions of dollars because the sky MIGHT be falling; I'd want them to be pretty damn sure. Which goes right back to why most people are irrelevant.
Ultimately, what to do about global warming will be addressed in research labs and government offices, and what the average Joe thinks won't matter very much. I suppose the nebulous fear that people feel about global warming does help keep research dollars flowing, but other than that it's pointless anxiety for most people.
Hmmmm, well if the ocean level continues to change at ~2 mm / yr, then it will only take 1,200 years before the water goes up enough to cover the Miami airport at 8 feet above sea level.
It is already possible to transmute certain particular radioactive species to safer species by using nuetron capture and other radiation techniques. At current you usually generate more waste in producing the radioactivity used for the transmutation than you save by such a step. It is far from obvious that this would always be so, or that you couldn't find ways to do so with a broader range of species than currently possible.
It is not impossible to imagine some nuclear reactor of the distant future which uses the excess radiation from the active fuel source as a means of rendering safe the spent fuel.
Okay, I'll agree the summary of the article is rather fitting and somewhat funny, but the rest of Restil's comments are in very bad taste.
In case no one noticed, the guy is mentally ill. He has serious problems, and they are not his fault. He didn't chose to "drive himself into depression" or any such thing. Manic depression (aka bipolar disorder) is one the most clearly nuerochemically linked and genetically linked mental illnesses there is. It's hardly his fault that some of his nuerotransmitters receptors are functioning incorrectly. Unlike simple (unipolar) depression, manic depression can't be solved by talk therapy alone, it is a physical illness of the brain that must be controlled with medication.
Yes, he's paranoid. Yes, he seems unable to hold a job. Yes, he has suicidal epsiodes. Is this his fault? No! He has a disease that literally makes his mind unable to function the way a normal person's does. Join the rest of us in the 21st century and quit blaming the patient for something beyond his control.
In the mean time, moderators, why am I reading this distasteful junk at Score:4?
For more info on bipolar disorder, see here, here, or here.
Thankfully it was only somewhat superheated, leading to violent bubbling and some spill over, and not the kind of violent explosion your link suggests is possible.
This summer I'm working at Lawrence Berkeley Lab, and some of the people near where I work have gotten a few grams of lunar material (Apollo 15, IIRC) from NASA for an experiment aiming to figure out the material's age of formation. Now they only need to look at a particular tiny part of the sample and NASA expects to get the rest back.
Now none of that is unreasonable, but what is unreasonable is the insurance policy they have to take out on the material against theft, accidental lost or destruction. Now insurers naturally want to know the value of what they are insuring. NASA's official and much repeated line is that all lunar material is priceless. This poses a serious problem for insurers, so the next question was what is the cost to replace the sample. No joke, they figured the cost of the policy, and hence the premiums, based on the cost of building a rocket, flying to the moon, collecting a new sample, and bringing it back. Not only that, but two members of the Berkeley physics department are officially down on paper as having volunteered to make the trip should it become neccesary.
I don't know what they are paying exactly, and being in a secured area of a restricted access research lab probably helps keep down the cost, but still it's not cheap holding on to lunar material that NASA expects to get back.
Most of it dates from the early to mid 20th. While, I don't have a really good feeling for what all is included, I do know that a substantial portion of it is coming from the kinds of early electrical gadgets that UCB was using in student labs. As far as I know though, none of this material has been identified as being initial run stuff from any of the historically important experiments of the early 20th. Some of the items do clearly replicate important experiments though, primarily for teaching purposes, I believe.
I couldn't find a complete list on Harvey Clar, but I bet there will be one closer to the full auction.
I'm a UCB physics grad student. The primary motivation for the sale isn't to make money or make room for new gear. They actually have to do it because the part of the physics building is scheduled for a seismic retrofit, and the temporary building can't accommodate all the old stuff in the attics.
Some material will be kept for display and for gifts to retiring faculty.
Let me qualify that by saying the way GR ought to be applied, as opposed to the way it often is. We don't generally propogate gravitional effects as travelling distortions to space time because it is too hard. Instantaneous changes are easier.
We already know that gravity propogates at the speed of light to within our ability to measure it's effects (which is reasonably good). Doing so is also a requirement of general relativity.
Ordinary gravitational attraction is dominated by "gravito-electric" force, or in normal language the force generated by stationary masses. In everyday concerns the Earth is the only mass that matters and it is stationary to a good approximation for nearly everything humans do.
The paper talks solely in terms of affecting "gravito-magnetic" forces, which are those exhibited by moving masses (and generally only significant among masses moving at an appreciable fraction of the speed of light). Simply put there just isn't enough gravito-magnetic force in every day life to notice any change. If there were an appreciable gravito-magnetic force in ordinary everyday gravity then yes you could test it, though I'm not clear how to expect it to react.
To put things another way, Newton described gravity purely in gravito-electric terms and most of us will never notice the more complex gravitiational interactions that Einstein discovered and this physicist cares about.
Consider the functions x^n for all positive integers n. 0^n = 0 and 1^n = 1 in all such cases. Thus this set of functions all go from (0,0) to (1,1) and are each distinct. This is a very small subset of all the curves from (0,0) to (1,1), but it is infinite to the same degree that the positive integers are infinite.
Certainly I can concieve of there being an infinite number of ways of doing such things. Perhaps there is some physical bound that prevents me of implementing all those ways, but to date I haven't seen any clear evidence for such limitation.
I could probably write down an algorithm for computing any number that I had taken an interest in, but I could also (at least in theory) write down a similar algorithmic approach to define any quantum state that I was interested in.
The real objection is not that there are things which can't be represented, but that you need to hold an infinte number of things all at once in order to do something useful. I was merely pointing out that we don't need all the numbers to do useful math.
Slashdot Mirror
I understand your point, that there is an unaccounted for environmental cost in current energy use, but making it more expensive (say with some kind of tax) is an unlikely fix. Any country or community that imposed such a tax would immediately be putting themselves at an economic disadvantage to their neighbors. Companies that could afford to would likely move where energy was cheap, little would be solved, and the local economy would suffer.
The only way to make such a plan succeed would be to impose it at the international level, which given the "success" of Kyoto seems an unlikely plan.
If you want people to truly pursue a solution you need one that corporations will go along with, which means not hurting the economy (or more correctly imposing less damage to the economy than doing nothing about global warming is doing). Alternative energy is a good example, because even the most aggresive polluter will acknowledge that oil supplies won't last forever.
While we can certainly solve the problems of CO2 emission by strictly limiting CO2, a solution that we can never get passed is no solution. A less tried but more socially acceptable alternative is to pursue technological and scientific solutions to these problems. I have faith that humanity is smart enough to overcome this bump in the road (though probably not before the consequences of global warming become obvious to even the most resolute opponent).
When one year is warm the surface of the ocean heats up and expands ever so slightly that you couldn't even notice. If the next year is a bit cooler then it shrinks a little and everything maintains a nice equilibrium. If instead that next year is also warm then the heat diffuses downward and everything expands a little more.
The oceans are such a large thermal reservoir that the heating of the last half century is only barely perceptible in the expansion of the ocean. The best available evidence is that temperatures globally have been incredibly flat over the last 10000 years (end of the last ice age) up till 1900 or so. The lack of significant long term changes in temperature has kept the ocean volume essentially constant during this time. The problem comes in if global average temperatures have a sustained increase.
If the temperatures jump even one degree Celsius and STAY that way, then the temperatures will gradually diffuse in the oceans over centuries until they reach a new equilibrium. A millenium from now when the entire ocean has warmed a fraction of a degree, the thermal expansion of the oceans will have raised sea levels 10-20 METERS.
Of course this assummes that we do nothing about global warming and simply bask in the warmth while the water rises. It starts at the surface, but if you keep things warm that warmth will saturate the ocean, it's just a matter of time.
Of course a 10% drop looks a lot less impressive when you realize that 2000 years ago was the strongest field intensity that the Earth has seen in the last 70,000 years. We still have to lose another 75% before we are in the regime that is generally associated with magnetic reversals.
Sooner or later the field will reverse again, but I don't expect to see it in my lifetime.
During the last 750 thousand years, the ice age cycle seems to last about 100,000 years with ~10-15% of that as warm interglacials (with 10-15 depending on how you define warm). We have been in an interglacial for about 8000 years, so empirically we are due for a switch in the next 5000 years or so, but we know that some interglacials have been shorter than 8000 years, so it's hard to say.
Incidently from 750k years ago to more than 2.5M years ago, the ice age cycle was ~41 thousand years long. The full fledged ice age cycle is generally explained as being forced by changes in the Earth's orbit (due to perturbations of other planets). Two of the most well known such perturbatins have 41 and 100 thousand year periods.
Of course he's not talking about an actual ice age, which would result in a global temperature dip ~15 F, but rather a locally important dip whose global impact would only be a degree or two. Such as the "Little Ice Age" that froze much of Europe circa 1700.
The idea for doing a calculation like this is
(Expected Probability of Dying from Impactor of mass M) = (Frequency of impactor of mass M)*(Percent of People expected to Die in Impact)*(Average Human Lifetime)
For major extinction events (like that which killed the dinosaurs), reasonable numbers are: 1/300,000,000yrs*100%*70yrs = 1/4,300,000.
So in some sense you have a 1 in 4.3 million chance of dying the way the dinosaurs did.
Of course that event was rare, but suppose you are a pessimist and think 60 million people (1%) will die from a rock of a size that hits Earth every 50,000 yrs, then this gives a 1 in 70,000 chance of dying in this sort of event.
The idea is to do a sum over the entire range of impactor sizes with some presumed frequency of impact and percentage of people killed, but because these quantities are highly uncertain, you can essentially claim values that will lead to virtually any result you want.
In any case, you should realize that the probability of dying by impact is mostly determined by the rate of major impacts, which given 2000 years of recorded history, are probably rare enough that one isn't going to jump on us even if it takes a century to figure what we would do about a asteroid on a collision course.
Qubits have a tendancy to degrade and lose their state. Researchers tend to be happy if you could get the right answer from a calculation 80-90% of the time. This just means you have to do the calculation multiple times to make sure they agree.
Given a 2*n digit number, it suffices to generate a palindrome if the sum of the i-th and (2n-i+1)-th digit is less than 10 for all i between 1 and n. It follows that at least (2n)/(2^n) numbers of length 2*n will immediately form palindromes. While less obvious, it is also true that if the sum of the i-th and (2n-i+1)-th digit is greater than 10 then the next iteration can only generate a palindrome if the sum of every digit and it's counterpart is greater than 10 (e.g. 9292 -> 12221). Not all numbers with this property will immediately form palindromes (e.g. 9393 -> 13332), but it is a requirement. This property holds for an additional (2n)/(2^n) numbers.
Hence the probability that a number of length 2*n will immediately form a palidrome is 1/(2^(n-1)) for each iteration.
On average, the number gains 0.5 digits per iteration of the algorithm. Consequently for a number with 2*n digits, after infinite iterations, you expect to have encountered a number of palindromes approximately equal to Sum(1/2^(n-1+k/2)), k=0 to infinity => ~6.8*2^(-n).
A straight forward density argument shows that there have to be some Lychrel numbers and that most numbers with a large number of digits are Lychrel numbers, but of course it doesn't tell you which particular numbers have this property.
Obviously I haven't been entirely rigorous, but afterall this is slashdot.
No, I don't remember the name for the effect. Actually I think that I am off by a factor of 10^3 (grams and kilograms are the same thing, right?). 1 Million years, 1 Billion years, doesn't make a lot of difference to the point.
Actually it's very easy to get something to crash into the sun. Just place it up there and leave it alone.
Photons carry momentum, relativistically there is non-zero angle (~v/c) between the apparent direction of motion of the photon and the line between the sun and the object. Absorbing photons consequently imparts momentum which has a component opposite to the direction of motion of the object about the sun, hence removes angular momentum.
Provided the surface area of the object is not really large compared to it's mass, ie, it's not solar sail, this effect dominates over light pressure and causes the orbit to decay. For small (~ 10 m) meteors at 1 AU in circular orbit the characteristic time before it collapses into the sun is about a million years.
The same principle would apply to canisters of waste placed in solar orbit, which is fine provided you don't mind waiting a million years for it to get to the sun.
If you are interested the characteristic time goes proportional to density*object size*(distance to sun)^2, and is roughly 10^16 years for something the size of the Earth (ie. it's not horribly relevant).
You're wrong.
The end of the elevator will follow a circle which is inclined with respect to the ecliptic. Let us say that the z direction is perpendicular to the ecliptic plane, then the end of the space elevator has z = R*cos(w*t)*sin(phi), where R is the radius of it's orbit, w is an angular frequency, t is time and phi is the angle of inclination relative to the ecliptic plane. Therefore v_z, the velocity in the z direction, = -R*w*sin(w*t)sin(phi). Clearly there are times when v_z is 0, and the question then becomes are there any times when v_z = 0 and the rest of v is pointed opposite to the motion of the Earth.
I claim that both these conditions are satisfied at 12 noon on the summer and winter solstices. I could prove it, but that would take a lot more space, and I'm hoping you'll understand without my taking the effort.
Besides, it's all moot, since we aren't going to be throwing waste at the sun from some rope ten times the distance from here to the moon.
Assumming a stiff space elevator that rotates at the same speed as the Earth (ie. once per 24 hours), then to kill the 30 km/s velocity of the Earth with respect to the sun, you'd have a space elevator that is 30km/s /(1/24hr) = 2.5e6 km. For comparison, the distance to the moon is only 3.8e5 km.
Since the length and mass distribution of a space elevator is highly constrained by the need to have it orbit once per 24 hours, I highly doubt that that anyone is contemplating building one more than a factor of 2 past the 3.5e4 km that defines geosynchronous orbit, and certainly not 7 times past the orbit of the moon.
Certainly getting it away from the earth is a big plus, but it isn't going to help much in getting it to go towards the sun.
Forgive me, I agree that global warming is no joking matter, but you could use a better argument.
Venice is a total red herring. The reason Venice is sinking is primarily caused by the depletion (mostly by the mainland) of the aquifer that extends out under the bay and the island. I don't recall whether water usage has changed since identifying the problem, but I do remember that a large portion of the depletion actually resulted from WW2 era industrialization.
Bangledesh flooding might in fact be related to global warming, but the direct cause is increased rainfall (e.g. more/stronger monsoons) in the local river basins.
In neither case is changing global sea levels the main source of their problems. I suspect that there might be some islands that have a bone to pick with sea level change, but at current I don't know of any locales where this is their primary environmental concern.
As for chemicals in drinking water or defective tires, of course there is always a small chance that these things are happening to me. What you probably meant to say was that it would be foolish to ignore it if there was some evidence to suggest it was true. While I've never seen anything particularly bad about my tap water, there certainly is at least some evidence to suggest global warming is happening and is potentially very bad.
Honestly though, I don't think it's "mad" for most people to ignore global warming, because in all reality most people are irrelevant to the debate. Few people have the scientific background to contribute meaningfully to the debate, and even fewer are in the position to make policy decisions that will matter. Sure, it's all well and good that you recycle and turn out the lights in empty rooms, but even if the whole world started doing that it's unlikely to matter as much to global warming as, for instance, if US politicians insisted on a 10% increase in car fuel efficiency.
Maybe you think advocacy matters in setting policy? But even if you and a million of your friends yelled about the dangers of global warming till blue in the face, politicians are only going to do enough to placate you or shut you up, unless you can present a well reasoned, solid, and scientific case to justify the huge expense of actually doing anything significant about global warming. Frankly, I wouldn't want my politicians to spend billions of dollars because the sky MIGHT be falling; I'd want them to be pretty damn sure. Which goes right back to why most people are irrelevant.
Ultimately, what to do about global warming will be addressed in research labs and government offices, and what the average Joe thinks won't matter very much. I suppose the nebulous fear that people feel about global warming does help keep research dollars flowing, but other than that it's pointless anxiety for most people.
Hmmmm, well if the ocean level continues to change at ~2 mm / yr, then it will only take 1,200 years before the water goes up enough to cover the Miami airport at 8 feet above sea level.
It is already possible to transmute certain particular radioactive species to safer species by using nuetron capture and other radiation techniques. At current you usually generate more waste in producing the radioactivity used for the transmutation than you save by such a step. It is far from obvious that this would always be so, or that you couldn't find ways to do so with a broader range of species than currently possible.
It is not impossible to imagine some nuclear reactor of the distant future which uses the excess radiation from the active fuel source as a means of rendering safe the spent fuel.
Hahaha! Funny if true. But the real answer is that he probably just did it to get attention.
Bipolars have one of the highest suicide rates (both attempts and completions) of any mental illness.
Okay, I'll agree the summary of the article is rather fitting and somewhat funny, but the rest of Restil's comments are in very bad taste.
In case no one noticed, the guy is mentally ill. He has serious problems, and they are not his fault. He didn't chose to "drive himself into depression" or any such thing. Manic depression (aka bipolar disorder) is one the most clearly nuerochemically linked and genetically linked mental illnesses there is. It's hardly his fault that some of his nuerotransmitters receptors are functioning incorrectly. Unlike simple (unipolar) depression, manic depression can't be solved by talk therapy alone, it is a physical illness of the brain that must be controlled with medication.
Yes, he's paranoid. Yes, he seems unable to hold a job. Yes, he has suicidal epsiodes. Is this his fault? No! He has a disease that literally makes his mind unable to function the way a normal person's does. Join the rest of us in the 21st century and quit blaming the patient for something beyond his control.
In the mean time, moderators, why am I reading this distasteful junk at Score:4?
For more info on bipolar disorder, see here, here, or here.
Been there, done that.
Thankfully it was only somewhat superheated, leading to violent bubbling and some spill over, and not the kind of violent explosion your link suggests is possible.
This summer I'm working at Lawrence Berkeley Lab, and some of the people near where I work have gotten a few grams of lunar material (Apollo 15, IIRC) from NASA for an experiment aiming to figure out the material's age of formation. Now they only need to look at a particular tiny part of the sample and NASA expects to get the rest back.
Now none of that is unreasonable, but what is unreasonable is the insurance policy they have to take out on the material against theft, accidental lost or destruction. Now insurers naturally want to know the value of what they are insuring. NASA's official and much repeated line is that all lunar material is priceless. This poses a serious problem for insurers, so the next question was what is the cost to replace the sample. No joke, they figured the cost of the policy, and hence the premiums, based on the cost of building a rocket, flying to the moon, collecting a new sample, and bringing it back. Not only that, but two members of the Berkeley physics department are officially down on paper as having volunteered to make the trip should it become neccesary.
I don't know what they are paying exactly, and being in a secured area of a restricted access research lab probably helps keep down the cost, but still it's not cheap holding on to lunar material that NASA expects to get back.
Most of it dates from the early to mid 20th. While, I don't have a really good feeling for what all is included, I do know that a substantial portion of it is coming from the kinds of early electrical gadgets that UCB was using in student labs. As far as I know though, none of this material has been identified as being initial run stuff from any of the historically important experiments of the early 20th. Some of the items do clearly replicate important experiments though, primarily for teaching purposes, I believe.
I couldn't find a complete list on Harvey Clar, but I bet there will be one closer to the full auction.
Contra Costa Times
UCB Campus News
I'm a UCB physics grad student. The primary motivation for the sale isn't to make money or make room for new gear. They actually have to do it because the part of the physics building is scheduled for a seismic retrofit, and the temporary building can't accommodate all the old stuff in the attics.
Some material will be kept for display and for gifts to retiring faculty.
Let me qualify that by saying the way GR ought to be applied, as opposed to the way it often is. We don't generally propogate gravitional effects as travelling distortions to space time because it is too hard. Instantaneous changes are easier.
We already know that gravity propogates at the speed of light to within our ability to measure it's effects (which is reasonably good). Doing so is also a requirement of general relativity.
Ordinary gravitational attraction is dominated by "gravito-electric" force, or in normal language the force generated by stationary masses. In everyday concerns the Earth is the only mass that matters and it is stationary to a good approximation for nearly everything humans do.
The paper talks solely in terms of affecting "gravito-magnetic" forces, which are those exhibited by moving masses (and generally only significant among masses moving at an appreciable fraction of the speed of light). Simply put there just isn't enough gravito-magnetic force in every day life to notice any change. If there were an appreciable gravito-magnetic force in ordinary everyday gravity then yes you could test it, though I'm not clear how to expect it to react.
To put things another way, Newton described gravity purely in gravito-electric terms and most of us will never notice the more complex gravitiational interactions that Einstein discovered and this physicist cares about.
Consider the functions x^n for all positive integers n. 0^n = 0 and 1^n = 1 in all such cases. Thus this set of functions all go from (0,0) to (1,1) and are each distinct. This is a very small subset of all the curves from (0,0) to (1,1), but it is infinite to the same degree that the positive integers are infinite.
Certainly I can concieve of there being an infinite number of ways of doing such things. Perhaps there is some physical bound that prevents me of implementing all those ways, but to date I haven't seen any clear evidence for such limitation.
Sure,
I could probably write down an algorithm for computing any number that I had taken an interest in, but I could also (at least in theory) write down a similar algorithmic approach to define any quantum state that I was interested in.
The real objection is not that there are things which can't be represented, but that you need to hold an infinte number of things all at once in order to do something useful. I was merely pointing out that we don't need all the numbers to do useful math.