The specific example you speak of is called the Ultraviolet Catastrophe. At the time, scientists believed that Newtonian mechanics was a full description of the universe. Scientists were shocked when they found it was not possible to explain the behaviour of a 'black body' (which is just a hot glowing object with an ideal emissivity) Classical physics dictates that the energy in a hot object when released as radiation should partition itself equally among all possible modes. In this case, it dictates that the higher the frequency, the more energy would be carried away (at any given temperature) with no limit to how high the frequencies can go. Thus, an object at any temperature should emit an infinite amount of energy at the higher frequency range. Well, this is clearly impossible.
The solution is now considered to be an early form of Quantum Mechanics, though it is taught well before any introduction to QM. Part of the theory requires the fact (or idea) that radiation energy is carried in packets of specific size. These became known as photons.
Ok. I don't see what this has to do with rising sea levels.
You don't believe that New Orleans should be rebuilt? From what I've been told (a good while ago) the aren't rebuilding the dikes which they used to reclaim (claim?) the swamps as buildable ground. These are to the east and west of the city.
As for the river and the lake. Are they at risk of flowing into the city? If so, that's a different problem.
Most of the summer is Smog Alert Day? That's awful! I know a lot of cities form a kind of inversion layer dome keeping smog inside the city. Is this what's happening in Atlanta? I wonder if anyone has looked at the engineering feasibility of building a clean air intake tunnel.
According to Wikipedia, London has an average elevation of 24m above sea level. So. They might lose some waterfront property, but the city isn't going to end up under water.
New Orleans has an elevation ranging from -2m to 6m.
I have a hard time believe that 'up to a billion people' live with a meter of sea-level. And even if this was true, I don't believe the rising sea level will do much damage to humans. The total sea level rise since the 1880s has been 20cm. http://en.wikipedia.org/wiki/Sea_level_rise (I know... I need to find better sources than Wikipedia...)
Now in comparison, the tide has an amplitude of up to one meter (usually smaller). Any people living within 1 meter of sea level will be having problems NOW, not when the ocean levels rise up by another 20 cm in the next 50 years.
If it's the storms you're worried about, I suspect we will be just fine. The portions of New Orleans above sea level survived just fine. I've got a buddy studying down there.
The correct answer to grandparent's post is that the transition to and from the warmer periods during the Mesozoic era were much slower allowing animals enough time to evolve and adapt to their new conditions. This is not possible for (all of) the animals at the current rate of heating. It's not the absolute temperature which is dangerous, but the rapid change.
Really? I've had the opposite experience. For a while, I had an unmoderated open student email exchange flowing straight into an account which I accessed with Thunderbird. That address got some 40 spam each day, and 20 of them (all the image spam) went right through the filters. There was no text other than the paragraph from Lord of the Rings at the bottom for the intelligent filter to have a crack at. I trained the thing every day (since I had to delete spam every day)
However, including server side filtering seems to work wonderfully. I now get 1-2 per day on the same address. SpamAssassin has IP blacklists, which I believe is what made the difference.
I too get pissed of by over zealous environmentalists. Many have a view of what is right, but this is not backed up by any real evidence. *cough... Greenpeace... cough*
I'm a bit critical of your argument though. I don't see that anyone would benefit from creating an unjustified fear of climate change. Perhaps you mean to say that you think scientists simply have it wrong.
There are a few major holes if what you've said.
Volcanoes do not contribute a significant source of carbon. Human activities emit ~130 times the CO2 as do volcanoes. from: http://volcanoes.usgs.gov/Hazards/What/VolGas/volg as.html which is liked as citation 14 from the wikipedia article on CO2
Scientists have calculated that volcanoes emit between about 130-230 million tonnes (145-255 million tons) of CO2 into the atmosphere every year (Gerlach, 1999, 1991). This estimate includes both subaerial and submarine volcanoes, about in equal amounts. Emissions of CO2 by human activities, including fossil fuel burning, cement production, and gas flaring, amount to about 27 billion tonnes per year (30 billion tons) [ ( Marland, et al., 2006) - The reference gives the amount of released carbon (C), rather than CO2, through 2003.]. Human activities release more than 130 times the amount of CO2 emitted by volcanoes--the equivalent of more than 8,000 additional volcanoes like Kilauea (Kilauea emits about 3.3 million tonnes/year)! (Gerlach et. al., 2002) According to: http://www.waterencyclopedia.com/Bi-Ca/Carbon-Diox ide-in-the-Ocean-and-Atmosphere.html Ocean CO2 levels have risen 30% over the last 150 years. This seems to agree that there is a large influx of CO2 coming from SOMEWHERE. It also seems to disagree with your point saying that the source of atmospheric CO2 is from the oceans. It would be nice to have a graph of ocean CO2 levels as a function of time to compare against atmospheric levels. If your hypothesis is correct, then we should see a large decrease in ocean CO2 levels beginning in the 1980s. If the hypothesis of human carbon sources is correct, then we should see a level or increasing trend throughout this time.
You also proposed animal exhalation as a source of carbon. I don't think I've ever heard of this before. Though I would presume that replacing trees and animals with cars and people (or factories and people) would tend to produce more CO2 than it removed.
You also make an interesting point that human carbon emissions began in the 50s, while we don't see any change in global temperature until the mid 70s or early 80s. I don't see the smoking gun against the case that global warming is caused by humans though. Have you ever taken an ecology course? (I haven't, and was strongly warned by a biology professor to avoid them) Apparently one thing you are taught in such courses is that the reacting system (say... local carrot population) lags about 90 degrees from the affecting system (increase in rabbit population eating the carrots) It's reasonable to believe the earth's surface as a heated body has a fair amount of 'inertia' and would lag behind the cause of its warming by a few decades.
Can anyone find a CO2 concentration vs. time graph for the oceans? It would be very telling.
Sorry, I was unclear. What I meant to say is that with fuel economy in mind, one should use the accelerator with the aim of minimising the use of the brake. eg. If you tailgate on the highway (by use of your accelerator) it doesn't cost you any more gas, until you're forced to brake because you followed too close, and then are forced to use the accelerator regain that lost speed. One can say, if you didn't need to use the brake there, you wouldn't have wasted that petrol.
You can also save gas by driving below the speed limit, but that's not really safe, and you'll piss off everyone both inside and outside of your car.
I've noticed this too, though not nearly as badly. I think, red light up ahead... no reason to use the gas right? I'll just end up braking all that energy away when I get to the light, and I won't actually be getting anywhere any faster.
Now, in Greater Toronto Area, this roads usually have enough lanes for the occasional toronto driver (I'm not one) to accelerate around me at which point I giggle slilently to myself when they brake hard at the light. Now, I can understand WHY they're driving like that. If you're downtown, you almost have to or else you'll actually be slowed down significantly by people cutting you off. Not much point in the outskirts though.
But if you're driving for fuel economy, the thing to remember is that it's the brake pedal that uses up fuel, not the gas. You have to get up to speed one way or another, but if you can prevent dumping that energy away, then you're doing good.
"Physical Vapour Deposition (PVD) technology to coat its dies"
This process is used to make silicon semiconductors (computer chips) so it is actually not that surprising that it could look like nano technology under a high powered microscope.
TFA indicates that he used a high powered microscope to characterize the coin.
And yes, the surface of the coin LOOKS like nano technology as it has a protective coating deposited using chemical vapour deposition, the same process used to make computer chips.
Howdy. I'm a grad student in the fusion reactor field.
"emitting large amounts of radioactive materials." This statement is false. A fusion powerplant won't 'emit' anything (in terms of gasses, or any kind of bulk material). There won't be anything transported away from the reactor. The 'waste' problem with a fusion reactor is it produces more neutrons than a fission reactor by a few times per kilowatt. So the reactor vessel and the building to a lesser extent (much less with the advent of low activation concrete) will transmute and become radioactive. Now the reactor vessel weighs a few tonnes in itself, so you have a few tonnes of low level radioactive waste. But it is only dangerous for ~ 100 years as opposed to ~100 generations.
Unfortunately, all these neutrons means we wouldn't be able to hand over a fusion powerplant to Iran. Neutrons can be used to breed weapons grade uranium and plutonium. Tritium is also bred, which can be used in an H-bomb after they figure out the fission bomb.
"A properly-operating reactor isn't going to emit any significant radioactive material into the environment. Maybe they're thinking about accidental Deuterium and He3 releases, which don't represent any kind of threat to the environment." That's right. In fact, Deuterium and He3 are harmless. They're natural isotopes that aren't radioactive. You could drink deuterated water and you'd never know.
Ok, that's not totally true. If say... half of your water intake was heavy water (!expensive) then when the deuterated water was incorporated into proteins by your body, it would have a small chance due to the extra weight to make the protein fold into a funny shape, and then your body would have to discard that protein. So if you drank enough heavy water, you'd starve to death.:D
That's odd. I never understood that phrase "the terrorists have, in fact, already won."
We're talking about violence from our own citizens, which is entirerly unrelated to 9-11. Furthermore, have the terrorists won? That would imply that they had a goal, and achieved it.
Seriously though. Do you disagree with me? Over-reactions WILL happen. How many false suspensions would you tollerate to prevent a massacre? Better question still, how many massacres would it take before you'd be ok having children disciplined for suspicious behaviour?
Not really related to the current story. There could be a virginia tech incident on a daily basis, and after reading that story, I'd still say that kid should not have been suspended.
The article doesn't mention an arrest or any legal charges whatsoever. He was simply suspended from the school... Ok. And sent to some crappy re-education centre.
Ok, I usually like to play Devil's advocate. Generally speaking, a school has good reason when they discipline students. There was a case reviewed by ABC regarding a student who was suspended for bringing a nail clipper to school despite rules that clearly stated weapons were not to be brought to school. Yes, it seems very absurd, but do you honestly think any teacher would take notice if he wasn't using the knife like attachment to threaten other students?
HOWEVER. In this case... It sounds like someone got scared (and who can blame them) and over-reacted. Then again, I would prefer to have one hundred thousand over reactions as depicted in the article than one more university or high school massacre.
Well, sure. But we're not terribly worried about votes being messed up one at a time.
Here in Canada, it would be pretty simple for me to personally go around voting at every station in the city. All I need to do is forge a power bill, and that's really gosh darn easy. Now, unless I can forge 2 pieces of photo ID along with, I'll end up going to jail afterwards.
The point is, a small number of votes is easily messed up, but what we want to ensure is that someone can't mess up the whole ballot box.
Imagine if a site KNEW that you just LOVED deals, so they'd mark down that 8-bit tie just when you strolled by the site. Or, maybe the site KNOWS that you just pissed off your wife and increases the prices of flowers knowing that you're going to buy anyways.
Another poster claims a maximum efficiency of 6.5%.
What would be cool is if the waste energy wasn't in heat but just in unabsorbed wavelengths. Then we could cheaply make windows which would be a bit tinted (which we like anyways) and then daisy chain them to produce electricity. Say, in sky scrapers where it's all glass anyways.
It would be very neat if they were cheap enough that it wouldn't really matter where you put it for it to pay for itself.
This is why Mars has larger mountains and deeper valleys than earth, because the one plate does not move, and that mountain on the top of the hotspot never moved away from the source of its growth.
First, I'm going to state that I'm an environmentalist, and that everything you've said makes good sense. But there's another side of things you should think about.
Perhaps you're right that in North America, we consume too much. But there are a good many countries that don't have this sort of development. Now, these countries are advancing, and they're going through many of the same pains that industrial and cultural revolutions with cost dramatic amounts of energy and resources. Without these, the quality of life will remain appallingly low (by who's standards right?)
So while you're standing on your high horse preaching consumption reduction, realize that there are countries that can not do so. In my opinion it is vital that these countries increase their consumption until their level of education naturally limits population growth.
So while conservation is important, and necessary, a more complete solution is to establish high limit energy sources which have a minimal tax on the environment. (did I mention that I'm a graduate student in Nuclear Fusion...)
Slashdot Mirror
Yes. Sorta.
The specific example you speak of is called the Ultraviolet Catastrophe.
At the time, scientists believed that Newtonian mechanics was a full description of the universe. Scientists were shocked when they found it was not possible to explain the behaviour of a 'black body' (which is just a hot glowing object with an ideal emissivity)
Classical physics dictates that the energy in a hot object when released as radiation should partition itself equally among all possible modes. In this case, it dictates that the higher the frequency, the more energy would be carried away (at any given temperature) with no limit to how high the frequencies can go. Thus, an object at any temperature should emit an infinite amount of energy at the higher frequency range. Well, this is clearly impossible.
The solution is now considered to be an early form of Quantum Mechanics, though it is taught well before any introduction to QM. Part of the theory requires the fact (or idea) that radiation energy is carried in packets of specific size. These became known as photons.
Ok. I don't see what this has to do with rising sea levels.
You don't believe that New Orleans should be rebuilt?
From what I've been told (a good while ago) the aren't rebuilding the dikes which they used to reclaim (claim?) the swamps as buildable ground. These are to the east and west of the city.
As for the river and the lake. Are they at risk of flowing into the city? If so, that's a different problem.
Well said!
Most of the summer is Smog Alert Day? That's awful!
I know a lot of cities form a kind of inversion layer dome keeping smog inside the city. Is this what's happening in Atlanta? I wonder if anyone has looked at the engineering feasibility of building a clean air intake tunnel.
Yeah... You're right. The article is a bit flakie.
Still. I thought it was informative. It's kinda nice to have all that junk in one place.
According to Wikipedia, London has an average elevation of 24m above sea level.
So. They might lose some waterfront property, but the city isn't going to end up under water.
New Orleans has an elevation ranging from -2m to 6m.
I have a hard time believe that 'up to a billion people' live with a meter of sea-level.
And even if this was true, I don't believe the rising sea level will do much damage to humans. The total sea level rise since the 1880s has been 20cm. http://en.wikipedia.org/wiki/Sea_level_rise
(I know... I need to find better sources than Wikipedia...)
Now in comparison, the tide has an amplitude of up to one meter (usually smaller). Any people living within 1 meter of sea level will be having problems NOW, not when the ocean levels rise up by another 20 cm in the next 50 years.
If it's the storms you're worried about, I suspect we will be just fine. The portions of New Orleans above sea level survived just fine. I've got a buddy studying down there.
The correct answer to grandparent's post is that the transition to and from the warmer periods during the Mesozoic era were much slower allowing animals enough time to evolve and adapt to their new conditions. This is not possible for (all of) the animals at the current rate of heating. It's not the absolute temperature which is dangerous, but the rapid change.
Really? I've had the opposite experience.
For a while, I had an unmoderated open student email exchange flowing straight into an account which I accessed with Thunderbird. That address got some 40 spam each day, and 20 of them (all the image spam) went right through the filters. There was no text other than the paragraph from Lord of the Rings at the bottom for the intelligent filter to have a crack at. I trained the thing every day (since I had to delete spam every day)
However, including server side filtering seems to work wonderfully. I now get 1-2 per day on the same address. SpamAssassin has IP blacklists, which I believe is what made the difference.
No. It doesn't.
I too get pissed of by over zealous environmentalists. Many have a view of what is right, but this is not backed up by any real evidence. *cough... Greenpeace... cough*
I'm a bit critical of your argument though. I don't see that anyone would benefit from creating an unjustified fear of climate change. Perhaps you mean to say that you think scientists simply have it wrong.
There are a few major holes if what you've said.
Volcanoes do not contribute a significant source of carbon. Human activities emit ~130 times the CO2 as do volcanoes.
from: http://volcanoes.usgs.gov/Hazards/What/VolGas/vol
Ocean CO2 levels have risen 30% over the last 150 years. This seems to agree that there is a large influx of CO2 coming from SOMEWHERE. It also seems to disagree with your point saying that the source of atmospheric CO2 is from the oceans. It would be nice to have a graph of ocean CO2 levels as a function of time to compare against atmospheric levels. If your hypothesis is correct, then we should see a large decrease in ocean CO2 levels beginning in the 1980s. If the hypothesis of human carbon sources is correct, then we should see a level or increasing trend throughout this time.
You also proposed animal exhalation as a source of carbon. I don't think I've ever heard of this before. Though I would presume that replacing trees and animals with cars and people (or factories and people) would tend to produce more CO2 than it removed.
You also make an interesting point that human carbon emissions began in the 50s, while we don't see any change in global temperature until the mid 70s or early 80s. I don't see the smoking gun against the case that global warming is caused by humans though. Have you ever taken an ecology course? (I haven't, and was strongly warned by a biology professor to avoid them) Apparently one thing you are taught in such courses is that the reacting system (say... local carrot population) lags about 90 degrees from the affecting system (increase in rabbit population eating the carrots)
It's reasonable to believe the earth's surface as a heated body has a fair amount of 'inertia' and would lag behind the cause of its warming by a few decades.
Can anyone find a CO2 concentration vs. time graph for the oceans? It would be very telling.
Point made.
Though one could argue in the days of geocentric universe that 'science' had just barely been established.
Besides. The empirical evidence supporting the geocentric concept is quite profound, even though a fair amount of it was based on intuition.
True.
Sorry, I was unclear.
What I meant to say is that with fuel economy in mind, one should use the accelerator with the aim of minimising the use of the brake. eg. If you tailgate on the highway (by use of your accelerator) it doesn't cost you any more gas, until you're forced to brake because you followed too close, and then are forced to use the accelerator regain that lost speed. One can say, if you didn't need to use the brake there, you wouldn't have wasted that petrol.
You can also save gas by driving below the speed limit, but that's not really safe, and you'll piss off everyone both inside and outside of your car.
Perhaps the hypothesis is that it was THIS particular genetic mutation which split the species begining the human genetic line.
Wow.
I've noticed this too, though not nearly as badly.
I think, red light up ahead... no reason to use the gas right? I'll just end up braking all that energy away when I get to the light, and I won't actually be getting anywhere any faster.
Now, in Greater Toronto Area, this roads usually have enough lanes for the occasional toronto driver (I'm not one) to accelerate around me at which point I giggle slilently to myself when they brake hard at the light. Now, I can understand WHY they're driving like that. If you're downtown, you almost have to or else you'll actually be slowed down significantly by people cutting you off. Not much point in the outskirts though.
But if you're driving for fuel economy, the thing to remember is that it's the brake pedal that uses up fuel, not the gas. You have to get up to speed one way or another, but if you can prevent dumping that energy away, then you're doing good.
"Physical Vapour Deposition (PVD) technology to coat its dies"
This process is used to make silicon semiconductors (computer chips) so it is actually not that surprising that it could look like nano technology under a high powered microscope.
TFA indicates that he used a high powered microscope to characterize the coin.
And yes, the surface of the coin LOOKS like nano technology as it has a protective coating deposited using chemical vapour deposition, the same process used to make computer chips.
Howdy. I'm a grad student in the fusion reactor field.
:D
"emitting large amounts of radioactive materials."
This statement is false. A fusion powerplant won't 'emit' anything (in terms of gasses, or any kind of bulk material). There won't be anything transported away from the reactor. The 'waste' problem with a fusion reactor is it produces more neutrons than a fission reactor by a few times per kilowatt. So the reactor vessel and the building to a lesser extent (much less with the advent of low activation concrete) will transmute and become radioactive. Now the reactor vessel weighs a few tonnes in itself, so you have a few tonnes of low level radioactive waste. But it is only dangerous for ~ 100 years as opposed to ~100 generations.
Unfortunately, all these neutrons means we wouldn't be able to hand over a fusion powerplant to Iran. Neutrons can be used to breed weapons grade uranium and plutonium. Tritium is also bred, which can be used in an H-bomb after they figure out the fission bomb.
"A properly-operating reactor isn't going to emit any significant radioactive material into the environment. Maybe they're thinking about accidental Deuterium and He3 releases, which don't represent any kind of threat to the environment."
That's right. In fact, Deuterium and He3 are harmless. They're natural isotopes that aren't radioactive. You could drink deuterated water and you'd never know.
Ok, that's not totally true. If say... half of your water intake was heavy water (!expensive) then when the deuterated water was incorporated into proteins by your body, it would have a small chance due to the extra weight to make the protein fold into a funny shape, and then your body would have to discard that protein. So if you drank enough heavy water, you'd starve to death.
That's odd. I never understood that phrase "the terrorists have, in fact, already won."
We're talking about violence from our own citizens, which is entirerly unrelated to 9-11. Furthermore, have the terrorists won? That would imply that they had a goal, and achieved it.
Good joke.
Seriously though. Do you disagree with me?
Over-reactions WILL happen. How many false suspensions would you tollerate to prevent a massacre? Better question still, how many massacres would it take before you'd be ok having children disciplined for suspicious behaviour?
Not really related to the current story. There could be a virginia tech incident on a daily basis, and after reading that story, I'd still say that kid should not have been suspended.
The article doesn't mention an arrest or any legal charges whatsoever.
He was simply suspended from the school... Ok. And sent to some crappy re-education centre.
Ok, I usually like to play Devil's advocate. Generally speaking, a school has good reason when they discipline students. There was a case reviewed by ABC regarding a student who was suspended for bringing a nail clipper to school despite rules that clearly stated weapons were not to be brought to school. Yes, it seems very absurd, but do you honestly think any teacher would take notice if he wasn't using the knife like attachment to threaten other students?
HOWEVER. In this case... It sounds like someone got scared (and who can blame them) and over-reacted. Then again, I would prefer to have one hundred thousand over reactions as depicted in the article than one more university or high school massacre.
Well, sure. But we're not terribly worried about votes being messed up one at a time.
Here in Canada, it would be pretty simple for me to personally go around voting at every station in the city. All I need to do is forge a power bill, and that's really gosh darn easy. Now, unless I can forge 2 pieces of photo ID along with, I'll end up going to jail afterwards.
The point is, a small number of votes is easily messed up, but what we want to ensure is that someone can't mess up the whole ballot box.
Imagine if a site KNEW that you just LOVED deals, so they'd mark down that 8-bit tie just when you strolled by the site. Or, maybe the site KNOWS that you just pissed off your wife and increases the prices of flowers knowing that you're going to buy anyways.
Well, I'd say that cost cutting due to competition leads to 'general crappiness of the status quo.'
I mearly meant that it would be fantastic if these pv cells were cheap enough to replace tinted plate glass.
Another poster claims a maximum efficiency of 6.5%.
What would be cool is if the waste energy wasn't in heat but just in unabsorbed wavelengths. Then we could cheaply make windows which would be a bit tinted (which we like anyways) and then daisy chain them to produce electricity. Say, in sky scrapers where it's all glass anyways.
It would be very neat if they were cheap enough that it wouldn't really matter where you put it for it to pay for itself.
Mars does not have plate activity like earth.
This is why Mars has larger mountains and deeper valleys than earth, because the one plate does not move, and that mountain on the top of the hotspot never moved away from the source of its growth.
First, I'm going to state that I'm an environmentalist, and that everything you've said makes good sense. But there's another side of things you should think about.
Perhaps you're right that in North America, we consume too much.
But there are a good many countries that don't have this sort of development. Now, these countries are advancing, and they're going through many of the same pains that industrial and cultural revolutions with cost dramatic amounts of energy and resources. Without these, the quality of life will remain appallingly low (by who's standards right?)
So while you're standing on your high horse preaching consumption reduction, realize that there are countries that can not do so. In my opinion it is vital that these countries increase their consumption until their level of education naturally limits population growth.
So while conservation is important, and necessary, a more complete solution is to establish high limit energy sources which have a minimal tax on the environment. (did I mention that I'm a graduate student in Nuclear Fusion...)