I would submit that, there, you are using the "fear factor" by suggesting that the sinks may not catch up at all.
OK - they will catch up at some point. The issue is where is that point? A degree and 100 years? 10 degrees and 1000 years? Or is the new equilibrium point similar to Venus? The runaway greenhouse effect is an extreme (and not seriously contemplated, I should add) possibility, since we have no proof that the climate is inherently stable to all perturbations - in fact likely it isn't. I'm not trying to up the "fear factor", but I am saying that it's not clear to anyone if/when/how the system will reestablish equilibrium after we double or triple atmospheric CO2 levels. An interesting example is that of North American forests - which were long touted as big carbon sinks. Well, now big forest fires are starting to return that carbon into the atmosphere.
In short, the Earth will establish equilibrium. Whether that includes a large human population is open to debate - it certainly doesn't include large dinosaur populations. The point being that climate change has in the past wiped out species.
Sure, the climate will change. The climate will change regardless of what we do or don't do. It may change in different ways, but we can't even be sure of HOW it will differ given two courses of action. If we can't say with any certainty how the climate will react to any of several scenarios, how can we honestly state that one is worse than the other?
It's amusing that our debate is mirroring the larger one of the past few decades. First it was "There is no warming", followed by "So there is warming. But it's insignificant". Then it's "nobody really knows who's fault it is".
Next you'll probably say either that we have to study the problem more before we act, or that the evil Chinese should act first since in the years to come they will produce more CO2.
What we can say is that we are perturbing the climate system in a way that it hasn't seen before, and with a very large perturbation (doubling or tripling CO2 in 200 years is a large, rapid change). Something will happen, and the best models seem to indicate rather unpleasant effects.
First, all models have shown is that the more they improve them, the less global warming is expected.
Do you have proof of this statement? I can recall a few announcements in the last couple of years where the estimates were revised upward, but it'll take time to find the references. In fact, the IPCC 2000 report (which is effectivly a summary of many, many models), revised their estimate upward from 1995. So I don't think your statement is true.
Second, it is not even proven whether global warming will cause sea levels to rise. Most of the sea level rise would have to come from Antartica--and the temperature could rise 10 degrees and that ice wouldn't melt.
That too is debatable. I take it you are referring to the West Antarctice ice sheet? There was a recent article in Science talking about how recent observations of ice dynamics (e.g. the recent Ross (?) ice shelf collapse) that seem to indicate that ice sheets can collapse very quickly with only small perturbations. Besides, the debate as I understand it is whether the West Antarctic Ice Shelf will go after a 5 degree rise - 10 degrees will almost certainly take it out. That gives you 10 meters of sea level rise right there. (On the upside, though, we wouldn't have to hear more about bungled elections in Miami)
And if it did happen to melt and sea level did rise, who is to say that earth doesn't want to go into an ice age and only our CO2 production is avoiding it?
And what is to say that tomorrow we won't be invaded by large green two-penised^H^H^H^H headed aliens that just happen to be allergic to CO2, thus having Exxon save the day? Seriously though,
folks, if models and observations start indicating that is happening, we'll deal with it then. In the mean time, we shouldn't use such specious arguments to avoid dealing with a better known threat.
I agree, let's improve efficiency. But let's work with what we have. Going cold turkey on carbon fuels--a course of action virtually required if we are to meet CO2 goals called "essential" by some scientists--is not an option right now.
Will it ever be? I think we could do more than we are, and we won't have viable alternatives until we start investing enough to bootstrap new technologies. In fact, very few modern technologies have been adpoted without large amount of initial government subsidy. The Internet (how many years of government funding?) and even the car (the Interstate system was a huge subsidy) are examples.
But if you compare the science of astronomy to the climate science the difference is truly shocking. We are constantly reading about new discoveries, changes to old thoughts in astronomy because of some new pulsar they found, etc. It bounces all over. When it comes to climate science, all we hear is how the earth is warming and we are at fault with an impressive level of certainty
Are you an astronomer by any chance? There are certain things most astronomers will state with "impressive certainty", like the fact that the Earth is round, or that the universe started in a Big Bang, or what the production rate of solar neutrinos is (which depends on some really fiendishly complex models, yet we are so certain of it that we invented new physics (netrino mixing) to explain. Later verified by observation, I should add. )
We hear about global warming because it is an observational fact, physically plausible, and of some concern globally. There is no vast conspiracy to "conceal the truth", intentional or not.
Those scientists that disagree with those that promote global warming are ridiculed or written off as having been "purchased" by oil interests. Sure, they're still alive, but they are burned at the stake in terms of funding and reputation in their field.
I don't know about that - S Fred Singer is still around and keeps getting invited to seminars here.
If a scientist is right, sooner or later scientific opinion will come around to his point of view. It may take a LONG time, but the point of science is that it happens faster than with the alternatives (i.e. never).
To give you an idea, you have to go to Saturn Ring G [nasa.gov] at 165,000km from Saturn's center before you get a ring more than 0.1-1km in "thickness."
But the rings are very "wide", of the Sun isn't exctly above the equator the projected shadow will depend on how wide the ring is - potentially 1000's of kms.If the ring is even close to optically thick (i.e. blocks light going through it), it may potentially reduce incoming sunlight noticeably (a few percent is a big effect). If it has any dust it can likely be optically thick.
Work out how many 0.1-mm particles you can make from one 10 km asteroid (10^21) then work out how much surface area they have (10^16 m^2). That's a pretty large sunshade.
For earth, I'm quite certain the ring would be on a smaller scale than Saturn.
More proof by assertion?
No mention of dust. I would think that makes sense since a meteor impact on Earth would result in most of the dust staying in the atmosphere since it would be quickly slowed down by the atmosphere given the small particle size, while larger rocks and boulders might make it to orbit. I doubt you'd find much 0.01mm particles in orbit, at least from a meteor impact.
Interesting point, but check out one of the above comments discussing how the ring is formed. In order to end up with a circular ring in the equatorial plane you likely need a lot of collisions between the boulders. These collisions generate large amounts of dust (the astreroid belt provides an example of this).
I'm not saying I necessarily belive his idea, but it's not that easy to dismiss out of hand.
Gotta love those climate models of scenarios that are impossible to compare to reality. Heck, the climate models have been SO accurate so far as far as global warming goes, why not duplicate their success with a climate model of something completely impossible to compare with reality to validate the model.
Now you are just letting a political opinion about a different matter affect your thinking.
The fact is, the CO2 produced by humans is a fraction of the total amount of CO2 produced by nature. I don't dispute that we generate CO2. I dispute that it makes a difference. Our CO2 production is far overwhelmed by nature's CO2 production.
They why do we see a steady rise in the level of atmospheric CO2 over the last 50 years, an increase that is about what we'd expect based on the amount of fossil fuel burning, etc? (Again, the Keeling curve). Natural CO2 releases may be larger, but if they are in equilibrium with CO2 sinks, even a small increase in net CO2 input can cause a steady rise in atmospheric CO2 levels. (At least until the sinks catch up, which takes time, and may not occur at all). Either way, we are seeing an increase, and isotopic signatures show that the carbon comes from fossil fuels (no C12).
Another way to make the point: look closely at the Keeling curve and you will see small variations that are in sync with the seasons. This is telling you that natural changes in CO2 respiration exist, are measurable, and are smaller than the large human-induced trend. In raw numbers, humans dump about 6Gt (gigatons of Carbon) per year into the atmosphere. The biosphere absorbs about half of that, the rest stays in the air.
I don't dispute that there could be some net heating. I DO dispute that it's significant
Well, there are several groups that have made estimates of the heating. As I recall it will likely be between 0.5 and 6 degrees (C) in the next century, with a peak in the probability function around 1-2. That is a larger increase than in other interglacial times, and it puts us in a climate regime that we haven't been in for at least a few million years (high CO2, warm. The typical situation has been colder with less CO2).
We can argue a lot about detailed effects, but the climate will be different from now. There are a lot of models that suggest shifts in agriculture, and sea level rise. They may not be a problem for some rich guy in Colorado, but it will be a serious problem for Bangladesh (they have many). Of course, if you don't care about Bangladesh, fine. But keep releasing CO2 and in the next century it will be a problem for Florida.
No, you don't have to come up with a reason for the system to show natural warming .
If you accept that we are causing an increase in CO2, and you accept the physics of IR absorbption, my argument stands - why is the warming we see NOT due to the CO2 we release?
There have been very sudden movements in both directions in the past
For climate records such as ice cores it is often impossible to get good time resolution - so you can't tell the difference between an instantaneous rise and one that takes 2000 years. The rise in the past century is at least as rapid as any we have seen, and faster than most. Also, there may have been climate change, but nothing says it didn't have serious effects on life at the time. There have been large species die-offs related to climate change in the past.
If anything, this reinfoces the point that it may be hazardous to jolt the climate severely. maybe not in terms of wiping out all life on the planet, but certainly in terms of causing e.g. agricultural disruption.
To pretend that those scientists that are promoting the theory of global warming have absolutely no financial interest in the results and are any more professional or ethical than those paid for by oil companies is very, very naive.
I don't know about that. There tends to be an extra layer of insulation between government-funded scientists (who by and large worry about global warming) and the financial interests. Certainly with the current U.S. administration there is no incentive for government scientists to exaggerate the seriousness of global warming.
The problem is that there are politicians out there advocating drastic changes in our social, political, and economic systems based on partial, in-progress results.
Actually, they seem to be advocating small changes in how we produce and consume energy, changes that will likely have to be made sooner or later anyway (we can't go on burning oil this inefficiently forever). In fact, dealing with global warming may well stimulate innovation and help the economy. After all, improving energy efficiency make the economy work better. The converse is certainly true - look at the former Soviet Union for an example of what can happen to a wasteful industrial economy.
Another problem is that the scientists themselves are telling us (the world AND the politicians) what we need to do. That's not science, that's politics.
Since when does the mere fact that someone is a scientist disqualify him or her from making policy recommendations? After all, in the U.S. every idiot is entitled to an opinion, logical or not. If someone who is intelligent and well-educated spends a lot of time studying a problem and comes to the conclusion that action is needed, why should we ignore that persons opinion? I know anti-intellectualism is alive and well in the states, but that doesn't make it wise.
Scientists are the "clergy" of the 21st century. When "scientists" start making policy we will again have a theocracy that the "separation of church and state" was supposed to protect us from. Just now the clergy will be made up of "scientists" rather than religious people. The political result is the same.
Now this is a lovely topic for a long discussion, but I have to get back to work. However, I will say this: there is a big difference between science and religion. Religion claims to have a monopoly on the truth, and hence once the Pope or the Mullah or clergy or whatever has spoken (as the mouthpiece of God, of course) there can be no argument. Science, when it works properly, is always ready to admit error. That makes it possible to improve science. Why does this matter? Well, it makes for a big difference in the political end result: a theocracy burns dissenters at the stake. A democracy with engaged scientists has a fruitful, ongoing debate. Also, with scientists involved in the debate you can actually get informed opinions. Otherwise it's just a big gab-fest,i.e. slashdot.
And many who claim to be global-warming skeptics have long ago gone beyond the point where they could be convinced by any reasonable evidence. I mean, really, there is a lot of data: temperature records, tree rings, ice cores, satellite data, sediment records, even bore-hole temperatures all show a recent trend of unusually strong warming.
Couple that with the undisputed fact that CO2 increases due to fossil fuel burning have been measured for a long time (the Keeling curve, e.g. these plots ) Now, throw in the physics of radiative transfer to see how increases in CO2 trap IR radiation and hence increase temperatures, and I'd say you have a pretty strong case. You have a plausible mechanism, observations of the putative cause, and observations of the effect.
I think at this point it's harder to come up with a mechanism why we wouldn't be causing global warming; you have to explain a) why the observed human-caused CO2 increase doesn't cause a net heating, while at the same time b) you have to come up with a reason for the system to still show some warming from "natural" causes. Warming that is very different (in that it is very rapid) from what is seen is climate records of the past. Oh, and you also have to explain why your point of view isn't at all influenced by financial interests in maintaining the status quo (remember, scientists working on global warming don't get paid to cry wolf - if anything they'd get more research funds if they could provide a soothing reassurance that there is no global warming).
It is true that the climate is variable and complex, and that we are only beginning to understand it well. It is also true that scientific opinion changes as new data, theories and people get involved. However, the point of science (as opposed to pretty much any other intellectual activity) is that it eventually converges toward the right answer. That is often a long, painful process - but I think we can be confident that we understand climate better now than we did in the 70's. Unfortunately the answers we are finding makes a lot of people uncomfortable. But instead of "shooting the messenger" (by trying to discredit the scientists), wouldn't it be wiser to try and deal with reality as it is?
Actually, there has been a direct detection; one of the extra-solar planets (HD 209458) has been observed to transit. That means they've obseved the dip in brightness of the parent star when it gets (partially) eclipsed by the planet. It's a very, very solid detection (there is a gorgeous light-curve taken with HST). Check out this link for more info, e.g. the light curve is available through a link at the bottom of the page.
I would say that is a pretty direct detection, as Charbonneau et al. have even detected sodium in the atmosphere of that planet.
The issue you are talking about concerns one star out of close to a hundred with planet candidates. Don't be so quick to dismiss some very nice work that people (several independent groups) have been doing for years now.
You start to sound like a crank
I know I'll get modded down for saying this to the Slashdot crowd, but I think this is a situation where computers are NOT the answer.
After the last voting disaster a bunch of smart people
looked at the situation and recommended simple optical scanning approach.
That means Grandma uses a black marker or some such to fill in a bubble. Or circle the candidate, or write in etc. Computerizing things may help with registration, but for the actual vote simpler is better.
What a fun discussion. If you think about exponential growth it really hits you that it wouldn't take long to take over the galaxy, even without FTL travel. Couple that with Darwinian selection favoring those civilizations that choose to expand (those that stay in one place either die out e.g. from asteroid impact, or get conquered by those that do expand)...
One possibility is that one civilization already has taken over, and doesn't like competition. In which case we should expect to see an asteroid traveling at 0.5c headed our way sometime soon...
There really is no reason to _expect_ any other intelligence to be friendly. We probably wouldn't be if we were on top...
Well, here's an idea. Since there are only at most a few hundred people in the country with a) the knowledge to weponize antrax b) access to that particular strain, why don't we round them all up, call them potential terrorists and keep them indefinitely without trial (say, in Cuba), until one of them confesses...
Just make sure the flight computer (or display computer) doesn't decide that the data it is getting can't possibly be right and that it should reset. While the poor sod flying the Airbus in question is trying to recover from an upset that incuded a 75 degree roll in 1.5 seconds... (True story - check AvWeek)
Anyway, the discussion isn't about if fighter pilots should have advanced automation; it's whether or not the idiot next to you on the freeway should have 58 different scrollable menus in order to adjust the air conditioning.
Let me get this straight - these guys combed through a database of ??? earthquakes and found a whopping two instances where two earthquakes hapened within a few seconds of each other on nearly-opposite sides of the world. Given how frequent these small earthquakes are I'm surprised they only found two - just from random chance.
And they use this rather sketchy data to make claims about a very extraordinary discovery... an until now completely unknown form of matter.
This isn't the first time I wish a bit more critical thought had been applied by the journalist.
Or the reviewer for that matter.
Hey, I work for NASA - if anyone has a left-over EG&G photon-counting module or three I would be interested in buying them. Not the new kind by Perkin-Elmer - the old ones from the early 90's.
Background - the old EG&G ones were good. Then P-E bought that division and the modules
they sell - while nominaly the same kind - burn out far too easily (high dark current).
I've even loked on eBay, but they can't be found for love or money...
This whole argument is kind of stupid; just bury it deep enough that modern mining technology is required to get to it - i.e. that you can't tunnel through the rock without explosives, and can't bring up the tailings by animal power alone.
The future is almost impossible to predict, but we can say the following: either our descendents will be as technologically advanced (or more) as we are, or they wont. If they are advanced they will know the danger and take precautions. If they are primitive then they won't be able to drive a mine shaft deep enough to get to the waste.
A good example - look at the tunnel under the English channel. Napoleon tried to drive a tunnel there using early-industrial technology but had to give up. The technology required for that tunnel include electricity, advanced metallurgy, a good understanding of geology, and likely computers, seismic sensors and lasers (the latter three are required to avoid drilling into unstable rock). It's a solid bet that any society that posesses those technologies will also understand the atom and radioactivity (It's really pretty straightforward stuff). This is especially true given how many other technological artefacts will be lying around anyway.
The thing that really pisses me off about these arguments is how they ignore the more obvious problems we are leaving to our descendants 10,000 years from now - like how to run an industrial society without either nuclear power or fossil fuels (we seem too afraid of the former and the latter will be depleted by then). Or how about the recent discovery of an asteroid that might possibly hit the Earth 900 years from now - shouldn't we be concerned about tracking that, and moving it if indeed it is on a collision course?
Also the sharply pointed glare/lensfx spikes around the bright stars look like they are faked-in as well to me... Were they artistically added, were they artifacts of the original camera, or does it "really" look that way?
The spikes are a common artifact of the cameras; a human eye would only see these if you had been crying or suffered from some form of eye trouble (poss astigmatism but I'm not sure).
The spikes are caused by diffraction around the secondary mirror support structure. Astronomers call them "spiders" and you'll see them on most large telescopes. A typical tourist camera is small enough not to need such supports and so lacks the spikes.
In fact, the spikes are a way to tell if the image is authentic or not, and I know colleagues of mine who can tell what telescope an image is from by the shape of the spikes. (e.g. the Keck telescopes have 6 spikes instead of four)
And I've found just exactly the opposite - the very best teachers where I am (a small institute of technology on one of the U.S. coasts) are almost always among the most respected researchers in their fields.
It's not an either-or situation. Congress wouldn't say "OK, lets take the 14 billion from NASA and spend it on the poor starving children in Africa" (not to mention that now you'd have poor starving children of former NASA engineers). Think instead of NASA as a small (compared to other government expenditures) investment in knowledge, with a potentially large payoff that may benefit everyone on the planet. After all, NASA satellites monitor the ozone layer and El Nino events - raising awareness of environmental damage, and providing warning...
I think you're suffering from wishful thinking. If the space staion gets cut it won't be long before space science goes too - it's too small of a constituency to get serious funding. So as interesting as space science and astronomy is, you have to realize it's one very small piglet surviving on the leftovers of the public trough.
Without human spaceflight, and without senators from Florida, Alabama and Texas to guard NASA funding you'd be reduced to stroking the egos of billionaires like Bill Gates (and the Keck foundation, I admit).
Don't blame me - I'm an astronomer too. Just keep in mind how little most people actually care about FUNDING science, and be grateful for the funding we get.
The new optical interferometry system that the Keck telescopes use promise far better resolution than even that, and if something needs to be fixed, it doesn't cost a half-billion dollars to get someone there to fix it.
I don't know about that - have you ever tried to rent a car in Kona on the big island? A Shuttle launch looks cheap in comparison.
Seriously though, folks, as cool as interferometry and adaptive optics are (I work with that stuff, and it's AWESOME), there is still a need for space astronomy; some wavelengths don't penetrate the atmosphere and can only be seen from space, and for looking in the mid-infra-red there is too much background emission on the ground. In short, if you want to for instance see Earth-like planets around other stars you have to do both, i.e. interferometry (and/or adaptive optics) _in_space_.
As for retiring Hubble - space is a harsh environment. Things break and wear out. At some point it is cheaper to just build a new one.
If we don't act, 250 million Americans (and a billion or two people in the rest of the world) will die. Or we can nuke the bastard. Maybe a few million will die if the nut has it in the middle of his capital city, but you will have a very hard time finding anyone who says that a few billion innocent deaths is preferable one-tenth of one percent of that number dying in a preemptive strike intended to save those lives.
More importantly, when you've vaporized all the evidence, you won't have any pesky reporters claiming it was actually a factory producing penicillin instead of smallpox...
Slashdot Mirror
I would submit that, there, you are using the "fear factor" by suggesting that the sinks may not catch up at all.
OK - they will catch up at some point. The issue is where is that point? A degree and 100 years? 10 degrees and 1000 years? Or is the new equilibrium point similar to Venus? The runaway greenhouse effect is an extreme (and not seriously contemplated, I should add) possibility, since we have no proof that the climate is inherently stable to all perturbations - in fact likely it isn't. I'm not trying to up the "fear factor", but I am saying that it's not clear to anyone if/when/how the system will reestablish equilibrium after we double or triple atmospheric CO2 levels. An interesting example is that of North American forests - which were long touted as big carbon sinks. Well, now big forest fires are starting to return that carbon into the atmosphere.
In short, the Earth will establish equilibrium. Whether that includes a large human population is open to debate - it certainly doesn't include large dinosaur populations. The point being that climate change has in the past wiped out species.
Sure, the climate will change. The climate will change regardless of what we do or don't do. It may change in different ways, but we can't even be sure of HOW it will differ given two courses of action. If we can't say with any certainty how the climate will react to any of several scenarios, how can we honestly state that one is worse than the other?
It's amusing that our debate is mirroring the larger one of the past few decades. First it was "There is no warming", followed by "So there is warming. But it's insignificant". Then it's "nobody really knows who's fault it is". Next you'll probably say either that we have to study the problem more before we act, or that the evil Chinese should act first since in the years to come they will produce more CO2.
What we can say is that we are perturbing the climate system in a way that it hasn't seen before, and with a very large perturbation (doubling or tripling CO2 in 200 years is a large, rapid change). Something will happen, and the best models seem to indicate rather unpleasant effects.
First, all models have shown is that the more they improve them, the less global warming is expected.
Do you have proof of this statement? I can recall a few announcements in the last couple of years where the estimates were revised upward, but it'll take time to find the references. In fact, the IPCC 2000 report (which is effectivly a summary of many, many models), revised their estimate upward from 1995. So I don't think your statement is true.
Second, it is not even proven whether global warming will cause sea levels to rise. Most of the sea level rise would have to come from Antartica--and the temperature could rise 10 degrees and that ice wouldn't melt.
That too is debatable. I take it you are referring to the West Antarctice ice sheet? There was a recent article in Science talking about how recent observations of ice dynamics (e.g. the recent Ross (?) ice shelf collapse) that seem to indicate that ice sheets can collapse very quickly with only small perturbations. Besides, the debate as I understand it is whether the West Antarctic Ice Shelf will go after a 5 degree rise - 10 degrees will almost certainly take it out. That gives you 10 meters of sea level rise right there. (On the upside, though, we wouldn't have to hear more about bungled elections in Miami)
And if it did happen to melt and sea level did rise, who is to say that earth doesn't want to go into an ice age and only our CO2 production is avoiding it?
And what is to say that tomorrow we won't be invaded by large green two-penised^H^H^H^H headed aliens that just happen to be allergic to CO2, thus having Exxon save the day? Seriously though, folks, if models and observations start indicating that is happening, we'll deal with it then. In the mean time, we shouldn't use such specious arguments to avoid dealing with a better known threat.
I agree, let's improve efficiency. But let's work with what we have. Going cold turkey on carbon fuels--a course of action virtually required if we are to meet CO2 goals called "essential" by some scientists--is not an option right now.
Will it ever be? I think we could do more than we are, and we won't have viable alternatives until we start investing enough to bootstrap new technologies. In fact, very few modern technologies have been adpoted without large amount of initial government subsidy. The Internet (how many years of government funding?) and even the car (the Interstate system was a huge subsidy) are examples.
But if you compare the science of astronomy to the climate science the difference is truly shocking. We are constantly reading about new discoveries, changes to old thoughts in astronomy because of some new pulsar they found, etc. It bounces all over. When it comes to climate science, all we hear is how the earth is warming and we are at fault with an impressive level of certainty
Are you an astronomer by any chance? There are certain things most astronomers will state with "impressive certainty", like the fact that the Earth is round, or that the universe started in a Big Bang, or what the production rate of solar neutrinos is (which depends on some really fiendishly complex models, yet we are so certain of it that we invented new physics (netrino mixing) to explain. Later verified by observation, I should add. )
We hear about global warming because it is an observational fact, physically plausible, and of some concern globally. There is no vast conspiracy to "conceal the truth", intentional or not.
Those scientists that disagree with those that promote global warming are ridiculed or written off as having been "purchased" by oil interests. Sure, they're still alive, but they are burned at the stake in terms of funding and reputation in their field.
I don't know about that - S Fred Singer is still around and keeps getting invited to seminars here. If a scientist is right, sooner or later scientific opinion will come around to his point of view. It may take a LONG time, but the point of science is that it happens faster than with the alternatives (i.e. never).
But the rings are very "wide", of the Sun isn't exctly above the equator the projected shadow will depend on how wide the ring is - potentially 1000's of kms.If the ring is even close to optically thick (i.e. blocks light going through it), it may potentially reduce incoming sunlight noticeably (a few percent is a big effect). If it has any dust it can likely be optically thick. Work out how many 0.1-mm particles you can make from one 10 km asteroid (10^21) then work out how much surface area they have (10^16 m^2). That's a pretty large sunshade.
For earth, I'm quite certain the ring would be on a smaller scale than Saturn.
More proof by assertion?
No mention of dust. I would think that makes sense since a meteor impact on Earth would result in most of the dust staying in the atmosphere since it would be quickly slowed down by the atmosphere given the small particle size, while larger rocks and boulders might make it to orbit. I doubt you'd find much 0.01mm particles in orbit, at least from a meteor impact.
Interesting point, but check out one of the above comments discussing how the ring is formed. In order to end up with a circular ring in the equatorial plane you likely need a lot of collisions between the boulders. These collisions generate large amounts of dust (the astreroid belt provides an example of this).
I'm not saying I necessarily belive his idea, but it's not that easy to dismiss out of hand.
Gotta love those climate models of scenarios that are impossible to compare to reality. Heck, the climate models have been SO accurate so far as far as global warming goes, why not duplicate their success with a climate model of something completely impossible to compare with reality to validate the model.
Now you are just letting a political opinion about a different matter affect your thinking.
They why do we see a steady rise in the level of atmospheric CO2 over the last 50 years, an increase that is about what we'd expect based on the amount of fossil fuel burning, etc? (Again, the Keeling curve). Natural CO2 releases may be larger, but if they are in equilibrium with CO2 sinks, even a small increase in net CO2 input can cause a steady rise in atmospheric CO2 levels. (At least until the sinks catch up, which takes time, and may not occur at all). Either way, we are seeing an increase, and isotopic signatures show that the carbon comes from fossil fuels (no C12).
Another way to make the point: look closely at the Keeling curve and you will see small variations that are in sync with the seasons. This is telling you that natural changes in CO2 respiration exist, are measurable, and are smaller than the large human-induced trend. In raw numbers, humans dump about 6Gt (gigatons of Carbon) per year into the atmosphere. The biosphere absorbs about half of that, the rest stays in the air.
I don't dispute that there could be some net heating. I DO dispute that it's significant
Well, there are several groups that have made estimates of the heating. As I recall it will likely be between 0.5 and 6 degrees (C) in the next century, with a peak in the probability function around 1-2. That is a larger increase than in other interglacial times, and it puts us in a climate regime that we haven't been in for at least a few million years (high CO2, warm. The typical situation has been colder with less CO2). We can argue a lot about detailed effects, but the climate will be different from now. There are a lot of models that suggest shifts in agriculture, and sea level rise. They may not be a problem for some rich guy in Colorado, but it will be a serious problem for Bangladesh (they have many). Of course, if you don't care about Bangladesh, fine. But keep releasing CO2 and in the next century it will be a problem for Florida.
No, you don't have to come up with a reason for the system to show natural warming .
If you accept that we are causing an increase in CO2, and you accept the physics of IR absorbption, my argument stands - why is the warming we see NOT due to the CO2 we release?
There have been very sudden movements in both directions in the past
For climate records such as ice cores it is often impossible to get good time resolution - so you can't tell the difference between an instantaneous rise and one that takes 2000 years. The rise in the past century is at least as rapid as any we have seen, and faster than most. Also, there may have been climate change, but nothing says it didn't have serious effects on life at the time. There have been large species die-offs related to climate change in the past. If anything, this reinfoces the point that it may be hazardous to jolt the climate severely. maybe not in terms of wiping out all life on the planet, but certainly in terms of causing e.g. agricultural disruption.
To pretend that those scientists that are promoting the theory of global warming have absolutely no financial interest in the results and are any more professional or ethical than those paid for by oil companies is very, very naive.
I don't know about that. There tends to be an extra layer of insulation between government-funded scientists (who by and large worry about global warming) and the financial interests. Certainly with the current U.S. administration there is no incentive for government scientists to exaggerate the seriousness of global warming.
The problem is that there are politicians out there advocating drastic changes in our social, political, and economic systems based on partial, in-progress results.
Actually, they seem to be advocating small changes in how we produce and consume energy, changes that will likely have to be made sooner or later anyway (we can't go on burning oil this inefficiently forever). In fact, dealing with global warming may well stimulate innovation and help the economy. After all, improving energy efficiency make the economy work better. The converse is certainly true - look at the former Soviet Union for an example of what can happen to a wasteful industrial economy.
Another problem is that the scientists themselves are telling us (the world AND the politicians) what we need to do. That's not science, that's politics.
Since when does the mere fact that someone is a scientist disqualify him or her from making policy recommendations? After all, in the U.S. every idiot is entitled to an opinion, logical or not. If someone who is intelligent and well-educated spends a lot of time studying a problem and comes to the conclusion that action is needed, why should we ignore that persons opinion? I know anti-intellectualism is alive and well in the states, but that doesn't make it wise.
Scientists are the "clergy" of the 21st century. When "scientists" start making policy we will again have a theocracy that the "separation of church and state" was supposed to protect us from. Just now the clergy will be made up of "scientists" rather than religious people. The political result is the same.
Now this is a lovely topic for a long discussion, but I have to get back to work. However, I will say this: there is a big difference between science and religion. Religion claims to have a monopoly on the truth, and hence once the Pope or the Mullah or clergy or whatever has spoken (as the mouthpiece of God, of course) there can be no argument. Science, when it works properly, is always ready to admit error. That makes it possible to improve science. Why does this matter? Well, it makes for a big difference in the political end result: a theocracy burns dissenters at the stake. A democracy with engaged scientists has a fruitful, ongoing debate. Also, with scientists involved in the debate you can actually get informed opinions. Otherwise it's just a big gab-fest ,i.e. slashdot.
Couple that with the undisputed fact that CO2 increases due to fossil fuel burning have been measured for a long time (the Keeling curve, e.g. these plots ) Now, throw in the physics of radiative transfer to see how increases in CO2 trap IR radiation and hence increase temperatures, and I'd say you have a pretty strong case. You have a plausible mechanism, observations of the putative cause, and observations of the effect.
I think at this point it's harder to come up with a mechanism why we wouldn't be causing global warming; you have to explain a) why the observed human-caused CO2 increase doesn't cause a net heating, while at the same time b) you have to come up with a reason for the system to still show some warming from "natural" causes. Warming that is very different (in that it is very rapid) from what is seen is climate records of the past. Oh, and you also have to explain why your point of view isn't at all influenced by financial interests in maintaining the status quo (remember, scientists working on global warming don't get paid to cry wolf - if anything they'd get more research funds if they could provide a soothing reassurance that there is no global warming).
It is true that the climate is variable and complex, and that we are only beginning to understand it well. It is also true that scientific opinion changes as new data, theories and people get involved. However, the point of science (as opposed to pretty much any other intellectual activity) is that it eventually converges toward the right answer. That is often a long, painful process - but I think we can be confident that we understand climate better now than we did in the 70's. Unfortunately the answers we are finding makes a lot of people uncomfortable. But instead of "shooting the messenger" (by trying to discredit the scientists), wouldn't it be wiser to try and deal with reality as it is?
I would say that is a pretty direct detection, as Charbonneau et al. have even detected sodium in the atmosphere of that planet.
The issue you are talking about concerns one star out of close to a hundred with planet candidates. Don't be so quick to dismiss some very nice work that people (several independent groups) have been doing for years now. You start to sound like a crank
After the last voting disaster a bunch of smart people looked at the situation and recommended simple optical scanning approach. That means Grandma uses a black marker or some such to fill in a bubble. Or circle the candidate, or write in etc. Computerizing things may help with registration, but for the actual vote simpler is better.
"IE ock Konqeuror bryr sig into om att kolla utgivaren av certifikatet. Det gör SSL i bägge browsers till något av ett skämt. Bork bork..."
One possibility is that one civilization already has taken over, and doesn't like competition. In which case we should expect to see an asteroid traveling at 0.5c headed our way sometime soon...
There really is no reason to _expect_ any other intelligence to be friendly. We probably wouldn't be if we were on top...
It was rather startling...
Anyway, the discussion isn't about if fighter pilots should have advanced automation; it's whether or not the idiot next to you on the freeway should have 58 different scrollable menus in order to adjust the air conditioning.
And they use this rather sketchy data to make claims about a very extraordinary discovery... an until now completely unknown form of matter.
This isn't the first time I wish a bit more critical thought had been applied by the journalist. Or the reviewer for that matter.
Background - the old EG&G ones were good. Then P-E bought that division and the modules they sell - while nominaly the same kind - burn out far too easily (high dark current).
I've even loked on eBay, but they can't be found for love or money...
The future is almost impossible to predict, but we can say the following: either our descendents will be as technologically advanced (or more) as we are, or they wont. If they are advanced they will know the danger and take precautions. If they are primitive then they won't be able to drive a mine shaft deep enough to get to the waste.
A good example - look at the tunnel under the English channel. Napoleon tried to drive a tunnel there using early-industrial technology but had to give up. The technology required for that tunnel include electricity, advanced metallurgy, a good understanding of geology, and likely computers, seismic sensors and lasers (the latter three are required to avoid drilling into unstable rock). It's a solid bet that any society that posesses those technologies will also understand the atom and radioactivity (It's really pretty straightforward stuff). This is especially true given how many other technological artefacts will be lying around anyway.
The thing that really pisses me off about these arguments is how they ignore the more obvious problems we are leaving to our descendants 10,000 years from now - like how to run an industrial society without either nuclear power or fossil fuels (we seem too afraid of the former and the latter will be depleted by then). Or how about the recent discovery of an asteroid that might possibly hit the Earth 900 years from now - shouldn't we be concerned about tracking that, and moving it if indeed it is on a collision course?
The spikes are a common artifact of the cameras; a human eye would only see these if you had been crying or suffered from some form of eye trouble (poss astigmatism but I'm not sure).
The spikes are caused by diffraction around the secondary mirror support structure. Astronomers call them "spiders" and you'll see them on most large telescopes. A typical tourist camera is small enough not to need such supports and so lacks the spikes.
In fact, the spikes are a way to tell if the image is authentic or not, and I know colleagues of mine who can tell what telescope an image is from by the shape of the spikes. (e.g. the Keck telescopes have 6 spikes instead of four)
Or you could use a watch with hands and use the Sun to find North.
Not the only one. But I discovered Smith during a break..
Mod this up! Insightful, and just plain RIGHT.
The data shown is not seriously disputed, and will hopefully hammer home the point (especially the second one!).
Without human spaceflight, and without senators from Florida, Alabama and Texas to guard NASA funding you'd be reduced to stroking the egos of billionaires like Bill Gates (and the Keck foundation, I admit).
Don't blame me - I'm an astronomer too. Just keep in mind how little most people actually care about FUNDING science, and be grateful for the funding we get.
I don't know about that - have you ever tried to rent a car in Kona on the big island? A Shuttle launch looks cheap in comparison.
Seriously though, folks, as cool as interferometry and adaptive optics are (I work with that stuff, and it's AWESOME), there is still a need for space astronomy; some wavelengths don't penetrate the atmosphere and can only be seen from space, and for looking in the mid-infra-red there is too much background emission on the ground. In short, if you want to for instance see Earth-like planets around other stars you have to do both, i.e. interferometry (and/or adaptive optics) _in_space_.
As for retiring Hubble - space is a harsh environment. Things break and wear out. At some point it is cheaper to just build a new one.
More importantly, when you've vaporized all the evidence, you won't have any pesky reporters claiming it was actually a factory producing penicillin instead of smallpox...