For legal reasons (stupid international treaties), I'm told I shouldn't report most of my list. However, I can state that I don't want anyone in the afterlife being able to say I never vaporized Ann Coulter with a high-powered laser, if you get my drift.
Well, if it's going to be the apocalypse (and I'm not going to be responsible, much to my chagrin), can you just make sure I get a few weeks' notice? There are... things... I want to do.
Thanks. Some actual information is way more helpful than the vague claims swirling about. I thought about trying to figure out where bulbs are being produced, but didn't have a lot of luck with the Google.
They don't have to make such claims. If the incandescent bulbs involve the same shipping overhead as the CFLs (as the grandparent is sarcastically suggesting), then the claims that CFLs are more environmentally friendly stand up. That's the point, period. The shipping costs mentioned (without any sort of supporting data, I might add) in the summary is only a valid issue if incandescents are made locally.
Columbus was unaware of Eriksson's trip, as far as I know. As such, it's a lousy comparison with the Moon landings, an event that NASA has a whole wealth of data about.
I do agree with your second example, ISS is a re-do of Mir. I also think ISS is a waste of time and money (as do many others here), so I'm not sure that that example works in favor of arguing to go back to the Moon.
Oh, it matters. If a substantial fraction of the cost for Apollo was just figuring out how the heck a rocket that size *works* and what people needed for the missions, we'd save a bundle of money by using that research again. I think that that's more or less what the post I was responding to assumed.
But I doubt that such costs were really a huge fraction of the Apollo cost to begin with and you seem to concur.
It depends a lot on where the money needs to be spent. There have been a lot of advancements in technology (especially computers) since the 60s, so I imagine that pretty much the entire control system would have to be replaced. Plus it's a larger rocket and a larger capsule which will require new design rules and testing. And it's hard to imagine that the price to actually build and operate the thing, once designed, has dropped a lot. The raw materials are still the same and the fuel is governed by physics more than by brilliance of design. (Given that it's bigger and has more people, costs have probably risen.)
Simply knowing the aerodynamics of rockets might not be that much of a savings. Or it might be; I can't say without better information than I think any of us here has.
So let's take a fact then. Every time there has been a major volcanic explosion in history, global effects, it was followed by sudden and sometimes extreme cooling. Mt. Tambora in Indonesia exploded in 1815 and 1816 became "the year without a summer."
Except that the dust is the major driver in that, not clouds. And no, not "clouds that form on dust". Just the aerosols themselves tend to cool the lower atmosphere. This is well-known and part of the models.
Look, you can want clouds to solve the global warming problems all you want, but the data quite simply disagree with you. Arguing your intuition doesn't change that.
The Venusian atmosphere is NOT water vapor though and comparing Venus's CO2 (96%)
Yes, it's made up of a much weaker greenhouse gas. Still, the clouds don't cool the planet. See the point?
(And yes, it's closer to the Sun. That doesn't change the physics and the trade-off between greenhouse gases and albedo.)
If the albedo becomes very high, where most of the atmosphere is white, where is the heat coming from?
A substantial amount of light still makes it through even thick clouds. You'll note that a cloudy day is still very distinguishable from night, for example. And if you've got a lot of greenhouse gases at work, you don't need a lot of insolation to stay hot.
There are a lot of competing effects at play with clouds, it's easy to get confused. I suggest you check out the link that someone posted above. It explains it nicely.
Actually, I think it's high clouds that warm since they have a colder emission temperature than the surface does. I'd have to dig up my RT in Planetary Atmospheres notes, though. It's been quite a while.
See my post above; clouds don't always cool things. And heck, even a high albedo doesn't help much if you've got too much greenhouse gasses: ask Venus.
In fact, we're pretty sure that if you put enough water vapor into the atmosphere, eventually the system runs away, getting hotter and hotter until all the water evaporates.
Actually, while water has a relatively short residency in the atmosphere (so does methane, incidentally... it just turns into CO2 in about a decade), there's also a whole lot of it and more constantly being added. As a result, water vapor does most of the work raising Earth's mean surface temperature from (as I recall) about 255 K to 288 K, a critical 35 K shift.
Good point, although to be fair, this idea seems to be a mix of redirection and actual cooling. The latter wouldn't have the negative effect on plants that the former would.
1) Where does the energy come from to spray this water?
2) Clouds are fickle where temperature is concerned. Depending on the type of cloud, they can either raise or lower the temperature. (The article, I see, also notes this.) This is one of the trickiest points of climate modeling, if memory serves.
3) Water vapor is also a particularly powerful greenhouse gas. Pumping a lot more of it into the air could exacerbate the problem rather than fix it. (Also noted in the article, but not actually discussed.)
I provided the citation, that makes it eminently verifiable. If you're capable of going to a seminar or reading papers, you should know how to use ADSABS to look up the abstract. There was this thing called "looking it up" before people got used to being spoon-fed links on the internet. But because you apparently aren't capable of doing your own research: http://adsabs.harvard.edu/abs/2008DPS....40.1201G
And you should check the seminars' sources. As Kevin Grazier pointed out in his DPS presentation, there's not real study to back up the claims that Jupiter protects things. It just entered conventional wisdom through the back door and people stopped questioning it.
Remember: being told something a lot isn't the same as having it demonstrated.
Actually, a random small thing is more likely to to slung about by Jupiter than to hit it. How do you think things get sent into the inner solar system to begin with? Neptune doesn't generally change KBOs' orbits enough to send them to Earth, but Neptune can pass them to Jupiter and then to Earth. In fact, in the numerical study I cited, they found that objects were more likely to have encountered Jupiter most recently before a collision with Earth than any other body. Arguably, Jupiter makes things worse.
In any case, note the study I cited. You're intuition is wrong, Jupiter doesn't shield us.
The Pacific ocean didn't even exist a billion years ago, let alone 4.5 billion years ago (when no continents existed). It's hard to call it the scar of anything. It's also difficult to see how plate tectonics are attempts to reach a more stable state, except in the sense that Earth is trying to cool. (The locations of the continents are immaterial to this.)
Actually, no. First of all, it's not really tides from Jupiter that deflect anything. Second, the idea that Jupiter is a shield is based on basically no actual foundation. Grazier et al. had a poster at DPS this year where they showed the results of numerical integrations. They demonstrated that Jupiter, in fact, provides little shielding. (How can it, it doesn't really block a lot of the possible entrance to the inner solar system?).
How does "500 million years old" approach the 4.5 Gyr age of the Earth and Moon, to you? And I never said there were no rocks that old, just that they were scarce. That's true. (And Canada ain't the only place with old rocks. Africa and Australia both feature some rivals.)
Also, last I checked, the old rocks ever found were less than 4.3 Gyr. That's still 250 Myr shy of the age of the Moon.
(And you might want to check your dating methods. Carbon dating doesn't work really well on multi-Gyr-old rocks. You're more likely to go for uranium or some other long-lived isotope.)
Ug, the Earth's composition is like the Moon's because we're made of the same stuff (Earth's mantle). The moon lacks (or nearly lacks) iron because it only got mantle material and not the iron cores of the two bodies.
Capture doesn't work: the bodies are really too similar in composition and the physics of capturing a moon that large around a planet as small as Earth are scary.
I did a similar calculation to see how much energy it would take to loft the Moon into an orbit 2 Earth-radii up. (Energy for the subsequent evolution is taken from Earth's spin.) It's not quite Earth's binding energy, but it's still within a few orders of magnitude.
Throw into that the fact that accretion isn't that efficient, so you'd need minimum 10x the mass of the Moon (I'm guessing), especially when a lot of the mass is on an orbit to re-impact the Earth when it is first blown off.
You don't have to super-heat them at all, that's my point. The Earth is a fluid even today. Over timescales of billions of years, any wound would have been erased.
Slashdot Mirror
For legal reasons (stupid international treaties), I'm told I shouldn't report most of my list. However, I can state that I don't want anyone in the afterlife being able to say I never vaporized Ann Coulter with a high-powered laser, if you get my drift.
Honestly, I doubt anyone would have to pay for it if we reach the end of the world.
Well, if it's going to be the apocalypse (and I'm not going to be responsible, much to my chagrin), can you just make sure I get a few weeks' notice? There are... things... I want to do.
Thanks. Some actual information is way more helpful than the vague claims swirling about. I thought about trying to figure out where bulbs are being produced, but didn't have a lot of luck with the Google.
They don't have to make such claims. If the incandescent bulbs involve the same shipping overhead as the CFLs (as the grandparent is sarcastically suggesting), then the claims that CFLs are more environmentally friendly stand up. That's the point, period. The shipping costs mentioned (without any sort of supporting data, I might add) in the summary is only a valid issue if incandescents are made locally.
Columbus was unaware of Eriksson's trip, as far as I know. As such, it's a lousy comparison with the Moon landings, an event that NASA has a whole wealth of data about.
I do agree with your second example, ISS is a re-do of Mir. I also think ISS is a waste of time and money (as do many others here), so I'm not sure that that example works in favor of arguing to go back to the Moon.
Oh, it matters. If a substantial fraction of the cost for Apollo was just figuring out how the heck a rocket that size *works* and what people needed for the missions, we'd save a bundle of money by using that research again. I think that that's more or less what the post I was responding to assumed.
But I doubt that such costs were really a huge fraction of the Apollo cost to begin with and you seem to concur.
It depends a lot on where the money needs to be spent. There have been a lot of advancements in technology (especially computers) since the 60s, so I imagine that pretty much the entire control system would have to be replaced. Plus it's a larger rocket and a larger capsule which will require new design rules and testing. And it's hard to imagine that the price to actually build and operate the thing, once designed, has dropped a lot. The raw materials are still the same and the fuel is governed by physics more than by brilliance of design. (Given that it's bigger and has more people, costs have probably risen.)
Simply knowing the aerodynamics of rockets might not be that much of a savings. Or it might be; I can't say without better information than I think any of us here has.
So let's take a fact then. Every time there has been a major volcanic explosion in history, global effects, it was followed by sudden and sometimes extreme cooling. Mt. Tambora in Indonesia exploded in 1815 and 1816 became "the year without a summer."
Except that the dust is the major driver in that, not clouds. And no, not "clouds that form on dust". Just the aerosols themselves tend to cool the lower atmosphere. This is well-known and part of the models.
Look, you can want clouds to solve the global warming problems all you want, but the data quite simply disagree with you. Arguing your intuition doesn't change that.
The Venusian atmosphere is NOT water vapor though and comparing Venus's CO2 (96%)
Yes, it's made up of a much weaker greenhouse gas. Still, the clouds don't cool the planet. See the point?
(And yes, it's closer to the Sun. That doesn't change the physics and the trade-off between greenhouse gases and albedo.)
If the albedo becomes very high, where most of the atmosphere is white, where is the heat coming from?
A substantial amount of light still makes it through even thick clouds. You'll note that a cloudy day is still very distinguishable from night, for example. And if you've got a lot of greenhouse gases at work, you don't need a lot of insolation to stay hot.
There are a lot of competing effects at play with clouds, it's easy to get confused. I suggest you check out the link that someone posted above. It explains it nicely.
Oo, helpful link. Thanks!
Actually, I think it's high clouds that warm since they have a colder emission temperature than the surface does. I'd have to dig up my RT in Planetary Atmospheres notes, though. It's been quite a while.
See my post above; clouds don't always cool things. And heck, even a high albedo doesn't help much if you've got too much greenhouse gasses: ask Venus.
In fact, we're pretty sure that if you put enough water vapor into the atmosphere, eventually the system runs away, getting hotter and hotter until all the water evaporates.
Actually, while water has a relatively short residency in the atmosphere (so does methane, incidentally... it just turns into CO2 in about a decade), there's also a whole lot of it and more constantly being added. As a result, water vapor does most of the work raising Earth's mean surface temperature from (as I recall) about 255 K to 288 K, a critical 35 K shift.
Good point, although to be fair, this idea seems to be a mix of redirection and actual cooling. The latter wouldn't have the negative effect on plants that the former would.
1) Where does the energy come from to spray this water?
2) Clouds are fickle where temperature is concerned. Depending on the type of cloud, they can either raise or lower the temperature. (The article, I see, also notes this.) This is one of the trickiest points of climate modeling, if memory serves.
3) Water vapor is also a particularly powerful greenhouse gas. Pumping a lot more of it into the air could exacerbate the problem rather than fix it. (Also noted in the article, but not actually discussed.)
I don't understand your question.
I provided the citation, that makes it eminently verifiable. If you're capable of going to a seminar or reading papers, you should know how to use ADSABS to look up the abstract. There was this thing called "looking it up" before people got used to being spoon-fed links on the internet. But because you apparently aren't capable of doing your own research: http://adsabs.harvard.edu/abs/2008DPS....40.1201G
And you should check the seminars' sources. As Kevin Grazier pointed out in his DPS presentation, there's not real study to back up the claims that Jupiter protects things. It just entered conventional wisdom through the back door and people stopped questioning it.
Remember: being told something a lot isn't the same as having it demonstrated.
Actually, a random small thing is more likely to to slung about by Jupiter than to hit it. How do you think things get sent into the inner solar system to begin with? Neptune doesn't generally change KBOs' orbits enough to send them to Earth, but Neptune can pass them to Jupiter and then to Earth. In fact, in the numerical study I cited, they found that objects were more likely to have encountered Jupiter most recently before a collision with Earth than any other body. Arguably, Jupiter makes things worse.
In any case, note the study I cited. You're intuition is wrong, Jupiter doesn't shield us.
The Pacific ocean didn't even exist a billion years ago, let alone 4.5 billion years ago (when no continents existed). It's hard to call it the scar of anything. It's also difficult to see how plate tectonics are attempts to reach a more stable state, except in the sense that Earth is trying to cool. (The locations of the continents are immaterial to this.)
Actually, no. First of all, it's not really tides from Jupiter that deflect anything. Second, the idea that Jupiter is a shield is based on basically no actual foundation. Grazier et al. had a poster at DPS this year where they showed the results of numerical integrations. They demonstrated that Jupiter, in fact, provides little shielding. (How can it, it doesn't really block a lot of the possible entrance to the inner solar system?).
How does "500 million years old" approach the 4.5 Gyr age of the Earth and Moon, to you? And I never said there were no rocks that old, just that they were scarce. That's true. (And Canada ain't the only place with old rocks. Africa and Australia both feature some rivals.)
Also, last I checked, the old rocks ever found were less than 4.3 Gyr. That's still 250 Myr shy of the age of the Moon.
(And you might want to check your dating methods. Carbon dating doesn't work really well on multi-Gyr-old rocks. You're more likely to go for uranium or some other long-lived isotope.)
Ug, the Earth's composition is like the Moon's because we're made of the same stuff (Earth's mantle). The moon lacks (or nearly lacks) iron because it only got mantle material and not the iron cores of the two bodies.
Capture doesn't work: the bodies are really too similar in composition and the physics of capturing a moon that large around a planet as small as Earth are scary.
I did a similar calculation to see how much energy it would take to loft the Moon into an orbit 2 Earth-radii up. (Energy for the subsequent evolution is taken from Earth's spin.) It's not quite Earth's binding energy, but it's still within a few orders of magnitude.
Throw into that the fact that accretion isn't that efficient, so you'd need minimum 10x the mass of the Moon (I'm guessing), especially when a lot of the mass is on an orbit to re-impact the Earth when it is first blown off.
You don't have to super-heat them at all, that's my point. The Earth is a fluid even today. Over timescales of billions of years, any wound would have been erased.