That sounds scary, but alternatives to this technology include needle EEGs and surgical brain implants (e.g., for disabled people to control protheses). I expect those also carry a risk of infection and are far more invasive. Compared to normal contact EEGs (another potential alternative), there may be an additional risk.
They say that it only needs to penetrate the very top layer of skin in order to stay in place. I've gotten painless scrapes before where I could see that the skin had been penetrated, but it was just extremely shallow. The patent application says the teeth are only 0.01" long and oriented mostly horizontally, not vertically. Someone in the comments section of TFA from Pittsburgh, where this was invented, says they've tried it an experienced "little to no discomfort". Someone else pointed out that ticks stay attached to you and most people don't even notice.
The shift won't be uniform either inside or outside the black hole; there's always a difference between looking toward or away from the horizon. Spinning makes the asymmetry worse; then there is a preferred axis too.
Very old black holes or neutron stars probably don't spin much, as they've radiated away their angular momentum, but probably pretty much everything spins a little.
First off, you make it sound like oil companies earning money is wrong. I don't know about you, but when I start a business, I expect to make money. No one starts a business to lose money.
I'm not saying oil companies earning money is wrong. I'm saying that I don't really care if THEY benefit from the oil. I care if society benefits, and if I benefit. If it makes oil companies richer but not me or the average citizen, then that changes my opinion of the value of the activity. So I have to ask, is the change in oil price that the consumer sees (e.g., in gas prices) worth the drawbacks of the activity? I'm sure if I was an oil executive whose salary depends on oil profits, my cost-benefit analysis would run rather differently.
Second, Shell is saying the time from start to pumping oil would be less than 6 months. That oil would be on the market in less than a year.
That disagrees with the studies I've read (e.g., from the DOE), which indicate a decade or so before you see serious market penetration, and the effect on the global price of oil won't amount to much more than tens of cents on a gallon of gas at best lasting maybe 20 years. Maybe more than that right at first, since there's usually a jump due to speculation, then less than that, and perhaps a rise again at the end as it runs out. The oil companies are not hurting for oil right now; they're already sitting on substantial reserves. I'm sure oil companies could rush some of that oil to market to claim that it's making a difference to supply and prices, but the time until it actually makes a difference is maybe rather longer. Also, since it is a global market, it could be the case that OPEC will just release some of their reserves and neutralize the price drop.
I'm just glad the prices are back down.
Well, it's nice for my wallet, but I personally would like them to be higher, because I think we need to be reducing fossil fuel consumption, and a price signal is the best way to induce demand destruction. We already saw some of that happen with the recent gas crunch. I'm willing to pay a risk premium.
I think simply the threat of us drilling scared the Saudi markets into lowering their prices.
Probably true, but also probably a transient response.
Here is an applet which shows what the universe looks like if you're near or falling into a black hole. It lets you choose either a freely falling observer, or a stationary (hovering) observer. (The latter should only work if you're outside the hole, since there are no stationary observers inside a black hole. Nevertheless, the applet works for stationary observers inside the hole. I don't know what that means.) The applet only deals with a non-rotating black hole.
As you can see, a black hole does not produce a uniform redshift which is the same in every direction, and so it's not an explanation for cosmological redshift. Black holes have weird optical distortions if you're facing toward or away from the horizon and can have both red and blue shift.
Photons are never at rest so it doesn't make sense to speak of their "rest mass" or "rest frame". Physicists speak of "invariant mass", which is zero for a photon, and is nonzero for particles which can be at rest. "Rest mass" is always positive and is a special case of "invariant mass", which can be positive or zero. The other concept is relativistic mass(-energy). That's the quantity which is nonzero (E/c^2) for photons.
The size of land they are talking about using in the ANWR has been compared to a postage stamp on a football field.
I am sure it has been compared to that, but is it a correct comparison? I don't know. The right number is "ecological impact", not "land surface area", but it's probably hard to quantify. From a surface area perspective, it should include not only the area taken up by the drilling apparatus, but also by support buildings, roads, pipelines, etc. From a non-areal perspective, it needs to account for the ecosystems affected, including any rare species, distant populations whose migratory pathways may be interrupted by development activity, the effects of any secondary pollution, etc. The EPA does this kind of total system analysis, but I haven't read any of their studies on ANWR.
No matter what we do, wherever we do it, there will be an impact to the environment, or some species. But we can't stop everything we do because it will effect a frog, or herd of caribou or whatever. On the other hand, we can't be totally irresponsible either.
That's true.
You also have to weigh it against the benefit of the action. Drilling in ANWR would make money for oil companies, but the consumer isn't going to see any of that oil within the next decade or two, and it's not going to appreciably affect the price of gas at the pump or reduce dependence on foreign oil. The benefits of ANWR drilling to society as a whole seem somewhat dubious to me. There are very few truly unspoiled wildlife refuges left in the U.S. Is it worth it to develop part of one for limited benefits? That's unclear to me. Of course, the drilling doesn't affect the whole area, but it's yet another encroachment on one of the few remaining protected areas. Of course, drilling does provide more oil and lower prices, but in the grand scheme not much.
Environmentalists don't really complain about the idea of building one oil rig. Of those who are against, say, ANWR drilling, they mostly complain about building many oil rigs, and all the road and pipeline infrastructure needed to support them. Also, there isn't really any wildlife at the South Pole, other than assorted gnats.
One might consider that dark matter had some mass distribution, and the ordinary matter just got pulled into match.
You're right. Dark matter is thought to play an important role in "seeding" the distribution of galaxies in the early universe. I'm not sure that black holes have anything to do with it, though.
Perhaps a supermassive dark matter "black hole" of some sort existed all along and then formed an ordinary black hole in the same place. Then again, a "black hole" formed by dark matter would behave identically to an ordinary matter black hole for all intents and purposes (a black hole's only attributes are its mass and angular momentum, and presumably dark matter could have both of those).
A black hole is the same no matter what went into forming it, for the reasons you give (see the "no hair" theorem). So nobody talks about "dark matter black holes". It would be hard to think of dark matter as forming black holes in the first place, because it's not very strongly interacting and you probably can't make big clumps of matter like stars out of it.
Did the galaxies form and then the black holes formed in their cores with all that extra mass concentration? Did the black holes form first and nucleate the galaxy? Did a dark matter concentration form first and nucleate the rest of the galaxy?
I haven't kept up to date with these questions. I think small galaxies were nucleated around clumps of dark matter. Once the galaxies formed, small black holes formed within them and grew. The galaxies and the black holes within became larger when they collided and merged with each other.
Then you have some string theory variants that suggest that gravity can travel between branes in a multiverse of sorts. Perhaps a galaxy in this universe forms because the region of space is "close" to a galaxy that already exists in some other universe. Dark matter might just be galaxies in other universes.
I believe that has been proposed, but I don't know of any serious attempts to really work out the full implications of that idea. It's a lot more speculative than dark matter just being a different kind of particle, IMHO.
IceCube is designed to detect neutrino events only from the northern hemisphere. Neutrinos from the sky in the southern hemisphere get confused with other atmospheric muons events. So they screen out all events coming from above, and only look at those coming from below, i.e. from the north. Neutrinos have no problem passing through the Earth, but all other particles do, so they know that events from below come from neutrinos.
Still, you can rephrase the question: why don't they build a detector in the Arctic to look for southern events? The only place there's that much land ice is Greenland. There isn't much infrastructure there. There is some already at the South Pole. I suspect that's the reason. But if IceCube proves successful, maybe they'll think about a Greenland version.
big equipment is needed to study the extremely small or the extremely large (particle physics and astronomy)
I should clarify that this is certainly not always the case: there is a lot of astronomy and even particle physics that you can still do without enormous resources. But there are some things that just require giant experiments, because of the scale of the problem.
The 3/2 factor is not obvious. You have to get fairly deep into the spacetime geometry before it falls out of the equations. Or at least, I'm not aware of any "intuitive" explanation for the exact value of that factor.
That's the science where you have to build the biggest equipment, because big equipment is needed to study the extremely small or the extremely large (particle physics and astronomy).
Biomedicine/genomics is slowly starting to encroach on physics in terms of Big Science. But there is also tons of science which is not Big Science.
And mostly, telescopes?
Telescopes and particle accelerators. See above.
If someone goes to the NSF and asks for billions to build a really big computer to do AI research on, the NSF tells them to go talk to IBM.
The NSF mostly funds science (national Science foundation). Computer science doesn't get as much of a priority with them, since it's more mathematics/engineering.
Also, with a billion-dollar particle accelerator, people are likely to discover new fundamental things about the universe we live in. With a billion-dollar computer, can we guarantee any breakthroughs in AI? I don't know that hardware is the limiting factor here.
I'm surprised no Trek writer ever thought of this.
Check out the plot to the TOS episode The Squire of Gothos. The main adversary is an alien whose knowledge of Earth comes from telescopic study which is out-of-date due to light speed lag.
What if the light is emitted at the horizon at exactly a tangential angle, assuming a perfectly spherical and unchanging event horizon?
It will fall in, instead of remaining at the horizon, in an inspiralling orbit.
Think of it this way: shooting light straight out is the most effective way to get light to escape the hole. Any other angle and you're not aiming it as much away from the hole as you could be. The horizon is the threshold between which light can or cannot escape. If light that's headed straight out remains stationary, then light that's headed out at an angle will definitely fall in, and so will tangential light.
Similarly, light can exactly hit the event horizon and be in a perpetual orbit around the black hole at exactly the boundary of the event horizon
Not quite.
The only way for light to remain at the horizon is if it is emitted straight outwards at the horizon. It doesn't orbit around the hole, but "hovers". Of course, this is unstable: emitted slightly inside the horizon, it doesn't make it out; emitted outside, it radiates off to infinity.
There is a location outside the horizon where light can orbit around the hole in a circular fashion. This is the "photon sphere", at 1.5 times the horizon radius. This is also unstable.
Similarly, light can exactly hit the event horizon and be in a perpetual orbit around the black hole at exactly the boundary of the event horizon, until the black hole eats something and causes the event horizon to slightly increase, causing the previous "shell" of photons to fall inward.
There's a slight difference between the event horizon and a "trapped horizon". I think you're describing a trapped horizon. An event horizon is defined according to whether light can escape to infinity at any time infinitely far into the future; in order to define its location, you have to know the entire future history of what might fall into the hole. A trapped horizon is a more local concept, and infalling matter can change whether you're at a trapped horizon or not.
Well, one thing we can observe is that when gas or dust falls onto a compact object which theory predicts is a neutron star, it makes a big flash of light as it smashes into the star's surface. On the other hand, when we see matter fall into what theory predicts is a black hole, it just disappears. (I'm not talking about the radiating matter in the accretion disk, I'm talking about stuff that actually falls in.) That's pretty good evidence, other than gravitational effects on orbits, that there really is an event horizon there. And it happens precisely for the objects that theory predicts are massive enough to be black holes. I can't remember the references to the papers which first found this, but they've been around for about 10 years.
Do we know what caused the black hole to form in the first place?
I think that the currently favored theory is that galaxies grow from smaller galaxies with little black holes in them. When they collide and merge, so do their central black holes.
So, does that mean that a star died somewhere in our galaxy to cause the black hole to form?
In all, lots of stars go into forming a supermassive black hole.
What are the potential implications of this discovery?
It helps us to understand how galaxies and the black holes in them form.
Is there a chance that we could send probes to observe this thing (however we observe black holes) or what?
Not really. It's tens of thousands of light years away. It's hard enough to travel a few light years to the nearest star in a reasonable time.
I know that I heard something about a satellite that could gather information about gravity phenomena
LISA? Or Gravity Probe B?
Perhaps sending one of those suckers toward the black hole could yield some interesting results?
We can't send anything towards a black hole that would make a real difference in distance to the hole. We can make measurements within our own solar system of events happening outside of it, though: a gravitational-wave telescope like LIGO/LISA could detect colliding black holes.
Does this mean that jump starting research on better detection of radiation from black holes is a good idea?
No. Hawking radiation is far too weak to detect. I could work it out, but I just looked in Wikipedia. For a solar-mass black hole the Hawking radiation is only 10^-28 watts, and it decreases with the square of the mass (bigger holes emit less). For a multi-million solar mass black hole it would thus be even more ridiculously weak.
Detecting the gravitational radiation from colliding black holes, on the other hand, may be feasible, since you have two massive bodies smacking into each other.
Never heard of Hawking radiation... Assuming it's something to do with Stephen Hawking?
Yup. It's what he's perhaps most famous for. You can find it on Wikipedia.
Hell, the cosmic microwave radiation would drown out the Hawking radiation of a black hole that size. By a lot. Hawking radiation is weak for any astrophysical-sized object, and is even weaker for a supermassive black hole.
I'm not sure if anyone has specifically studied the effects of cloud cover. However, the models used in the recent studies do have dynamical cloud effects including the cloud greenhouse effect, so in principle this already should be included in the calculation. I don't think the cloud effect can mitigate the massive amounts of soot blocking out sunlight.
People have proposed something similar as a solution to global warming, e.g. aerosol geoengineering. Basically, artificial volcanoes. It would work insofar as it can be used to modify the global average temperature (which is not the whole of climate). It has a number of potentially severe drawbacks (written by the same guy whose nuclear winter research I linked).
Slashdot Mirror
That sounds scary, but alternatives to this technology include needle EEGs and surgical brain implants (e.g., for disabled people to control protheses). I expect those also carry a risk of infection and are far more invasive. Compared to normal contact EEGs (another potential alternative), there may be an additional risk.
They say that it only needs to penetrate the very top layer of skin in order to stay in place. I've gotten painless scrapes before where I could see that the skin had been penetrated, but it was just extremely shallow. The patent application says the teeth are only 0.01" long and oriented mostly horizontally, not vertically. Someone in the comments section of TFA from Pittsburgh, where this was invented, says they've tried it an experienced "little to no discomfort". Someone else pointed out that ticks stay attached to you and most people don't even notice.
The shift won't be uniform either inside or outside the black hole; there's always a difference between looking toward or away from the horizon. Spinning makes the asymmetry worse; then there is a preferred axis too.
Very old black holes or neutron stars probably don't spin much, as they've radiated away their angular momentum, but probably pretty much everything spins a little.
First off, you make it sound like oil companies earning money is wrong. I don't know about you, but when I start a business, I expect to make money. No one starts a business to lose money.
I'm not saying oil companies earning money is wrong. I'm saying that I don't really care if THEY benefit from the oil. I care if society benefits, and if I benefit. If it makes oil companies richer but not me or the average citizen, then that changes my opinion of the value of the activity. So I have to ask, is the change in oil price that the consumer sees (e.g., in gas prices) worth the drawbacks of the activity? I'm sure if I was an oil executive whose salary depends on oil profits, my cost-benefit analysis would run rather differently.
Second, Shell is saying the time from start to pumping oil would be less than 6 months. That oil would be on the market in less than a year.
That disagrees with the studies I've read (e.g., from the DOE), which indicate a decade or so before you see serious market penetration, and the effect on the global price of oil won't amount to much more than tens of cents on a gallon of gas at best lasting maybe 20 years. Maybe more than that right at first, since there's usually a jump due to speculation, then less than that, and perhaps a rise again at the end as it runs out. The oil companies are not hurting for oil right now; they're already sitting on substantial reserves. I'm sure oil companies could rush some of that oil to market to claim that it's making a difference to supply and prices, but the time until it actually makes a difference is maybe rather longer. Also, since it is a global market, it could be the case that OPEC will just release some of their reserves and neutralize the price drop.
I'm just glad the prices are back down.
Well, it's nice for my wallet, but I personally would like them to be higher, because I think we need to be reducing fossil fuel consumption, and a price signal is the best way to induce demand destruction. We already saw some of that happen with the recent gas crunch. I'm willing to pay a risk premium.
I think simply the threat of us drilling scared the Saudi markets into lowering their prices.
Probably true, but also probably a transient response.
Here is an applet which shows what the universe looks like if you're near or falling into a black hole. It lets you choose either a freely falling observer, or a stationary (hovering) observer. (The latter should only work if you're outside the hole, since there are no stationary observers inside a black hole. Nevertheless, the applet works for stationary observers inside the hole. I don't know what that means.) The applet only deals with a non-rotating black hole.
As you can see, a black hole does not produce a uniform redshift which is the same in every direction, and so it's not an explanation for cosmological redshift. Black holes have weird optical distortions if you're facing toward or away from the horizon and can have both red and blue shift.
Photons are never at rest so it doesn't make sense to speak of their "rest mass" or "rest frame". Physicists speak of "invariant mass", which is zero for a photon, and is nonzero for particles which can be at rest. "Rest mass" is always positive and is a special case of "invariant mass", which can be positive or zero. The other concept is relativistic mass(-energy). That's the quantity which is nonzero (E/c^2) for photons.
It's Time Cube. Duh.
The size of land they are talking about using in the ANWR has been compared to a postage stamp on a football field.
I am sure it has been compared to that, but is it a correct comparison? I don't know. The right number is "ecological impact", not "land surface area", but it's probably hard to quantify. From a surface area perspective, it should include not only the area taken up by the drilling apparatus, but also by support buildings, roads, pipelines, etc. From a non-areal perspective, it needs to account for the ecosystems affected, including any rare species, distant populations whose migratory pathways may be interrupted by development activity, the effects of any secondary pollution, etc. The EPA does this kind of total system analysis, but I haven't read any of their studies on ANWR.
No matter what we do, wherever we do it, there will be an impact to the environment, or some species. But we can't stop everything we do because it will effect a frog, or herd of caribou or whatever. On the other hand, we can't be totally irresponsible either.
That's true.
You also have to weigh it against the benefit of the action. Drilling in ANWR would make money for oil companies, but the consumer isn't going to see any of that oil within the next decade or two, and it's not going to appreciably affect the price of gas at the pump or reduce dependence on foreign oil. The benefits of ANWR drilling to society as a whole seem somewhat dubious to me. There are very few truly unspoiled wildlife refuges left in the U.S. Is it worth it to develop part of one for limited benefits? That's unclear to me. Of course, the drilling doesn't affect the whole area, but it's yet another encroachment on one of the few remaining protected areas. Of course, drilling does provide more oil and lower prices, but in the grand scheme not much.
Environmentalists don't really complain about the idea of building one oil rig. Of those who are against, say, ANWR drilling, they mostly complain about building many oil rigs, and all the road and pipeline infrastructure needed to support them. Also, there isn't really any wildlife at the South Pole, other than assorted gnats.
So make them implement their own language to program in. I'm thinking a Malbolge compiler targeting a quantum Turing virtual machine.
One might consider that dark matter had some mass distribution, and the ordinary matter just got pulled into match.
You're right. Dark matter is thought to play an important role in "seeding" the distribution of galaxies in the early universe. I'm not sure that black holes have anything to do with it, though.
Perhaps a supermassive dark matter "black hole" of some sort existed all along and then formed an ordinary black hole in the same place. Then again, a "black hole" formed by dark matter would behave identically to an ordinary matter black hole for all intents and purposes (a black hole's only attributes are its mass and angular momentum, and presumably dark matter could have both of those).
A black hole is the same no matter what went into forming it, for the reasons you give (see the "no hair" theorem). So nobody talks about "dark matter black holes". It would be hard to think of dark matter as forming black holes in the first place, because it's not very strongly interacting and you probably can't make big clumps of matter like stars out of it.
Did the galaxies form and then the black holes formed in their cores with all that extra mass concentration? Did the black holes form first and nucleate the galaxy? Did a dark matter concentration form first and nucleate the rest of the galaxy?
I haven't kept up to date with these questions. I think small galaxies were nucleated around clumps of dark matter. Once the galaxies formed, small black holes formed within them and grew. The galaxies and the black holes within became larger when they collided and merged with each other.
Then you have some string theory variants that suggest that gravity can travel between branes in a multiverse of sorts. Perhaps a galaxy in this universe forms because the region of space is "close" to a galaxy that already exists in some other universe. Dark matter might just be galaxies in other universes.
I believe that has been proposed, but I don't know of any serious attempts to really work out the full implications of that idea. It's a lot more speculative than dark matter just being a different kind of particle, IMHO.
IceCube is designed to detect neutrino events only from the northern hemisphere. Neutrinos from the sky in the southern hemisphere get confused with other atmospheric muons events. So they screen out all events coming from above, and only look at those coming from below, i.e. from the north. Neutrinos have no problem passing through the Earth, but all other particles do, so they know that events from below come from neutrinos.
Still, you can rephrase the question: why don't they build a detector in the Arctic to look for southern events? The only place there's that much land ice is Greenland. There isn't much infrastructure there. There is some already at the South Pole. I suspect that's the reason. But if IceCube proves successful, maybe they'll think about a Greenland version.
big equipment is needed to study the extremely small or the extremely large (particle physics and astronomy)
I should clarify that this is certainly not always the case: there is a lot of astronomy and even particle physics that you can still do without enormous resources. But there are some things that just require giant experiments, because of the scale of the problem.
The 3/2 factor is not obvious. You have to get fairly deep into the spacetime geometry before it falls out of the equations. Or at least, I'm not aware of any "intuitive" explanation for the exact value of that factor.
And how come it's always physics physics physics?
That's the science where you have to build the biggest equipment, because big equipment is needed to study the extremely small or the extremely large (particle physics and astronomy).
Biomedicine/genomics is slowly starting to encroach on physics in terms of Big Science. But there is also tons of science which is not Big Science.
And mostly, telescopes?
Telescopes and particle accelerators. See above.
If someone goes to the NSF and asks for billions to build a really big computer to do AI research on, the NSF tells them to go talk to IBM.
The NSF mostly funds science (national Science foundation). Computer science doesn't get as much of a priority with them, since it's more mathematics/engineering.
Also, with a billion-dollar particle accelerator, people are likely to discover new fundamental things about the universe we live in. With a billion-dollar computer, can we guarantee any breakthroughs in AI? I don't know that hardware is the limiting factor here.
I'm surprised no Trek writer ever thought of this.
Check out the plot to the TOS episode The Squire of Gothos. The main adversary is an alien whose knowledge of Earth comes from telescopic study which is out-of-date due to light speed lag.
What if the light is emitted at the horizon at exactly a tangential angle, assuming a perfectly spherical and unchanging event horizon?
It will fall in, instead of remaining at the horizon, in an inspiralling orbit.
Think of it this way: shooting light straight out is the most effective way to get light to escape the hole. Any other angle and you're not aiming it as much away from the hole as you could be. The horizon is the threshold between which light can or cannot escape. If light that's headed straight out remains stationary, then light that's headed out at an angle will definitely fall in, and so will tangential light.
Similarly, light can exactly hit the event horizon and be in a perpetual orbit around the black hole at exactly the boundary of the event horizon
Not quite.
The only way for light to remain at the horizon is if it is emitted straight outwards at the horizon. It doesn't orbit around the hole, but "hovers". Of course, this is unstable: emitted slightly inside the horizon, it doesn't make it out; emitted outside, it radiates off to infinity.
There is a location outside the horizon where light can orbit around the hole in a circular fashion. This is the "photon sphere", at 1.5 times the horizon radius. This is also unstable.
Similarly, light can exactly hit the event horizon and be in a perpetual orbit around the black hole at exactly the boundary of the event horizon, until the black hole eats something and causes the event horizon to slightly increase, causing the previous "shell" of photons to fall inward.
There's a slight difference between the event horizon and a "trapped horizon". I think you're describing a trapped horizon. An event horizon is defined according to whether light can escape to infinity at any time infinitely far into the future; in order to define its location, you have to know the entire future history of what might fall into the hole. A trapped horizon is a more local concept, and infalling matter can change whether you're at a trapped horizon or not.
Well, one thing we can observe is that when gas or dust falls onto a compact object which theory predicts is a neutron star, it makes a big flash of light as it smashes into the star's surface. On the other hand, when we see matter fall into what theory predicts is a black hole, it just disappears. (I'm not talking about the radiating matter in the accretion disk, I'm talking about stuff that actually falls in.) That's pretty good evidence, other than gravitational effects on orbits, that there really is an event horizon there. And it happens precisely for the objects that theory predicts are massive enough to be black holes. I can't remember the references to the papers which first found this, but they've been around for about 10 years.
Do we know what caused the black hole to form in the first place?
I think that the currently favored theory is that galaxies grow from smaller galaxies with little black holes in them. When they collide and merge, so do their central black holes.
So, does that mean that a star died somewhere in our galaxy to cause the black hole to form?
In all, lots of stars go into forming a supermassive black hole.
What are the potential implications of this discovery?
It helps us to understand how galaxies and the black holes in them form.
Is there a chance that we could send probes to observe this thing (however we observe black holes) or what?
Not really. It's tens of thousands of light years away. It's hard enough to travel a few light years to the nearest star in a reasonable time.
I know that I heard something about a satellite that could gather information about gravity phenomena
LISA? Or Gravity Probe B?
Perhaps sending one of those suckers toward the black hole could yield some interesting results?
We can't send anything towards a black hole that would make a real difference in distance to the hole. We can make measurements within our own solar system of events happening outside of it, though: a gravitational-wave telescope like LIGO/LISA could detect colliding black holes.
Does this mean that jump starting research on better detection of radiation from black holes is a good idea?
No. Hawking radiation is far too weak to detect. I could work it out, but I just looked in Wikipedia. For a solar-mass black hole the Hawking radiation is only 10^-28 watts, and it decreases with the square of the mass (bigger holes emit less). For a multi-million solar mass black hole it would thus be even more ridiculously weak.
Detecting the gravitational radiation from colliding black holes, on the other hand, may be feasible, since you have two massive bodies smacking into each other.
Never heard of Hawking radiation... Assuming it's something to do with Stephen Hawking?
Yup. It's what he's perhaps most famous for. You can find it on Wikipedia.
Hell, the cosmic microwave radiation would drown out the Hawking radiation of a black hole that size. By a lot. Hawking radiation is weak for any astrophysical-sized object, and is even weaker for a supermassive black hole.
I'm not sure if anyone has specifically studied the effects of cloud cover. However, the models used in the recent studies do have dynamical cloud effects including the cloud greenhouse effect, so in principle this already should be included in the calculation. I don't think the cloud effect can mitigate the massive amounts of soot blocking out sunlight.
Jesus, doesn't anyone read threads before posting anymore? You're the fifth person to make this joke, and nothing but this joke. Very witty.
People have proposed something similar as a solution to global warming, e.g. aerosol geoengineering. Basically, artificial volcanoes. It would work insofar as it can be used to modify the global average temperature (which is not the whole of climate). It has a number of potentially severe drawbacks (written by the same guy whose nuclear winter research I linked).