The energy input to extract tar sands is high -- the equivalent of 1 barrel of oil to extract three barrels of 'synthetic crude' -- but there's no reason for this energy to come from conventional oil. For example, it's been proposed to supply the heat for in situ liquefaction of the bitumun by using steam from nuclear reactors.
Yeah, we periodically hear of the big breakthrough that will reduce the cost of PV cells. This has been happening for decades, but PV sales are still overwhelmingly conventional silicon (and may be getting more expensive now that PV production has exhausted the surplus Si byproduct feed from fabs.) So don't be credulous about the latest claim; judging by history it will very likely go nowhere.
Nuclear has gotten a lot of money from the government, but then nuclear has provided a lot in return to the government, like bombs and nuclear propulsion for warships and subs.
Uranium is quite a bit more abundant than is often depicted; remember that at today's U price the cost of the natural uranium itself is a very small part of the cost of nuclear energy, so its price could go up a lot without significant impact. When and if that happens, we can build powerplants with improved breeding to extend the resource even more.
If you can dispute that, please provide a reference for your pesonal residential grid electric supplier you use -a URL is fine- and what the contract terms are
This is the Chicago are; we're supplied by ComEd. Residential rates are 8.75 cents/kWh (plus a fixed service fee of $7.13/month). There are also taxes, IIRC, but I don't remember what they are.
According to this page, PV electricity is still about 30 cents/kWh in the sunniest locations. Chicago is far from the sunniest location; let's say 50 cents/kWh here. So solar is not competitive with grid power for my by about a factor of five.
Our ability to extract coal is entirely dependent upon cheap oil
This is simply wrong. We could mine coal with equipment powered entirely by liquid fuels derived from the coal. Fischer-Tropsch diesel from coal would actually be cheaper than the current price of diesel fuel, now that oil is close to $60/barrel.
Fast breeders aren't the only kind of breeder. Some thermal reactor types achieve breeding ratios very close to 1 with the Th-U cycle. As an example, CANDU reactors work well with this cycle, and have excellent neutron economy, Recent advances in heavy water production will help reduce the cost of CANDU plants.
The individual particles in the plasma are deflected. The effect is that the magnetic field induces a current in the plasma, and a force is exerted on the current by the magnetic field.
You grossly misrepresent the actual state of affairs.
The truth is that mainstream cosmologists have closely examined the theories of Arp, Alfven, etc. The theories are not accepted by the mainstream because they have grave defects.
For example, modern telescopes can detect the fuzz of the distant host galaxies around quasars. The red shift of these stars is the same as the red shift of the quasars. This shows that the red shift is indeed cosmological, and that Arp's associations are just accidental.
The 'plasma universe' model cannot explain the incredibly homogeniety of the cosmic microwave background radiation, or the abundance of light elements.
Lerner's book contained numerous bloopers, things that were known to be untrue at the time he wrote it.
By the way it is utterly incapable of explaining the neutrino observations.
Re:Labeling in science circles annoys the most
on
Supernova 1987A Decoded
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· Score: 4, Insightful
Scientists don't like to play with theories that are obviously wrong, as this one is. Science is a search for how the universe really works, and bullshit purporting to be truth is deeply offensive to that goal.
While (1) seems correct, (2) is misleading. Reprocessing of nuclear fuel would not be happening in the US even if the government didn't put up roadblocks -- uranium is still far too cheap for it to make sense.
What's happening with spent fuel is probably what should have been done from the beginning. Fuel rods that have cooled for a decade or more are being sealed in air-cooled armored casks. These casks are safe, relatively cheap, and secure. They won't corrode for centuries, and they leave the fuel accessible for future reprocessing or other advanced disposal options.
You also make better use of the conductor (it can always be operating at high current, rather than oscillating through zero 120 times a second.) And for long distance transmission, DC power lines are immune to voltages induced by geomagnetic storms. These can harm AC systems by adding induced quasi-DC currents, which can damage transformers.
And it's wrong another way. You don't electrolyze pure water, its resistivity is far too high. Electrolytic hydrogen generators typically use strongly alkaline solutions as the electrolyte.
The most common way in making hydrogen is electrolyzing pure water.
Sorry, but this is just wrong. Millions of tons of hydrogen are made every year around the world (for ammonia synthesis, for example), and very little of it comes from electrolysis. Thermal reforming of natural gas and other carbonaceous compounds is much more economical.
Confinement of positrons is certainly straightforward in a Penning Trap. Unfortunately, the Brillouin limit means the total mass-energy of the stored positrons is always at most the stored magnetic energy of the magnet used in the trap.
This is completely inadequate for prpulsion purposes.
Making positrons is actually much easier than making antiprotons. Pair production on photons produced in accelerators should give efficiencies of 5 to 10% -- and the positrons are much easier to cool.
The big problem with positrons is storing them. Unless these people have a major new idea to get around the Brillouin limit on Penning Traps, the energy stored per mass of equipment will be too small to be interesting (even worse than the energy/mass of chemical propellants.)
> The space shuttle program was ruined in its early days by too many government/military/nasa requirements,
But it *had* to do that. The economic case for the shuttle only made sense if you launched it a lot (remember those 50 flights/year projections?), and that required that it serviced as many markets as possible (real and imaginary).
If it had been tailored to a specific purpose, its launch rate would have been far too low to ever recoup its development cost. As it was, this was the case anyway.
The correct decision would have been to do what the Soviets did and continue to incrementally improve expendable launchers.
> I wouldn't dare let private enterprise anywhere near scientifically important space travel.
You *do* realize that this is mostly unmanned, right? What part is not, such as HST servicing, was in retrospect more expensive than just using expendable boosters and building more than one spacecraft if necessary.
Oh, and NASA buys its expendable launch services from the private sector, and has for years.
Building spacecraft on the moon is not something that will be done soon. Not because metals are scarce, but because spacecraft are complicated devices that require enormous industrial infrastructure behind them. You're not going to transplant that industry to the moon anytime soon, and you're not going to save money (even considering launch costs) when the cost of labor on the moon will be many orders of magnitude higher than on Earth.
Somethings we may see sooner are mining the moon for propellant (lunar polar water, organics, stuff derived from those), and possibly extraction of platinum group elements if PGE-rich asteroid impact sites can be located. None of these activities require sophisticated manufacturing on the moon.
Slashdot Mirror
The energy input to extract tar sands is high -- the equivalent of 1 barrel of oil to extract three barrels of 'synthetic crude' -- but there's no reason for this energy to come from conventional oil. For example, it's been proposed to supply the heat for in situ liquefaction of the bitumun by using steam from nuclear reactors.
Yeah, we periodically hear of the big breakthrough that will reduce the cost of PV cells. This has been happening for decades, but PV sales are still overwhelmingly conventional silicon (and may be getting more expensive now that PV production has exhausted the surplus Si byproduct feed from fabs.) So don't be credulous about the latest claim; judging by history it will very likely go nowhere.
Nuclear has gotten a lot of money from the government, but then nuclear has provided a lot in return to the government, like bombs and nuclear propulsion for warships and subs.
Uranium is quite a bit more abundant than is often depicted; remember that at today's U price the cost of the natural uranium itself is a very small part of the cost of nuclear energy, so its price could go up a lot without significant impact. When and if that happens, we can build powerplants with improved breeding to extend the resource even more.
If you can dispute that, please provide a reference for your pesonal residential grid electric supplier you use -a URL is fine- and what the contract terms are
This is the Chicago are; we're supplied by ComEd. Residential rates are 8.75 cents/kWh (plus a fixed service fee of $7.13/month). There are also taxes, IIRC, but I don't remember what they are.
According to this page, PV electricity is still about 30 cents/kWh in the sunniest locations. Chicago is far from the sunniest location; let's say 50 cents/kWh here. So solar is not competitive with grid power for my by about a factor of five.
What about the huge piles of toxic and somewhat radioactive U-238 that you get at the end?
Do you own a house in the suburbs? If so, the soil in your yard probably contains several pounds of U-238. It's a rather common element.
Our ability to extract coal is entirely dependent upon cheap oil
This is simply wrong. We could mine coal with equipment powered entirely by liquid fuels derived from the coal. Fischer-Tropsch diesel from coal would actually be cheaper than the current price of diesel fuel, now that oil is close to $60/barrel.
Fast breeders aren't the only kind of breeder. Some thermal reactor types achieve breeding ratios very close to 1 with the Th-U cycle. As an example, CANDU reactors work well with this cycle, and have excellent neutron economy, Recent advances in heavy water production will help reduce the cost of CANDU plants.
3. Extreme cost of photovoltaic modules.
The individual particles in the plasma are deflected. The effect is that the magnetic field induces a current in the plasma, and a force is exerted on the current by the magnetic field.
You grossly misrepresent the actual state of affairs.
The truth is that mainstream cosmologists have closely examined the theories of Arp, Alfven, etc. The theories are not accepted by the mainstream because they have grave defects.
For example, modern telescopes can detect the fuzz of the distant host galaxies around quasars. The red shift of these stars is the same as the red shift of the quasars. This shows that the red shift is indeed cosmological, and that Arp's associations are just accidental.
The 'plasma universe' model cannot explain the incredibly homogeniety of the cosmic microwave background radiation, or the abundance of light elements.
Lerner's book contained numerous bloopers, things that were known to be untrue at the time he wrote it.
Yeah, right. People go into science because it's a great way to get rich. [rolls eyes]
Explain again why the government, or any religion, has a stake in the core-collapse theory of supernovas?
Seems to me you prefer facile, but ridiculous, conspiracy theories as a substitute for actual understanding.
However, Lerner borders on crankhood himself.
And from other processes, such as photon + photon --> nu + nu-bar, and e+ + e- --> nu + nu-bar.
and how are you so sure that this is so wrong?
By the way it is utterly incapable of explaining the neutrino observations.
Scientists don't like to play with theories that are obviously wrong, as this one is. Science is a search for how the universe really works, and bullshit purporting to be truth is deeply offensive to that goal.
While (1) seems correct, (2) is misleading. Reprocessing of nuclear fuel would not be happening in the US even if the government didn't put up roadblocks -- uranium is still far too cheap for it to make sense.
What's happening with spent fuel is probably what should have been done from the beginning. Fuel rods that have cooled for a decade or more are being sealed in air-cooled armored casks. These casks are safe, relatively cheap, and secure. They won't corrode for centuries, and they leave the fuel accessible for future reprocessing or other advanced disposal options.
You also make better use of the conductor (it can always be operating at high current, rather than oscillating through zero 120 times a second.) And for long distance transmission, DC power lines are immune to voltages induced by geomagnetic storms. These can harm AC systems by adding induced quasi-DC currents, which can damage transformers.
Watier
The Grinder
Selenium
Last January there was a workshop on open source web test tools in Austin.
And it's wrong another way. You don't electrolyze pure water, its resistivity is far too high. Electrolytic hydrogen generators typically use strongly alkaline solutions as the electrolyte.
Sorry, but this is just wrong. Millions of tons of hydrogen are made every year around the world (for ammonia synthesis, for example), and very little of it comes from electrolysis. Thermal reforming of natural gas and other carbonaceous compounds is much more economical.
Confinement of positrons is certainly straightforward in a Penning Trap. Unfortunately, the Brillouin limit means the total mass-energy of the stored positrons is always at most the stored magnetic energy of the magnet used in the trap.
This is completely inadequate for prpulsion purposes.
The posters here missed the mark.
Making positrons is actually much easier than making antiprotons. Pair production on photons produced in accelerators should give efficiencies of 5 to 10% -- and the positrons are much easier to cool.
The big problem with positrons is storing them. Unless these people have a major new idea to get around the Brillouin limit on Penning Traps, the energy stored per mass of equipment will be too small to be interesting (even worse than the energy/mass of chemical propellants.)
> The space shuttle program was ruined in its early days by too many government/military/nasa requirements,
But it *had* to do that. The economic case for the shuttle only made sense if you launched it a lot (remember those 50 flights/year projections?), and that required that it serviced as many markets as possible (real and imaginary).
If it had been tailored to a specific purpose, its launch rate would have been far too low to ever recoup its development cost. As it was, this was the case anyway.
The correct decision would have been to do what the Soviets did and continue to incrementally improve expendable launchers.
> I wouldn't dare let private enterprise anywhere near scientifically important space travel.
You *do* realize that this is mostly unmanned, right? What part is not, such as HST servicing, was in retrospect more expensive than just using expendable boosters and building more than one spacecraft if necessary.
Oh, and NASA buys its expendable launch services from the private sector, and has for years.
Building spacecraft on the moon is not something that will be done soon. Not because metals are scarce, but because spacecraft are complicated devices that require enormous industrial infrastructure behind them. You're not going to transplant that industry to the moon anytime soon, and you're not going to save money (even considering launch costs) when the cost of labor on the moon will be many orders of magnitude higher than on Earth.
Somethings we may see sooner are mining the moon for propellant (lunar polar water, organics, stuff derived from those), and possibly extraction of platinum group elements if PGE-rich asteroid impact sites can be located. None of these activities require sophisticated manufacturing on the moon.
> Carl Sagan is a big blow-hard.
That would be a neat trick, seeing as how he's dead.
Why cut it loose? Because keeping it around costs a huge amount of money, and it won't be doing anything near enough to justify the expense.
And ISS should be abandoned as well. It also has no purpose justifying the cost of operating it.