In the novel, the Shipstone's eponymous inventor realised "that the problem was not a shortage of energy but lay in the transporting of energy. Energy is everywhere—in sunlight, in wind, in mountain streams, in temperature gradients of all sorts wherever found, in coal, in fossil oil, in radioactive ores, in green growing things. Especially in ocean depths and in outer space energy is free for the taking in amounts lavish beyond all human comprehension.
"Those who spoke of "energy scarcity" and of "conserving energy" simply did not understand the situation. The sky was "raining soup"; what was needed was a bucket in which to carry it."
Ever since then, I've been far more interested in new methods of storing and transporting energy than in new methods of generating energy.
Also, what happens if the mechanisms that contain the "Star in a Bottle" fail? Will the French Alps suddenly and catastrophically acquire a new valley?
Also, what happens if the mechanisms that contain the "Star
in a Bottle" fail? Will the French Alps suddenly and
catastrophically acquire a new valley?
From a previous comment on another fusion story, two years ago: http://news.ycombinator.com/item?id=2839722
Fusion reactors are fundamentally different from fission
reactors. You have to get a tenuous wisp of hydrogen (the
reactor in this particular experiment was running at 10
mTorr, or 0.0013% atmospheric pressure) very, very hot, and
keep it away from solid matter, which is millions of
degrees of colder than the fuel plasma, and will suck all
of the energy out of the reaction.
You shut off the containment coils, and tremendously hot
plasma ions leap away from each other, instantly stopping
the reaction. If the reaction somehow "runs away", which it
absolutely can't, then it brushes the walls of the vacuum
chamber, poisoning it with cold metal ions, like injecting
lead shavings that have been chilled to absolute zero
directly into your heart.
If our magical "runaway reaction" somehow overcomes this,
and melts a hole in the vacuum chamber, then the atmosphere
rushes in, both freezing cold and at intolerably high
pressure, like the North Sea flooding into the hull of a
submarine resting on the ocean floor.
Fusion reactors don't melt down, or explode. At all. It
just can't happen, much like how a Yugo rear-ending a
garbage truck in Brooklyn doesn't instantly consume all of
New York City in a gasoline fireball.
My new favorite metaphor.
"Putting a speed limiter on a Zamboni just in case the accelerator gets stuck"
Which might sound plausible for anyone that never heard of Yugo, or the speed of light.
Which comes out to 17.7 billion tons of tnt, or 1.1 million times the force unleashed on Hiroshima.
If we're being pedantic.
However I've found a calculator that does do kilotons of TNT:
So one Ferrari is 37.13 * 10^6 kilotons. Hiroshima was 15 kt, so one Ferrari contains the energy released in 2,475,333.3 Hiroshima atomic bombs.
And for reference, 1 kilotonTNT is:
At 3600 kcal/lb fat, one kilotonTNT is equivalent to 278,611.11 lb of fat. Which is to say, if everyone (313 million people) in the US lost 1/5 of an ounce each, the energy released would be equivalent to one Hiroshima bomb.
1,167 MWh, or 1.2 GWh. Roughly the energy a large generating plant produces in an hour. Which is to say that the time over which you release energy matters.
And you've also inspired me to figure out how to add my own units definitions, so now I have kttnt:
686 barrels of oil, almost exactly 100 tons of oil, 1.16 GWh, 143 toncoal, 154 tons of charcoal, or about 51 grams of pure uranium.
And checking: 100 tons / 51 grams is 1,778,793, which is to say, atomic energy has roughly 1 million times the energy storage density of our best chemical energy sources.
You'll note that 100 tons of oil is a lot less than a kiloton (1000 tons) of TNT. Turns out that what makes TNT so special isn't its energy content but the rate of release of that energy. Oil (or aviation fuel as the occupants of 120 Cortlandt St., NYC, discovered a few years back) has about 10 times the energy content of explosives, it just delivers it over a longer period of time.
I don't think this will destroy a mountain, but I would expect the reactor and building to be catastrophically destroyed by the vacuum chamber implosion, along with some, shall we say, interesting, but certainly powerful, effects from the solenoid and other magnets.
Unlikely. The reaction is not self-sustaining; it needs the very high pressure provided by the containment, and without that it would fizzle rather than boom (a hydrogen bomb works by using a fission explosion to compress the hydrogen part enough to fuse). The tritium in the fuel is radioactive and releasing it into the atmosphere would be... not ideal, but the reactor doesn't use a lot of it and it's light enough to fly off into space fairly quickly.
Fusion reactors are like balancing a pencil on its tip. If anything goes wrong it simply falls over. Fission reactors are different in two ways. One, it's possible for them to have a positive feedback in fission reaction rate due to lolss of coolant (this is called a "positive void coefficient"), but this can be changed in the design of the reactor and all modern reactors have a negative void coefficient. Two, fission byproducts are both extremely radiologically hazardous and continually producing heat from decay over long periods of time. This means that reactor fuel and used decomissioned fuel still needs to be actively cooled for a very long time, and if not then it can melt down which is very difficult to contain. These two problems are the genesis of the disasters at Chernobyl and Fukushima, respectively.
In contrast, the products of fusion reactor operations don't get hot and as mentioned the reaction will just stop running if anything goes pear shaped. These factors alone are major reasons why fusion power is so desirable. It wouldn't use of fossil fuels nor produce CO2 and would be unimaginably safer than fission power.
It's probably worth pointing out that those two things are the inverse of each other. The elements that take the longest to decay are inherently the least radioactive, because that's what radioactivity is: The consequence of radioactive decay. Something with a half life of 24,000 years is barely radioactive at all. Something with a half life of 24 seconds will give you radiation poisoning very quickly if you encounter a lot of it but won't be anywhere to be found if you come back in an hour.
The waste problem is also largely a political rather than scientific problem. The commonly-cited 24,000 year half life is for Plutonium-239 ("weapons grade plutonium"), which can be mixed at the outset with Plutonium-240 to make it unsuitable for bombs and impossible to separate, and then used as reactor fuel to destroy it entirely.
The most radiologically dangerous fission byproducts (largely Sr-90 and Cs-137) are the ones with ~30 year half lives, making them radioactive enough to cause significant damage and also long-lived enough to persist for several decades, but they also have significant market value in nuclear medicine or radioisotope thermoelectric generators or scientific research.
The massive political stupidity is in not removing the spent fuel from the reactor site and separating it into its constituent elements so that it can be put to productive use rather than sitting around waiting for disaster to strike. And the entire concept of burying it under a mountain for a million years is just ridiculous.
Take oil, for example; it is just a method of storing energy. In the same way, the hydrogen atom is the stored energy. Any of the methods you mentioned - sunlight, wind, streams, temperature gradients, etc. - are all examples of that same stored energy. The game is in converting it for our consumption. We're never actually "generating" energy.
With that in mind, the single item with the highest "energy density" is the hydrogen atom. When we are capable of "transporting" it's stored energy to one of our storage mediums, we will have all the energy we need.
Seems like it's worth the risk.
It is also fairly easy to transform hydrogen just by burning it. Of course burning fossil fuels and releasing tons of CO2 is how we got into whole global warming business anyways, so we want a more efficient transformation technology.
But wait, it get's more complicated. Compare transportation and storage of hydrogen versus electricity. Vast difference, requires radically different technologies, so let's not call all energy 'same'.
For example, moving transportation off of messy and expensive fossil fuels is almost all about storage. If there was a $5, 2kg battery that could hold enough charge for a car to go 3000 miles, the world would switch to electric cars almost instantaneously.
We are also using fossil fuels to generate energy for lots of fixed usage where transmission is already in place. Take all of the coal power plants in the country and replace them with magical clean energy generation plants and you've made a vast improvement without any change in storage technology.
If storage was magically solved, then you could use wind and solar and whatever much more easily, and replace fossil fuels that way. But storage seems to be a much tougher game.
I had fears that fusion could become fission but seems like that is not possible.
To a first approximation a magical 100% effective explosion of a 500 MW fusion plant would be about as destructive as the explosion of a 500 MW coal plant. So yeah, dead stacked like cordwood and an impressive hole in the ground, but not much more than a nasty industrial accident. You'd lose a lot of windows but in bulk the building foundation would likely survive.
Why an explosion would magically be 100% as effective as splitting a steam boiler like a bratwurst is a mystery, as the short version of why it takes so long to build these things is before they work they fail containment a lot of times. So its like building that 500 MW coal burner and designing it to split in half and get put back together over and over until with some fine tuning it works.
In the long run, in like 2300 AD or whatever, I'm sure cheapskates will create some fascinating industrial accidents by neglecting to build in ablative shielding or liq H2 overpressure burst disks or whatever and the accidents will be quite exciting as a typical industrial accident.
In this case the bucket's main contribution would be to collect the water, not carry it. If soup were indeed raining from the sky, a bowl or small cup would suffice.
As seen in the article, the most worrying concern could be having the four-story tall metallic magnetic core launched through the roof with twice the thrust of a space shuttle.
The challenge for fusion is that it's so phenomenally difficult to tap that gradient (without annoying the neighbors) that it may well prove impossible forever.
They'll get a shiny useless building at best. A perforated building at worst. With a lot more vapor.
As others have said, this is hot fusion not cold fusion, so the answer is most likely it would damage some very expensive components. The holy grail of fusion research (which so far seems largely unachievable) would be fusion at something relatively close to room temperature (so called cold fusion), as opposed to this experiment where you're dealing with temperatures comparable to the heart of the sun. The reason that's such a big deal is that before actual fusion occurs on a hot fusion reactor, you obviously must first reach the target temperature which takes a not inconsiderable amount of energy to achieve, and then further energy to maintain. The trick to making hot fusion practical is to somehow get more energy out, than you have to put in to maintain those insanely high temperatures. Obviously if you can find a way to still achieve fusion at a much lower temperature the situation becomes much easier as you've got a bigger gradient to play with (I.E. it produces the same amount of power, but requires much less power to get it to the state necessary to produce that power).
In order to achieve the massive temperatures necessary they do a couple things. First, you're talking about an incredibly tiny volume of space that's being heated to these temperatures (think of this as the difference between boiling the ocean vs. boiling a cup of water). Secondly they reduce the pressure to near vacuum. Thirdly they maintain these conditions inside of a magnetic bottle which is necessary primarily to provide insulation, both for the fusion material (the hydrogen) and for the apparatus that are heating and containing the fusion material (super conductors like it very cold and must be very close to the fusion material, so you're talking a pretty steep temperature gradient here).
Now, assuming they actually get this thing working, it's going to consist of a very very tiny super hot ball of very very thin hydrogen gas, surrounded by a near vacuum, and then a shell of super cold super conducting magnets. If containment were to suddenly fail, that small ball of gas would very rapidly expand outward until it collided with the walls of the containment vessel which would most likely consist of super conducting magnets, and whatever insulating material they can find to slap between them and the hydrogen. But remember, this is a very tiny quantity of hydrogen and it's surrounded by what is effectively a vacuum, as it expands outwards it will rapidly cool and become even more tenuous. Some of the atoms my still be energetic enough upon impacting the containment vessel to pit it or otherwise damage it, but absolute worse case scenario they do some damage to the super conductors and the vessel walls. There's basically no scenario in which containment failure leads to anything that the average person would describe as an explosion.
Now, what I would personally be worried about, and would be far more destructive is not a loss of containment, but some sort of catastrophic failure of the super conducting elements. Still probably not something anyone would worry about outside the facility, but it has a lot more potential to do damage that might conceivably hurt someone in the plant than something like loss of containment would.
When I was a lot younger I was taken on a tour of JET (http://www.efda.org/jet/) and was overawed with the size of it. ITER is an order of magnitude bigger.
The machine that follows ITER is where things get really interesting. Called DEMO, it's still in the planning phase - but will provide a template for future commercial fusion power generation. They're talking about possibly putting fusion generated power into the grid by 2040. Truly exciting stuff.
It was still just a hole in the ground then - they were getting ready to put in the seismic dampeners for the base layer of the Tokamak structure. Since then I've had it liked on Facebook so I can see the progress bit by bit.
I love that this sentence sounds like 50s pulp scifi.
Shear is a verb (or noun); I shear the sheep
Sheer is an adjective; I was awestruck by the sheer cliffs
I'm happy to see any money going into fusion research, but it does seem that Focus Fusion has a much better chance of delivering in the near term. If you're unfamiliar with the technology, check out the Google tech talk below.
We're terrified of the fact that we live in an arational, incomprehensible world. It's a comforting fiction that some large conspiracy controls everything for the benefit of itself at the expense of everyone else, because at least that admits the possibility of control. And if societies can be controlled, at least in principle they can be fixed.
Much scarier is the idea that power stumbles blindly around like a drunken three legged elephant, arbitrarily murdering half a million people for no coherent reason beyond, well, why not?
If you want to say that the US invaded Iraq because the embargo was going to fail anyways, and this way Iraqi oil production would be delayed by years causing oil production in Texas to be more profitable at least then you'd have a conspiracy theory that made sense.
But really it was mostly Saddam overestimating US intelligence capabilities, assuming we'd know that he didn't have any nukes despite what he was telling his supporters, while really the US was relying on the reports from those of Saddam's supporters who defected.
Cui Bono doesn't work in a world where there are multiple equally intelligent forces trying to fool each other.
Hans Blix (UN inspector) repeatedly, emphatically explained that Saddam had no WMDs. Etc.
Saddam would have been quite happy to give it to us as the price of remaining in power.
Saddam had completely capituated and agreed to all of Cheney Bush demands.
They invaded any way.
From a plutocratic viewpoint, that might well be a considered as vile an act as say, using bio-weapons on the Kurdish separatists.
But I do agree with the above points that we spend an awful lot of time fighting symptoms, when we don't worry nearly enough about ridding ourselves of oil dependency. Energy independence is a long out problem with a lot of vested interests lined up against it - this is precisely the type of investment that does warrant government funding.
"According to those attending National Security Council meetings in the days after September 11,
The primary impetus for invading Iraq…was to make an example
of [Saddam] Hussein, to create a demonstration model to guide
the behavior of anyone with the temerity to acquire destructive
weapons or, in any way, flout the authority of the United States."
Given that those same people spent much of the Clinton Administration advocating for war on Iraq from outside of government, its a pretty good bet that that was part of the reason.
Though, to be fair, there's plenty of reason to consider that the "job that Pops started" was itself about oil, and that insofar as Iraq was targetted as an example to others, one of the reasons the particular example was chosen is because Iraq -- to borrow one of those vary same Bush II war cheerleaders description of why North Korea was treated differently than Iraq -- "floats on a sea of oil".
It also leaves out a very significant factor : vote winning. Patriotism wins elections, because it, in of itself, is just another form of groupthink.
If you're a military contractor, a military buildup or war is optimal.
Beyond that, the idea that there is any action Iraq could have taken which would have caused the dollar to fall in value 40-50% is ludicrous at its face. The economy of Iraq compared to that of the United States is tiny. The dollar reserves held by Iraq are tiny. And frankly while the oil production of Iraq is not tiny, Saudi Arabia could make up the difference without breaking a sweat. (Saudi Arabia produces well below capacity to manage the price.)
Finally, I don't think that a decline in the dollar of 50% would have quite the effect described in the article. As the largest external holder of dollar denominated debt, China would smart, but even more than the paper loss on there debt, their exports would no longer be competitive in the US, and they would lose their leading customer. (Which is why China would not let it happen...) On the other hand, American manufacturing and natural resources would once again more become competitive as real wages and costs fell. Such a decline in the currency would lead to a real decline in quality of life no doubt, but its quite possible, that rather than a recession, you'd see very low unemployment.
What do you base that on? I've found very little in the open literature.
This is a strange sentence.
(1) Notice Height of object-A;
(2) Notice Weight of object-A;
(3) Compare Weight of object-A to Weight of object-B
where object-B is known more for its property of
Height than of its Weight.
But what a silly line of reasoning. Is it a common conclusion that taller things should also be heavier things?
Further, this seems to me to be of the same breed as "bigger than the state of Rhode Island"-type of arbitrary comparisons -- only in this instance more confusing!
> Some in the field believe that a working machine would be a monument to human achievement surpassing the pyramids of Giza.
Which suggests that the pyramids of Giza are a monument of human achievement that hasn't yet been surpassed. You only need to take a look at almost any 20th century bridge, skyscraper or even ship to know that that isn't really true. Certainly the pyramids of Giza are a monument of ancient Egyptian achievement, but the last few centuries have completely and utterly surpassed that.
> [...] the last few centuries have completely and utterly surpassed that
In terms of what they were built for, that is travel through time mostly unharmed for several thousands of years, a literal vessel of eternity, this claim is undebatably false. Few things we have built in the last two centuries will survive more than a decade if left unattended, and even fewer more than a century. It takes but a trip to Normandy to see german bunkers getting swallowed by nature. The smarter we get, the less durable we build things: we split atoms, we flick electrons and we land proxy explorers on nearby celestial bodies but our grandeur is a delusion and nothing will remain should our kin be obliterated. The testament of mankind that are such incredible buildings can only be surpassed by moving our butt out of this rock and sustain a decent living on the next one, ensuring our species survival. Any technological achievement is but a bullet point towards that goal.
There are many differences between bunkers and the pyramids. The biggest one is that bunkers were designed to be as low profile as possible. They are nowhere near the scale of the pyramids. Probably the next most important difference is the location. The pyramids were built in a desert environment which is hostile to the biggest enemy of manmade buildings - vegetation.
I'm not arguing that the pyramids aren't an incredible feat, or a monument to the achievement of an otherwise very low-technology early society. What I'm arguing against is the idea that the building of a fusion reactor would somehow be the first human development which would surpass the pyramids of giza as a monument of human achievement. The fact we have spacecraft in distant orbits which will remain exactly as they are for centuries or millenia is surely a much greater monument (albeit one which is hard to find). Our major cities (which are so entrenched that even if they were abandoned today would exist in some form for centuries, and certainly be easily identified for millenia) are vast monuments of human achievement. Can you really argue that the entirety of London is less of a monument of human achievement than the pyramids of giza?
Or, especially for the SF Bay Area crowd, you could go to the Marin headlands and see US bunkers from the same era -- intended to defend against Japanese attack -- doing the same thing. Shorter trip.
I totally understand that I am cherry-picking here. There are many things in the world that are over- or under-valued when you compare their economic contribution to their societal contribution. I just thought this would be an interesting point to make on Hacker News.
No, you could say that it would cost you $20B to build a copy of ITER -- very different. You can't buy ITER for what was paid to build it. Or maybe you can. We have no idea because the valuation is unknown. The project is so risky, we're spreading the cost around 35 countries. If we thought it was more of a sure thing, every country would be trying to build their own. Many companies, too.
Though think about how popular of a communications platform that WhatsApp is, particularly in parts of Asia and Africa. It's transformed the communications industry in those areas!
That still may not account for the relatively small difference between the two, but it helps put into perspective exactly why WhatsApp was so valuable.
Had carriers priced themselves properly, WhatsApp would have never had a foothold.
This is a roundabout way of saying that you are really looking at just the cost - what it takes to build this thing. Nobody is appreciating the value of it except the nations that signed up - and they're not selling a percentage.
According to researchers at a demonstration reactor in Japan, a fusion generator should be feasible in the 2030s and no later than the 2050s. Japan is pursuing its own research program with several operational facilities that are exploring several fusion paths.
Also, they are already planning the successor to ITER, a commercial plant called DEMO
Even the USA/Russians could not come to an agreement to build such a project.
"We're only 30 years away? Bah, what's the rush?"
And WhatsApp cost how much?
" As the meeting ended, he noted that there was not enough time to vet the components that occupy the third floor: plans had to be gathered, specifications brought up to date, problems reconciled. “It is not reasonable,” he said. “It means that we would need to process thousands of data points in three weeks.” Chiocchio asked if things would speed up after early floors were finished, but there were simply too many details to work through before delivering drawings to the contractor. “We have no more float,” Cordier said. “If we delay now, we will have a real delay. The only way to avoid a schedule loss is to increase our resources to cope with it.”
That afternoon, Chiocchio joined me for lunch. He seemed exhausted. iter, by the time it is finished, will contain ten million individual parts, but he had only twenty-eight people working for him. He later showed me a room near his office where three men sit at workstations every day to hunt down conflicts. Before each man, there was the huge iter puzzle in miniature, filling up two computer screens. Up close, the design looked as though someone had taken the industrial landscape that runs alongside the New Jersey Turnpike and compressed it into a cube the volume of a Holiday Inn. “We have to check everything, from clashes to interfaces—like here,” one of the men said, pointing to a schematic where a support structure for the tokamak was not lining up with an embedment plate."
Comparison to existing powerplants: http://www.wolframalpha.com/input/?i=500+megawatts
TL;DR: We already have significantly bigger plants. ('average' coal and nuclear plant produces about twice as much power)
To counter, the biggest nuclear power plant, Kashiwazaki-Kariwa, has 7 generating units which are each above 1 GW. Two of those units are at ~1.3GW, nearly double a Three Gorges turbine.
For more perspective, the smallest nuke in the States is Fort Calhoun which has a single reactor at 502MW.
The fact that it's "only" half a coal plant is hardly a criticism.
If fusion requires wonder-of-the-world kind of technology to not even break even, it makes me somewhat pessimistic. (However, I still say, more power to them, fund them, let's see where this goes)
Actually, it's supposed to reach about 10x breakeven, but there can be reasonable debate on how possible that is. Ignition is something different, when the fusion power itself keeps the plasma hot enough to sustain it. This is unlikely for ITER.
But your point is valid. It won't actually function as a power plant.
> If fusion requires wonder-of-the-world kind of technology to not even break even, it makes me somewhat pessimistic. (However, I still say, more power to them, fund them, let's see where this goes)
I agree, and I too think it's well worth it. I'm certainly not suggested we rely entirely on fusion research for getting us through the upcoming energy crisis, but it will be essential if we ever want long-term (centuries) sustainable industrial growth.
$10b is nothing compared to what was destroyed in the GFC. It's nothing compared to what the US spent on a largely futile war in Iraq. It is nothing compared to what G8 governments spend every year on defence. FFS, damages from Hurricane Sandy are estimated at twice that figure. It's peanuts.
Somewhere along the line, the message that this is R&D, and not science has been lost. Politicians honestly seem to think that this is another of those toys that scientists are always wanting to build, and not the solution to the world's energy problems. Dear politicians - no, this is not another space telescope. It's not even another LHC. It is nothing more or less than the one technology that can save the planet from the worst ravages of climate change, and they quibble about the cost. Madness.
I am not making an anti-American point here. UK politics has equally daft politicians. But politics is full of people like this:
> "Wind is God's way of balancing heat. Wind is the way you shift heat from areas where it's hotter to areas where it's cooler. That's what wind is. Wouldn't it be ironic if in the interest of global warming we mandated massive switches to energy, which is a finite resource, which slows the winds down, which causes the temperature to go up? Now, I'm not saying that's going to happen, Mr. Chairman, but that is definitely something on the massive scale. I mean, it does make some sense. You stop something, you can't transfer that heat, and the heat goes up. It's just something to think about."
I certainly don't have a great idea. I'm assuming you won't be able to put a fusion reactor in a car or airplane. Will a fusion power plant be roughly the scale of a current fission plant? What will be the output? What are the risks? And how much do we trust these projections?
Edit; for those just discovering polywell fusion; Bremelstrung radiation is the primary reason why it may or may not be practicable.
Some of these are well-funded, others are struggling. Even some of the other tokamaks are struggling. MIT's Alcator C-Mod has the highest magnetic field of any tokamak in the world, and the potential to lead to a smaller, cheaper power plant. The whole project was nearly cancelled a year ago.
At least in the UK, the total potential for geothermal energy is quite small, much less than other sources such as wind and solar. But its a nice short-term supplement, we can construct them today.
Having working fusion would be an amazing thing. The raw materials (lithium and deuterium) are plentiful enough that they will basically never run out, it would provide energy forever.
Anyone else struck by the wildly reductionist sentiment in that statement?
Wait, they are manufacturing helium? Thought that wasn't possible?
Or just converting gas to liquid?
In the electromagnets, there will be liquid helium. This is to keep the wires in the electromagnets cold enough to be superconducting. This liquid helium is mined from the earth and then cooled to a liquid in the cryogenics plant.
So overall, they are "manufacturing" cryogenically-cooled-helium by taking helium from the ground and cooling it. They are also "manufacturing" helium atoms at a very small quantities by fusing hydrogen atoms together.
Liquid helium is extremely cold, and hence not the easiest thing to transport. If you need liquid He, you need to make your own, from regular He gas.
A fusion reactor such as this will make helium from hydrogen, and would be the only way we have to do so. It probably won't do it in industrially interesting quantities though.
edit: but they appear to be talking about support infrastructure, not a product of the fusion.
Second only to matter/antimatter annihilation, nuclear fusion is the most energy-dense process in the universe. And the fuel consists of about 0.03% of the world's oceans.
I am not sure about this one comment in the article submitted by OP. As far as I understand the temperature at the center of the earth should be as high as that of the Sun. The core is known to be the heaviest and hottest part of our planet.
> I am not sure about this one comment in the article submitted by OP. As far as I understand the temperature at the center of the earth should be as high as that of the Sun.
I think the most recent estimates have the core temperature of the Earth at about the surface temperature of the Sun, plus or minus a few hundred kelvin. (In the neighborhood of 6000K)
The core temperature of the sun, and the temperatures expected in the reactor described, are several orders of magnitude hotter, on the order of 10^7 K.
Yes, a vacuum may stop convection but heat can escape through radiation. What then? That's why I would want this thing so far away that the angular projection of the Earth onto it is small.
This one however, I dunno. Sounds like things could go wrong with that much energy. When they made the first atomic bomb, they had theories about what might happen but not 100% sure and there were some surprises.
But I'll take death from this over death from fracking.
Remember, this is only a 500 megawatt device, and the reaction is so unstable that if it somehow escapes the containment of the device it dies instantly. It can't "run away" like some fission reactions can.
edit: Not actually sure how much energy it takes to "vaporize a car in seconds." In terms of energy this thing is roughly equivalent to any other fairly large power plant.
There's no unrequested fission surplus situation possible here...
The density is not that low, but the total amount of ultra-hot matter is pretty small. If magnetic confinement is lost, the plasma will expand and cool; there is no sustained fusion without the confinement. The core would probably be wrecked, but that's about it.
I'm sorry but I don't understand the distinction.
While its contained, the density is not that low; if it loses containment, the density will become low as it expands. At least, that's my understanding of the distinction here.
I should probably disclaim: I worked on a Tokamak in undergrad.
Don't let ignorance fuel fear of technological advancement.