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The Best Science Writing Online 2012
Showcasing more than fifty of the most provocative, original, and significant online essays from 2011, The Best Science Writing Online 2012 will change the way...
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[Below is the original script. But a few changes may have been made during the recording of this audio podcast.]
The sun pumps out some 383 quadrillion watts of energy every second thanks to fusion. So, it's not surprising we've been trying for the last 50 years to harness the abundant clean energy from that process.
The sun simply fuses two hydrogen atoms together to produce a helium atom--and liberates energy in the process.
But it takes the Sun's powerful gravity and temperatures of around 14 million degrees Celsius to get these hydrogen atoms stripped down to just their nuclei and able to fuse inside an ionized gas known as plasma.
In fact, it will take temperatures of 100 million degrees C to get fusion going on a scale that could fit on our planet. Plus, there's the issue of turbulence.
Like the Earth's atmosphere, plasma likes to swirl because of temperature and pressure differences from point to point. The result is storms that can cool the plasma and halt fusion.
The International Thermonuclear Experimental Reactor or ITER to be built in Cadarache, France will rely on magnetic fields roughly 100,000 times stronger than the Earth's to contain the plasma and hold in its heat. At the right density, pressure and temperature, voilà, fusion!
Unfortunately, all existing fusion machines require more energy to operate than they produce. And ITER will cost at least $15 billion to build.
Fusion may have been going on in the Sun for more than four billion years but it still remains just out of reach here on Earth.
—David Biello
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19 Comments
Add Comment"383 quadrillion watts of energy every second"
Reply | Report Abuse | Link to thisWhat!?
383 quadrillion Joules per second squared???
Amazing!
This is why fission was supposed to just be a stop-gap measure and the ultimate goal was fusion reactors. Unfortunately, it hasn't been pursued with the cash and enthusiasm one would expect.
Reply | Report Abuse | Link to thisThanks Dalgety, i was about to write that! Also, the sun doesn't emit 383 quadrillion watts, it emits 383 yottawatts. But what's a factor of 10^15 between friends?
Reply | Report Abuse | Link to thisI think it's really disgraceful that nobody at Scientific American these days seems to know the difference between *power* and *energy*. As others have noted, the phrase "watts per second" is meaningless. The phrase "watts per second of energy" is even worse. As Wolfgang Pauli once said, "That's not right. That's not *even* wrong!"
Reply | Report Abuse | Link to thisOne wonders what Martin Garner must think of all this.
Also, fusion on the sun occurs when *FOUR* hydrogen atoms fuse into one helium atom. Factcheck?
Reply | Report Abuse | Link to this100,000 times the earth's magnetic field (about 0.5 Gauss or 50 micro Teslas) is about 5 Teslas. This is routinely acheived in MRI equipment. I recently bought a permanent magnet with 0.7 Teslas for $67.50!
Reply | Report Abuse | Link to thisWhy spend $15 Billion?
PeterT
Propertius, I'm sure Martin *Gardner* would be sore puzzled by the bad self-editing these bloggers seem addicted to.
Reply | Report Abuse | Link to thisThere are other fusion reactor designs which might be the way ahead -
* inertial confinement fusion - via high power lasers
*inertial electrostatic confinement fusion - via ions creating a deep potential well
*plasma focus fusion - which uses a plasma focus to create self-compressing plasmoids
...the first is the most fusion ready, though recently criticised by Friedhardt Winterberg, one of the Grand Old Men of fusion physics, but the other two are the least studied and yet could result in bigger breakthroughs according to their proponents.
As for the expense the magnets aren't the limiting factor. Containing massive amounts of ultra-pure vacuum, liquid lithium and keeping superconducting magnets cool next door to 100 million K plasma is what creates a gargantuan, money-hungry tokamak. That and not knowing what a steady intense flux of MeV neutrons will do to the materials, except bad things, is why the ITER program is a Beast.
Fusion produces neutrons, that cannot be directed or deviated in any way. Neutrons alter the nucleus of elements, transforming them into different ones, with different mechanical and quantum and physical properties. Iron is the most stable element under a neutron flow, but iron is magnetizable and may produce problems under the strong magnetic field required for industrial fusion. Is this a realistic doubt? Regards
Reply | Report Abuse | Link to thisTo summarize many of the posts, 60-second does, this time, the predictable "dumbing down" of science to fit it in 60 seconds, a process which is totally unnecessary to make a fit. I have been keeping track of media's role in confusing the public about watts and watt-hours, power and energy; this is just the latest. I've seen "watts per second" or a similar confusion about once a week. It's usually calling kWh kW.
Reply | Report Abuse | Link to thisIt's understandable that the editors would not want to use "joules every second" because the lay-person has no idea what a joule is or can do. Therefore, the phrase should be "some 383 quadrillion watts all the time."
The confusion between quadrillions of watts and yottawatts is apparently that between the output of the sun in all directions and the part of that reaching the earth. Sounds to me like the editors cut words to fit 60 seconds without considering the way those cuts changed the meaning.
Unfortunately, Mr. Biello read the transcript verbatim this time; and, it really did sound like times when my students read without comprehension. I've heard Biello do a better job in the past.
David Biello makes a statement of fact out of a theoretical idea. Clearly he has has not read Don Scott's Electric Sky and has failed to realise that the 1930s internal fusion sun theory is on shaky ground. Too much contradictory evidence has piled up and continues to arrive via satellites, etc.
Reply | Report Abuse | Link to thisThe sun is much more likely to be a plasma focus device with external electron flow from the massive galactic currents circulating in the Milky Way. Why is the outer solar atmosphere 1million degs while the surface is barely 6000? Surely the 'fusion core' should be the hottest - we can only guess its temperature is relatively cool by looking into sunspot dark (not light!) umbra.
That is why the plasma focus solution is probably the only feasible energy producer with little research effort compared to the Beast of Tokamak!
Hi!
Reply | Report Abuse | Link to thisHi!
Reply | Report Abuse | Link to thisTwenty years and still counting. Work is good, until you need a gov handout. I want this so very badly, but reality is a cast iron containment chamber.
Reply | Report Abuse | Link to thisHe3! Hard to come by but the only atom we can use that is stable enough not to destroy it's containment
Reply | Report Abuse | Link to thisIt takes 4 hydrogen atoms to fuse into a helium atom not 2. The atomic weight of hydrogen is 1 and helium is 4, in round numbers. Somebody must be confused by the molecular weight of a hydrogen molecule (which is two hydrogen atoms). Molecules do not exist at the high temperature of the sun's surface let alone in its unimaginably hot core.
Reply | Report Abuse | Link to thisYou don't usually fuse hydrogen 1 atoms - you would normally use deuterium which has 1 proton and 1 neutron. Hence you would only use 2 hydrogen nuclei to produce helium.
Reply | Report Abuse | Link to thisFusion reactors? Are they talking about tokamaks here? I am probably mixed up so somebody correct me. I know that tokamaks do employ magnetic fields to contain plasma upwards of eight or nine hundred million degrees, which is necessary for nuclear fusion. But, I though there were a number of tokamaks spread all over, including one in New Jersey, which set a temperature record.
Reply | Report Abuse | Link to thisHelium, released from the core of the earth and its own nuclear fusion, migrates into natural gas. The gas taken from those huge natural resources is piped into the cities and burned as a clean fuel. Prior to arriving at any distribution or usage point, however; the helium is extracted and pumped into empty salt domes deep underground and stored. The helium belongs to the Federal Government. What do they do with it and why do they want it? What Federal Agencies deal with this stored helium? Who has an answer to this puzzle?
Reply | Report Abuse | Link to thisAlso, the atomic physics of fusion are well known, however; the ability to create the hydrogen to helium fusion and release the enormous amount of energy available will take a little trick that the sun does easily and yet it remains hidden from us. Uncover this little trick and atomic fusion, though extremely dangerous, will work.
Helium, released from the core of the earth and its own nuclear fusion, migrates into natural gas. The gas taken from those huge natural resources is piped into the cities and burned as a clean fuel. Prior to arriving at any distribution or usage point, however; the helium is extracted and pumped into empty salt domes deep underground and stored. The helium belongs to the Federal Government. What do they do with it and why do they want it? What Federal Agencies deal with this stored helium? Who has an answer to this puzzle?
Reply | Report Abuse | Link to thisAlso, the atomic physics of fusion are well known, however; the ability to create the hydrogen to helium fusion and release the enormous amount of energy available will take a little trick that the sun does easily and yet it remains hidden from us. Uncover this little trick and atomic fusion, though extremely dangerous, will work.