I'm not sure about fission or if indeed laser induced fission is even possible...but I can speak to the fusion issue though. Here at the LLE we're building a >2 Petawatt laser (to be done in ~2 years) to work with the current 60 beam 30Kj ~40-50 terawatt laser that's already here. The idea is that the 60 beam (spherically symmetric) laser will fire and compress a fuel pellet to a fraction of its original size. At the point of maximum temperature and pressure just before stagnation and then expansion, the petawatt laser will fire and be injected in ~1picosecond into the core of the compressed plasma injecting a huge amount of power and high energy electrons into the area providing 10-100 fold increase in fusion output. this is simply due to the hotter protons deuterons tritons etc. having greater kinetic energy and therefore more likelyhood of overcoming the culomb barrier upon colliding and then fusing. The current record neutron yeild on the 60 beam laser is nearly 10^14 this will be increased with the injection of the 2Kj petawatt to the near-ignition regime.
Hi, I would like to personally assure you that I most certianly did NOT cut and paste any part of the article summary above. I'm sorry if you found it too full of "technobabble" but I was merely using proper terms to describe why this is an important discovery in the most accurate and concise way I could. I know not everyone knows what TeV or petawatt means and that's why I provided links to explanations and pictures of terms I thought might be too obscure. Simply reading the story should've provided a reasonable level of understanding and familiarity with the common physics terms used to describe these things. I feel that instead of dumbing things down as much a possible to espress things in "laymans terms" it is far better instead to, within reason, express the most information possible about a story in the smallest amount of space (it IS a summary after all). If this needs to involve a bit of jargon (with links to explanations of that jargon for the uninitiated but curious) so be it.:o)
"I call bullshit. If the frequency is doubled, the wavelength is halved, and ~400 nm is around the boundary between violet and UV, not green."
If you had any idea WTF you were talking about, idiot, you would know that a ~800nm diode laser is used to optically pump a small crystal of Nd:YVO which then lases at 1064nm and whose output is then freq. doubled to 532nm (green) by a piece of potassium titanate phosphate KTP.
The problem is your super cheapo $3 pointer you bought in the walmart checkout line was probably manufactured in a Shenzhen sweatshop somewhere, where only every 1,000th unit off the (if that even...?) line is tested to comply with the 5mW CDRH limit. Do you trust the pointer you have not to be emitting 7 or 3 or 10mW? I definitely don't. The red GaAlAsP(I think...) semiconducor red laser pointers I suspect are fairly consistent in output power due to the simplicity of the electronics that power them. I'm much more afraid of the now common green DPSS frequency doubling laser pointers, the output coupler on the end of the pointer is designed to block the IR pumping energy from the ~800nm semiconductor laser in the rear of the pointer which can be emitting hundreds of mW of power. If the window is designed poorly or fials somehow you can have a very dangerous device on your hands.
Unlikely to the point of impossibility I'm afraid. CO2 lasers suffer from divergence issues like any other laser and even with a perfect TEMoo beam you'd need kilowatts of output power (tens to hundreds of kilowatts of input power since lasers are so woefully inefficient) and the ability to track the plane with extraordinarily high precision to keep the spot within a few inch^2 area to heat it sufficiently. I think it is impossible for the amateur to achieve the conditions necessary to do damage. If I had to put a dollar amount on what it would take to make something like this feasible I would say 100's of thousands to millions of dollars and then what's the point when rocket launchers are so much cheaper?...
CO2 emits @ ~ 10 microns wavelength. So far as I know (large) airplaine windows are made from polycarbonate or at least have a polycarbonate layer in them. That is going to mean almost 100% absorption and therefore 0% transmission. A CO2 laser presents a much greater danger from skin burns and the like than from eye damage. The eye's aqueous humor and lenses are also opaque to 10um light and you would therefore experience heating of the epithelium over the cornea and not damage to the retina; which I while suspect would be very painful you'd probably have enough time to shut your eyelid and prevent further damage.
Also I'd like to say that the story poster's alarmist warnings of 5mW lasers is completely unfounded. The extremely high (relatively, anyway) divergence experienced by almost all cheapo, poorly colimated 5mW laser pointers means the beam will be at least inches wide if shone on something as far away as an airplaine at thousands of feet up. The amount of light that can enter the pupil from a "legal" 5mW laser pointer at such a large beamwidth is distracting but totally harmless.
I want to donate to my local PBS station so they can pay for showings of really good shows like the one descibed here, I really do. But when "pledge week" comes around what do I see on 24 hours a friggin day? Yes, that's right, Depak fucking Chopra and chorus line of other pseudoscientific wooly headed psychics, new agers and "inner peace" practitioners. All with the mantra of "well we get high viewership numbers when we show these things...". I'm sorry but until they get their head out of thier ass and realize that I watch PBS for the shows which are scientific, logical, rational and INTERESTING they will not be getting my money.
You get RR at 6Mb/s? Do you have the "buisness" version or something? I'm in Rochester and have 3Mb/s which has been constant for the last few years....
I'm still plodding through the 20+ GB I downloaded before they "relaunched" and am discovering fantastic alternative bands from the early 90's that I'd never even heard of before, but now love. Sorry Emusic but you were great while you lasted.
I think what's really fascinating is that its not really a "beast" at all. Its barely bigger than a large refridgerator and the energy able to be released from such a small amount of matter is just mindbending, enough to easily completely obliterate an entire city in an instant. With such a fantastically huge amount of power at the immediate command of us foolish humans, it's amazing we've made it this long....
Purposterous. The total amount of energy falling on the earth is over 100 thousand Terawatt-years/year. The total amount of electrical and all other energy generated by humans.... ~10 Terawatt-years/year. Even assuming total conversion to heat that's a totally inconsequential amount looking at the whole heat flux of the atmosphere.
"Plus, wind power is the only mitigation of global warming, because if the whole world converted to wind power in 15 years, the amount of power being extracted from the atmosphere would be more than the increase in greenhouse gas atmospheric energy forcing since 1600."
Just where did this emptyheaded "fact" come from I wonder. What does this person think happens to the electricity when it's used? Turns into magic pixie dust maybe? Almost all the electricity used today is CONVERTED TO HEAT! The miniscule amount of energy derived from electricity that is actually radiated off of the planet in the form of light(non-IR that is) which could potentially extract energy from the atmosphere and "get rid" of it is totally negligable. The idea that wind power can somehow reverse global warming is so far beyond asinine its hard to put into words.
Mathematical Physicists tend to apply solutions to differential equations like the 2-body Shrodinger's equation as if they know how to solve an arbitrary differential equation.
Gosh, I wonder what the artistic physicists think...
And how exactly wil ESA be getting the data from a 1G pixel survey of the universe back down here? Onboard 10Tb tape drive? Magic pixies? Sending such a vast quantity of information back down to earth with anything less than an optical frequency (read: laser) trasmitter (which dont exsist yet for spacecraft) is laughably unfeasable.
Considering that it was travelling back TOWARD earth at 25 thousand miles an hour and the shuttle ORBITS the earth at 17 thousand miles an hour 300-400 miles up, what do you think?
My complaint was not with the "People who learn whole-word reading can't sound out new words or actually use the language" but was instead directed at the "teachers are afraid to mark spelling incorrect because it could cripple the child's image of (him|her)self in later life, there is a huge problem." part, perhaps I should've made that more clear.
" I don't know who the hell Charlotte Thompson is, and I'm not going to google her for this.
?? Charlotte Thomson is the author of the book at the website www.deliberatedumbingdown.com the persons sentiment you 'seconded'.
" if I've misused something that leaks through your tinfoil hat
What did I say that would make you think I had a tinfoil hat? Did you misunderstand me?
When reading is taught 'whole word' and teachers are afraid to mark spelling incorrect because it could cripple the child's image of (him|her)self in later life, there is a huge problem. People who learn whole-word reading can't sound out new words or actually use the language. They can pass a very basic competetancy test.
This is idiotic nonsense and it deserves to be called as such. I don't know what schools everyone here or Charlotte Thompson (from the link above) are talking about but I went to an average public school in NY and while I had a bad/dumb teacher or two I NEVER encountered the pervasively moronic systems anecdotally described by her (or here).
One quick look at that Charlotte Thompson site instantly reveals her to be the conspiracy theory spinning (oh no! evolution is taught in the schools: "Department of Education suported by Bush is involved in implementing communist agenda: School to work agenda, Humanistic atheistic curriculum including evolution, internationalism, etc. No right/no wrong curriculum.."), 'know it all', frightened, religious nut job she is. If people are insistant on inventing conspiratorial crises to explain poorly performing students and their fixation with demonizing public schools, that's fine, just don't go parading it around like it's some miraculous revalation that only YOU've discovered. That serves no one.
Looking at the redshift of some common spectral line will give you an immediate answer. What I want to know is if the neutrino pulse was detected at one of our observatories like super kamiokande like supernova 1987a was. This one is much further away so I don't know if it was possible....
Oxygen and Fluorine arent nearly in the same league when it comes to reactivity. For instance carbohydrates (a mix of C H and O) will burn in an atmosphere of O2 if given an ignition source but in an atmosphere of F2 they will burn hypergolically.
I'm afraid can't see how this would work. In an atmosphere of HF and F2 how could reaction catalyzing complex molecules ever exist for more than a few seconds, they would be broken down and oxidized very quickly, rendering them useless. Fluorine is just too hungry for electrons!:) Also the HF would quickly dissolve various minerals etc. and form insoluble salts thereby sequestering all the F out of the atmosphere and into the lithosphere in solid bonded form in a short (geological) time period.
It appears that the abstract you linked to, while it uses a techniqe called microgravimetry is actually a TOTALLY different technique. The former, the kind used in the pyramid investigation measures small gravitational fluctuations in the induced by varying small and large masses in the earth's crust while the latter chemistry experiment does not measure changes in the earth's gravity but measures tiny mass fluctuations in a sample exposed to a constant gravity of earth. This is much more simillar to techniques like thermogravimetric analysis.
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I'm not sure about fission or if indeed laser induced fission is even possible...but I can speak to the fusion issue though. Here at the LLE we're building a >2 Petawatt laser (to be done in ~2 years) to work with the current 60 beam 30Kj ~40-50 terawatt laser that's already here. The idea is that the 60 beam (spherically symmetric) laser will fire and compress a fuel pellet to a fraction of its original size. At the point of maximum temperature and pressure just before stagnation and then expansion, the petawatt laser will fire and be injected in ~1picosecond into the core of the compressed plasma injecting a huge amount of power and high energy electrons into the area providing 10-100 fold increase in fusion output. this is simply due to the hotter protons deuterons tritons etc. having greater kinetic energy and therefore more likelyhood of overcoming the culomb barrier upon colliding and then fusing. The current record neutron yeild on the 60 beam laser is nearly 10^14 this will be increased with the injection of the 2Kj petawatt to the near-ignition regime.
Hi, I would like to personally assure you that I most certianly did NOT cut and paste any part of the article summary above. I'm sorry if you found it too full of "technobabble" but I was merely using proper terms to describe why this is an important discovery in the most accurate and concise way I could. I know not everyone knows what TeV or petawatt means and that's why I provided links to explanations and pictures of terms I thought might be too obscure. Simply reading the story should've provided a reasonable level of understanding and familiarity with the common physics terms used to describe these things. I feel that instead of dumbing things down as much a possible to espress things in "laymans terms" it is far better instead to, within reason, express the most information possible about a story in the smallest amount of space (it IS a summary after all). If this needs to involve a bit of jargon (with links to explanations of that jargon for the uninitiated but curious) so be it. :o)
"I call bullshit. If the frequency is doubled, the wavelength is halved, and ~400 nm is around the boundary between violet and UV, not green."
If you had any idea WTF you were talking about, idiot, you would know that a ~800nm diode laser is used to optically pump a small crystal of Nd:YVO which then lases at 1064nm and whose output is then freq. doubled to 532nm (green) by a piece of potassium titanate phosphate KTP.
oh really? force your eyelids open and poke a pencil around in there then let me know how that works out for you. :)
The problem is your super cheapo $3 pointer you bought in the walmart checkout line was probably manufactured in a Shenzhen sweatshop somewhere, where only every 1,000th unit off the (if that even...?) line is tested to comply with the 5mW CDRH limit. Do you trust the pointer you have not to be emitting 7 or 3 or 10mW? I definitely don't. The red GaAlAsP(I think...) semiconducor red laser pointers I suspect are fairly consistent in output power due to the simplicity of the electronics that power them. I'm much more afraid of the now common green DPSS frequency doubling laser pointers, the output coupler on the end of the pointer is designed to block the IR pumping energy from the ~800nm semiconductor laser in the rear of the pointer which can be emitting hundreds of mW of power. If the window is designed poorly or fials somehow you can have a very dangerous device on your hands.
Unlikely to the point of impossibility I'm afraid. CO2 lasers suffer from divergence issues like any other laser and even with a perfect TEMoo beam you'd need kilowatts of output power (tens to hundreds of kilowatts of input power since lasers are so woefully inefficient) and the ability to track the plane with extraordinarily high precision to keep the spot within a few inch^2 area to heat it sufficiently. I think it is impossible for the amateur to achieve the conditions necessary to do damage. If I had to put a dollar amount on what it would take to make something like this feasible I would say 100's of thousands to millions of dollars and then what's the point when rocket launchers are so much cheaper?...
CO2 emits @ ~ 10 microns wavelength. So far as I know (large) airplaine windows are made from polycarbonate or at least have a polycarbonate layer in them. That is going to mean almost 100% absorption and therefore 0% transmission. A CO2 laser presents a much greater danger from skin burns and the like than from eye damage. The eye's aqueous humor and lenses are also opaque to 10um light and you would therefore experience heating of the epithelium over the cornea and not damage to the retina; which I while suspect would be very painful you'd probably have enough time to shut your eyelid and prevent further damage.
Also I'd like to say that the story poster's alarmist warnings of 5mW lasers is completely unfounded. The extremely high (relatively, anyway) divergence experienced by almost all cheapo, poorly colimated 5mW laser pointers means the beam will be at least inches wide if shone on something as far away as an airplaine at thousands of feet up. The amount of light that can enter the pupil from a "legal" 5mW laser pointer at such a large beamwidth is distracting but totally harmless.
I want to donate to my local PBS station so they can pay for showings of really good shows like the one descibed here, I really do. But when "pledge week" comes around what do I see on 24 hours a friggin day? Yes, that's right, Depak fucking Chopra and chorus line of other pseudoscientific wooly headed psychics, new agers and "inner peace" practitioners. All with the mantra of "well we get high viewership numbers when we show these things...". I'm sorry but until they get their head out of thier ass and realize that I watch PBS for the shows which are scientific, logical, rational and INTERESTING they will not be getting my money.
You get RR at 6Mb/s? Do you have the "buisness" version or something? I'm in Rochester and have 3Mb/s which has been constant for the last few years....
my mod points back :)
I'm still plodding through the 20+ GB I downloaded before they "relaunched" and am discovering fantastic alternative bands from the early 90's that I'd never even heard of before, but now love. Sorry Emusic but you were great while you lasted.
I think what's really fascinating is that its not really a "beast" at all. Its barely bigger than a large refridgerator and the energy able to be released from such a small amount of matter is just mindbending, enough to easily completely obliterate an entire city in an instant. With such a fantastically huge amount of power at the immediate command of us foolish humans, it's amazing we've made it this long....
Purposterous. The total amount of energy falling on the earth is over 100 thousand Terawatt-years/year. The total amount of electrical and all other energy generated by humans .... ~10 Terawatt-years/year. Even assuming total conversion to heat that's a totally inconsequential amount looking at the whole heat flux of the atmosphere.
"Plus, wind power is the only mitigation of global warming, because if the whole world converted to wind power in 15 years, the amount of power being extracted from the atmosphere would be more than the increase in greenhouse gas atmospheric energy forcing since 1600."
Just where did this emptyheaded "fact" come from I wonder. What does this person think happens to the electricity when it's used? Turns into magic pixie dust maybe? Almost all the electricity used today is CONVERTED TO HEAT! The miniscule amount of energy derived from electricity that is actually radiated off of the planet in the form of light(non-IR that is) which could potentially extract energy from the atmosphere and "get rid" of it is totally negligable. The idea that wind power can somehow reverse global warming is so far beyond asinine its hard to put into words.
Mathematical Physicists tend to apply solutions to differential equations like the 2-body Shrodinger's equation as if they know how to solve an arbitrary differential equation.
Gosh, I wonder what the artistic physicists think...
I don't think you understand what a survey is.
And how exactly wil ESA be getting the data from a 1G pixel survey of the universe back down here? Onboard 10Tb tape drive? Magic pixies? Sending such a vast quantity of information back down to earth with anything less than an optical frequency (read: laser) trasmitter (which dont exsist yet for spacecraft) is laughably unfeasable.
Considering that it was travelling back TOWARD earth at 25 thousand miles an hour and the shuttle ORBITS the earth at 17 thousand miles an hour 300-400 miles up, what do you think?
My complaint was not with the "People who learn whole-word reading can't sound out new words or actually use the language" but was instead directed at the "teachers are afraid to mark spelling incorrect because it could cripple the child's image of (him|her)self in later life, there is a huge problem." part, perhaps I should've made that more clear.
" I don't know who the hell Charlotte Thompson is, and I'm not going to google her for this.
??
Charlotte Thomson is the author of the book at the website www.deliberatedumbingdown.com the persons sentiment you 'seconded'.
" if I've misused something that leaks through your tinfoil hat
What did I say that would make you think I had a tinfoil hat? Did you misunderstand me?
When reading is taught 'whole word' and teachers are afraid to mark spelling incorrect because it could cripple the child's image of (him|her)self in later life, there is a huge problem. People who learn whole-word reading can't sound out new words or actually use the language. They can pass a very basic competetancy test.
This is idiotic nonsense and it deserves to be called as such. I don't know what schools everyone here or Charlotte Thompson (from the link above) are talking about but I went to an average public school in NY and while I had a bad/dumb teacher or two I NEVER encountered the pervasively moronic systems anecdotally described by her (or here).
One quick look at that Charlotte Thompson site instantly reveals her to be the conspiracy theory spinning (oh no! evolution is taught in the schools: "Department of Education suported by Bush is involved in implementing communist agenda: School to work agenda, Humanistic atheistic curriculum including evolution, internationalism, etc. No right/no wrong curriculum.."), 'know it all', frightened, religious nut job she is. If people are insistant on inventing conspiratorial crises to explain poorly performing students and their fixation with demonizing public schools, that's fine, just don't go parading it around like it's some miraculous revalation that only YOU've discovered. That serves no one.
the neutrino pulse for 87a was seen hours before the optical observation.... http://zebu.uoregon.edu/~soper/StarDeath/sn1987a.h tml
Looking at the redshift of some common spectral line will give you an immediate answer. What I want to know is if the neutrino pulse was detected at one of our observatories like super kamiokande like supernova 1987a was. This one is much further away so I don't know if it was possible....
Oxygen and Fluorine arent nearly in the same league when it comes to reactivity. For instance carbohydrates (a mix of C H and O) will burn in an atmosphere of O2 if given an ignition source but in an atmosphere of F2 they will burn hypergolically.
I'm afraid can't see how this would work. In an atmosphere of HF and F2 how could reaction catalyzing complex molecules ever exist for more than a few seconds, they would be broken down and oxidized very quickly, rendering them useless. Fluorine is just too hungry for electrons! :) Also the HF would quickly dissolve various minerals etc. and form insoluble salts thereby sequestering all the F out of the atmosphere and into the lithosphere in solid bonded form in a short (geological) time period.
It appears that the abstract you linked to, while it uses a techniqe called microgravimetry is actually a TOTALLY different technique. The former, the kind used in the pyramid investigation measures small gravitational fluctuations in the induced by varying small and large masses in the earth's crust while the latter chemistry experiment does not measure changes in the earth's gravity but measures tiny mass fluctuations in a sample exposed to a constant gravity of earth. This is much more simillar to techniques like thermogravimetric analysis.