World energy consumption is 15 terawatts. Assuming my gp calculations are correct, and all energy was produced by fusion, there would be 36 million cubic meters of helium created each year. At that rate it would be 30 years to generate the billion cubic meters that was in the reserve in 1995.
Assume we go the p+B -> 3He + 9Mev.
1 mole of p yield 3 moles of He - or 24 * 3 liters of gas at STP.
It also yields 9 * 1.6*10^-13 * 6*10^23 = 9 *10^11 joules = 9*10^11 Watt seconds.
So for 72 liters ( 0.072 m^3) of He, you would need a giga watt for about 15 minutes.
Your table top fusor is now plasma, you just used up more electricity than I will likely use in my life, and you can fill a small balloon.
Lucas went defunct in 1996. The lord of darkness went dark. But the spirit lives on. The story reminded me of a TR-6 I had in college. You never knew what would happen when you turned the key. Nine out of ten it would start.
I have not seen anyone answer you. Twenty years ago when I studies such things, 1% for something like a HeNe laser was good. I hear the National Ignition Facility lasers are good to maybe 4%. The quantum efficiency of a laser diode might be as high as 60%.
You have a couple of considerations. In an optically pumped laser, you have the efficiency of creating the pump photons. These put the lasing medium in an excited state which happens as some fraction less than 100%. Lastly, the excited state medium can either spontaneously emit, or emit via stimulation. You need the one to start the laser, but any spontaneous emission after that counts towards inefficacy.
In high res - 6 colors - black, white, blue, orange, green, purple. But two adjacent bytes were either blue/orange or green/purple depending on the high bit for the first byte, as I recall..... I still pronounce the root beer as Hi-Res.
Which brings up a rather glaring point: SLAC, Fermilab, CERN, et al have been colliding protons together for decades. You'd think they would have noted something funny in the statistics by now to indicate that their colliding objects were consistenly not colliding with the predicted probabilities. If "size" means anything, it means the most when you try to make objects bash each other head-on.
I think beam current can be measured with good accuracy, but beam spacial profile is much harder to measure - something I worked on briefly at SLAC. In getting beams to collide I am pretty sure it is a matter of twiddling a few degrees of freedom looking for the maximum collision rate. I doubt any one is looking for an expected collision rate at high accuracy, just happy to be getting collisions.
I think you need to consider integrated light gathering time. If Hubble is looking at something towards the poles, it can remain fixed on the target for days, the Hubble Deep Field exposure was 11 days long. For most terrestrial scopes you have maybe 6 hours of exposure.
Hubble 2.4 meter mirror: Gemini has an 8.1 meter mirror. My naive estimate is (2.4)^2/(8.1)^2 = 0.08. So would have to spend 10x the observing time. And this assumes Hubble has the requisite insturments.
Ok, I'll just agree with you because you are right. But, do you think that Apple has some artificial scarcity ploy going? Do they have a few hundred thousand iPad they are holding onto so all their stores stay sold out?
I don't think it is a ploy when people coming in to the store have to wait a week to get their iPad. I am pretty sure Apple would rather sell it to me when I show up than take the risk I won't come back.
Almost right. It is only every year that you want access to the distribution channel. If you developed your own app and installed it in your devices one time, there is no need to continue paying the yearly developer license fee to use the installed app; unless you want to continue distributing it or need to deploy a new version.
-dZ.
I do not think that is quite true. The keys expire. I had a dev copy of my app on my phone, and after about a year the provision expired; it was easier to just buy my own app for $.30 than to go through the hassle of getting another developer's provision every year.
Rather than entrusting the phone to a 3rd party such as the bartender at the bar where the phone was found, the finder believed a 3rd party like Gizmodo was more likely to be trustworthy and more likely to be able to ascertain the true owner. It's not an unreasonable assumption to have made.
You should find yourself a new bar if this is what you think. I trust my bartender with my beer, I will certainly trust her with some stranger's phone; especially since it is the bar I would come back to if I lost my phone there.
Look up Gravity B; 43 years from NASA funding to launch. I won't read the details, but higher B field usually means higher resolution in mass spectrometry. Maybe longer life will make up for it; but a 0 field forever will tell you nothing.
Orbit at low altitude is about 90 minutes. An ICBM has to go at most half way around the world, so 45 minutes from launch is about the max time you would expect for an ICBM. Montana to Afghanistan is 6,000 miles, or a 22 minute flight; overflight of Russia might be problematic. As pointed out in other posts sub launch to target is less than 10 minutes.
I've looked for an ARM device with more than 256meg ram. I think I only found one. So I wonder if the arm cores in general have a limited number of adress lines.
Slashdot Mirror
World energy consumption is 15 terawatts. Assuming my gp calculations are correct, and all energy was produced by fusion, there would be 36 million cubic meters of helium created each year. At that rate it would be 30 years to generate the billion cubic meters that was in the reserve in 1995.
Assume we go the p+B -> 3He + 9Mev.
1 mole of p yield 3 moles of He - or 24 * 3 liters of gas at STP.
It also yields 9 * 1.6*10^-13 * 6*10^23 = 9 *10^11 joules = 9*10^11 Watt seconds.
So for 72 liters ( 0.072 m^3) of He, you would need a giga watt for about 15 minutes.
Your table top fusor is now plasma, you just used up more electricity than I will likely use in my life, and you can fill a small balloon.
Most, if not all, of the Helium on Earth is from alpha decay.
Last time I believe Wikipedia.
http://en.wikipedia.org/wiki/Lucas_Industries
Lucas went defunct in 1996. The lord of darkness went dark. But the spirit lives on. The story reminded me of a TR-6 I had in college. You never knew what would happen when you turned the key. Nine out of ten it would start.
I have not seen anyone answer you. Twenty years ago when I studies such things, 1% for something like a HeNe laser was good. I hear the National Ignition Facility lasers are good to maybe 4%. The quantum efficiency of a laser diode might be as high as 60%. You have a couple of considerations. In an optically pumped laser, you have the efficiency of creating the pump photons. These put the lasing medium in an excited state which happens as some fraction less than 100%. Lastly, the excited state medium can either spontaneously emit, or emit via stimulation. You need the one to start the laser, but any spontaneous emission after that counts towards inefficacy.
http://ieeexplore.ieee.org/xpl/freeabs_all.jsp?arnumber=307495
Suggests NIF lasers might be 10% efficent http://en.wikipedia.org/wiki/Inertial_confinement_fusion
In high res - 6 colors - black, white, blue, orange, green, purple. But two adjacent bytes were either blue/orange or green/purple depending on the high bit for the first byte, as I recall.....
I still pronounce the root beer as Hi-Res.
Which brings up a rather glaring point: SLAC, Fermilab, CERN, et al have been colliding protons together for decades. You'd think they would have noted something funny in the statistics by now to indicate that their colliding objects were consistenly not colliding with the predicted probabilities. If "size" means anything, it means the most when you try to make objects bash each other head-on.
I think beam current can be measured with good accuracy, but beam spacial profile is much harder to measure - something I worked on briefly at SLAC. In getting beams to collide I am pretty sure it is a matter of twiddling a few degrees of freedom looking for the maximum collision rate. I doubt any one is looking for an expected collision rate at high accuracy, just happy to be getting collisions.
I think you need to consider integrated light gathering time. If Hubble is looking at something towards the poles, it can remain fixed on the target for days, the Hubble Deep Field exposure was 11 days long. For most terrestrial scopes you have maybe 6 hours of exposure. Hubble 2.4 meter mirror: Gemini has an 8.1 meter mirror. My naive estimate is (2.4)^2/(8.1)^2 = 0.08. So would have to spend 10x the observing time. And this assumes Hubble has the requisite insturments.
http://esp.cr.usgs.gov/info/lacs/lead.htm
Roman ingots to shield particle detector
http://www.nature.com/news/2010/100415/full/news.2010.186.html
Not quite the same:Wake on Demand lets Snow Leopard sleep with one eye open
http://www.macworld.com/article/142468/2009/08/wake_on_demand.html
You can do more than just wake up a system, you can maintain a proxy for all advertised services like file sharing and printing.
Apple telling these developers you can only use our ad service is just blatant abuse at this point.
It is somewhat more subtle. One interpretation is that Apple is protecting user privacy. Reading the text of the TOS : http://mediamemo.allthingsd.com/20100412/is-apple-closing-off-the-iphone-to-rival-ad-networks/ it seems pretty reasonable from an app user POV.
I also think this is an informative take: http://davidbarnard.com/post/684540619/anti-competitive-and-potentially-creepy
I also seem to recall Cray-1 had 64 bit words, hence 64 bit floats. All I can find for ARM is 32 bit floats.
I feel the same way about swap pages.
Ok, I'll just agree with you because you are right. But, do you think that Apple has some artificial scarcity ploy going? Do they have a few hundred thousand iPad they are holding onto so all their stores stay sold out?
I don't think it is a ploy when people coming in to the store have to wait a week to get their iPad. I am pretty sure Apple would rather sell it to me when I show up than take the risk I won't come back.
Almost right. It is only every year that you want access to the distribution channel. If you developed your own app and installed it in your devices one time, there is no need to continue paying the yearly developer license fee to use the installed app; unless you want to continue distributing it or need to deploy a new version.
-dZ.
I do not think that is quite true. The keys expire. I had a dev copy of my app on my phone, and after about a year the provision expired; it was easier to just buy my own app for $.30 than to go through the hassle of getting another developer's provision every year.
They can and they have - at least the technical constraints.
I am not seeing any phone that currently supports the whole flash experience: http://www.adobe.com/mobile/supported_devices/ Just the Flash Lite option.
Rather than entrusting the phone to a 3rd party such as the bartender at the bar where the phone was found, the finder believed a 3rd party like Gizmodo was more likely to be trustworthy and more likely to be able to ascertain the true owner. It's not an unreasonable assumption to have made.
You should find yourself a new bar if this is what you think. I trust my bartender with my beer, I will certainly trust her with some stranger's phone; especially since it is the bar I would come back to if I lost my phone there.
Look up Gravity B; 43 years from NASA funding to launch. I won't read the details, but higher B field usually means higher resolution in mass spectrometry. Maybe longer life will make up for it; but a 0 field forever will tell you nothing.
Orbit at low altitude is about 90 minutes. An ICBM has to go at most half way around the world, so 45 minutes from launch is about the max time you would expect for an ICBM. Montana to Afghanistan is 6,000 miles, or a 22 minute flight; overflight of Russia might be problematic. As pointed out in other posts sub launch to target is less than 10 minutes.
Don't taste me bro!
I'm working a $20M DARPA project. Client is in Swing, and server computation engine is in Java. It has no browser component.
I've looked for an ARM device with more than 256meg ram. I think I only found one. So I wonder if the arm cores in general have a limited number of adress lines.