actually i was kidding. and you can definitly discern individual sunspots with the unaided eye. the chinese have kept records on sunspot activity for the past 2000 years.
you can easily calculate the size of a sunspot necessary for unaided visual observation. start with the Rayleigh resolution criterion which relates the minimum observable angle to the size of the optical aperture ie. the pupil of your eye. pupil diameter normally varies between 1 and 5 mm, depending on the ambient brightness. If we take 1.5 mm as the maximum dilation in relatively bright light, and the mean wavelength of visible light as 500 nanometres, we find a resolution of 3.3x10-4 radians or 70 arc seconds. to subtend this angle at the Earth, a sunspot would have to be about 50,000 km in diameter and it would occupy an area of two billion (2000 million) square kilometres or 700 millionths of the visible solar hemisphere and extend over 4 heliographic degrees. while this is extremely large in terrestrial terms, approximately 2 to 3% of all sunspot groups will have this area. solar cycles (approximately 11 years to complete) have produce almost 4000 groups over their lifetime. so you can expect that 100 sunspots or compact sunspot groups will be visible to the unaided eye during a solar cycle.
all you have to do is make sure you use a dark filter or view the sun at sunset/rise when you may even get a size magnification effect making spot viewing even more probable.
hmmm that latest picture came from the extreme ultraviolet imaging telescope and was of the 30.4 nanometer Helium/Silicon 11 line.
In that band the sun's surface is totally obscured by the hot corona above. for a clear view of the surface look at the intensitygram.
i'm betting those HeNe tubes were less than 5 milliwatts though. IMHO saying visible light simply won't damage your eyes no matter how intense it is, is just plain false.
the energy of a laser beam can be intensified up to 100,000 times by the focusing action of the eye. If the irradiance entering the eye is 1 mW/cm2, the irradiance at the retina will be 100 W/cm2.
so if you have anything over 30mW, no matter what wavelength(except far ultraviolet and mid to far infrared which will cause burns to the cornea) in a direct beam impact of the eye you are almost absolutely sure deposit enough energy in your retina to cause fast heating and burn even considering the blink reflex.
looking at the sun directly may be bad and it may be good.....
Galileo went blind in the year 1637 at the age of 73 probably because he had a penchant for staring directly at the sun to make observations. of course one of the reasons he earned international fame is that he discovered sunspots!
for more information on the type of sunspot (beta gamma delta) try here: spaceweather.com
also, that article from the BBC was posted on friday, the sunspot is now at the center of the solar disk and pointed more directly at earth. the latest magnetograms and intensitygrams are up at the SOHO site here.
For some background on emersons hilarious bigoted(and just plain stupid) posts go to his info and read the post he just made on linux in africa. Either he is a toal idiot or one the most fantastic trolls ever!
Oh my god emerson! Did you eat dinner tooday!? Holy shit you were "modifing with the very seeds of humanity" by altering their glucose content. You'll surely suffer eternal damnation for this abomination of tinkering with life's sacred inner workings!
people who cant even understand "regular" windows!? i would think that a GUI could only get so dumbed down and sugary sweet before the target audiences' mean IQ is low enough that they wouldn't even be interested in using computers at all anyway. and then.....who is going to use this software.
".......afterall, this IS about defense - it is defense against mother nature"
[clipped from the SNPP]
Lisa asks Mr. Burns if his plant has a recycling center. Mr. Burns can't even comprehend what the word recycling means. "Ree-cy-cleeng?" Zoom to Mr. Burns' head, where we dissolve to an opening dictionary. The page begins with the word "Ragamuffin" as we scroll down to a series of other tyrannical, threatening R words. Mr. Burns tells Lisa that he doesn't know what the word means, and calls her a "ragamuffin." Lisa tells him about how recycling helps Mother Nature, to which Mr. Burns starts spitting upon mother nature for the disasters she's given man. Mr. Burns states the opinion, "Surely, you agree we can do without her!" Lisa: "No i don't agree!". Mr. Burns is shocked. Smithers scolds her for questioning Mr. Burns. Burns calls off Smithers, and just tells Lisa to shut up because if he listened to people like her, he wouldn't be worth $200 million today. Lisa, however, read Mr. Burns' "recent" biography, which portrays him as being only
worth $100 million. Mr. Burns looks to Smithers, who hesitantly informs him that he's actually worth considerably less than that. Mr. Burns announces his departure. Skinner says, "Monty Burns, everybody!" and starts applauding.
where did i say anywhere that tokamaks, stellarators, spheromaks, 'fusors', z-pinches......whatever, are useless? my point was simply, with respect to commercial power generation, that controlling and confining fusion reactions for the times AND densities necessary to create ignition, and efficient power production; is simply not achievable with current technology. no matter what the method.
2H2(from the electrolyzed water) + CO2(from your breath, the air, whatever) ---> CH4(methane [natural gas]) + O2
robert zubrin is proposing this as the method by which a mars spacecraft could produce its own fuel for the return trip using the CO2 marian atmosphere and sunlight BTW.:]
H2O -->electrolysis--> 2 H2 1 O2
2H2(from the electrolyzed water) + CO2(from your breath, the air, whatever) ---> CH4(methane [natural gas]) + O2
robert zubrin is proposing this as the method by which a mars spacecraft could produce its own fuel for the return trip using the CO2 marian atmosphere and sunlight BTW.:]
Yes it is possible to reuse spent nuclear fuel rods by breeding the U-238 into fissionable Plutonium-239. However there are serious problems with this, namely the unbelievable toxicity of plutonium, the danger of nuclear weapons proliferation that would be produced by entering said Plutonium into commercial circulation, the huge amount of waste produced in separating and purifying the Pu and the necessary use of liquid metal coolants(very dangerous, can't use water like normal reactors) in the core. It was for these reasons that the US abandoned all hopes for breeder reactors in the 70's and 80's along with Britain, France and Germany (contrary to the suggestion by another poster that "Carter did it").
That said, you mentioned you thought there is no concerted effort to develop nuclear fusion power. I would agree that there is NOT enough money being put into research for fusion, however, FUSION IS EXTREMELY DIFFICULT TO ACHIEVE AND CONTROL!
I work at the University of Rochesters' Omega Laser (most powerful in the world for now) which is used for inertial confinement fusion research and it takes pretty much the most clever engineering of the smartest scientists in the world just to produce stable fusion reactions that last mere millionths of a second long. No one knows how to design a fusion reactor that does not suffer from turbulent plasma instabilities and that achieves high density ultrahot ion temperatures at the same time. Pull of the design of a stable fusion reactor and the nobel is yours for the taking.
Lisa and Bart simultaneous: can we have a pool dad?
Lisa and Bart: can we have a pool dad?
Lisa and Bart: can we have a pool dad?
Lisa and Bart: can we have a pool dad?
Lisa and Bart: can we have a pool dad?
just Bart: can we ha....(lisa motions for him to stop)
Homer: I understand. Let us celebrate our new arrangement with the adding of chocolate to milk.
did anyone actually see the picture of that thing? it looks like it has a pressurized tank hanging off a main tank. i can just picture a fire in the lab... no get the pin, wait pull the lever downward no... you have to turn the nozzle topwise, no TOPWISE!
In 1985 the Soviet Union's "Vega 1" probe, while on it's way to Halley's comet flew past Venus and dropped off a Venera style lander and a balloon to investigate the Venusian middle cloud layer. The balloon floated in the atmosphere for about 48 hours at an altitude of 54 km. they repeated the trick with Vega 2 only 4 days later. of course they weren't passively inflated with the evaporation of a volatile liquid like the one in the article, if I remember correctly I think they had to take along their own pressurized tanks.
what are you talking about. the mars pathfinder mission in 97 that used a parachute then a ballon to bounce land worked fantastically. the mars polar lander last year used conventional rocket firings and parachutes to slow down.....supposedly anyway.
i disagree with Mr.Sketch, i think the above should be moderated DOWN for its gross amount of pseudoscience and misinformation.
Moray B. King starts out his book by telling the reader that earth is being visited by alien spaceships all the time. As if that were not enough to discredit him immediately he goes on in his book to explain how his lifelong goal has been to get people to build so called "free energy machines" (ahem...remind you of anything?? maybe the quest to build perpetual motion machines in the 19th century before thermodynamics came to light?)
no one doubts that so called zero point energy exists. even the promenent physicist steven weinberg agrees with that. it has been proven to exist by the casimir effect http://www.sciam.com/askexpert/physics/physics44/p hysics44.html . though dont be so quick to assume it is going to solve the worlds energy needs. in the same interview with alan alda for the PBS program 'scientific american frontiers' S.Weinberg states that the total amount of "free energy" in the volme of space the size of the earth would be equal to about the energy in a gallon of gas. i suggest carl sagan's 'the demon haunted world' or michael shermer's 'why people believe weird things'.
yea spontaneous generation was disproved a century and a half ago. but abiotic synthesis was not! these are two separate things, the latter of which having mounds of evidence supporting it as the most probable method by witch life started here. spontaneous generation says that organisms spring fully formed from the aether(false). abiotic synthesis (supported by such experiments like the stanley miller experiment)says that life started by a long chain of events inevitably initiated by the laws of physics and the interaction of matter.
by the way as long as you list divine intervention as being the only other choice for the creation of life, why dont you note leprechauns or evles? they have just as much evidence for being the Creators of life as your god.
apparently there IS a europa orbiter being designed at JPL [ http://www.jpl.nasa.gov/ice_fire/EO_Info.htm ] but it will only be able to tell wether or not there is a subsurface ocean, how thick the covering ice is and how intense europas magnetic field is. IMHO we already have more than enough circumstantial evidence supporting the existance of a liquid ocean on the moon. why not attatch a probe capable of melting thru the ice to see if there really IS life down there?! IANAAP(astrophysicist) but i think the technology exists right now to do this. the heat source for melting ice could be contained in the tip of the probe as a mass of noble metal encapsulated(to prevent contamination of the europan ocean) Plutonium 238(its natural radiation makes it hot) and the probe could power itself using the heat differential between the surrounding ice/water and the hot probe tip. radioisotopic thermoelectric generators last a VERY long time and the probe would theoretically have decades to break thru the other side of the ice layer before its thermoelectric junction fails to produce power (heck the voyager probes are STILL TRANSMITTING!! and their RTG's are over 25 yrs old). why dont we start designing this thing NOW?!
(DAMNIT I FORGOT TO SIGN IN THE FIRST TIME!)
i think you are referring to the stanley miller experiment.t in 1953 he set up an electric discharge in an atmosphere of hydrogen, methane, ammonia and waer; and whadda ya know, after a week, found a bunch of amino acids floating around in the residue. the electric field they are talking about in the article (what must be a very weak one) is the supposed suspect of producing the magnetic field anomaly around europa. in other words if there is a magnetic field around europa it is almost certainly being produced by a salty ocean.
Slashdot Mirror
actually i was kidding. and you can definitly discern individual sunspots with the unaided eye. the chinese have kept records on sunspot activity for the past 2000 years.
you can easily calculate the size of a sunspot necessary for unaided visual observation. start with the Rayleigh resolution criterion which relates the minimum observable angle to the size of the optical aperture ie. the pupil of your eye. pupil diameter normally varies between 1 and 5 mm, depending on the ambient brightness. If we take 1.5 mm as the maximum dilation in relatively bright light, and the mean wavelength of visible light as 500 nanometres, we find a resolution of 3.3x10-4 radians or 70 arc seconds. to subtend this angle at the Earth, a sunspot would have to be about 50,000 km in diameter and it would occupy an area of two billion (2000 million) square kilometres or 700 millionths of the visible solar hemisphere and extend over 4 heliographic degrees. while this is extremely large in terrestrial terms, approximately 2 to 3% of all sunspot groups will have this area. solar cycles (approximately 11 years to complete) have produce almost 4000 groups over their lifetime. so you can expect that 100 sunspots or compact sunspot groups will be visible to the unaided eye during a solar cycle.
all you have to do is make sure you use a dark filter or view the sun at sunset/rise when you may even get a size magnification effect making spot viewing even more probable.
hmmm that latest picture came from the extreme ultraviolet imaging telescope and was of the 30.4 nanometer Helium/Silicon 11 line. In that band the sun's surface is totally obscured by the hot corona above. for a clear view of the surface look at the intensitygram.
i'm betting those HeNe tubes were less than 5 milliwatts though. IMHO saying visible light simply won't damage your eyes no matter how intense it is, is just plain false.
the energy of a laser beam can be intensified up to 100,000 times by the focusing action of the eye. If the irradiance entering the eye is 1 mW/cm2, the irradiance at the retina will be 100 W/cm2.
so if you have anything over 30mW, no matter what wavelength(except far ultraviolet and mid to far infrared which will cause burns to the cornea) in a direct beam impact of the eye you are almost absolutely sure deposit enough energy in your retina to cause fast heating and burn even considering the blink reflex.
looking at the sun directly may be bad and it may be good.....
Galileo went blind in the year 1637 at the age of 73 probably because he had a penchant for staring directly at the sun to make observations. of course one of the reasons he earned international fame is that he discovered sunspots!
i say why not take your chances.
for more information on the type of sunspot (beta gamma delta) try here: spaceweather.com
also, that article from the BBC was posted on friday, the sunspot is now at the center of the solar disk and pointed more directly at earth. the latest magnetograms and intensitygrams are up at the SOHO site here.
why the hell would i have to "keep track" of anything. all you have to do is look at what he posted retard.
For some background on emersons hilarious bigoted(and just plain stupid) posts go to his info and read the post he just made on linux in africa. Either he is a toal idiot or one the most fantastic trolls ever!
Oh my god emerson! Did you eat dinner tooday!? Holy shit you were "modifing with the very seeds of humanity" by altering their glucose content. You'll surely suffer eternal damnation for this abomination of tinkering with life's sacred inner workings!
but.....linux was born in Helsinki.
people who cant even understand "regular" windows!? i would think that a GUI could only get so dumbed down and sugary sweet before the target audiences' mean IQ is low enough that they wouldn't even be interested in using computers at all anyway. and then .....who is going to use this software.
".......afterall, this IS about defense - it is defense against mother nature"
[clipped from the SNPP]
Lisa asks Mr. Burns if his plant has a recycling center. Mr. Burns can't even comprehend what the word recycling means. "Ree-cy-cleeng?" Zoom to Mr. Burns' head, where we dissolve to an opening dictionary. The page begins with the word "Ragamuffin" as we scroll down to a series of other tyrannical, threatening R words. Mr. Burns tells Lisa that he doesn't know what the word means, and calls her a "ragamuffin." Lisa tells him about how recycling helps Mother Nature, to which Mr. Burns starts spitting upon mother nature for the disasters she's given man. Mr. Burns states the opinion, "Surely, you agree we can do without her!" Lisa: "No i don't agree!". Mr. Burns is shocked. Smithers scolds her for questioning Mr. Burns. Burns calls off Smithers, and just tells Lisa to shut up because if he listened to people like her, he wouldn't be worth $200 million today. Lisa, however, read Mr. Burns' "recent" biography, which portrays him as being only
worth $100 million. Mr. Burns looks to Smithers, who hesitantly informs him that he's actually worth considerably less than that. Mr. Burns announces his departure. Skinner says, "Monty Burns, everybody!" and starts applauding.
no that was ABCnews.com, his name is Fred Moody and he's an idiot
where did i say anywhere that tokamaks, stellarators, spheromaks, 'fusors', z-pinches......whatever, are useless? my point was simply, with respect to commercial power generation, that controlling and confining fusion reactions for the times AND densities necessary to create ignition, and efficient power production; is simply not achievable with current technology. no matter what the method.
oops forgot the first 2 :]
H2O -->electrolysis--> 2 H2 1 O2
:]
2H2(from the electrolyzed water) + CO2(from your breath, the air, whatever) ---> CH4(methane [natural gas]) + O2
robert zubrin is proposing this as the method by which a mars spacecraft could produce its own fuel for the return trip using the CO2 marian atmosphere and sunlight BTW.
H2O -->electrolysis--> 2 H2 1 O2 2H2(from the electrolyzed water) + CO2(from your breath, the air, whatever) ---> CH4(methane [natural gas]) + O2 robert zubrin is proposing this as the method by which a mars spacecraft could produce its own fuel for the return trip using the CO2 marian atmosphere and sunlight BTW. :]
Yes it is possible to reuse spent nuclear fuel rods by breeding the U-238 into fissionable Plutonium-239. However there are serious problems with this, namely the unbelievable toxicity of plutonium, the danger of nuclear weapons proliferation that would be produced by entering said Plutonium into commercial circulation, the huge amount of waste produced in separating and purifying the Pu and the necessary use of liquid metal coolants(very dangerous, can't use water like normal reactors) in the core. It was for these reasons that the US abandoned all hopes for breeder reactors in the 70's and 80's along with Britain, France and Germany (contrary to the suggestion by another poster that "Carter did it").
That said, you mentioned you thought there is no concerted effort to develop nuclear fusion power. I would agree that there is NOT enough money being put into research for fusion, however, FUSION IS EXTREMELY DIFFICULT TO ACHIEVE AND CONTROL!
I work at the University of Rochesters' Omega Laser (most powerful in the world for now) which is used for inertial confinement fusion research and it takes pretty much the most clever engineering of the smartest scientists in the world just to produce stable fusion reactions that last mere millionths of a second long. No one knows how to design a fusion reactor that does not suffer from turbulent plasma instabilities and that achieves high density ultrahot ion temperatures at the same time. Pull of the design of a stable fusion reactor and the nobel is yours for the taking.
actually i think it was:
Lisa and Bart simultaneous: can we have a pool dad?
Lisa and Bart: can we have a pool dad?
Lisa and Bart: can we have a pool dad?
Lisa and Bart: can we have a pool dad?
Lisa and Bart: can we have a pool dad?
just Bart: can we ha....(lisa motions for him to stop)
Homer: I understand. Let us celebrate our new arrangement with the adding of chocolate to milk.
did anyone actually see the picture of that thing? it looks like it has a pressurized tank hanging off a main tank. i can just picture a fire in the lab... no get the pin, wait pull the lever downward no ... you have to turn the nozzle topwise, no TOPWISE!
http://robotics.jpl.nasa.gov/aerobot/studies/vega_ detail.html
chock full o' detail!!
In 1985 the Soviet Union's "Vega 1" probe, while on it's way to Halley's comet flew past Venus and dropped off a Venera style lander and a balloon to investigate the Venusian middle cloud layer. The balloon floated in the atmosphere for about 48 hours at an altitude of 54 km. they repeated the trick with Vega 2 only 4 days later. of course they weren't passively inflated with the evaporation of a volatile liquid like the one in the article, if I remember correctly I think they had to take along their own pressurized tanks.
what are you talking about. the mars pathfinder mission in 97 that used a parachute then a ballon to bounce land worked fantastically. the mars polar lander last year used conventional rocket firings and parachutes to slow down.....supposedly anyway.
i disagree with Mr.Sketch, i think the above should be moderated DOWN for its gross amount of pseudoscience and misinformation.
p hysics44.html . though dont be so quick to assume it is going to solve the worlds energy needs. in the same interview with alan alda for the PBS program 'scientific american frontiers' S.Weinberg states that the total amount of "free energy" in the volme of space the size of the earth would be equal to about the energy in a gallon of gas. i suggest carl sagan's 'the demon haunted world' or michael shermer's 'why people believe weird things'.
Moray B. King starts out his book by telling the reader that earth is being visited by alien spaceships all the time. As if that were not enough to discredit him immediately he goes on in his book to explain how his lifelong goal has been to get people to build so called "free energy machines" (ahem...remind you of anything?? maybe the quest to build perpetual motion machines in the 19th century before thermodynamics came to light?)
no one doubts that so called zero point energy exists. even the promenent physicist steven weinberg agrees with that. it has been proven to exist by the casimir effect http://www.sciam.com/askexpert/physics/physics44/
yea spontaneous generation was disproved a century and a half ago. but abiotic synthesis was not! these are two separate things, the latter of which having mounds of evidence supporting it as the most probable method by witch life started here. spontaneous generation says that organisms spring fully formed from the aether(false). abiotic synthesis (supported by such experiments like the stanley miller experiment)says that life started by a long chain of events inevitably initiated by the laws of physics and the interaction of matter.
by the way as long as you list divine intervention as being the only other choice for the creation of life, why dont you note leprechauns or evles? they have just as much evidence for being the Creators of life as your god.
apparently there IS a europa orbiter being designed at JPL [ http://www.jpl.nasa.gov/ice_fire/EO_Info.htm ] but it will only be able to tell wether or not there is a subsurface ocean, how thick the covering ice is and how intense europas magnetic field is. IMHO we already have more than enough circumstantial evidence supporting the existance of a liquid ocean on the moon. why not attatch a probe capable of melting thru the ice to see if there really IS life down there?! IANAAP(astrophysicist) but i think the technology exists right now to do this. the heat source for melting ice could be contained in the tip of the probe as a mass of noble metal encapsulated(to prevent contamination of the europan ocean) Plutonium 238(its natural radiation makes it hot) and the probe could power itself using the heat differential between the surrounding ice/water and the hot probe tip. radioisotopic thermoelectric generators last a VERY long time and the probe would theoretically have decades to break thru the other side of the ice layer before its thermoelectric junction fails to produce power (heck the voyager probes are STILL TRANSMITTING!! and their RTG's are over 25 yrs old). why dont we start designing this thing NOW?!
(DAMNIT I FORGOT TO SIGN IN THE FIRST TIME!)
i think you are referring to the stanley miller experiment.t in 1953 he set up an electric discharge in an atmosphere of hydrogen, methane, ammonia and waer; and whadda ya know, after a week, found a bunch of amino acids floating around in the residue. the electric field they are talking about in the article (what must be a very weak one) is the supposed suspect of producing the magnetic field anomaly around europa. in other words if there is a magnetic field around europa it is almost certainly being produced by a salty ocean.