Time for some more early-nuclear age stories.
A 14-lb sphere of relatively-pure plutonium (just slightly below the 'critical mass' to cause a runaway reaction or explosion) actually went critical on two occasions at the Los Alamos Labory in 1945 and 1946. Both instances resulted in the death by radiation poisoning of a noted scientist involved.
The experiments involved were (or have come to be) known as "tickling the dragon's tail" since they both involved in some manner, slowly, slowly building up the reflections of neutrons (which cause fission in plutonium atoms) into this nicely-machined spherical piece of metal. Incidentally, the core itself was relative safe to handle, and any number of people did, holding it in their hands (it's rather heavy) and remarking how warm it was: the refined plutonium sphere gave off a fair amount of heat as a byproduct of its continuing nuclear decay.Surprisingly, it's not particularly dangerous to hold: plutonium decays by emitting alpha particles (a helium nucleus: two protons and two neutrons bound together) which which won't penetrate a few centimeters of air, a piece of paper, clothing or the human skin. When inhaled or ingested, that's another matter...
Following adapted from the Wikipedia article: http://en.wikipedia.org/wiki/Harry_K._Daghlian,_Jr.
Anyway,in the experiment, Daghlian was attempting to build a neutron reflector by manually stacking a series of 4.4 kg tungsten carbide bricks in an incremental fashion around the plutonium core. The purpose of the neutron reflector was to reduce the mass required for the plutonium core to attain criticality.
As he was moving the final brick over the assembly, neutron counters alerted Daghlian to the fact that the addition of this brick would render the system supercritical. As he withdrew his hand, he accidentally dropped the brick onto the center of the assembly. Since the assembly was nearly in the critical state, the accidental addition of the last brick caused the reaction to go immediately into the prompt critical region of supercritical behavior. This resulted in a power excursion.
Daghlian panicked immediately after dropping the brick and attempted to knock off the brick without success; he was forced to partially disassemble the tungsten-carbide pile to halt the reaction. Daghlian was estimated to have received a dose of 510 rem (5.1 Sv) of neutron radiation, from a yield of 10^16 fissions. He died 25 days later from acute radiation poisoning.
In the second (as perhaps more famous) incident using this same plutonium core, the noted Physicist Louis Slotin was also killed.
On May 21, 1946, Slotin and seven other colleagues performed an experiment that involved the creation of one of the first steps of a fission reaction by placing two half-spheres of beryllium (a neutron reflector) around a plutonium core. The experiment used the same plutonium core that had irradiated Daghlian, later called the "Demon core" for its role in the two accidents. Slotin grasped the upper beryllium hemisphere with his left hand through a thumb hole at the top while he maintained the separation of the half-spheres using the blade of a screwdriver with his right hand, having removed the shims normally used.Using a screwdriver was not a normal part of the experimental protocol.
At 3:20 p.m., the screwdriver slipped and the upper beryllium hemisphere fell, causing a "prompt critical" reaction and a burst of hard radiation. At the time, the scientists in the room observed the "blue glow" of air ionization and felt a "heat wave". In addition, Slotin experienced a sour taste in his mouth and an intense burning sensation in his left hand. Slotin instinctively jerked his left hand upward, lifting the upper beryllium hemisphere and dropping it to the floor, ending the reaction. However, he had already been exposed to a lethal dose (around 2100 rems, or 21 Sv) of neutron and gamma radiation. Slotin's radiation dose was equivalent to the amount that he would have been exposed to by being 1500 m (4800 ft) away from the detonation of an atomic bomb.
As soon as Slotin left the building, he vomited, a common reaction from exposure to extremely intense ionizing radiation. Slotin's colleagues rushed him to the hospital, but irreversible damage had already been done. His parents were informed of their son's inevitable death and a number of volunteers donated blood for transfusions, but the efforts proved futile. Louis Slotin died nine days later on May 30, in the presence of his parents. He was buried in Winnipeg on June 2, 1946.
At first, the incident was classified and not made known even within the laboratory; Robert Oppenheimer and other colleagues later reported severe emotional distress at having to carry on with normal work and social activities while they secretly knew that their colleague lay dying.
This particular plutonium core ("The Demon Core") was later used in the Crossroads Able nuclear test.
Friday, August 27, 2010
Friday, August 20, 2010
The largest and perhaps oldest organism on earth?
What is the oldest organism on earth? What is the largest? Both of these turn out to to be difficult questions and may really depend on how you define the terms. In terms of area, a 'fungal mat' in Oregon discovered in 1992 is said to cover approximately 1500 acres, but both the area and whether this should be considered one organism is still a matter of debate. A single Giant Sequoia tree may weigh 4.5 million pounds. The bristlecone pine is a long-lived single organism with one specimen (named "Methuselah") having been ring-dated at almost 4,800 year old -- making it the oldest 'non-clonal' organism. The most intriguing candidate for both crowns is a 'group' of aspens in the Wasatch Mountains of Utah, which actually has a name: "Pando" -- Latin for "I spread."
Pando is more than 106 acres in size, and consists of more than 47,000 tree trunks (you'd assume that these are separate organisms, but they're not) collectively weighing more than 13 million pounds.
Although aspens do come in male and female varieties, the species seldom flowers and instead an individual propagates itself by vegetative reproduction: it sends out roots, which travel some distance before they sprout up and appear as separate plants. In fact, they are all genetically-identical clones of the orginal individual -- all just upshoots of a common root system, and can truly be considered one organism. That would make Pando the largest (by weight) of any organism on the planet. The oldest? The bristlecone pine is no longer considered the oldest or longest-living organism by most biologists, due to the existence of 'clonal colonies' such as Pando. Other species than aspens spread similarly, and one of the oldest (calculated) clone is a creosote bush estimated to be 11,700 years old.
Earlier biologists and botanists have postulated that some clones (the whole collective of visible, above-ground manifestations is actually called a 'clone') may have lifespans in the millions of years, or even be effectively immortal, barring a cataclysmic event; and even cataclysmic events such as fires and conflagrations are actually beneficial to these clones. These events do not destroy the deep-below-ground clonal root structure, and actually clear the area of competing species -- such as conifers -- with which they compete largely for needed sunlight.
Earlier this year, the 'immortality' idea was effectively discredited, however. Like any organism, even a clone's system was found to accumulate -- albeit very slowly -- natural mutations which affect and reduce the vegetative reproduction rates of these clonal colonies. Estimate show that after perhaps 20,000 years, the 'spreading capability' (reproductive viability) of the clonal structure (not the individual trees -- they die after 200 years at the most) may decline by as much as 50%, threatening the continued expansion of the clone.
Neverthess, both the Pando and other aspen clones in Europe have been estimated to be between at least 10,000 to 20,000 years old.
Pando is more than 106 acres in size, and consists of more than 47,000 tree trunks (you'd assume that these are separate organisms, but they're not) collectively weighing more than 13 million pounds.
Although aspens do come in male and female varieties, the species seldom flowers and instead an individual propagates itself by vegetative reproduction: it sends out roots, which travel some distance before they sprout up and appear as separate plants. In fact, they are all genetically-identical clones of the orginal individual -- all just upshoots of a common root system, and can truly be considered one organism. That would make Pando the largest (by weight) of any organism on the planet. The oldest? The bristlecone pine is no longer considered the oldest or longest-living organism by most biologists, due to the existence of 'clonal colonies' such as Pando. Other species than aspens spread similarly, and one of the oldest (calculated) clone is a creosote bush estimated to be 11,700 years old.
Earlier biologists and botanists have postulated that some clones (the whole collective of visible, above-ground manifestations is actually called a 'clone') may have lifespans in the millions of years, or even be effectively immortal, barring a cataclysmic event; and even cataclysmic events such as fires and conflagrations are actually beneficial to these clones. These events do not destroy the deep-below-ground clonal root structure, and actually clear the area of competing species -- such as conifers -- with which they compete largely for needed sunlight.
Earlier this year, the 'immortality' idea was effectively discredited, however. Like any organism, even a clone's system was found to accumulate -- albeit very slowly -- natural mutations which affect and reduce the vegetative reproduction rates of these clonal colonies. Estimate show that after perhaps 20,000 years, the 'spreading capability' (reproductive viability) of the clonal structure (not the individual trees -- they die after 200 years at the most) may decline by as much as 50%, threatening the continued expansion of the clone.
Neverthess, both the Pando and other aspen clones in Europe have been estimated to be between at least 10,000 to 20,000 years old.
Sunday, August 15, 2010
Scientists call for a global nuclear renaissance in new study
Scientists outline a 20-year master plan for the global renaissance of nuclear energy that could see nuclear reactors with replaceable parts, portable mini-reactors, and ship-borne reactors supplying countries with clean energy, in research published today in the journal Science.
The scientists, from Imperial College London and the University of Cambridge, suggest a two-stage plan in their review paper that could see countries with existing nuclear infrastructure replacing or extending the life of nuclear power stations, followed by a second phase of global expansion in the industry by the year 2030. The team say their roadmap could fill an energy gap as old nuclear, gas and coal fired plants around the world are decommissioned, while helping to reduce the planet's dependency on fossil fuels.
Professor Robin Grimes, from the Department of Materials at Imperial College London, says: "Our study explores the exciting opportunities that a renaissance in nuclear energy could bring to the world. Imagine portable nuclear power plants at the end of their working lives that can be safely shipped back by to the manufacturer for recycling, eliminating the need for countries to deal with radioactive waste. With the right investment, these new technologies could be feasible. Concerns about climate change, energy security and depleting fossil fuel reserves have spurred a revival of interest in nuclear power generation and our research sets out a strategy for growing the industry long-term, while processing and transporting nuclear waste in a safe and responsible way."
The researchers suggest in their study that based on how technologies are developing, new types of reactors could come online that are much more efficient than current reactors by 2030. At the moment, most countries have light water reactors, which only use a small percentage of the uranium for energy, which means that the uranium is used inefficiently. The team suggest that new 'fast reactors' could be developed that could use uranium approximately 15 times more efficiently, which would mean that uranium supplies could last longer, ensuring energy security for countries.
Another idea is to develop reactors with replaceable parts so that they can last in excess of 70 years, compared to 40 or 50 years that plants can currently operate at. Reactors are subjected to harsh conditions including extreme radiation and temperatures, meaning that parts degrade over time, affecting the life of the reactor. Making replaceable parts for reactors would make them more cost effective and safe to run over longer periods of time
==============================================
Note from Bill Krog:
it's already happening: check out info about Hyperion Power Generation at http://www.hyperionpowergeneration.com/
They are in the production stage now -- and have hundreds of overseas orders -- for the "Hyperion Power Module", which basically is likened to a nuclear battery.
Which technology licensed to them by Los Alamos National Laboratories, the company is in production of a Nuclear Power Module, which is basically a 1.5 meter by 2 meter, self contained and sealed cube. It needs no complicated outside control station or system, is self-regulating and incapable of 'melt-down' type accidents, and is deliverable to the emplacement site worldwide by flatbed truck, ship or railcar. Once its delivered, all that's needed is (for security purposes) to dig a hole, bury it and surround it by a fence. The modular units will deliver 25MW of electicity energy (enough for about 20-25,000 American-style homes ) for 8-10 years. ("Stackable" for greater output). They are emplaced by the Company, and when they near the end of their useful life, the Company simply replaces them, like a battery.
They have NO carbon output/footprint, release NO gases, warmed water, particulates, etc, into the atmosphere, produce NO measureable radioacivity outside their own structure, cannot 'melt-down' or 'runaway' and neither use nor produce any nuclear materials which are usable in weapons-making applications, and fully meet all IAEA non-proliferation standards. You won't find a wind- or solar-based solution which will give you years of 25MW of base-load electricity 24/7/365, reagardless of whether the wind is blowing or not, or if the sun is shining or not, and which doesn't require hundreds or thousands of acres of land.
The scientists, from Imperial College London and the University of Cambridge, suggest a two-stage plan in their review paper that could see countries with existing nuclear infrastructure replacing or extending the life of nuclear power stations, followed by a second phase of global expansion in the industry by the year 2030. The team say their roadmap could fill an energy gap as old nuclear, gas and coal fired plants around the world are decommissioned, while helping to reduce the planet's dependency on fossil fuels.
Professor Robin Grimes, from the Department of Materials at Imperial College London, says: "Our study explores the exciting opportunities that a renaissance in nuclear energy could bring to the world. Imagine portable nuclear power plants at the end of their working lives that can be safely shipped back by to the manufacturer for recycling, eliminating the need for countries to deal with radioactive waste. With the right investment, these new technologies could be feasible. Concerns about climate change, energy security and depleting fossil fuel reserves have spurred a revival of interest in nuclear power generation and our research sets out a strategy for growing the industry long-term, while processing and transporting nuclear waste in a safe and responsible way."
The researchers suggest in their study that based on how technologies are developing, new types of reactors could come online that are much more efficient than current reactors by 2030. At the moment, most countries have light water reactors, which only use a small percentage of the uranium for energy, which means that the uranium is used inefficiently. The team suggest that new 'fast reactors' could be developed that could use uranium approximately 15 times more efficiently, which would mean that uranium supplies could last longer, ensuring energy security for countries.
Another idea is to develop reactors with replaceable parts so that they can last in excess of 70 years, compared to 40 or 50 years that plants can currently operate at. Reactors are subjected to harsh conditions including extreme radiation and temperatures, meaning that parts degrade over time, affecting the life of the reactor. Making replaceable parts for reactors would make them more cost effective and safe to run over longer periods of time
==============================================
Note from Bill Krog:
it's already happening: check out info about Hyperion Power Generation at http://www.hyperionpowergeneration.com/
They are in the production stage now -- and have hundreds of overseas orders -- for the "Hyperion Power Module", which basically is likened to a nuclear battery.
Which technology licensed to them by Los Alamos National Laboratories, the company is in production of a Nuclear Power Module, which is basically a 1.5 meter by 2 meter, self contained and sealed cube. It needs no complicated outside control station or system, is self-regulating and incapable of 'melt-down' type accidents, and is deliverable to the emplacement site worldwide by flatbed truck, ship or railcar. Once its delivered, all that's needed is (for security purposes) to dig a hole, bury it and surround it by a fence. The modular units will deliver 25MW of electicity energy (enough for about 20-25,000 American-style homes ) for 8-10 years. ("Stackable" for greater output). They are emplaced by the Company, and when they near the end of their useful life, the Company simply replaces them, like a battery.
They have NO carbon output/footprint, release NO gases, warmed water, particulates, etc, into the atmosphere, produce NO measureable radioacivity outside their own structure, cannot 'melt-down' or 'runaway' and neither use nor produce any nuclear materials which are usable in weapons-making applications, and fully meet all IAEA non-proliferation standards. You won't find a wind- or solar-based solution which will give you years of 25MW of base-load electricity 24/7/365, reagardless of whether the wind is blowing or not, or if the sun is shining or not, and which doesn't require hundreds or thousands of acres of land.
"We Gotta Get Outa This Place...
As the old song says.
Stephen Hawking (a bright person) said recently that mankind's only chance of long-term survival lies in colonising space, as humans drain Earth of resources and face a terrifying array of new threats.
"The human race shouldn't have all its eggs in one basket, or on one planet," the renowned astrophysicist told the website Big Think, a forum which airs ideas on many subjects from experts.
"Our only chance of long-term survival is not to remain inward looking on planet Earth, but to spread out into space," he added.
He warned that the human race was likely to face an increased number of events that threaten its very existence, as the Cuban missile crisis did in 1962.
The Cold War showdown saw the United States and Soviet Union in a confrontation over Soviet missiles deployed in Cuba, near US shores, and brought the world to the brink of nuclear war.
"We are entering an increasingly dangerous period of our history," said Hawking.
"Our population and our use of the finite resources of planet Earth are growing exponentially, along with our technical ability to change the environment for good or ill."If we want to survive beyond the next century, "our future is in space," added the scientist.
"That is why I'm in favour of manned, or should I say 'personed', space flight."
His comments came after he warned in a recent television series that mankind should avoid contact with aliens at all costs, as the consequences could be devastating.
Stephen Hawking (a bright person) said recently that mankind's only chance of long-term survival lies in colonising space, as humans drain Earth of resources and face a terrifying array of new threats.
"The human race shouldn't have all its eggs in one basket, or on one planet," the renowned astrophysicist told the website Big Think, a forum which airs ideas on many subjects from experts.
"Our only chance of long-term survival is not to remain inward looking on planet Earth, but to spread out into space," he added.
He warned that the human race was likely to face an increased number of events that threaten its very existence, as the Cuban missile crisis did in 1962.
The Cold War showdown saw the United States and Soviet Union in a confrontation over Soviet missiles deployed in Cuba, near US shores, and brought the world to the brink of nuclear war.
"We are entering an increasingly dangerous period of our history," said Hawking.
"Our population and our use of the finite resources of planet Earth are growing exponentially, along with our technical ability to change the environment for good or ill."If we want to survive beyond the next century, "our future is in space," added the scientist.
"That is why I'm in favour of manned, or should I say 'personed', space flight."
His comments came after he warned in a recent television series that mankind should avoid contact with aliens at all costs, as the consequences could be devastating.
Monday, August 9, 2010
NuDets
Or 'Nuclear Detonations' as you may know them.
Here a link to a computer-animated 'art work', showing all the known nuclear detonations worlwide by date, by country, etc. Very nicely done.
http://gizmodo.com/5600704/the-explosions-of-every-nuclear-bomb-to-date
The US total of 1030 corresponds to the official number acknowledged and published in the 'official record' of such things, the US Government publication "United States Nuclear Tests - July 1945 through September 1942"
DOE/NV -- 209 REV 15 Pub. December 2000.
If you'd like to see exactly where these 1030 detonations occurred, you can check my Google Map at:
http://maps.google.com/maps/ms?ie=UTF8&hl=en&msa=0&msid=116945134295436436626.00044ff490bf518b65562&ll=44.150681,-148.447266&spn=36.757543,107.050781&t=h&z=4
This lists/shows the sites of all nuclear tests done in the USA, including Alaska, Nevada, Colorado, and Mississippi.
The map indicates the shot name, type, purpose, published yield and the the location of the surface-ground-zero of the drillhole or emplacement location. The location is accurate -- according to the US Government publication -- to to +- 100 meters or so; so the subsidence craters do not necessarily line up with the map markers, due both to the the location error, and to that fact that the map marker is the drill hole or emplacement location, not necessarily the spot directly underneath the center of the existant subsidence crater (if any).
NOTE: the Google map has five pages and is slow to load due to the number of data points and markers. In addition, if you are on Page 1 for example, only the markers/data for those points on Page 1 are shown. Navigate to the other pages to redisplay the map, and show the appropriate points/markers, which are listed in alphabetical order by shot name.
PS: if you look up and zoom in on 'Sedan' on Page 4, when you zoom close enough you will see the labelled roads in a circle, surrounding this large cratering shot. If you follow 'Groom Lake Road" to the east from the top of the circular road, as it winds through the mountains and desert, in about 18 miles you will come to an airbase with runways, on a dry lake bed. This is the renowned "Area 51" where the USA to this day tests and flies experimental and ultra-secret aircraft.
Here a link to a computer-animated 'art work', showing all the known nuclear detonations worlwide by date, by country, etc. Very nicely done.
http://gizmodo.com/5600704/the-explosions-of-every-nuclear-bomb-to-date
The US total of 1030 corresponds to the official number acknowledged and published in the 'official record' of such things, the US Government publication "United States Nuclear Tests - July 1945 through September 1942"
DOE/NV -- 209 REV 15 Pub. December 2000.
If you'd like to see exactly where these 1030 detonations occurred, you can check my Google Map at:
http://maps.google.com/maps/ms?ie=UTF8&hl=en&msa=0&msid=116945134295436436626.00044ff490bf518b65562&ll=44.150681,-148.447266&spn=36.757543,107.050781&t=h&z=4
This lists/shows the sites of all nuclear tests done in the USA, including Alaska, Nevada, Colorado, and Mississippi.
The map indicates the shot name, type, purpose, published yield and the the location of the surface-ground-zero of the drillhole or emplacement location. The location is accurate -- according to the US Government publication -- to to +- 100 meters or so; so the subsidence craters do not necessarily line up with the map markers, due both to the the location error, and to that fact that the map marker is the drill hole or emplacement location, not necessarily the spot directly underneath the center of the existant subsidence crater (if any).
NOTE: the Google map has five pages and is slow to load due to the number of data points and markers. In addition, if you are on Page 1 for example, only the markers/data for those points on Page 1 are shown. Navigate to the other pages to redisplay the map, and show the appropriate points/markers, which are listed in alphabetical order by shot name.
PS: if you look up and zoom in on 'Sedan' on Page 4, when you zoom close enough you will see the labelled roads in a circle, surrounding this large cratering shot. If you follow 'Groom Lake Road" to the east from the top of the circular road, as it winds through the mountains and desert, in about 18 miles you will come to an airbase with runways, on a dry lake bed. This is the renowned "Area 51" where the USA to this day tests and flies experimental and ultra-secret aircraft.
Saturday, August 7, 2010
'Extreme Skier Dies on K2'
It was reported today that skier and mountaineer Fredrik Ericcson died Friday, while trying to summit K2 in Pakistan -- the second-highest mountain in the world. Ericcson was attempting to be the first man to ski from summit to base camp on K2. According to his friends, Ericcson and his climbing partners had begun the 'summit push' between 1:00am and 1:30am in low-visibility weather. Somewhere along the summit route at about 8,300 meters (27,231 feet) Ericcson "lost his purchase and was unable to arrest his fall." (This would be a fall of almost 4,300 feet).
His body, resting at about 7,000 meters will remain where it lies and likely no attempt will be made to recover it, due to the extreme danger. K2 is considered much more difficult than Everest to ascend, and in terms of number of ascent attempts vs. number of climber deaths, is the most dangerous of all of the "eight-thousanders" (peaks over 8,000 meters) in the world.
His body, resting at about 7,000 meters will remain where it lies and likely no attempt will be made to recover it, due to the extreme danger. K2 is considered much more difficult than Everest to ascend, and in terms of number of ascent attempts vs. number of climber deaths, is the most dangerous of all of the "eight-thousanders" (peaks over 8,000 meters) in the world.
Thursday, August 5, 2010
BYU Scientists Convert Matter Into Mormonism
PROVO, UT—A team of physicists from Brigham Young University announced yesterday that they have succeeded in converting a tiny particle of matter into the truth and sanctity of the Book of Mormon.
http://www.theonion.com/articles/byu-scientists-convert-matter-into-mormonism,1681/
http://www.theonion.com/articles/byu-scientists-convert-matter-into-mormonism,1681/
Poems from "A Space Child's Mother Goose"
published 1958: Verses by Frederick Winsor
===============================
1.
Probable-Possible, my black hen
She lays eggs in the Relative When.
She doesn't lay eggs is the Positive Now
Because she's unable to Postulate How.
8.
Three jolly sailors from Blaydon-on-Tyne
They went to sea in a bottle by Klein.
Since the sea was entirely inside the hull
The scenery seen was exceedingly dull.
20.
Russell and Whitehead and Hegel and Kant!
Maybe I shall and maybe I shan't.
Maybe I shan't and maybe I shall.
Kant Russell Whitehead, Hegel et. al.
===============================
1.
Probable-Possible, my black hen
She lays eggs in the Relative When.
She doesn't lay eggs is the Positive Now
Because she's unable to Postulate How.
8.
Three jolly sailors from Blaydon-on-Tyne
They went to sea in a bottle by Klein.
Since the sea was entirely inside the hull
The scenery seen was exceedingly dull.
20.
Russell and Whitehead and Hegel and Kant!
Maybe I shall and maybe I shan't.
Maybe I shan't and maybe I shall.
Kant Russell Whitehead, Hegel et. al.
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