greg goebel / public domain
* VECTORS is an original newsletter of fact and commentary on aerospace, technology, science, and historical topics.
* It's been generally accepted that human emissions of "greenhouse gases" are causing the Earth to warm up, and the general response has been to push for reductions in greenhouse gas emissions. However, a number of researchers have suggested whizzier ideas for dealing with the "hothouse Earth" problem.
Such notions are collectively known as "geo-engineering", and there's been considerable activity in the field recently, with series of papers published in scientific journals, and conferences set up on the topic. The most exotic scheme so far is the idea of placing a constellation of "sunshade" spacecraft at the Earth-Sun Lagrange point -- the location in space where the gravitational force of the Earth and Sun balance, where spacecraft can be kept on station with relatively little effort.
Roger Angel, an astronomer at the University of Arizona well known for his work on advanced telescopes, envisions each spacecraft as being about a meter across, with the total mass of the constellation running to about 20 million tonnes. The spacecraft would be shot into space using a magnetic launcher. They would have solar-powered ion thrusters to move them to the Lagrange point and keep them on station once they were there. Dr. Angel estimates the cost of the scheme at a trillion dollars. He admits it would only be attractive if all other options failed.
Paul Crutzen, a Nobelist atmospheric chemist, wants to take a hint from nature. Volcanic eruptions can throw particulates into the upper atmosphere that cause a cooling effect; a similar effect from particulate air pollutants also caused a small degree of cooling some decades back that switched to warming once air pollution controls became widespread. Dr. Crutzen thinks that it might be possible to inject harmless aerosols into the upper atmosphere to obtain the same effect. Others have suggested the scheme might be used locally, for example to help preserve the polar icecaps.
John Latham of the US National Center for Atmospheric Research (NCAR) in Boulder, Colorado, has a simpler idea: spraying droplets of seawater into the air to generate low-lying, highly reflective oceanic clouds. The trick is to figure out an economical method to generate the sprays. Stephen Salter of the University of Edinburgh has an idea: build a fleet of unmanned vessels that could generate the sprays using wind power. Each vessel would cost a few million and spray about 10 kilograms of seawater a second. 50 vessels could be able to cancel a year's carbon-dioxide emissions, though an additional fleet would be needed each year until emissions were brought under control.
Dr. Salter believes his scheme would be relatively economical and precise. Fleets could be dispatched to the North Atlantic in the summer to protect the Greenland ice sheets, and transfer to Antarctica six months later. He also suggests that the cooling clouds could be used to lower sea temperatures in tropical areas and help prevent hurricanes from forming.
Other ideas have included seeding the ocean with nutrients, for example iron, to encourage the growth of photosynthetic plankton that would soak up carbon dioxide; or to cover deserts with reflective sheets. Critics have been highly skeptical of such schemes -- one estimates that about half the world's deserts would need to be carpeted with reflective sheets to be effective -- and there are sensible worries that such "fixes" might well have unintended consequences.
There are Greens who oppose the whole notion of geo-engineering on the principle that it encourages people to believe that there is a quick technological fix to the problem of climate change, discouraging efforts to take real action. On the other side of the coin, advocates can point out that if matters go from bad to worse too rapidly, the technological fix might be the only thing available to save the planet from disaster.
* The notion of "commercial space" has been around for decades; it has been largely marked by strings of failures, but there are still those willing to dare. For the last few years, Robert T. Bigelow, a Las Vegas real-estate tycoon, has been pushing a new commercial space project: a commercial space station. Bigelow is not trying to tap into the "space tourism" market, which really doesn't exist just yet; he plans to lease or sell his orbital facility to the world's official space programs. What sets Bigelow's idea apart from most commercial space ventures is that he's got hardware in orbit. That in itself would attract attention; the fact that his technology is a departure from traditional space station schemes also excites interest.
The "Genesis I" prototype space station is now orbiting the Earth at an altitude of 560 kilometers (360 miles), having been put into space by a Russian Dnepr booster on 12 July 2006. An engineering mockup of Genesis I sits in the Bigelow plant in the desert outside of Las Vegas. The mockup is a gray fabric-covered cylinder about 4.4 meters (13 feet 5 inches) long and 2.5 meters (8 feet 2 inches), with an internal volume of 11.5 cubic meters (406 cubic feet). The fabric is not just an outer layer over a metal frame: it provides the outer structure of the station and is kept in shape by air pressure. The fabric is not some cheap cloth like that used to make clothes, of course: it's a multilayer construct, several centimeters thick, that not only provides structure but also thermal control.
Bigelow believes that an "inflatable" space station could cut procurement and launch costs by 25% to 50% compared to existing space station technology. An inflatable station is cheaper to build, and is lighter and more compact, permitting it to be launched on a cheaper booster. Genesis I is strictly a technology testbed, carrying only instruments and cameras, inflated to about a half an atmosphere pressure.
The Bigelow station has its roots in work performed by the US National Aeronautics & Space Administration (NASA) on a "TransHab" inflatable space station in the 1990s, which was envisioned as an orbital module with a volume of 340 cubic meters (12,000 cubic feet) and a mass of 13.2 tonnes (14.5 tons). This gave a volume to mass ratio of 25:1; in comparison, a typical International Space Station (ISS) module has a ratio of 9:1. The big worry was that a micrometeorite would puncture the TransHab, causing it to disastrously deflate. The solution was to design the fabric to be extremely strong, four times stronger than required to deal with any stress it might normally be expected to endure.
The skin consisted of several layers, described from the inside out:
TransHab's skin was 41 centimeters (16 inches) thick and had 60 separate layers. The multiple layers were able to tolerate impacts of aluminum projectiles 1.7 centimeters (two-thirds of an inch) in diameter slammed into it at 25,200 KPH (15,650 MPH). Even if punctured, the hefty inflatable structure would collapse very slowly, giving the occupants plenty of time to apply a patch, or evacuate if it came to that.
NASA axed the effort in 2002. Bigelow had heard about the project and was intrigued; he bought up the patents and hired the NASA TransHab project leader, William Schneider, as a consultant. The design wasn't quite ready for flight at the time: one serious ommission was windows, which proved so tricky to fit into the TransHab that NASA had simply not bothered with them. Bigelow felt that windows would be an absolute necessity for his purposes. Tests to destruction were performed on prototype window installations, some resulting in loud bangs that led to complaints from neighbors. The final window design is 40 centimeters (16 inches) thick.
The production Genesis modules also needed power, control, communications, and other flight systems. Bigelow was able to obtain most of these off-the-shelf from aerospace manufacturers. System reliability was enhanced by "dissimilar redundancy": not only were are redundant critical systems, the two pairs of systems are also implemented differently so they wouldn't fail in the same way. One of the functions of the orbiting Genesis I module was to evaluate systems for later flights. Incidentally, the Genesis I had dual communications systems, one at each end; since it didn't have attitude control, that ensured that communications would not be lost.
Bigelow handles mission control of the flights. Interestingly, the company obtains tracking more or less for free: the US Department of Defense tracks space objects and publishes the data, and the company uses orbital prediction software to determine when Genesis I is within a line of sight to one of the two company ground stations -- one in Las Vegas and the other in Arlington, Virginia. Two more ground stations are being brought online, one in Alaska and the other in Hawaii. Genesis I is in an orbit with a lifetime of 7 to 13 years, giving the company plenty of observations of how it functions in orbit.
Bigelow hopes to launch the "Genesis II" test module in 2007. It will be the same size as the Genesis I but will have improved subsystems. It is to be followed in late 2008 by a half-scale "Galaxy" module, and then a "Sundancer" small station with a crew of three. The Sundancer will have dimensions of 8.69 by 6.28 meters (28 feet 7 inches by 20 feet 7 inches) and a volume of 180 cubic meters (6,351 cubic feet). It will have a propulsion module, a Soyuz-type docking port at one end, and a new lightweight NASA Low Impact Docking System at the other end.
Bigelow's goal is to perform two test flights a year up to the launch of the production man-rated station. Bigelow envisions an operational station based on two "BA330" modules, each with an internal volume of 330 cubic meters (11,645 cubic feet) and space for six crew, mated together by a central node module. The node module will also be fitted with a propulsion module, and will have docking ports for Soyuz or Shenzou space capsules. The plan is to have a fully operational station in orbit by 2015.
Bigelow seems on track to obtain a functional space module. The question remains as to whether there will be enough demand for the product to make it pay off. Bigelow is optimistic, he wouldn't be moving forward so aggressively if he wasn't, but he is perfectly aware that he is trying to buck the notoriously poor record of past space commercialization efforts.
* The rapid proliferation of radio-frequency identification (RFID) systems has made some people nervous, and they have become more nervous as the day when humans are commonly implanted with RFID chips seems to be quickly approaching.
The idea has its clear attractions. An implantable RFID chip, about the size of a grain of rice, could store or provide links to personal information such as the identity, nationality, security clearances, and medical profile of its host. A simple wave of an implanted hand could unlock a door, start a car, or let an emergency medical team know that the host is a diabetic. Since the implant is powered by an external reader, there is no need for it to have batteries, giving it a very long service lifetime.
There is also the downside: will employers be able to demand that hirelings accept an implant? Once implanted, not only will an employer be able to track an employee's movements, but every checkout counter in a store would be able to identify the employee.
The notion of implantable RFID was in the domain of experimenters until 2004, when the US Food & Drug Administration (FDA) approved an RFID tag for human implantation. The tag, known as the "VeriChip", can be read to provide a 16-digit code that indexes the host's medical records under the "VeriMed" system. A few thousand people have received the implants so far.
The company that makes the implant, Verichip Corporation -- a branch of Applied Digital Solutions in Delray, Florida -- is also promoting the VeriChip as a security system, and has a handful of clients using it for that purpose. In a few nightclubs in Europe and the US, patrons can get "chipped", so that every time they enter they will have their favorite drink waiting for them after they walk through the door. In addition, VeriChip has ideas for using the implants as replacements for military dogtags, and has proposed chipping guest workers coming into the USA.
* All this might sound like a gleaming future to a hardcore RFID enthusiast, but it makes everyone else a bit uneasy, since the potential for invasion of privacy and government intrusion is much too obvious. There's not too much difficulty with the main objective of RFID implants, as a scheme for identifying patients in distress who might not be able to communicate, allowing their medical records to be accessed. As long as the patient gives informed consent and the privacy of the patient's medical records is protected, the opportunities for abuse are limited.
However, VeriChip's proposal to chip guest workers has drawn fire. There's practical issues to consider: who pays for the chipping, who tracks the chips, who replaces the chips if they are compromised, and who handles any adverse reactions to the implantation. More importantly, it wouldn't really be voluntary, and it has an uncomfortable similarity to marking the workers with tattoos.
A public survey conducted by researchers at Bridgewater State University in Massachusetts suggested that the public resistance to chipping in general is high, with only a third of those surveyed said they would accept an implant and about half saying they would not. To the extent that it was acceptable, it was mostly only as a health-information measure, and not as a means of providing identification.
The use of implants as a health-information measure does open up a legal door by which the government can mandate their use. After all, public schools have immunization requirements, and there's no inherent legal obstacle to insisting that the students have implants as well. Actually, even VeriChip doesn't see such a broad measure as desireable and only advocates chipping people who are more likely than others to end up in the emergency room -- people with chronic health problems, who are undergoing chemotherapy or other drastic treatments, who have medical implants, and so on. Most other people can simply carry a card in their wallets or a memory chip with their health records. In fact, it's uncertain that implants have much advantage over less invasive alternatives; an RFID-enabled bracelet would be cheaper and less intrusive. A study is now underway in New Jersey to examine the issue.
Still, non-medical uses of chipping open up a Pandora's box of issues. Suppose a company chips all its employees? If an employee leaves the company or the company folds, is the company required to remove the implant? (It's not hard to do, incidentally.)
More importantly, what data gets put on the implant, and who gets to read it? The VeriChip only provides an ID number, which makes of little general use, and readers can only interrogate it from about a hand's width away. However, implants are likely to become more capable and there's no technical obstacle to building readers with longer range. More capable chips will require encryption -- the VeriChip doesn't have it -- to ensure security; nobody likes the idea of a stranger scanning information out of them without their knowledge, much less their consent.
Several US states have passed laws forbidding the mandatory use of implants, but that won't prevent implants from becoming effective requirements for some lines of work. There are no laws requiring encryption of implants yet, in fact there aren't laws to make the unauthorized reading of an implant illegal. Right now there is no immediate necessity of doing so -- but the time may come more quickly than expected.
* BRITAIN THINKS ABOUT THE BOMB: While work on atomic power went on in the US and Germany, another effort along such lines was taking place in Britain. Otto Frisch, nervous about Hitler's warmongering, had gone to the UK from Copenhagen in the summer of 1939 to talk about employment there, only to find his bridge back home burned with the outbreak of war. His friends had to arrange storage of his belongings. He found employment as an assistant lecturer in the physics department of the University of Birmingham, headed by Mark Oliphant, an Australian, another one of Rutherford's alumnai.
The British Chemical Society asked him to write a paper on the current state of nuclear physics. Frisch considered the possibility of a chain reaction in the paper and, influenced by the opinions of his old boss Niels Bohr, discounted it. Frisch then ran into another German physicist in England named Rudolf Peierls, a German of Jewish ancestry who had come to Cambridge in 1933 on a fellowship and had no choice but to stay there when Hitler purged the German educational establishment later in that year. Frisch ended up boarding with Peierls and his Russian wife, where the two physicists had plenty of opportunity to talk shop. Peierls thought that a nuclear weapon was possible, but he calculated that the "critical mass" -- the amount of fissionable material needed to set up an explosive chain reaction -- was "on the order of tons", meaning it wasn't a very practical idea. Although secrecy in nuclear research was starting to bite, Peierls published his result, on the basis that it was so discouraging that it could do no harm.
The war was quiet for the moment, the British and French simply staring off the Germans along the border in what was called a "sitting war". The Soviets disturbed the silence at the end of November 1939 by invading Finland -- which would prove all but a complete disaster for the Red Army, with an unusually harsh winter helping the Finns to blunt the Red offensive and kill vast numbers of Soviet troops. The Soviets would regroup and finally push the Finns into a corner four months later, but the territorial concessions obtained from the war were, as one Soviet general put it, "about enough to bury our dead". Worse, the weakness and disorganization of the Red Army, badly bled by purges, was apparent for the world to see.
As the "Winter War" neared its pathetic end in February 1940, Frisch and Peierls were reconsidering the mechanics of the chain reaction, using uranium-235. The result of the improved calculations were surprising: a nuclear explosion could be supported by a few kilograms of fissionable material. When Peierls calculated what the explosive yield of the weapon would be, the two physicists were "staggered". Frisch then worked out what sort of resources would be required to separate that quantity of uranium-235 from uranium-238; it would take a major investment of industrial resources, but concluded that "the cost of such a plant would be insignificant compared to the cost of the war." The concept had just ceased to be harmless.
They took their figures to Mark Oliphant, who immediately told them to write up a short paper on it. The paper calculated that 5 kilograms (11 pounds) of uranium-235 would have the explosive yield of thousands of tonnes of dynamite. It also provided preliminary details on how the bomb would be built, with two masses of uranium-235, which would be slammed together to create a critical mass. They speculated that the two masses could be slammed together by heavy springs, but emphasized that it would have to be done quickly, or the chain reaction would start before the masses were fully together -- resulting in "predetonation" and an explosive fizzle. A proper detonation would not only result in a horrendous explosion, it would also produce lethal ionizing radiation at the time of the blast and afterward.
The report concluded with a strategic survey, pointing out that such a weapon would be highly indiscriminate, causing massive civilian casualties. The report suggested that would render the use of the weapon unthinkable -- though within a few years the British, the threshold of the unthinkable having been broken by the Luftwaffe bombings of British cities, would be indiscriminately bombing German cities with little squeamishness over the deaths of enemy noncombatants. However, it also suggested the Germans were likely working on such a weapon and Britain had no alternative to developing it.
Oliphant added a cover letter and sent the report off to Henry Tizard, an Oxford chemist and chairman of the "Tizard Committee", a government board involved in consideration of advanced technologies for defense. The committee had already been instrumental in the development of British radar.
* That was in March 1940. A few weeks later, the war went active again. In early April, the British announced that Norwegian waters would be mined to deny Norwegian resources to Germany. Norway had been neutral, but with its neutrality broken the Germans promptly invaded Denmark and Norway on 8 April. The Danes knew that resistance was futile and surrendered the next morning; the Norwegians fought on with assistance from British forces for another month, the leadership finally withdrawing to Britain to form a government-in-exile. The only compensation to the British was that the Royal Navy had ferociously chewed up the Kriegsmarine, the German Navy, during the operation. Niels Bohr remained in Denmark, believing he should stay on and use his authority to resist attempts by the Germans to impose Nazi laws on his country.
In the meantime, Tizard had been considering the paper Oliphant had sent. Tizard was skeptical but formed up an investigative committee chaired by G.P. Thomson, an Imperial College physicist and J.J. Thomson's son, the committee also including James Chadwick and John Cockcroft, another one of Rutherford's boys. The committee met for the first time on 10 April, as a report from the committee reported later: "We entered the project with more skepticism than belief, though we felt it was a matter that had to be investigated."
The necessity was reinforced by intelligence passed on by the French of German attempts to purchase heavy water from a Norsk Hydro, a Norwegian electrochemical firm, the only company in the world that produced the liquid. The company sold the heavy water for lab research at a hefty markup, with monthly production running to about enough to fill up a jug, which was all the lab market would bear. The German industrial giant I.G. Farben not only wanted to buy Norsk Hydro's entire stock, about enough to fill up an oil drum, and guarantee large follow-on shipments on an ongoing basis.
When puzzled Norsk Hydro officials asked why I.G. Farben wanted to buy such astounding quantities of heavy water at such expense, the Germans refused to say. The Norwegians refused to sell. A French bank had a controlling interest in Norsk Hydro and the news got back to France. French physicists were well aware that the most obvious reason to buy such massive quantities of heavy water was for moderating nuclear reactions, and in early March a French agent went to Norway to buy up the heavy water. The agent told the general manager of Norsk Hydro what was going on and offered to pay handsomely for part of the stock; the manager simply gave him the entire lot, which was smuggled back to France. Now the Norsk Hydro facility was in German hands.
The fear of what the Germans might be doing didn't affect the committee's skepticism at the outset. However, the group looked over the Frisch-Peierls report and quickly realized it was the genuine article, to be just as staggered by the possibilities. A second meeting on 24 April was characterized by obvious excitement. Further studies were initiated, with Frisch and Peierls out of the loop for the moment.
Then the war went much more active than the British and French had expected. On 10 May 1940, a huge German offensive jumped off, sweeping down through the Low Countries into northern France. Neville Chamberlain was now too discredited to lead the British government and resigned on the same day; Winston Churchill immediately moved into the prime minister's office. Although the situation didn't seem desperate at the outset, it quickly became so: the Low Countries fell, with the Germans then shattering the Anglo-French defense of Northern France. As the end of May neared, the catastrophe was evident.
The British Expeditionary Force fell back on the port town of Dunkirk; a massive sealift operation to 4 June managed to rescue most of the troops, but they had lost their heavy equipment. The French sued for peace on 22 June 1940. The peace treaty that followed allowed the Germans to occupy northern France, while southern France remained under the highly conditional control of a French government in Vichy. Hitler felt, with some good reason, that he had just won the war: the defeat of France shocked the world, and he had no doubt that the British would soon give up the fight and make a deal with him. However, Churchill had absolutely no illusions about Hitler, wanted nothing to do with another "deal" like the one Chamberlain had made at Munich, and in public speeches all but spat in Hitler's face.
* THE MAUD COMMITTEE: Although the British were in a very difficult situation after the fall of France, Churchill became an embodiment of defiance against Hitler, with the British people rallying to his banner. Even many of the expatriates in Britain felt caught up in the patriotic fervor and desire to fight the Nazis.
The "nuclear club" was starting to investigate the brass tacks of building an atomic bomb. One of the first practical issues was isotope separation, sorting out uranium-235 from uranium-238. There were a number of different ways to do it in principle, but Peierls and Franz Simon -- yet another German Jew chased out by Hitler, with Simon ironically a holder of the Iron Cross First Class, just like Hitler -- felt that "gaseous diffusion" was the best way to go. The idea was to create a gas incorporating uranium and allow it diffuse through a membrane; the gas incorporating the lighter uranium-235 will have lighter molecules and will diffuse through the membrane more quickly. The "enrichment" of uranium-235 compared to uranium-238 was slight for any single session -- well less than a percent even under the best conditions -- so it had to be done over and over again to build up useful concentrations of uranium-235.
The tools for gaseous diffusion then available only worked on a small scale, far too small to obtain enough uranium-235 for building a bomb. As Frisch put it: "It was like getting a doctor who had after great labour made a miniscule quantity of a new drug and then saying to him: 'Now we want enough to pave the streets.'" Simon felt that it could be done by converting uranium to uranium hexafluoride gas (UF6) and passing it through a metal foil barrier full of small perforations, inserted in the middle of a cylinder. Experiments were performed to see if the idea could be made to work, though at the outset the gas being separated was water vapor and carbon dioxide -- uranium hexafluoride was a hideously nasty gas, thoroughly corrosive and toxic, known only too appropriately as "hex". Trying to figure out a material that stand up to hex promised to be a real problem.
* By late June 1940, G.P. Thomson's committee had taken a name: MAUD. It sounded like an acronym but wasn't, amounting to little more than a meaningless label chosen to confuse snoops into trying to pick apart what it stood for. The name wasn't entirely arbitrary: Lise Meitner had sent a telegram to a friend in England, with Meitner reporting that she had recently met with Niels Bohr and his wife Margarethe, concluding that they were well and adding: PLEASE INFORM COCKROFT AND MAUD RAY KENT. Cockroft was informed, obtaining a copy of the message. He thought that MAUD RAY KENT was an anagram; it was unscrambled to mean RADIUM TAKEN and seen as a hint of German nuclear activities. Actually, a few years later it was learned that Maud Ray was the name of a woman from Kent who had cared for Bohr's kids when the Bohrs were in England. The name MAUD had demonstrated its ability to mislead even before the committee adopted it.
The effort was starting to get attention in high places as well. In June, Peierls and Simon spoke with Frederic Lindemann about the prospects for an atomic bomb. Although Peierls commented that he didn't know Lindemann well enough "to translate his grunts correctly" -- Lindemann was not known for his social graces -- the two physicists felt they had made a good impression. They had, and Lindemann, who retained his close contact with Winston Churchill, was able to take the message to 10 Downing Street. Churchill regarded the "Prof", as he called Lindemann, as a prime source of scientific and technical advice, and the Prof's comments carried far more weight than any report dropped on Mr. Churchill's desk.
For the moment, however, Churchill had more immediate concerns. By mid-August, Britain was under air attack from the Luftwaffe, the German air force. Raids had begun in a spotty fashion during the Battle of France, but for a time Hitler had held off, hoping the British would come to their senses and make a deal with him. Churchill made it scathingly clear that wasn't going to happen, and so the "Battle of Britain" began. It seemed at the time to be a "softening up" phase preparatory to an amphibious invasion, and in fact the Wehrmacht was working on an invasion plan, codenamed OPERATION SEA LION.
In reality, Hitler didn't have the resources -- landing craft and the like -- for an amphibious operation of that magnitude, and Royal Navy superiority on the seas made the idea thoroughly dodgy, all the more so because of the way the Royal Navy had thrashed the Kriegsmarine off of the coasts of Norway. His thought processes on the matter seem in hindsight to have been confused and indecisive, as if he hadn't really thought the matter out before and was making things up as he went along, hoping they could be made to work. They couldn't, and in the end, the result was that the air assault on Britain effectively ended up being an exercise in intimidation. Maybe if the British were hammered enough, they would dump the pigheaded Churchill and make a deal.
Hitler no longer regarded the British as a real threat anyway. He perceived that after his staggering victories, he had effectively won the war against the French and British. Now he had other, more pressing plans for conquest to work on. Nazi "victory fever" was a blessing for the British, since German work on advanced technologies, never very well coordinated by the backbiting, corrupt, inefficient, and ignorant Nazi leadership hierarchy, was not seen as particularly important. Resources were withdrawn, technical experts were drafted from research positions into the Wehrmacht. It would take a few years to realize this was a serious misjudgement.
The early phases of the Battle of Britain involved attacks on airfields and other military targets, a tactic that pressed the British Royal Air Force (RAF) to the wall. Then an accident intervened. On 24 August, German bombers missed an oil storage depot on the banks of the Thames and hit central London instead. Churchill immediately sent RAF bombers to hit Berlin at night. The raids were a joke as far as their ability to inflict damage went, but they were extremely successful in provoking Hitler into a rage. The Luftwaffe was ordered to attack cities -- sparing the RAF airfields at the expense of the suffering of British civilians. Whether that had really been Churchill's intent is unclear, but it gave the RAF breathing space, at a high cost.
The Battle of Britain went on into September 1940, but the Luftwaffe was taking a beating, suffering losses well greater than those of the RAF. By the end of the month, the Luftwaffe raids had switched from day to night, beginning what would become known as the "Blitz". At the time, the British had little ability to effectively fight back against night attacks, but neither did the Luftwaffe have the ability to perform precise attacks on targets in the darkness. The result was that the raids could inflict pain and create chaos, but they couldn't do much to seriously affect the British capability to resist. In fact, the attacks simply inspired a certain bulldog tenacity in the British, and reports from London back to America during the Blitz also did much to persuade the American public that the time was coming to take on Hitler. The attacks also eroded British restraint towards retaliation in kind, and in time RAF Bomber Command would inflict a hideous retribution on the Germans.
* While the Blitz went on, at Oxford Franz Simon continued his work on uranium isotope separation for the MAUD committee. In December he completed his report, saying that a separation plant would cost about five million pounds and detailing its construction. He made up forty copies and drove them from door to door, not trusting the posts for such an important document.
TO BE CONTINUED
* RADIOACTIVE DATING / THE REDISCOVERY OF MENDEL: Critics of Darwinism have long proclaimed its imminent death, though the obituary has so far proven somewhat exaggerated. However, in the year 1900 Darwinism was as close to dead as it has been. Although the idea of evolution was now scientific dogma, Darwin's revelations about natural selection had become thoroughly confused, with few naturalists agreeing about what really drove evolution.
The first key to Darwin's revival was the discovery of radioactivity by the French physicist Anton Henri Becquerel (1852:1908), who discovered that some materials emitted a mysterious radiation that would fog photographic film. In a few years it would be understood that radioactivity was caused by the energetic breakdown of the atoms of the material themselves, and that the energies produced by such breakdowns were huge -- as given by the famous formulation of the German physicist Albert Einstein (1879:1955), "E=MC^2".
The physicists had discovered an energy process that allowed the Universe to be much older than Lord Kelvin had asserted. In fact, since different radioactive materials have different and highly specific decay rates or "half-lives", radioactivity gave geologists a tool to actually estimate the age of many mineral samples. Not only was the Universe now old enough to allow Darwinism to take place, it was also possible to provide reasonably hard dates on the fossil record.
* The second key rested in the first steps towards the understanding of heredity. By the 1880s, microscopic studies seemed to strongly hint that the mechanisms of heredity were associated with the cell nucleus. Unfertilized eggs and sperm carried "pronuclei", and observations showed that a sperm was little more than a pronucleus with a tail. A fertilized egg contained two pronuclei that quickly merged, to be followed by cell division and construction of the organism.
In 1882, a German biologist named Walther Flemming (1843:1905) published a report concerning his observations of a set of "threads", later called "chromosomes", in salamander larval cells, that seemed to divide along with the cell. New staining techniques and further improvements in microscopy brought the chromosomes into closer view, and showed that the chromosomes were duplicated before cell division. The chromosomes were suspected to be structures supporting the machinery of heredity, but nobody knew just how. Some believed that each chromosome contained a complete blueprint for the organism.
There is no indication that Gregor Mendel heard of this discovery before his death two years later. Progress forward depended on a Dutch botanist named Hugo de Vries (1848:1935). The Dutch are big on raising flowers and in the mid-1880s, de Vries began to investigate the breeding of flowers, leveraging off the statistical methods developed by Galton -- they were perfectly valid in themselves, and a particular example of Galton's wildly mixed legacy. By that time, it was known that threadlike entities named "chromosomes", found in the nucleus of a cell, were involved in cell replication: they existed in pairs that split up in the germ cells of parents, a process known as "meiosis", and then recombined in the egg cells of progeny.
De Vries and others believed, at the time on somewhat circumstantial evidence, that the chromosomes were carriers of hereditary information. Nobody had any clear idea of the details, but de Vries suggested, again correctly, that different traits were found as "units" positioned on the chromosomes. He had no idea of the precise nature of these "units", but he did give them the name "pangenes", in homage to Darwin's theory of pangenesis. De Vries, a focused and humorless man, pursued the concept through statistical analysis and plant cross-breeding experiments, and gradually came upon the idea of traits being passed from each parent in the form of pangenes, resulting in the 3:1 ratio of traits in descendants as observed by Mendel.
De Vries published this conclusion in 1900. He was aware of Mendel's 1866 paper, but didn't mention Mendel as a source. A German botanist named Carl Correns (1864:1933) had also been performing plant crossbreeding experiments and had come to conclusions similar to those of de Vries -- but Correns was quick to point to Mendel's priority.
It was difficult to say that the issue was highly controversial at the time, the revelation not being seen as revolutionary for the moment -- though it was. However, the end result was that Mendel's work had been fished out of the pigeonhole in which it had been gathering dust for over three decades. Not everyone was impressed with it, some even claiming it was a fraud, but others were intrigued and moved forward with the concept. A Danish botanist named Wilhelm Johannsen (1857:1927) gave the (then hypothetical) unit of heredity the name "gene", which the British evolutionist William Bateson (1861:1926) used to mint the word "genetics" for the study of heredity.
This is not to say that matters were on track. Many of the early "geneticists" like William Bateson didn't believe that genes physically resided on chromosomes, instead adopting ideas about energy states or waves or whatever, not coded arrangements of molecules. A German biologist named Theodor Boveri (1862:1915) and an American biologist named Walter Sutton (1877:1916) suggested otherwise, pointing out the strong connection between the "pairing" of genes with the division and then recombination of chromosomes, but for the moment the issue remained arguable.
* THOMAS HUNT MORGAN: It seemed at the time that the confusion over Darwinism was simply changing its terminology somewhat, but now the final arbiter of scientific disputes, cold hard data, intervened, in the form of careful studies performed by a meticulous American experimentalist, Thomas Hunt Morgan (1866:1945), at Columbia University in New York City.
Morgan was a pleasant gentleman from Kentucky, a nephew of Confederate cavalry raider John Hunt Morgan -- though Thomas never knew his famous uncle, John Hunt Morgan having been killed late in the Civil War. Thomas Hunt Morgan was a thorough "empiricist", focused on experimental data, with little respect for either religion or for the fuzziness of Darwinian thought as it existed at the time. Polite in his demeanor, he still mocked the vague hereditary ideas of the era as "invisible germs" whose sole functions were those "imagination bestows on them". Morgan wanted something more tangible, and he found it in the unlikely form of the little Drosophila melanogaster fruitfly.
He was cross-breeding fruitflies in his lab at Columbia by 1909. He found the flies "wonderful material -- they breed all year round and produce a new generation every twelve days." They were much better subjects than pea plants or flowers, permitting him to observe a hundred generations in less than four years. It was, however, untidy work, with the flies raised in rows of small milk bottles on rotten bananas in his "fly room" at Columbia, resulting in a unpleasant-smelling environment buzzing with little escaped flies.
Morgan was initially skeptical about Mendel since it seemed as though traits were blended in progeny, and the business of Mendel's 3:1 ratio was contradicted by the fact that in most animal species, males and females were born in roughly equal numbers -- gender didn't appear to be based on paired dominant and recessive traits, so why should anything else be? Morgan was actually looking for mutations and did not expect to validate Mendel.
After about a year of effort, the lab crew produced their first distinctive mutant -- a male fly with white eyes, instead of the normal red eyes. He crossbred the mutant male with a red-eyed female, then crossbred the progeny. All of the first generation had red eyes -- but the second generation featured both red eyes and white eyes, in a ratio of 3:1. In addition, all the white-eyed flies were male, without exception; it appeared the white eye color trait was linked to the hereditary mechanism that determined sex. Two more mutants were soon discovered: yellow body color and miniature wings. Both bred in a 3:1 ratio, and both were sex-linked. Over the next few years, dozens of mutations were uncovered; Morgan and his students were observing evolutionary variation in action.
The various mutations fell into four groups, with each group apparently being correlated with a particular chromosome. The only problem was that there were rare exceptions, such as very unusual cases of white-eyed female fruitflies. Such an inconsistency promised to make life difficult for the chromosome theory of inheritance, but Morgan discovered an out. In 1909 a Belgian cytologist -- cell researcher -- named Frans Janssens had observed that during meiosis, every rare now and then chromosome pairs would "cross over" at certain locations, to break apart and then reform.
Morgan deduced that the genes that he presumed existed were strung like beads on a string along a chromosome, and that the recombinations of chromosomes were likely to switch genes around. Furthermore, the likelihood of two genes on the same chromosome being separated from each other was obviously greater the farther they were apart -- that is, if they were close together then they were likely to be exchanged together, but if they were far apart one would be exchanged and the other left behind. This discovery turned out to be much more than merely a loophole: creation of "linkage maps" allowed Morgan and his students to actually locate genes on the chromosomes -- even though, at the time, they couldn't provide the slightest detail of what a gene actually was.
Morgan had validated Mendel without intending to, and became a believer in Mendelian genetics, as well as the chromosome theory of inheritance. He published his results in 1915 in THE MECHANISM OF MENDELIAN INHERITANCE, co-authored with three of his students, Alfred Sturtevant (1891:1970), Calvin Bridges (1889:1938), and Hermann Muller (1890:1967). The three would go on to become prominent geneticists in their own right, with Muller winning the Nobel prize in 1946.
Morgan had finally put genetics on a sound scientific basis, establishing it is as a matter of "hard heredity" -- though in doing so he didn't become a believer in Darwinian natural selection. Morgan only believed in what he could see in the lab, and natural selection was hard to demonstrate in breeding fruitflies. There is the saying that when one has a hammer all one sees is nails, and Morgan decided that the origins of species lay simply in mutations: mutations would accumulate, producing a new species, and natural selection was a secondary process at best. His view, which became known as "mutationism", would be a force in biology for some years, though it would be quickly undermined by those not so restricted in their view as Morgan. Despite his limited vision, however, Morgan remains a prophet of great honor, since his work opened doors that up to that time had seem securely locked.
* DISCOVERING PREHISTORIC HUMANS (1): Another weakness of Darwinism was the lack of information on human predecessors, but by the early 20th century that issue was being gradually addressed as well. The pioneer was a Dutch biologist named Eugene Dubois (1858:1940) who had been much impressed by Darwinian thinking in his youth. He began his career as a professor of anatomy at the University of Amsterdam, working on the comparative morphology of humans and animals. He soon set his sights on more ambitious research.
Darwin had suggested in DESCENT OF MAN that humans had arisen in Africa, but Lyell had observed in ANTIQUITY OF MAN that the most humanlike of the apes, the orangutan, the "Old Man Of The Woods" as locals called him, was from Southeast Asia, suggesting an alternate origin of humankind. Haeckel also favored an Asian origin of humankind, though his reasoning was based more on racial prejudice than evidence. Dubois favored Asian origins as well, and since the East Indies were part of the Dutch colonial empire at the time, he had a good place to start looking. He left the University of Amsterdam in 1887 and signed on as a medical doctor with the Dutch colonial army.
On arriving in the East Indies, Dubois spent four years hunting for prehuman remains on the islands of Java and Sumatra. The whole idea might have seemed preposterous and foolish to Dubois' scientific contemporaries -- except for the fact that he succeeded. In 1891, while digging in Java, his team found a fossil molar of some species of human and a skullcap that suggested the brain case of this particular species was substantially smaller than that of a modern human. A year later, in 1892, a thigh bone was discovered that suggested the species walked upright.
Dubois named the find Pithecanthropus erectus or "Upright Apeman", though it more popularly became known as "Java Man". Dubois claimed it was the "missing link" between apes and humans. Given the sketchiness of the find -- a molar, skullcap, and thighbone wasn't much to go on -- not all of his colleagues were impressed, some claiming the thing was just another ape and others wondering if all three fossil samples were even from the same creature. Dubois, who had returned to the Netherlands in 1895, became snarled up in the controversy, becoming more defensive to the point of outright paranoia, unwilling to let go of his samples for examination.
To confuse matters, in 1912 what appeared to be a fossil human was found at Piltdown in England, with a humanlike upper skull and an apelike jaw. Many were suspicious since the jaw joint elements were missing, suggesting that the "Piltdown Man" was a hoax, a plant. It would take over 40 years to learn that the Piltdown Man "fossil" was a human skull with an orangutan jaw. Nobody would ever know for certain who set up the hoax or why, but it did much to muddy the waters for years.
However, despite the obstacles, events began to lend weight to Dubois' claims. More fossils of a similar creature were found in China from 1929 and named "Peking Man". In time there was no doubt that these fossils were of an extinct humanlike species, which became known as Homo erectus; however, they were too similar to humans to really be much of a "missing link" with apes.
* By that time other candidates were available. In 1924, a South African student found a fossil skill at limestone quarry near the town of Taung. She handed the skull over to Raymond Dart (1893:1988), her Australian-born anatomy professor, who judged it to be a baboon skull at first. He requested that the quarry owner kindly send him any more fossils found there, and the owner obliged, sending two crates of neatly-packed fossils in the fall of 1924.
The fossils included enough of a skull of a child to permit a good reconstruction. He immediately recognized that the Taung fossils were not those of baboons; he excitedly announced in the scientific press in early 1925 that his discovery, which he called Australopithecus africanus, labelling it "an extinct link between man and his simian ancestor." Dart's notions were not universally popular among his scientific colleagues, in part because he was proposing that the savannahs of Africa and not the jungles of Asia were the "cradle of humanity".
Dart did have one enthusiastic advocate, a Scots-born anthropologist named Robert Broom (1866:1951), a recognized expert in African fossils. He was impressed by Dart's "Taung child" and accepted Dart's conclusions, performing expeditions to hunt for more fossils -- achieving success by finding remains of a half-dozen "australopithecines" at Sterkfontein, South Africa, in 1936. Broom also discovered fossil remains of a "heavy" species of australopithecine, which would eventually become known as Australopithecus robustus. It was becoming apparent that Dart had been on the right track, though the fossil evidence still remained sketchy and there was plenty of room for argument. Further progress was sidetracked for the moment by World War II.
TO BE CONTINUED
* Website additions for the month include:
Updated documents include:
All the reviews were updated this month. New reviews include:
This last month's online blog entries include items on: Communications infrastructure, THE MAKING OF THE FITTEST, XO security systems, domain-tasting scams, local money in Germany, biofuel versus food, mediation services, Mexican digital education systems, neglected tropical diseases, surrogate reproduction, recycling paper, Marine space assault vehicles, medical ID theft, nonobviousness & patents, ultracheap cars, and tort reform in the US states.
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