Thursday, April 26, 2007

"Twilight Zone" effect

Carbon dropped into the oceans is not automatically stored away for millennia. Instead, microorganisms living in the "twilight zone" captures much of the carbon and returns it to the biosphere. This is important for OTEC schemes that plan to sequester carbon by locking it up in algae and sinking it to the ocean bottom. From this study, it looks as if the material needs to be deposited at least 1000 meters down to get a maximum impact.

Thursday, April 19, 2007

Radiation Protection In Space

Radiation is a major hazard for anyone venturing into space. The commonly proposed way to deal with space radiation (particularly for settlements on planetary surfaces such as Luna and Mars) is to either build underground or to use a very thick wall of regolith to shield the settlers. But when you are in outer space (in an orbital settlement or a traveling ship, for instance) such radiation shields will be massive, with significant costs for transport.

A blog entry at Colony Worlds describes this problem, and a possible solution, which is to use artificial magnetic fields for settlements. This idea is not new. Other than providing extremely fast transport through the solar system, the M2P2 drive is designed to shield the passengers of a space ship from radiation. Such an drive would give potential settlers much easier access to places such as the inner moons of Jupiter (Io and European in particular).

The idea seems to be catching on as scientists are about to test a new "deflector shield" which creates an artificial magnetic field to deflect harmful radiation.

Now scientists at the Rutherford Appleton Laboratory in Oxfordshire plan to mimic nature. They will build a miniature magnetosphere in a laboratory to see if a deflector shield can be used to protect humans living on space craft and in bases on the Moon or Mars.

In order to work, an artificial mini-magnetosphere on a space craft will need to utilise many cutting edge technologies, such as superconductors and the magnetic confinement techniques used in nuclear fusion.

Thus science is following science fiction once again. The writers of Star Trek realised that any space craft containing humans would need protection from the hazardous effects of cosmic radiation. They envisioned a 'deflector shield" spreading out from the Starship Enterprise that the radiation would bounce off. These experiments will help to establish whether this idea could one day become a practical reality.

Another option is the transhumanist one, which is to modify the human body itself to withstand radiation.

Friday, April 13, 2007

Rebel with a Cause: The Optimistic Scientist

The TCSDaily recently conducted an interview with Freeman Dyson. Here are some of the highlights of the interview:

Benny Peiser: In your book "Infinite in all Directions" (1988) you discuss eschatological questions surrounding the theoretical issue of the end of the universe. As one of a very small number of optimistic cosmologists, you have developed a scientific theory of infinity. You write: "I have found a universe growing without limit in richness and complexity, a universe of life surviving forever and making itself known to its neighbors across unimaginable gulfs of space and time." This hopeful cosmology contrasts sharply with the apocalyptic Zeitgeist. What would you say are the most important intellectual principles and ideas that have sustained your optimism?

Freeman Dyson: My optimism about the long-term survival of life comes mainly from imagining what will happen when life escapes from this planet and becomes adapted to living in vacuum. There is then no real barrier to stop life from spreading through the universe. Hopping from one world to another will be about as easy as hopping from one island in the Pacific to another. And then life will diversify to fill the infinite variety of ecological niches in the universe, as it has done already on this planet.

If you want an intellectual principle to give this picture a philosophical name, you can call it "The Principle of Maximum Diversity." The principle of maximum diversity says that life evolves to make the universe as interesting as possible. A rain-forest contains a huge number of diverse species because specialization is cost-effective, just as Adam Smith observed in human societies. But I am impressed more by the visible examples of diversity in rain-forests and coral-reefs and human cultures than by any abstract philosophical principles.

Benny Peiser: In the first chapter of your new book, "The Scientist as Rebel," you write that the common element of the scientific vision "is rebellion against the restrictions imposed by the locally prevailing culture," and that scientists "should be artists and rebels, obeying their own instincts rather than social demands or philosophical principles."

Contrary to this liberal if not libertarian concept of scientific open-mindedness, there has been growing pressure on scientists to toe the line and endorse what is nowadays called the 'scientific consensus' - on numerous contentious issues. Dissenting scientists frequently face ostracism and denunciation when they dare to go against the current. Has Western science become more authoritarian in recent years or have rebellious scientists always had to face similar condemnation and resentment? And how can young scientists develop intellectual independence and autonomy in a bureaucratic world of funding dependency?

Freeman Dyson: Certainly the growing rigidity of scientific organizations is a real and serious problem. I like to remind young scientists of examples in the recent past when people without paper qualifications made great contributions. Two of my favorites are: Milton Humason, who drove mules carrying material up the mountain trail to build the Mount Wilson Observatory, and then when the observatory was built got a job as a janitor, and ended up as a staff astronomer second-in-command to Hubble. Bernhardt Schmidt, the inventor of the Schmidt telescope which revolutionized optical astronomy, who worked independently as a lens-grinder and beat the big optical companies at their own game. I tell young people that the new technologies of computing, telecommunication, optical detection and microchemistry actually empower the amateur to do things that only professionals could do before.

Amateurs and small companies will have a growing role in the future of science. This will compensate for the increasing bureaucratization of the big organizations. Bright young people will start their own companies and do their own science.

Benny Peiser: One of your most influential lectures is re-published in your new book. I am talking about your Bernal Lecture which you delivered in London in 1972, one year after Desmond Bernal's death. As you point out, the lecture provided the foundation for much of your writing in later years. What strikes me about your remarkably optimistic lecture is its almost religious tone. It was delivered at a time, similar to the period after World War I, when a new age of techno-pessimism came to the fore, reinforced by Hiroshima and Vietnam.

It is in this atmosphere of entrenched techno-scepticism and environmental anxiety that you advanced biological, genetic and geo-engineering as industrial trappings of social progress and environmental protection. At the height of ecological anxiety, in the same year as the Club of Rome proclaimed the "Limits to Growth," you envisaged endless technological advancement, terrestrial progress and the greening of the galaxy, famously predicting that "we shall learn to grow trees on comets."

At one point towards the end of your lecture, you christen your speech a "sermon." Indeed, your entire lecture reads as if it was written for a tormented audience searching for a glimmer of hope. In his book "The Religion of Technology", David Noble claims that the whole history of technological innovation and advancement has been primarily a religious endeavour. Noble claims that even today your ideas of technological solutions to terrestrial problems constitute in essence a religious conviction. How much of your cosmological view of the world has indeed been shaped by Judeo-Christian traditions? And do you see that there is an inherent link between your religious and your philosophical optimism?

Freeman Dyson: It is true that the tradition of Judeo-Christian religion is strongly coupled with philosophical optimism. Hope is high on the list of virtues. God did not put us here on earth to moan and groan. As my mother used to say, "God helps those who help themselves."

I am generally optimistic because our human heritage seems to have equipped us very well for dealing with challenges, from ice-ages and cave-bears to diseases and over-population. The whole species did cooperate to eliminate small-pox, and the women of Mexico did reduce their average family size from seven to two and a half in fifty years. Science has helped us to understand challenges and also to defeat them.

I am especially optimistic just now because of a seminal discovery that was made recently by comparing genomes of different species. David Haussler and his colleagues at UC Santa Cruz discovered a small patch of DNA which they call HAR1, short for Human Accelerated Region 1. This patch appears to be strictly conserved in the genomes of mouse, rat, chicken and chimpanzee, which means that it must have been performing an essential function that was unchanged for about three hundred million years from the last common ancestor of birds and mammals until today.

But the same patch appears grossly modified with eighteen mutations in the human genome, which means that it must have changed its function in the last six million years from the common ancestor of chimps and humans to modern humans. Somehow, that little patch of DNA expresses an essential difference between humans and other mammals. We know two other significant facts about HAR1. First, it does not code for a protein but codes for RNA. Second, the RNA for which it codes is active in the cortex of the human embryonic brain during the second trimester of pregnancy. It is likely that the rapid evolution of HAR1 has something to do with the rapid evolution of the human brain during the last six million years.

I am optimistic because I see the discovery of HAR1 as a seminal event in the history of science, marking the beginning of a new understanding of human evolution and human nature. I see it as a big step toward the fulfilment of the dream described in 1929 by Desmond Bernal, one of the pioneers of molecular biology, in his little book, "The World, the Flesh and the Devil: An Enquiry into the Future of the Three Enemies of the Rational Soul". Bernal saw science as our best tool for defeating the three enemies. The World means floods and famines and climate changes. The Flesh means diseases and senile infirmities. The Devil means the dark irrational passions that lead otherwise rational beings into strife and destruction. I am optimistic because I see HAR1 as a new tool leading us toward a deep understanding of human nature and toward the ultimate defeat of our last enemy.

Open Source Hardware

Do you have your fabber yet? I don't have mine just yet, but hopefully soon.

If so, then you can seel the products you make with it at an "open-source hardware marketplace" at MFGx. SpendMatters referred to the website as the MySpace for the Manufacturing Set.
Mitch Free seems like an unlikely person to be part of this whole social / community web-based 2.0 -- some might say 3.0 -- thing. After all, the manufacturing world does not exactly lend itself to online social networking, at least not yet. But Mitch is not one to listen to convention. His latest experiment is a free community site called MFGx which essentially is a custom-built online social networking community for manufacturers, large and small. It's quite cool, and already has some great threads and traffic on it.

One concept that Mitch introduced earlier this week in a discussion thread is fascinating. Mitch writes: "Should certain product manufacturers publish their designs for anyone to download and move towards an open source (hardware not software) model? I think so. Why, because it would leverage the masses to proliferate their low margin hardware platform and allow them to sell the high margin consumables or data content. Take Tivo for example, they will rebate your entire purchase price these days when you purchase a subscription to the Tivo service because they want to sell high margin data subscriptions ... So what if they just made their hardware design open source and allowed anyone to produce a Tivo platform device? It would allow greater proliferation of the platform and get them out of a 'lost leader' business, thus allowing them to sell more high margin subscriptions."

The concept of Open Source manufacturing is quite cool and forward looking. But many of the subjects on MFGx are much more pragmatic (such as containing volatile commodity prices and China sourcing). So even if you know nothing about this whole social networking phenomenon, get yourself over to MFGx and see how online communities can work in a business setting -- and why they're not just for kids on MySpace anymore!
This sort of social network will be essential for the future, especially if you are planning to settle the oceans or to settle space. Compared to those living on Earth, the first space settlers would have to made do with a shortage of many items that they want or need. A simple iPod could be very difficult to ship to a space settlement on Luna. But if you have the designs for an MP3/OGG music player, a fabber, and a store of mined material from Luna, then you could easily design your own.

Friday, April 06, 2007

More on DIY PCBs

I posted an entry on do-it-yourself printed circuit boards earlier today. The MAKE blog has just posted two new entries on the same topic.

Will Fabbers Change The World?

It seems inevitable that fabbers will cause an unprecedented revolution that will profoundly change the world. But of course, we should be cautious about making future predictions, given that nuclear fusion, which was 40 years away in 1960, is still 40 years away today. And just recently, I came across an article about the 21 Biggest Technology Flops. As home-based fabbers have only been available in the past 6 months, there are plenty of questions about this technology. One question is whether or not I will be able to fab with heavy metals. Another one is whether or not fabbers will be subject to Moore's Law.

A new Guardian article provides some optimism on the future of home-based fabrication.
Pushing the boundaries beyond simple shapes, Lipson has made a working battery, an electrically-activated polymer muscle and a touch sensor by printing different layers of material. His goal is to make a small robot with limbs, actuators, control circuitry and batteries.

The possibilities are limited by what you can extrude from interchangeable cartridges - quick-hardening plastic is the favourite, but the machine can also handle and layer plaster, Play-Doh, silicone, wax and metals or mixtures with a low melting point such as solder (made of tin and lead). Some users have found chocolate, cheese and cake icing (which may also be used as a temporary soluble support material for hollow structures) rewarding too.

This is plenty of progress in the space of 6 months on the first home-based fabber. Once RepRap demonstrates self-replication using fabbers, prepare for all hell to break loose.

"I think that within 10 years private individuals will be able to make for themselves virtually any manufactured product that is today sold by industry. I sometimes wonder if politicians realise that the entire basis of the human economy is about to undergo the biggest change since the invention of money." -- Adrian Bowyer
What do you want to build with your home-based fabber?

Make Your Own Circuit Board

In the past, I've blogged a lot about fabbers. As such it is no surprise that fabbers are a very exciting technology to me. DIY printed circuit boards (PCBs) are also very exciting. If you want high-powered fabrication, look no further than eMachineShop. If you want to design a good PCB, then Pad2Pad, the sister company of eMachineShop, is a good place to start.
Pad2Pad is the remarkable new way to get the custom printed circuit boards you need. Download our free PCB software, design your board, and click to order - it's that easy! Your boards will be manufactured and delivered at low cost.

Pad2Pad simplifies the whole process of getting circuit boards by up to 80% and open doors to new products and projects. Intelligent design software gives instant exact pricing, expert feedback, and unrivaled convenience. Pad2Pad provides you with a complete PCB solution to quickly move your electronic circuits to the market.

You can also create (and not just design) your own PCB. This MAKE Magazine blog entry shows you just how to create one in your own garage.