2007 October « Michael Graham Richard

Archive for October, 2007

Overcoming Bias: Torture or Dust Specks?

October 30, 2007

Eliezer Yudkowsky, a research fellow over at the Singularity Institute for Artificial Intelligence (see my previous post warning them about security issues), asks a very interesting question over at Overcoming Bias:

What’s the least bad, bad thing that can happen? Well, suppose a dust speck floated into your eye and irritated it just a little, for a fraction of a second, barely enough to make you notice before you blink and wipe away the dust speck. [...]

3^^^3 is an exponential tower of 3s which is 7,625,597,484,987 layers tall. You start with 1; raise 3 to the power of 1 to get 3; raise 3 to the power of 3 to get 27; raise 3 to the power of 27 to get 7625597484987; raise 3 to the power of 7625597484987 to get a number much larger than the number of atoms in the universe, but which could still be written down in base 10, on 100 square kilometers of paper; then raise 3 to that power; and continue until you’ve exponentiated 7625597484987 times. That’s 3^^^3. It’s the smallest simple inconceivably huge number I know.

Now here’s the moral dilemma. If neither event is going to happen to you personally, but you still had to choose one or the other:

Would you prefer that one person be horribly tortured for fifty years without hope or rest, or that 3^^^3 people get dust specks in their eyes?

I think the answer is obvious. How about you?

Below I’m going to reproduce what I wrote in the comments, but I encourage you to head over and read all the comments.

(more…)

Posted in Thoughts | 2 Comments »

Deflecting Earth-Bound Asteroids

October 28, 2007

Asteroid Impact
Image: Don Davis/NASA

Last April, I wrote a fairly detailed post about asteroids and near-Earth objects. In it, I mention the gravity deflection (a.k.a. “gravity tractor”) method which consists of stationing a spacecraft a short distance from the asteroid and using gravitational attraction to pull the asteroid off course.

New Scientist reports on a related study led by Massimiliano Vasile of the University of Glasgow in Scotland:

[researchers] compared nine of the many methods proposed to ward off such objects, including blasting them with nuclear explosions.

The team assessed the methods according to three performance criteria: the amount of change each method would make to the asteroid’s orbit, the amount of warning time needed and the mass of the spacecraft needed for the mission.

The method that came out on top was a swarm of mirror-carrying spacecraft. The spacecraft would be launched from Earth to hover near the asteroid and concentrate sunlight onto a point on the asteroid’s surface.

Asteroid being deflected by mirror-ships
Image: M Vasile et al, University of Glasgow

The concentrated light would be enough to heat up the surface of the asteroid to more than 2,100° Celcius, vaporising it into gases, creating enough thrust to change the course of the asteroid.

The scientists found that 10 of these spacecraft, each bearing a 20-metre-wide inflatable mirror, could deflect a 150-metre asteroid in about six months. With 100 spacecraft, it would take just a few days, once the spacecraft are in position.

To deflect a 20-kilometre asteroid, about the size of the one that wiped out the dinosaurs, it would take the combined work of 5000 mirror spacecraft focusing sunlight on the asteroid for three or more years.

5,000 ships is a lot, but 20-kilometer asteroids are also very rare. Chances are we’ll have to deal with much smaller ones a lot sooner.

What are the problems with some of the other methods according to the study? For the same mass launched into space, the gravity tractor takes more time. The nuclear explosion is about as effective as the mirrors, but there’s a danger that the asteroid could break up in many smaller pieces, making it harder to deal and unpredictable, even potentially more dangerous than it was.

Another option, especially for smaller rocks, is to simply ram a spacecraft into them (and then, as needed, use a gravity tractor or mirror(s) to fine tune the trajectory).

The most important thing is to start building up both our deflection tools and our detection tools. We don’t want to be caught with our pants down.

Sources:

In the Mail: Lehninger Principles of Biochemistry

October 25, 2007

Lehinger Cover

Lehninger Contents

Lehinger random page

Teaching Myself Molecular Biology

October 22, 2007

Molecular Biology Textbooks

I have decided to teach myself molecular biology in my free time. Not that I have lots of free time, but I figure I might as well use it to learn something really interesting.

I have ordered Lehninger Principles of Biochemistry (fourth edition, from 2004) and am planning to also get the fifth edition of Molecular Biology of the Cell by Alberts & al. when it comes out on December 31st, 2007 (the picture above is of the fourth edition).

Reviews for these two textbooks are great, and I’ve got some personal recommendations from friends who have studied biology.

These should give me a solid start. I’ll try to document my progress on this blog; hopefully this will inspire others to take that crucial first step and teach themselves subjects that can be intimidating at first. I won’t pretend I’m not intimidated… But this should be fun.

Updates:

Posted in Books, Science & Technology | 3 Comments »

Cemetery Excursions: Hunting Bacteria to Help LysoSENS

October 20, 2007

Today, I did something a bit special. I went out with a pointy little gardening shovel and some plastic bags to get soil samples for the LysoSENS research project.

LysoSENS is the latest Methuselah Foundation initiative aimed at tackling age-related storage diseases. These diseases, informally also called “junk” diseases, are caused by the accumulation of some pathogenic material in the body. With advancing age our bodies cannot degrade or remove this junk. Examples of candidate age-related storage diseases include

* Heart disease and stroke – cholesterol and oxidized cholesterol in the artery wall
* Alzheimer’s disease – Beta-amyloid plaques and neurofibrillary tangles in the brain
* Age-related macular degeneration – Lipofuscin of the retinal pigment epithelium
* Diabetes – Extracellular matrix protein crosslinks, due to exposure of the tissue to high sugar levels

In every case, it is thought that the selective removal of the respective substances would be extremely beneficial, although obviously nobody has directly tested this. LysoSENS is an attempt to do just that, in the worst case paving the ground for rethinking what age-related storage diseases are all about, and in the best case providing a cure for them.

So how is LysoSENS supposed to work? In brief, we are looking for enzymes capable of selectively degrading the respective target material in the environment. This idea is heavily inspired by the field of environmental bioremediation (using microbes to degrade environmental contaminants). We are working in the lab of Bruce Rittmann, a well-known environmental engineer, as he has the expertise to find microbes that degrade weird stuff. We hope that we can isolate enzymes from these microbes and deliver them in a manner similar to current FDA-approved treatments for heritable lysosome storage diseases, where the missing enzyme is tagged with certain sugars for targeting and then injected into the bloodstrem. You can learn more about the LysoSENS strategy from its originator and Methuselah Foundation chairperson Aubrey de Grey here (quick and easy) or here (detailed and technical).

Since they are looking for bacteria able to eat “junk” that our bodies are not able to degrade, a good place to look is cemeteries because we know that decomposing bodies don’t leave behind that “junk”; meaning that some organisms have filled that niche and are having lunch on it.

So I went out to three different cemeteries around town and collected soil samples. I took some notes on where and when I picked them up, packaged the whole thing (including a mini-Toblerone chocolate bar for the researchers) and mailed it to the Biodesign Institute in Arizona. It’s an easy way to help, and the more samples they get from varied and exotic ecosystems around the world, the more chances they have of finding the right bacteria and enzymes to cure these horrible age-related diseases mentioned above.

I encourage you to do the same, especially if you live somewhere interesting from a biodiversity point of view (near hot springs, near historical mass-graves, in a tropical jungle, etc). But even if you live somewhere “boring”, give it a shot. You never know, maybe your sample will contain the holy grail of junk-eating bacteria.

All the information you need, including instructions on how to collect the samples and where to mail them, is on this webpage: LysoSENS.

Update: LysoSENS Update.

Posted in Health, Science & Technology | 3 Comments »