March 05, 2014
For a better century
Centenarians epitomise our fears about growing old - Avi and me discuss why centenarians might not be role models for life extension. They have been lucky and are pretty vital for their age, but unfortunately they are still very frail. My 103 year old grandmother can certainly not fence like when she was in the olympics!
This is what we need to fix in ageing. Either slow the fundamental process down (hard!) or reduce the accumulation of damage (tricky, but less hard). Just treating symptoms may make life better, but not fundamentally better.
March 04, 2014
Cold equations and trolleys
The cold equations of ethics - a little discussion of Doctorow's criticism of some sf as teaching bad morality due to contrived contexts as applied to philosophy thought experiments.
Whitepaper about systemic risk of risk modelling
Here is our whitepaper about the systemic risk of modelling, the first official output of the FHI-Amlin project.
The first section is about what systemic risk is, and how people use the term - in finance, in ecology, in technology. The second section is about the "autopilot problem", how models lull us into false security. And the final section is about asymmetric error checking, how we accidentally introduce our biases into our models.
Here is a cheerful little film about the collaboration. After all, this is just the start.
March 03, 2014
Why I hate the rocket equation
Just after giving it, I noticed that the Tsiolkovsky rocket equation might be the favourite physics equation of Randall Munroe of XKCD - we have very divergent tastes.
I dislike the equation because it places a huge and cumbersome limit on space travel. I don't mind the lightspeed limit or the other relativistic annoyances, but the rocket equation really makes travel hard. So it is not an aesthetic problem, nor that it isn't neat as a physics result, but simply because it stops me from doing what I want. At least until I get a orbital elevator, good mass driver, beam propulsion and/or magsail.
February 24, 2014
More donuts, with warm filling
Who can resist a donut-world? I got quite a lot of interest in my torus-Earth post.
Here is a neat article in forskning.no: En ring med jord omkring (in Norwegian). It has some nice illustrations, including a sunset video (which just runs a few times faster than realtime - those sunsets are quick).
Edit: Also, there is a very nice article by Martijn van Calmthout in de Volkskrant 22 Feb 2014, "Welkom op planeet Donut" about these worlds. I like the term "astrofantasie" for what I did.
One thing I have been thinking about is the heat distribution inside the planet. Since it is symmetric under rotation around its rotation axis there will not be any longitudinal heat flow (to a first approximation), so it can be viewed as an elliptical cylinder. If we assume a constant heat production due to radioactive decay and constant thermal diffusion, the temperature will be described by Poisson's equation. So if we assume zero temperature at the surface, we get the following rough internal distribution in Donut:
It is at first appearance not too strange, a hot core surrounded by cooler layers up to the crust. However, when we look at the contour lines we see something interesting: the thermal gradient is higher at the poles than at the equators. We should hence expect volcanism and other geothermal activity to be higher near the poles. Also, the crust will be thinner than near the equators.
This makes plate tectonics even more tricky. A thick plate near the rimward equator moving hubward will start to melt on the underside (the poles might be seen as two enormous, ring-shaped hotspots), plus the compressive effects of having to fit into a smaller east-west space. Crust generated near the poles will be thin and presumably also change when it moves rimward or hubward. Subduction of too thick equator crust near the poles will likely be more vigorous (because of extra gravity and its excessive thickness), while polar crust might be less likely to subduct and could hence fold... I think: I am not enough of a geologist to make a proper guess here.
February 18, 2014
Artificial and natural intelligence
My slides can be seen here - I jumped past most of the brain interface things due to time constraints.
February 16, 2014
The ethics of emergent organisational stupidity
Confirmation bias, embarassment and organisational ethics. Or: why the FBI thought a person without passport could travel across the Atlantic to do terrorism, and the DHS fought tooth and nail to hide a minor bureaucratic mishap.
Anybody believing in conspiracy theory should take into account that the conspiracy will be just as full of these kind of pathologies as real organisations. It will do crazy things to protect itself from imaginary threats, cover-up minor things with enormous effort, and occasionally convince itself that random people Know Too Much. Which then lead to further craziness.