Archive for November, 2021

Nov 02 2021

Making Biofuel on Mars

Published by under Astronomy

NASA and China are both planning on sending people to Mars sometime in the 2030s. This is an ambitious goal and I would be pleasantly surprised if either hit that target. Sometime in the 2040s, and only if plans go fairly well, may be more realistic. There are many challenges to such a mission. NASA’s plan is to work out most of the technology by going back to the Moon first, setting up a semi-permanent presence there, and essentially using it as a stepping stone to Mars.

But Mars presents some of its own challenges, primarily, of course, the distance. Just getting to Mars and back is pushing the limits of how long astronauts can safely stay in space due to radiation exposure. There are no practical plans for shielding from cosmic rays (solar radiation is more manageable) and so NASA’s plan is just to keep missions within the three year safety window.

Another challenge Mars does not share with missions to the Moon is sourcing the fuel for a return trip. If you recall the rocket equation, the more fuel you need to get to your destination, the more fuel you need to carry that fuel, and so on. So small changes in weight and the needed change in velocity can lead to huge increases in fuel needs. We can get to the Moon with enough fuel to get back. We cannot get to Mars with enough fuel to get back. A mission to Mars will need to refuel on Mars in order to make the return trip. Robotic missions to Mars are one-way trips, so this has not been an issue before, but we would like to get our astronauts back home.

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Nov 01 2021

The Sri Lanka Organic Experiment

Published by under General Science

Cautionary tales are extremely useful, as long as we take the right lessons away from them. As the saying goes, the best way to learn is from mistakes, but even better is to learn from someone else’s mistake without having to commit it yourself (and suffer the consequences). Sri Lanka has now made itself into a cautionary tale, and I would like to amplify any learning that can come from it. The primary conceptual lesson here is that – when ideology trumps science, the outcome is likely to be very bad.

There is also a specific lesson here. Organic farming may sound good in principle (if you just listen to the ideological marketing), but in practice it is a disaster. Sri Lanka has decided to do what other countries have done before, namely impose from above a commandment on how to run an industry based entirely on the philosophical beliefs of the leader. Perhaps the most famous example of this is Lysenkoism in the former Soviet Union, where the archaic ideas of geneticist Trofim Lysenko were given official support and decimated Soviet agriculture, costing millions of lives.

President Gotabaya Rajapaksa of Sri Lanka has done something similar – banning agrichemicals in Sri Lanka and forcing all farmers to farm organically. The result was absolutely predictable, a crash in agricultural output. While Sri Lanka is a net food importer, they still are dependent on local rice and other staple crop productions. Their exports are also mainly agricultural, such as tea, rubber, and many spices. Some reporting has focused on the timing of the change, during a fragile recovery from a pandemic. Also some have pointed out that going suddenly full organic is a problem because most farmers don’t know how to do it, and there was no adjustment period.

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