[Just shooting from the hip here, for fun.]
I think we should send humans to Mars, but I don’t really think it’s possible to justify it as an instrumental means of achieving other more concrete goals. (I just take it as an intrinsic goal.) But here is Robert Zubrin making the best instrumental case I’ve heard.
My biggest criticism is that not finding evidence of life on Mars does not imply life is extraordinarily rare, because there are other options besides easy-starting life (with the great filter somewhere after) and extremely-hard-starting life. If you think it’s possible that there’s a filter strong enough to prevent single-cell life from developing interstellar travela , then it’s still very possible that single-cell life is hard-enough to start that we wouldn’t expect to find it on Mars, yet is still relatively common in the galaxy. Indeed, it’s easy (assuming a strong late filter) to imagine that life is easy to start with liquid water plus X, where X is a relative common planetary condition that just has never existed on Mars.
That said, Zubrin’s argument is better than I was expecting, and I agree that getting a quasi-definitive answer on whether there was ever life on Mars — even with my strong prior against it — is probably the best new evidence we are likely to collect for a very long time with regard to the prevalence of life in the universe. That should be taken seriously.
Bonus: Here’s Zubrin arguing persuasively against the crippling over emphasis of safety at NASA, with neat numbers extracted from discussion around the decision to send astronauts to repair Hubble.
These sorts of apparent large irrationalities/inconsistencies in how we allocate money to reduce risk to human lives make me wonder if we’re missing an important factor in how these decisions get made (besides “the world is mad”). For instance, one might defend the very conservative policy of the FDA for approving new drugs (which almost certainly could be liberalized to save lives on the net) by appealing to issues of trust. For instance, a standing policy that approves of killing a homeless man to donate his organs to save 6 lives, besides being intrinsically awful, could have large long-term consequences for how much everyone feels (rationally!) that they need to protect themselves from greater-good killings. Likewise, it might be that having a FDA that is conservative allows for a greater degree of trust and associated benefits even though it looks in the short-term to have bad implications for net lives lost.b
That said, if anyone should be allowed to take risks, its the very smart and well-informed astronauts who stand to do grand things (and reap the status benefits). It’s hard to find a sensible way to defend NASA’s conservatism.
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- I’m skeptical. When it comes to estimating extremely unlikely events, with multiple independent unlikely steps that all need to happen quickly, the development of the first replicator seems to require vastly more steps than relatively simple things like sexual reproduction. The only thing that makes me uncertain is the possibility that there are extremely simple replicators that resemble nothing like minimal cells, and there is a relatively natural progression to minimal cells that simply isn’t large enough to leave fossils. I would love to update on this if you know something I’m not thinking of.↵
- This doesn’t necessarily mean that the FDA decisions are getting made thoughtfully by people who have carefully considered and been persuaded by such arguments. It might be that we settle on stability increasing mechanisms and norms without being conscious of why they work.↵