So, what did I think of Project Hail Mary 🎥, after my scientific concerns?

I enjoyed it immensely. I had a great time. I was in a electrically-reclinable chair that vibrated during the loud parts (though that’s about the Leicester Square Odeon, not the film, of course).

I have things to say about the title, the expression used in it, but I’ll keep that for a separate post. The main flaws in the film — which, to be fair, is a blockbuster big-screen bonanza, and beautifully made — are scientific.

Starting with physics. It’s a long time since I knew enough special relativity to work out the time-dilation involved in a six light-year trip, and to be fair we’re not told how long it lasted for the induced-coma-experiencing Grace; but we do know it would be a lot longer on Earth, assuming the ship actually reached a significant percentage of lightspeed.

That point is perhaps implied at the end, but it should have been mentioned in the film — not least since they specifically say the Eridans don’t know about relativity.

Turning to the biology. Look, it’s just annoying that it’s so stupid, when there’s at least a couple of ways they could have told the same story, without requiring biological life to exist in an environment where, not only is it impossible for atoms to join together into molecules, even atoms don’t stay together. Stars are plasma, which means a big soup where the energy is so high electrons are stripped off the nuclei of atoms. You don’t get biology. You don’t even get chemistry.

Just make the ‘astrophages’ exist at some distance from the star, occluding it. Or have them be dark matter, instead of algae. It doesn’t matter. The story would be just as good, just as compelling, without being annoying.

Because it’s not about the science. It’s a love story. Love between human and — let’s not say ‘alien’, because everyone is alien out there. Between Earthling and Eridan.

Or friendship, if you don’t think it reaches love. I don’t mind.

It’s also about the limits of humanity and what we might be able to do even if we refuse, if we’re forced into an impossible situation. And language and communication and all sorts of stuff.

It’s really good. You should see it.