Project Hail Mary

Out of interest, has anyone here read Andy Weir’s new hard science fiction novel, Project Hail Mary? I picked it up yesterday and read it, and there are quite bit of biological concepts that may be prove interesting for discussion, such as evolutionary concepts and one particular organism’s capabilities. As Weir aims to write plausible science fiction, I wonder how much of it could be considered possible in our universe.

Not familiar with this author, sorry.

Maybe you can provide some details? Like what sort of Evolutionary Concepts?

Weir also wrote the Martian.

The plot revolves around an extraterrestrial single-cellos bacteria known as Astrophage. It is causing a solar dimming effect in the Sun because it feeds off off solar energy. It’s composition is of water, but it uses an internal heating and cooling mechanism that keeps the organism at a temperature of 91 degrees. Once it is done feeding off of one star, it detects the nearest thermal signature from another star and directly releases the spent energy (they somehow capture and store neutrinos, which can make antimatter), and uses it as a form of propulsion to travel to the next star system, and the cycle repeats. Also, it reproduces asexually using CO2.

Here are the discussion points:

1. Could such an organism be biologically possible (I can provide more details to specifics as needed)?
2. Ignoring the problem of abiogenesis, would billions of years be sufficient for the evolution of such a complex bacterium? 

hm.

Interesting questions.

Obviously bacteria needs something else besides sunlight, to survive. Some sort of nutrients.

And generally needs water as well.

Perhaps @tbwp10 might give some input on the matter (as he is the expert here).

I know Co2 is used for reproduction. As for the water, if the organism maintains a constant temperature, there is no need for water (as water is only used with the cell walls with this cell I think)? Plus, if it purely absorb energy, all you need to do is put some in a usable format for the cell’s functions and the rest for propulsion.

Okay.

So for any organism to reproduce, it needs more matter. 

For example, for a 50# dog to give birth to three 4# puppies, that extra 12#'s needs to come from somewhere. Not just thin air.

By the same measure, for a microbe to become 2 microbes, then it doubles its mass. So that extra mass needs to come from someplace.

I'm not familiar with the specifics of the fictional 'Astrophage', but just as a general statement on survivability it would seem that bacteria would have the best chance of success given their unparalleled metabolic diversity and range of habitats they can survive in from acidic boiling temperatures to the harsh vacuum of space.

The book 'Rare Earth: why complex life is uncommon in the universe' is an older book that is still relevant that explores this idea.