Founder, The Roots of Progress (rootsofprogress.org). Part-time tech consultant, Our World in Data. Former software engineering manager and tech startup founder.
Synthetic cells aren't inherently dangerous if they're not mirror cells (and aren't dangerous pathogens of course).
Failure to detect other life in the universe is only really evidence against advanced intelligent civilizations, I think. The universe could easily be absolutely teeming with bacterial life.
Re “take steps to stop it”, I was replying to @Purplehermann
The asymmetric advantage of bacteria is that they can invade your body but not vice versa.
I think until recently, most scientists assumed that mirror bacteria would (a) not be able to replicate well in an environment without many matching-chirality nutrients, and/or (b) would be caught by the immune system. It's only recently that a group of scientists got more concerned and did a more in-depth investigation of the question.
Yes, antibodies could adapt to mirror pathogens. The concern is that the system which generates antibodies wouldn't be strongly triggered. The Science article says: “For example, experiments show that mirror proteins resist cleavage into peptides for antigen presentation and do not reliably trigger important adaptive immune responses such as the production of antibodies (11, 12).”
Given that mirror life hasn't arisen independently on Earth in ~4B years, I don't think we need to take any steps to stop it from doing so in the future. Either abiogenesis is extremely rare, or when new life does arise naturally, it is so weak that it is outcompeted by more evolved life.
I agree that this is a risk from any extraterrestrial life we might encounter.
I appreciate that! Would like to get back to them at some point…
I don't intend to write something anodyne, and don't think I am doing so. Let me know what you think once I'm at least a few chapters in.
Thanks, added a more prominent link
Yes, they would not be made from mirror components!