A lab experiment with artificial intelligence just crossed a line nobody had crossed before, and it comes with both real promise and real risk.

Recently, scientists announced something that sounds like it belongs in a sci-fi movie. They used artificial intelligence to design new viruses that had never existed before in nature, then built them in a lab, and watched them work. Truly inventive and incredible technology, but had they opened Pandora’s box? The viruses were real. They infected bacteria, multiplied, and sometimes grew faster than the natural virus they were based on.

This isn’t a story about a virus escaping a lab by accident. This is a story about a virus being invented on purpose, by a computer program, following instructions written by scientists. It is a big moment for medicine and science. It is also a moment that raises hard questions about safety, and those questions do not have straightforward answers yet.

Here’s what happened, what it could mean for your health, what could go wrong, and what is being done to keep it safe. Of course, in an age when computer algorithms seem to recreate themselves and run without human interference, we have to wonder how safe our safeguards are.

What the scientists actually did