How to flash led without arduino or 555 ic

How do you know you haven't ruptured the hermetic seal.
You have three vary intelligent engineers telling you that
you've done something wrong. You answer that with a statement
that it didn't seem to have done any harm.
One wonders why you come to this bulletin board for advice
and then as a show of foolishness, choose to ignore that
advice.
If you were working in my department, you would have received
your first warning.
Let us hope that you don't someday create a design that people's
lives might depend on.
Dwight