So... when does life begin anyway?
So to answer your question we need to know when life begins. Given pro-choice vs anti-abortion debates this is not clear and resolved with any consensus. I'm giving 3 answers depending on when you decide life begins. Does it begin;
- at sperm and egg?
- at conception?
- at birth?
- at age 12 when telomeres start to shrink?
The answers for the last 2 are the same.
Fertility lab techs (next day), supermarket inventory managers (within a week), women trying to buy pregnancy tests (within a week).
In one extreme interpretation (ova and sperm are alive), all periods may stop (depending on how alive an ova in an ovary is considered), and all sperm are immature, so the first to notice will be Male fertility clinics, after every test returns failure for the same reason - underdeveloped, or missing, sperm.
Periods stop globally, and that's notable to each individual woman, but before that's correlated; inventory managers will notice that pads and tampons are no longer selling from supermarkets. These have a steady predictable rate of sale so it will be extremely suspicious when they're not moving.
Pregnancy tests will be sold out planet wide within a few days too.
Women who are 8.99 months pregnant, and retrenched maternity staff (within a week)
If life begins at conception, all embryos and fetuses will stop developing - because they're alive.
I'm greatly simplifying childbirth here, but if a baby is expected to be due in the next week, and it never finishes aging to the point that it's ready, I'd say it's very suspicious. Expectant mothers are going to held in suspense as their immortal fetus settles in for the long haul.
Birthing suites are expensive, there'll be scheduled c sections pre booked, and some will be induced chemically, but if they're still idle for a few days, or everyone is getting induced, that will raise some questions.
Or scientists working with surprisingly eternal shrews. (Within 6 weeks)
If due to magic the wave can differentiate between fetus and born, or you declare life begins at birth, then newborns will stop developing. This could take first time parents unfamiliar with what to expect a few months to realize, especially if behavior changes still occur from learning. (Repeat parents may get suspicious after a few weeks). I suspect parents taking infants a few months old to the doctor afraid their not gaining weight will be the first clue we have about it in humans.
If, as your recent comment implies, for the purpose of anti-aging ray life doesn't start until age 12, then adolescents will get stuck in early puberty. That sounds horrible, and may take a year to recognize or more, but there's a faster way if we go to non human mammals.
Your wave only affects mammals, and these mammals have a life span of about 6 months.
Any immortal affect is 100 times more noticeable on these than on humans. The scientists who are running tests on shrews and are waiting for some notable event in their development (puberty, death, litter, etc.) will be held in suspense until they start investigating.