> I’m sorry could you explain that more please? There is no universal “now”?

The technical term is "relativity of simultaneity"

Consider two events A and B that happen at "about" the same time, separated by a great distance. They are close enough to simultaneous that light from A cannot get to the location of B until after B has happened, and light from B arrives at A after A has happened.

Let's assume that A occurs at 1230 GMT on 11-Mar-2023, and is a political speech given worldwide coverage made in Scotland. And let's assume that B occurs at 1500 GMT on 11-Mar-2023 by Earth reckoning, and is a critical failure of the Voyager-1 probe which is currently 21 light hours away from Earth.

Observers of both events can calculate the time of each, and deduce which was 'first'.

However, these observers will not necessarily agree with each other.

An observer on Earth who notes both events will conclude, after light arrives 21 hours after Voyager's incident, that the speech was made 2½ hours before the probe failed.

But an alien probe moving through the solar system at 99.98% of lightspeed which saw both events might well conclude that the speech occurred 7 hours after the probe failed.

Both would be correct.

It's a completely counterintuitive mess, but the math checks out on it.

A small percentage of people who are tested have their sample sequenced as well.

If a lab performs 250000 PCR tests a week and gets 20000 positives, it will likely sequence 100 of the positives.

This then shows trends across the population in which variants are dominating.