Alternative enforcement mechanism (which would rule out Musk as an investor) would be to hardwire the editing so that any breeding results with "wild type" humans would be both female and profoundly haemophiliac. (Or that all male offspring have some lethal failure of oxygen metabolism. Whether that would be acceptable to Musk ... who cares?)

If the universe is said to be expanding, that means that the universe has a boundary.

Go and revise your non-Euclidian geometry. You clearly failed that exam.

It is possible for the universe to be finite in 3-dimensional extent, and unbounded.

But the demand for petrochemicals as chemical feedstocks will continue.

We might not burn the stuff, but we'll continue to want to put it into chemical plants because it's cheaper than making long hydrocarbon chains ourselves.

Until someone manages to commercialise algae-catalysed CO2 -> long chains reactions. Which without the fuel market, is not so attractive an investment.

Have you stopped believing in the Expanding Earth?

When did you accept the reality of tectonic subduction? Before or after you became a FLERFer? And have you stopped hitting your wife with your dog yet?

I don't think there's anything that absolutely precludes an "observer".

But there is something that absolutely precludes any observer from communicating to anywhere outside the black hole's event horizon. That is what "event horizon" means : events the other side of it cannot be observed.

Which is why there are occasional fusses over rotating (+/- small, primordial) black holes - some arguments on general relativistic frame dragging get used to "expose" the black hole's central singularity without a masking event horizon. And (TTBOMK) every time someone has come up with such an argument, after a few months someone else has shot a hole in it. Successfully. So far.

Space-time.

Dark Matter is [...] the necessary matter throughout the galaxy for it to orbit the way it does.

It's not just throughout *this* galaxy, but throughout almost every galaxy for which a rotation speed (profile) can be measured, and also individual galaxies orbiting in galactic clusters. It's not just the one case, but many observations.

It is a placeholder for something hypothesised, but not yet discovered.

... but for which substantial evidence has been claimed.

The challenge of this paper is that, in effect, it is saying "that evidence (interpreted as support for Dark Energy) is actually non-existent because the observations are a consequence of mis-reading progenitor-star ages, which changes the modelled SN brightnesses.

A hypothesis for which no test is feasible ... there are discussions about that sort of concept in Popper et al over the decades. But a workable description of such ideas is "useless". Personally, I think, with similar support, that it's invisible pink lizard-aliens moving the interferometer legs.

In fact, I believe that any universal rate of expansion [...] seems to require a universal frame of reference.

That step needs expansion or considerable clarification. Your reticence ("seems to") suggests that you agree.

If the expansion rate is a function of elapsed time since [Big Bang / end-of inflation / breaking of the Higgs symmetry/ whatever], then each local area would react similarly (without requiring long-distance communication - a not-very-hidden "hidden variable") without requiring either a universal reference frame, or FTL communication.

Would the rate of change of time also vary with [whatever] is (allegedly) causing changes in the expansion rate? Unclear - to me.

Wheeler, isn't it?