[ETL]

At a cosmology lecture some years ago I asked the speaker at the end of the talk if dark energy and dark matter might be “equivalent” as ordinary energy and matter are according to Einstein’s E=mc^2. She answered, without really giving it much thought, no. Then went on to the next person asking a question. I suspect she hadn’t any idea one way or the other.

[sparklite2]

I went to an astronomy lecture and asked at the end why the smaller galaxy of the Whirlpool cluster was red shifted so far back from the big galaxy that they could not possibly have an effect on each other, yet there looks to be a matter stream between them.

The astronomer got angry and told me they weren't going to throw away theories based on some isolated phenomenon.

In later years, radio astronomy verified a bridge between the galaxies.  I don't know how they explained the difference in red shift unless the previous measurements were incorrect.

[cuban leaf]

It’s like fish discovering water.

We’re swimming in it, yet we think space is empty. It isn’t. It’s stuffed. We’re just not sensitive to what it is stuffed with except for that tiny part we are sensitive to. We call it light. If you can see a star, it means that every micron between the star and your eye contains the light it admits. It is both energy and matter. And space is stuffed with it.

BTW, not to make too small a point of it, God is light.