Are Prejudices Against Dark Energy Unfounded?

I want to examine several points by a recent paper Why all these prejudices against a constant? It isn't that this is the best paper on dark energy in the world, just that it highlights several issues relating to dark energy.

This first post is just to whet your appetite.  I start off quoting the paper:

“Arguably the greatest mystery of humanity today is the prospect that 75% of the universe is made up of a substance known as ‘dark energy’ about which we have almost no knowledge at all.”

This is the opening sentence of a (good) popularization article on dark energy. It is just an example, out of very many that can be found in the popular-science and in the technical literature, of how the ‘dark-energy’ issue is perceived by many scientists, and presented to the large public.

You know it is true, people make a big deal about how "mysterious" dark energy is.

We argue here that there is something scientifically very wrong in this presentation. There is no “great mystery”... This is a phenomenon which is clearly predicted and simply described by well-understood current physical theory. It is well understood in the context of general relativity, which naturally includes a cosmological constant. We argue below that the common theoretical objections against this interpretation of the acceleration are either weak, or ill-founded.

I agree with this assessment. As we will discuss in a future post, if you accept GR, it should be straight forward to accept a cosmological constant.  And a small positive cosmological constant would produce exactly something exactly akin to to the dark energy we observe!  So, I also think portraying dark energy as something incredibly bizarre is to be over the top.

It is misleading to talk about “a mystery” (not to mention “the greatest mystery of humanity”), for a phenomenon that has a current simple and well-understood explanation within current physical theories.

It is especially wrong to talk about a mysterious “substance” to denote dark energy. The expression “substance” is inappropriate and misleading. It is like saying that the centrifugal force that pushes out from a merry-go-round is the “effect of a mysterious substance”.

Again, interesting point.

So we will see.  I will post various points the author raises and let you decide.  Personally, I agree people put far too much mystery into dark energy.  In some sense, it is a prediction of GR. (As I will explain this claim in my next post).

We all accept GR right?  So, why do we treat dark energy as such a mysterious thing?

Posts in the series:
1. Dark Energy As A Prediction Of General Relativity.
2. Coincidence Problems and Dark Energy.
3. The 120 Order Of Magnitude Problem.