Necessity of Dark Energy Questioned

ttnuagmada points us to an article about scientist David Wiltshire's suggestion that theorized dark energy is not needed to describe the expansion of the universe. His work challenges assumptions made about the distribution of matter in the universe. Early solutions to general relativity were based on a "smooth distribution" of matter. Wiltshire's approach focuses on a "lumpy" dispersal, which more accurately fits data from modern studies. We have discussed other theories about dark energy in the past. Quoting: "Through observational projects like the Sloan Digital Sky Survey and the 2 Degree Field survey, we now have a much better picture of the large-scale structure of the universe and we know that galaxies are not uniformly distributed. 'Rather, they are in clusters sprinkled thinly in filaments and "bubble walls" surrounding huge voids hundreds of millions of light-years across,' Wiltshire says.

Comments

Dark matter balloney

[flyingfsck]

If you cannot detect something at all with light or gravity effects, then it very likely isn't there. So, the whole dark matter thing is equivalent to calling in the gods to explain the unexplained with something even more inexplicable.

Re:Dark matter balloney

[Tablizer]

If you cannot detect something at all with light or gravity effects, then it very likely isn't there. So, the whole dark matter thing is equivalent to calling in the gods to explain the unexplained with something even more inexplicable.

I would compare it to just calling something "X". However, sticking the name "energy" or "matter" onto an unknown may be a bit presumptuous. But frankly, I can't find a better description that rolls off the tongue nicely in popular press science articles. You can't just keep saying, "effect X is making galaxies spin faster than expected" over and over again. You have to name it eventually.

Although, in the past they've often named it after the discoverer such that it may be the "Fergenhiemer Effect" or the like. Why they didn't do that this time with dark energy and dark matter is a curiosity in itself. I'll call it the "Tablizer Naming Mystery" after myself.

Perhaps we can barrow from that practice: "I didn't get dumped, I'm merely in a "dark relationship".

Re:Skeptical

[John Hasler]

He isn't saying that they didn't know about it: just that they didn't realize that they couldn't get away with simplifying their calculations by ignoring it.

That makes sense, but

[shadowofwind]

Why have they been wasting our time with this dark energy stuff for the last decade then? Why posit the dark energy if its only needed to fix a model that was derived with what has for a while now known to be a false assumption? It seems stupid. Instead of endless science articles on dark energy, instead there should have been articles on scientists working to solve pde's with really hard constraints that match modern astronomical observations. I don't get it. Is there more to the story?

Re:Can someone please explain?

[ErkDemon]

Nobel prizes are tricky. They're supposed to be for work that has some demonstrable practical benefit to mankind, so getting a prize for cosmology is difficult.

Although the basic idea has been kicking around for a while (ahem), this work seems to put some numbers to it. Basically, current cosmology has tended to be founded on the idea of a nice simple universe, and when theory moved from a "constant, flat" universe to an "expanding bubble" universe, we still tried to maintain the idea that things were nice and orderly.

This gave us the idea of an expanding hypersurface that was rather like the surface of an orange ... pitted and creased with gravitational detail, but essentially sphere-like.
On the other hand, if you allow expansion to run faster in the less-dense regions, perhaps as a consequence of the higher rate of timeflow in those regions, what you end up with is a more lobed shape that looks more like a raspberry.