No dark energy?

[Bluenose]

I ran across an interesting article that recent observations imply that dark energy does not exist and previous indications for dark energy and an accelerating expansion of the universe may be a an artifact of faulty assumptions about the luminosity of certain objects.


https://m.phys.org/news/2020-01-evidence-key-assumption-discovery-dark.html

[Recusant]

What a cool paper. Thank you for posting that, Bluenose!

There must be some interesting discussions taking place amongst cosmologists right now. 

[Dark Lightning]

I enjoyed reading that! There's still a lot to learn about our universe. When I studied Astrophysics back in the '80s, Dark Matter had yet to be floated as an idea. Astrophysics is still a topic that has a lot of wiggle room for ideas. We'll figure it out, eventually...maybe even before we die!  Well, not us here and now, of course.

[Inertialmass]

Ha!

Ya know, a hundred times while reading various pop sci expositions over the years, the skeptic in me just had to ask, "The Universe is really so so accommodating to astronomers as to provide them with standard candles???"  Or could it be that they adopted the peculiar phrase as a way of giving to themselves a kind of unconscious, wishful-thinking reassurance that the extrapolations are valid?

[Dark Lightning]

I guess when one tries to describe something as vast and old as the universe, there's not much in the way to stop extrapolation. We keep guessing, we get closer. Good old scientific method. If dark matter doesn't exist, that Nobel Prize is going to look kind of hollow.

[Recusant]

Ha!

Ya know, a hundred times while reading various pop sci expositions over the years, the skeptic in me just had to ask, "The Universe is really so so accommodating to astronomers as to provide them with standard candles???"  Or could it be that they adopted the peculiar phrase as a way of giving to themselves a kind of unconscious, wishful-thinking reassurance that the extrapolations are valid?

I did some reading about the use of type Ia supernovas as standard candles, and learned that a few years ago it was discovered that there was more variability than had been thought.

"Accelerating universe? Not so fast" | EurekAlert!

Certain types of supernovae, or exploding stars, are more diverse than previously thought, a University of Arizona-led team of astronomers has discovered. The results, reported in two papers published in the Astrophysical Journal, have implications for big cosmological questions, such as how fast the universe has been expanding since the Big Bang.

Most importantly, the findings hint at the possibility that the acceleration of the expansion of the universe might not be quite as fast as textbooks say.

The team, led by UA astronomer Peter A. Milne, discovered that type Ia supernovae, which have been considered so uniform that cosmologists have used them as cosmic "beacons" to plumb the depths of the universe, actually fall into different populations. The findings are analogous to sampling a selection of 100-watt light bulbs at the hardware store and discovering that they vary in brightness.

[Continues . . .]

[Inertialmass]

Certain types of supernovae, or exploding stars, are more diverse than previously thought...

Cool.  Thus anticipating this week's announcement by five years.

Trying to discover who coined the term, "standard candle," I ran onto this from away back in 1969:

https://iopscience.iop.org/article/10.1086/128847 (contains PDF link)

The Period-Luminosity Relation: A Historical Review 

Fernie, J. D.

...Of all the discoveries of ground-based astronomy in this century, only the smallest handful can claim to have made the front-page headlines of the world's newspapers. One such instance came in 1952, when the headlines cried the news that the universe was at least twice as big as hitherto believed. To astronomers, the event signaled a turning point in the history of the Cepheid period-luminosity relation. It was the revelation of a major error which had gone undetected in forty years' work on this subject. The story is an interesting one, in that it illuminates many facets of the scientist at work, persistently groping his way through research via misappre-hensions and downright mistakes...   

[Dark Lightning]

I wonder what physics teachers are using for candles now in high school physics labs. We did it with real candles, back in the day. 

[xSilverPhinx]

That's very interesting! Exciting times for cosmology.