Trying to keep these occasional Facebook Live videos going. (I’ve looked briefly into other venues such as Periscope, but FB is really easy and anyone can view without logging in if they like.)
So here is one I did this morning, about why cosmologists think dark matter and dark energy are things that really exist. I talk in particular about a recent paper by Nielsen, Guffanti, and Sarkar that questioned the evidence for universal acceleration (I think the evidence is still very good), and one by Erik Verlinde suggesting that emergent gravity can modify Einstein’s general relativity on large scales to explain away dark matter (I think it’s an intriguing idea, but am skeptical it can ever fit the data from the cosmic microwave background).
Feel free to propose topics for future conversations, or make suggestions about the format.
Sorry to but in here again, but I don’t think Occam’s razor can apply to QM from QM not being a classical concept. Occam’s Razor requires common sense, and QM defies common sense. Then the simplest answer may not be the correct one, because there would have to be a very complex circumstance going on that defies our understanding of the natural world. Occam’s Razor could only apply if you could come up with the simplest solution which would cause things to defy or sense of everyday reality.
I have read a lot of books which try to describe super-strings and tell what they are, but none of them are actually able to say exactly what a string actually “is”. The simplest form of a string is a photon. Then it would make it seem like the photon could be the basic constitute of everything. Matter and anti-matter collisions only produce photons. Then string theory describes strings in higher dimensions, so it would be like trying to consider different vibrations of photon’s world lines. That is how I try to think of QM anyways, even though it is unorthodox-ed.
John B,
Your statement “Occam’s Razor requires common sense, and QM defies common sense.” is common sense enough. Nevertheless, a useful point is brought up. Namely, what is common sense in classical physics vs. what is common sense in QM.
From the viewpoint of classical thinking, QM appears “spooky” to Einstein and “wonky” to Sean (my November 25 comment in Sean’s “Thanksgiving” blog). In this context, you could say, correctly, that QM defies common sense. The unspoken assumption here is that classical physics is more common sense than QM.
There is no problem with the above. But does that rule out the use of “simplicity” as a criterion in assessing either classical or QM thinking? The answer is no.
Let’s say there are two explanations A and B. Occcam asks mainly, “Is A simpler? Or is B simpler?” Will resort to two examples.
Example 1:
Verlinde’s entropic gravity. Let’s assume he offers two versions A and B.
A takes 44 pages.
B takes 4 pages.
Occam would prefer B.
Example 2:
Heisenberg uncertainty principle.
A. Standard physics involves the concept of complementarity and an equation.
B. Let’s assume classical physics is physical whereas QM is not.
Whenever one uses a classical physical ruler to measure anything QM, by nature non-physical, one necessarily obtains an uncertain reading. No equation, only “common sense”, is involved.
Occam would prefer B.
(Note B is only a proposal.)
KC
Thanks for the informative video. Ned Wright provides the following comment re the NGS paper http://www.astro.ucla.edu/~wright/cosmolog.htm#News):
“21 Oct 2016 – Nielsen, Guffanti & Sarkar have claimed that an improved treatment of statistics leads to a reduction of the statistical significance of the supernova evidence for an accelerating Universe, from 4 sigma using the standard analysis to 3 sigma in their new analysis. In their Figure 2, the non-accelerating Universe line touches the 3 sigma contour. In the standard analysis a similar Figure (3rd figure on my Supernova Cosmology page) shows the 4 sigma contour hitting the non-accelerating Universe line. This is not a big deal in any case, but more importantly the new statistical analysis is wrong. It assumes that the intrinsic luminosities of the supernovae in the observed sample are not correlated with their redshifts, and this assumption is easily shown to be false. The high redshift part of the JLA sample is on average brighter than the low redshift part, because distant low luminosity objects are harder to find, an effect long known to astronomers as the Malmquist bias.”
I’d be interested to know your thoughts on this paper https://arxiv.org/abs/1307.6589v24 claiming no evidence of time dilation signature. Also:
1. Does DM condense? You say that in the early universe DM enhances condensation and opposes rarefaction, but in galaxy halos it seems to remain fluffy.
2. Does the existence of DE imply that the assumption of homogeneity must be correct? My thinking here is that gravitational matter is by its nature clumpy but DE is very smooth. Therefore, on a sufficiently large scale the smooth regions will average out the clumpy regions (like the surface of the ocean compared with the land).
In response to BobC, I am far more naïve than Bob . . . or Sean. However, Sean’s technical inspirations are on the right track from my limited perspective. He is making all the right kind of arguments coming from a conventional perspective. He has also enumerated a long list of issues that must be resolved before anyone can complete the project he is describing. Personally, I believe he will eventually get there. Perhaps before anyone else. He is almost at the point of working the problem from the bottom up. Which as he has recognized as being a very necessary part of the solution, but hasn’t yet recognized the mechanism for identifying the delineating factors or a critical listing of misconceptions.
I just finished writing “The Topology of Quantum Timespace: A Theory of Everything.” Technically, it is not a polished conceptual submission to the community. However, it does address most of the conceptual features Sean is talking about. Anyone who wants to critique it can find it on Amazon. But from that perspective, Sean moving the community in the correct direction.