Greetings from Palmia Observatory,
Well here we are and the American Astronomical Society (AAS241) meeting is over in Seattle and we can report on a couple of key findings.
So, to attend the meeting in person, you were required to comply with AAS mandatory mask mandate, even though most scientific advice is that it is not necessary. I couldn't attend in person anyway this year due to other conditions at the observatory, but here you see me in my "doctor plague" mask thanks to my friends at Amazon.
|Hmm, I wonder if my "Doctor Plague" mask would work at AAS241? (Source: Palmia Observatory)|
But, for now, we can report on one of online plenary session discussion that seemed very applicable. Here we here from George Efstathiou, British astrophysicist at Cambridge, on his 50+ year journey exploring the nature of cosmology. In this press release from 1990 we learn about the uncertainty of explanations based just on cold dark matter and the consideration of a cosmological constant.
|Astronomer George Efstathiou and 1990 dark matter press release (Source: G. Efstathiou, AAS241)|
Efstathiou reviewed 50 years of exploration results and how no paradigm shifts have occurred in the last 25 years. He listed these shifts and his age at which they occurred so we see that an astronomer could have spent a lifetime looking for more data.
|Astronomer George Efstathiou and historical paradigm shift review (Source: G. Efstathiou, AAS241)|
And yet, we have a standard model of cosmology. As physicist wannabes we go through the solutions of general relativity make calculations assuming current estimates of dark matter and dark energy and yet have no positive idea about what those components are. Also inflation seems to fit the observational evidence very well, but no one has a sufficient description of how inflation starts and how it ends.
|Yes, we have a standard model of cosmology, but look what's missing (Source: G. Efstathiou, AAS241)|
Efstathiou presented some current research areas from which the data to support a paradigm shift might come from. He didn't specifically mention MOND, that is modified gravity, but if better evidence comes forward there it could represent a paradigm shift. MOND is often credited with making actual predictions while the CDM method is more about just fitting the data. We expect as LIGO resumes full time operation more data about gravitational mergers will occur. More data collected from JWST on gravitational lensing with very old galaxies is also becoming available, and we will likely comment about some of the latest JWST findings in a future blog post.
|Where the next paradigm shift is likely to come from (Source: G. Efstathiou, AAS241)|
We can't leave out the current tension between estimates of the Hubble constant and how these measurements don't agree, which leaves room for a paradigm shift. Many of us were hoping that the measurements based on the tip of red giant stars would resolved the issue, but instead it just settled in a Hubble constant value right in between the value set by the CMB estimate and the value determined by supernova distance estimates.
|Resolving the Hubble tension might result a paradigm shift (Source: G. Efstathiou, AAS241)|
So, that is a brief summary of one of the plenary sessions at AAS241. It was really neat to just recall and go over all of those earlier observations which helped define the standard model of cosmology. We attended another plenary session that we might review in out next blog post.
Until next time,
Post a Comment