Archive for August 5, 2020

Phase Four Postponed

Posted in Covid-19, Maynooth with tags , , on August 5, 2020 by telescoper

Yesterday the Irish government decided to postpone the last phase of its (already revised) Roadmap for Reopening and also make mandatory the wearing of face masks in shops. Phase Four was supposed to start on August 10th and was to include, among other things, the opening of pubs.

The reason for not proceeding with Phase Four is obvious when you look at yesterday’s  new cases graph:

(I keep updating the data here.

Note that the graph is logarithmic on the y-axes so the number of new cases is not large (currently averaging about 45 per day), but the trend is concerning; last week’s average was about 18. Most of the new cases are aged under 45 which perhaps accounts at least partly for the fact that the death curve is not rising: younger people are at lower risk of developing serious problems. The pattern of increasing infections but decreasing mortality figures is quite widespread across Europe, actually.

The recent cases in Ireland are occurring in clusters in particular locations. Of the 45 cases reported yesterday, for example, 33 were in County Kildare most of them at a single factory in Kildare itself (which has now been shut).

There has also been an increase in community transmission, though, which is perhaps even more dangerous than individual outbreaks.

It seems to me that pausing the planned relaxation of restrictions is a sensible thing to do at this stage. To open pubs now – which many continue to argue for – would in my view be extremely foolhardy.

I’m not sure what all this means for the new academic year which is due to start in September nor even the repeat examination period which are due to start next week but if cases continue to increase at their current rate it will severely impact our ability to return to on-campus activities.

 

 

New KiDS on the Blog!

Posted in The Universe and Stuff with tags , , , , , , , , , , on August 5, 2020 by telescoper

The above image is from the Kilo Degree Survey, performed using the OmegaCAM instrument on the European Southern Observatory’s VST Survey Telescope at Cerro Paranal in Northern Chile. I got it by googling `Pictures of KiDS’, which was probably unwise.

Here’s another picture, of part of the survey region.

A few people have asked me why I didn’t post about the new results from KiDs which came out last week. The answer is simply that I’ve been a bit busy, but here we go now with a post on the blog about the new KiDs papers. These appear as a bunch of five on the arXiv:

KiDS-1000 Methodology: Modelling and inference for joint weak gravitational lensing and spectroscopic galaxy clustering analysis

KiDS-1000 catalogue: weak gravitational lensing shear measurements

KiDS-1000 catalogue: Redshift distributions and their calibration

KiDS-1000 Cosmology: Cosmic shear constraints and comparison between two point statistics

KiDS-1000 Cosmology: Multi-probe weak gravitational lensing and spectroscopic galaxy clustering constraints

The result that stands out from the latest release is the suggestion that the Universe is about 8% less clumpy than the standard cosmological model suggests. The level of clumpiness is quantified by the parameter S8 which, according to Planck, has a value 0.832 ± 0.013 whereas KiDS gives 0.776 (+0.020/-0.014), a discrepancy of about 3σ. It’s not only the Hubble constant that is causing a bit of tension in cosmological circles!