dansdarkmatters

Oh, I did that thing where I write a blog post every two years... this time about what it means for something to be scientifically "settled" (or not). dansdarkmatters.wordpress.com/2026/02/16/why…

@qikipedia This value isn't really meaningful: it is a "by volume" calculation & hides an arbitrary choice of how densely to pack the matter for the sake of the calculation. Its fairer/better to express the density directly, or express it in terms of e.g. volume of space per hydrogen atom.

The universe is only 0.0000000000000000000042% matter.

New Simons Observatory UK position: Postdoctoral position at the University of Cambridge, UK, with a focus on science-readiness of LAT data, simulations and lensing. The closing date is 29 November. jobs.cam.ac.uk/job/48967/

Come and join the Williams lab @OfficialUoM @FBMH_UoM @The_MRC We are using single-cell Multiomics and in vivo CRISPR approaches to understand the molecular mechanisms underlying lineage segregation from the neural plate border 🐣jobs.manchester.ac.uk/Job/JobDetail?…

Two postdoc openings to work on Simons Observatory at Manchester. One on instrumentation to help build & deploy the first SO:UK SAT: jobs.manchester.ac.uk/Job/JobDetail?… One on data analysis, specifically in the areas of SZ and/or SAT analysis/BB: jobs.manchester.ac.uk/Job/JobDetail?… Closing date 4th Nov.

Job advert: post at Imperial College (UK) working on Cosmic Microwave Background data analysis for Simons Observatory imperial.ac.uk/jobs/search-jo… Please share widely 🙂

URGENT! Pls share. The last chance to register to vote in the General Election is 11.59pm tomorrow Tue 18 June. Potentially 8m aren't registered at their current address. Here's 4 key facts... 1) You can do it online here registertovote.service.gov.uk/country-of-res… 2) It's good for your finances. Not being on electoral roll can make it more difficult to be accepted for credit products like bank accounts or mortgages. 3) You can opt out of the 'Open Register' (which allows your info to be sold on) which will stop you getting junk mail marketing ) 4) You'll need ID when you do vote (not to register) if you don't have it, you can get it free until Wed 26 June gov.uk/apply-for-phot…

@DudeDarkmatter @lellifede not look like this extrapolation. Probably I'm not being very clear, sorry, maybe we can chat at a meeting sometime... 2/2

@DudeDarkmatter @lellifede Sure... maybe I can try to say this differently... if the source of (astrophysical)MOND is modified gravity, extrapolating MOND to cosmology is "1 to many"(even within a single theory) & the many can be v. different (some showing no cosmological MOND),so some/all of them will 1/2

Job advert: Research Software Engineer. At the UK data centre for the Simons Observatory project. The post primarily involves optimising & running analysis workflows for the small aperture telescopes. jobs.manchester.ac.uk/Job/JobDetail?… Please circulate to potentially interested candidates.

There’s an art to distilling these to the absolute minimal necessary text. The human brain can’t comprehend how stupid these things are without practice.

St George's Day is a good day to remember that the massive rise in English identity, about which a thousand op-eds were written, turned out to have happened purely because the ONS moved it above 'British' in the list of answers.

Onshore wind joins video games, the financial sector and higher education on the list of things that a) England is good at and b) England’s politicians hate twitter.com/jburnmurdoch/s…

A rare beast - a new blog post: "Why do you look at the speck of sawdust in your brother’s eye and pay no attention to the plank in your own eye?" dansdarkmatters.wordpress.com/2024/02/26/why…

There's currently two positions for postdoctoral researchers to join my team at @UoPCosmology , in #gravitationalwaves and large-scale structure #cosmology. Open for another ~10 days, links below 👇. Please share 🙏 jobregister.aas.org/ad/b2885fb5 jobregister.aas.org/ad/5faff99c

We have over 1300 signatures to our open letter and they are still coming. You have until 12 NOON TUESDAY to sign our letter standing up for EDI in science and telling the UK government they do not speak for scientists in their 'anti-woke' rhetoric Sign at hull.onlinesurveys.ac.uk/edi_in_science

@Quasilocal twitter.com/dansdarkmatter…

Whenever dark matter comes up, inevitably people focus on the rotation curves of galaxies, but since then hasn't everthing else we've seen just perfectly fit the picture of it being genuine matter? (As opposed to some modification to GR or whatever)

After much hiatus, I wrote another blog on something I've been musing about for a while... dansdarkmatters.wordpress.com/2023/07/21/dar…

This tool can be used for forecasts, and (more importantly) data analysis for future surveys. Stay tuned. 3/3.

In this paper we show how to calculate, for time dependent phenomenological modified gravity, the effect on the non-linear matter power spectrum up to around the scales where baryon-related uncertainties give us trouble in LCDM (which is about as far as it is worth going). 2/.

Paper day 🙂 arxiv.org/abs/2306.17240 Testing modified gravity in model independent ways is a crucial counterpart to detailed studies of specific toy models. Upcoming surveys (like just-launched Euclid) can do this well, but only if we understand the smaller "nonlinear" scales.1/