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Richard Sear - comp physics academic

@rpsear.bsky.social

Soft matter/biological physics academic at the University of Surrey in the UK

31 Posts42 Follower70 Folgt
Richard Sear - comp physics academic@rpsear.bsky.social · 4w ago

More power laws in COVID transmission, this time in data collected in a paper by Peng et al (pubs.acs.org/esthag/artic...) Maybe a slow power-law increase in transmission risk with exposure is generic? Maybe. chanceandnecessity.net/2026/07/28/p...

Power laws in COVID transmission

Peng and cowokers gathered together data on 12 (possibly not very representative) events where COVID was transmitted. For each event they estimated a relative infection risk factor Hr*. They then p…

chanceandnecessity.net

Richard Sear - comp physics academic@rpsear.bsky.social · 2mo ago

ChatGPT is getting a lot better at writing codes for simple science simulations (at least Lattice Boltzmann), partly because it breaks the problem down and asks for help. Claude went alone with poor results chanceandnecessity.net/2026/07/05/s...

(Some) LLMs (with some help) can now do a toy simulation of a droplet in shear

One area where LLMs like OpenAI’s ChatGPT, Anthropic’s Claude etc are already making a splash, is coding. But scientific coding is tricky, even small errors can result in the code crash…

chanceandnecessity.net

Richard Sear - comp physics academic@rpsear.bsky.social · 2mo ago

Am teaching myself a little bit about how neural nets work. These power the AI like ChatGPT that are changing our world. Blog post that takes you through how the simplest net - a single neuron - is trained and works (with code) chanceandnecessity.net/2026/07/02/t...

Training a toy neural net

I am no expert but as I understand it, a lot of LLMs like Anthropic’s Claude, and image generators like Stable Diffusion, are built on neural nets. And a lot of these neural nets are trained …

chanceandnecessity.net

Richard Sear - comp physics academic@rpsear.bsky.social · 2mo ago

LLMs like ChatGPT understand (to the extent that they understand something) via high dimensional vectors (they do a vast amount of vector/matrix maths to answer your questions). The image is a plot of what an LLM "understands" by physics chanceandnecessity.net/2026/06/14/p...

“Physics” as an LLM understands it

Large Language Models like OpenAI’s ChatGPT, Google’s Gemini, Anthropic’s Claude etc work with words but under their bonnets it is all maths. In particular the meaning of a word i…

chanceandnecessity.net

Richard Sear - comp physics academic@rpsear.bsky.social · 4mo ago

It is surprisingly easy in the era of ChatGPT-assisted coding and powerful time-series analysis tools to predict next year's mean CO2 level, at Mauna Loa where they've been measuring since 1958 ... chanceandnecessity.net/2026/05/04/p...

Predicting next year’s CO2 levels with simple machine learning

Due to us burning oil, coal, gas etc etc, the amount of CO2 in Earth’s atmosphere is increasing, and has been for well over a century. This is now well documented. Some of the first measureme…

chanceandnecessity.net

Richard Sear - comp physics academic@rpsear.bsky.social · 5mo ago

New blog post on fish that hunt other fish by detecting the electric fields produced by the prey. The electric fields are sensed by the beautifully named Ampullae of Lorenzini chanceandnecessity.net/2026/04/01/h...

Hunting by electric fields, and with the Ampullae of Lorenzini

This beautiful image is of the small-spotted catshark, and is by Hans Hillewaert (Wikimedia). They are carnivores and hunt on the seabed, where I think vision is poor. So they have evolved to hunt,…

chanceandnecessity.net

Richard Sear - comp physics academic@rpsear.bsky.social · 7mo ago

Rattlesnakes may push the limits of what physics allows in having thermal sensors that respond when warmed by a thousandth of a degree, due to the warmth emitted by a mouse they are hunting chanceandnecessity.net/2026/01/16/r...

Rattlesnakes and detecting warmth a thousandth of a degree at a time

This* is the head of a western diamond rattlesnake, a species of pit viper that is common in the USA and Mexico. Pit vipers are a family of species of snakes that called pit vipers because they hav…

chanceandnecessity.net

Richard Sear - comp physics academic@rpsear.bsky.social · 8mo ago

2025 has been a worrying year, so good to know there's one thing you shouldn't worry about: microplastics*. Blog post here: chanceandnecessity.net/2025/12/29/s... * Unless you're a lab mouse being forced fed crazy amounts of microplastics in not-very-ethical experiments

Surely microplastics are a very small problem?

I quite like Wired magazine but it has run an article called: People Who Drink Bottled Water on a Daily Basis Ingest 90,000 More Microplastic Particles Each Year. I just cannot make sense of this. …

chanceandnecessity.net

Richard Sear - comp physics academic@rpsear.bsky.social · 9mo ago

I don't know if RAGbots, ie LLM powered chatbots that suck in eg lecture notes, and answer questions on them, are the future of education, but they are easy to do yourself. Blog post w link to Python notebook: chanceandnecessity.net/2025/11/30/j...

Jumping on the LLM bandwagon with a RAGbot to answer questions on my lecture notes

Unless you have just emerged from a cave you will have heard of ChatGPT, Google Gemini, Claude, etc – collectively LLMs (Large Language Models, also called Generative AI models). Wikipedia ca…

chanceandnecessity.net

Richard Sear - comp physics academic@rpsear.bsky.social · 10mo ago

Ideally a hospital isolation ward for a disease transmitted across the air (COVID) would be the one place that's adequately ventilated to reduce transmission. Sadly not in Wales it isn't, I measured 1200 ppm CO2 - about 400 ppm above recommended chanceandnecessity.net/2025/10/27/p...

Poor ventilation in a COVID isolation ward of NHS Wales

My mother is in a COVID isolation ward in Morriston Hospital in South Wales. COVID really knocked her out but she was mostly back to normal when I visited on Sunday (26th Oct 2025), which is a reli…

chanceandnecessity.net

Richard Sear - comp physics academic@rpsear.bsky.social · last yr.

Surrey is hiring! We are appointing a teaching fellow for our longstanding Medical Physics MSc. For details, address for enquiries etc, see: jobs.surrey.ac.uk/Vacancy.aspx...

Job Vacancy at the University of Surrey: Lecturer A in Medical Physics (Teaching Track)

The University of Surrey is a global community of ideas and people, dedicated to life-changing education and research. We are ambitious and have a bold vision of what we want to achieve shaping oursel...

jobs.surrey.ac.uk

Richard Sear - comp physics academic@rpsear.bsky.social · last yr.

Best guess - using our limited knowledge of COVID transmission - is that a study 4 times larger than the Cambridge study would be large enough to prove air filtration reduces transmission in a hospital chanceandnecessity.net/2025/03/18/h...

How many need to become infected, to declare air filtering a success?

This post is, basically, a part II to the previous post on the study of Brock et al. on the effect of installing room air filters, on COVID transmission in hospitals. Brock et al. found that the ai…

chanceandnecessity.net

Richard Sear - comp physics academic@rpsear.bsky.social · last yr.

Cambridge hospital study found ~ 30% (+ error bars!) reduction in COVID transmission when air filters were used. This is expected if: a) this halved the airborne virus, b) the same variation of transmission w dose found in NHS app data applied in hospitals chanceandnecessity.net/2025/03/03/m...

Minimising hospital-acquired COVID in Cambridge

Hospitals are full of both infected people, and very susceptible people – people whose immune systems are, due to age or illness, very weak. This is a terrible combination but unavoidable. An…

chanceandnecessity.net

Richard Sear - comp physics academic@rpsear.bsky.social · 2y ago

Cold fusion is back on! But rebranded as Low Energy Nuclear Reactions (LENR). Oh wait it is just The Guardian printing a letter from slightly loopy Nobel Laureate & friends www.theguardian.com/environment/...

Cold fusion may be a viable energy alternative to end reliance on fossil fuels | Letters

Letters: A number of companies have been able to make these low-energy nuclear reactions work reliably, write Brian Josephson, David J Nagel, Alan Smith, Dr Jean-Paul Biberian and Yasuhiro Iwamura

theguardian.com

Richard Sear - comp physics academic@rpsear.bsky.social · 2y ago

@natureportfolio.bsky.social research highlight on my paper estimating that populations that mask up with FFP2/N95s reduce effective reproduction number for COVID by about a factor of 9 www.nature.com/articles/d41...

What if everyone had masked up? Analysis of app data has an answer

Modelling study based on almost 250,000 positive COVID-19 tests in the United Kingdom shows that universal masking could have cut transmission markedly.

nature.com