“None of us here, despite attending the wealthiest university in the entire world, make a living wage.”

They may not deliver the highest efficiency, but absorption refrigerators have earned a persistent place in camper vans and industrial plants thanks to a few distinct advantages: they can operate using waste heat alone as an energy source, and they can be quite reliable due to their lack of moving parts. It can be a bit hard to understand their working principles, though, which is why Ben Krasnow built a transparent Einstein-Szilard refrigerator.

There are no generalized solutions to the three-body problem. Say you have three planets orbiting each other: it’s impossible to calculate how they will move using Newton’s laws of motion and gravity.

Unlike the two-body problem, the three-body problem has no general closed-form analytic solution. The differential equations that govern the motions of three gravitating bodies are not integrable and cannot be solved to give explicit formulas for the positions of the bodies as a function of time. For most initial conditions, the dynamical system for three orbiting bodies is chaotic, and the only way to predict their motions is to estimate them using numerical methods.

But thousands of stable three-body orbits have been found — their paths repeat after a given interval. The Three Body Orbits website is an atlas of some of those orbits: you can watch each three-body system play itself out in a wide variety of different shapes and complexities. There’s this simple figure 8, this slightly less simple one, and this one that looks like a spirograph.

Underlying Source: https://www.threebodyorbits.com/

cross-posted from: https://piefed.world/c/scientificarticles/p/1502104/in-hospital-you-re-slightly-less-likely-to-die-if-your-doctor-s-a-woman

Canadian and US scientists say death and rehospitalisation rates among hospitalised patients are lower when patients have a female rather than a male doctor. The team looked at outcomes for nearly a million adult inpatients in Ontario, Canada, and found people treated by female doctors were less likely to die within 30 days, and less likely to end up back in hospital, than those treated by male doctors. The differences were modest, but the pattern held up under statistical testing, they say. For patients with a female doctor, 12.3% died within 30 days, compared with 13.7% among those with a male doctor. And 18.6% of patients with a female doctor ended up back in hospital, compared with 18.9% of those with a male doctor. The reasons for the differences remain mysterious, and the study authors suggest further work should look into this.

In recent weeks, some of Brazil’s leading scientific organizations, including the Brazilian Academy of Sciences in Rio de Janeiro, circulated an open letter endorsing Lula, a leftist former labour leader. It received more than 20,000 signatures. “It’s hard to express just how happy the scientific community and the Brazilian society is with Lula’s victory,” says Paulo Artaxo, a physicist at the University of São Paulo.

Many worried that, if Bolsonaro were elected, he might slash support for Brazilian science and undermine it in the way that his father, Jair Bolsonaro, did. Jair was Brazil’s president from 2019 to 2023, and during that time, he cut science funding and expressed anti-science rhetoric during the COVID-19 pandemic, casting doubt on vaccines and promoting unproven treatments. The former president could not run for office again because he was sentenced to prison over a coup plot that he instigated after he lost his bid for re-election to Lula in 2022. He is currently serving the sentence at home because of health concerns.

cross-posted from: https://piefed.world/c/scientificarticles/p/1496063/young-adults-with-cancer-report-getting-dismissed-by-doctors