A puzzle:

Imagine you begin a journey in Seattle WA, facing exactly due east. Then start traveling forward, in a straight line along the Earth's surface. You will travel across North America, and onto the Atlantic Ocean. Eventually, you will hit another country.

What is the first country you hit?

A memorably insane detail from 'The Doomsday Machine' by the late Daniel Ellsberg:

In 1960, the US Air Force would sometimes task the RAND Corporation with assessing new technical proposals. One memo titled "Project Retro" fell to Ellsberg to assess. The scheme, which had already passed through multiple agencies without being discarded, was prompted by the worry that a surprise Soviet attack with ICBMs could incapacitate US land-based missiles before they could retaliate.

Some gradients between two colours look good, others suck. It's easy to tell the difference, but what *is* that difference? I think @JoshWComeau has figured it out! Here's the thought: gradients trace a line between two points in colour space, but there's more than one way to represent colours in a (typically 3D) space.

Here's a way of visualising a Bayesian update —

You start with a sample space S, and a prior about the likelihood of H. You can think of learning new evidence like placing a smaller frame somewhere inside of S. The dots ":" are there because if you write in the areas of the left and right sides, you get the fractional odds. In this example we go from about 2:1 to about 1:3 (from the bigger to the smaller rectangle)

Should settling Mars be a current priority for longtermists? I think no, not by a long shot! (Let’s instead focus on preventing pandemics, decarbonising, making sure AGI doesn’t go terribly...)

Here’s why: The most compelling argument for travelling to Mars soon is that it’s a hedge against extinction on Earth. Launching some of our eggs into a different basket.

I agree that preventing anything as irreversible as extinction is hugely important!