Physics Buzz

Once in a rare while, the moon turns red—because the sky is blue. That might sound like nonsense, but it's the simplest accurate way to explain what happened early this morning, when the moon disappeared from view before returning with an eerie, rusty cast to it.

Last week, reader James from Melbourne wrote in: I was having a discussion with a colleague about what would hit the ground first if it fell from a plane (let’s say 15,000 ft). An elephant (let’s say African) or a standard brick. Curious to know your thoughts. Thanks! 

With the first parts of this series (read part I , part II , and part III ), we've built up the idea that the electric charge of a particle is very closely analogous to the angular momentum of an eddy in a fluid. Alike-spinning whirlpools repel, while opposite-spinning ones attract and, when they meet, annihilate one another—with the energy they contained radiating away as waves , just like matter and antimatter. But the surface of a pond is only two-dimensional, so to find out just how far this analogy goes, we're going to have to stretch our imaginations into higher spaces. Let's dive in.

Seeing bare tree branches silhouetted against a sunset sky is one of the best things about winter. Bereft of leaves, the trees reveal their intricate skeletons—almost fractal, reminiscent of neurons, or the network of blood vessels that perfuse the body. These complex patterns of growth and branching are produced by an invisible algorithm—less a blueprint than a computer program—encoded in the tree’s DNA, optimized over millions of years of evolution. Taking data on sunlight, airflow, and proximity to other branches, the tree regulates the expression of growth hormones to ensure that it’s making the most of its space. With all the care that goes into their creation, it’s no surprise that the patterns they produce come out so marvelously complex.

When magnetic fields clash, they can rapidly unleash powerful explosions. Now scientists may have solved the decades-old mystery behind how these outbursts can happen so quickly. The findings could one day help explain the origins of the most powerful explosions in the universe and point to ways to build stable nuclear fusion reactors.

This post is part of a series, (read Part I and Part II ) introducing a heuristic method for thinking about spacetime and charge that I like to call "the pond". Electromagnetic waves are often described as being similar to waves on water, and it turns out the analogy can be extended—if photons are waves, charged particles are like whirlpools: excitations with a little bit of angular momentum to them which allows them to persist.

"A good idea is useless if does not convince others. An idea that is only convincing to oneself is dead." These wise words represent a hard-learned lesson for Dr. Ramon Ferrer-i-Cancho, a scientist in the Complexity and Quantitative Linguistics lab at the Universitat Politècnica de Catalunya. Ferrer-i-Cancho has spent nearly two decades fleshing out a mathematical theory to describe the natural elegance of languages, fighting skepticism and intellectual inertia every step of the way. Now, with a publication in the American Physical Society's journal  Physical Review E , he hopes to both refute and convert his dissenters once and for all.