The author did not know what he or she was taking about, let alone Newton’s third law. Quanta usually publishes great pieces but once in a while it gets entangled …

What was the issue?

I really couldn't figure out what on earth the article is talking about? Where is flocking patterns of bitds even in the scope of Newton's third law? The article reads like pseudo-science.

The article is crackpot nonsense:

> But many systems exist and persist far from equilibrium. Perhaps the most glaring example is life itself. We’re kept out of equilibrium by our metabolism, which converts matter into energy.

Our metabolisms convert matter into energy? Lmao I think not, our metabolisms are chemical processes, not nuclear. Making and breaking chemical bonds is NOT converting matter into energy. The author is nuts, I thought Quanta was better than this but I guess they're on my shitlist now.

They had to build a fleet of robots to study emergent behavior?! Have they heard of this amazing tool that can simulate pretty much any physical behavior for pennies on the dollars called "computer"?

Considering that the next figure is a computer simulation from the same citation, yes I believe they have heard of such an amazing tool.

I chalk up the physical robots to a bit of a PR stunt. Cool little robots is quite a bit more endearing than arrows on a computer screen. But that said, implementing such a system in physical robots could also be a kind of sanity check to ensure you aren't cheating the simulation by some kind of fault in your simulation. It's quite easy to share information between agents that you don't want being shared without realizing it. Something as simple as being a little careless with global variables could spoil the whole thing.

I wouldn't get so worked up about it.

Ha. I stopped at the gif with rotating robots.

Stephen Wolfram did this emergent behavior stuff with a computer in his book "A New Kind Of Science."

Newton’s third law is just the conservation of momentum... and lots of interesting systems don’t conserve momentum!

But closed systems?

Sure! A ball in a box is a closed system the doesn’t conserve momentum.

How so?

Consider that the evolution of the system will be the same regardless of where the box is located, and as such the system has translational invariance. Per Noether's theorem it must conserve linear momentum.

I meant the infinitely massive box of physicists dreams. Translational symmetry is broken by the boundaries of the world

You mean, a box that is immovable because it has infinite mass?

Hmmm I don't get it. What boundaries, the box boundaries? How does it break translational symmetry?

Anyway in this case I think at least elastic collisions will still conserve momentum, eg this https://en.wikipedia.org/wiki/Elastic_collision#/media/File:... conserves momentum even if the box has infinite mass.

Just another 'theory' to seek massive funding for..