13 Comments

Isotropy, and its counterpart, anisotropy, is also important is earthquake science. The speed of seismic waves through Earth’s interior may not be isotropic in all directions. Specifically in the upper mantle, shearing of tectonic plates on the viscous mantle shears rocks and forms anisotropic layering that preserves spreading history of the crust. Analysis of the fast and slow directions of seismic waves provides details about how the Earth has evolved overtime. Thanks for the read, Andrew!

Expand full comment
author

That's an excellent example, Jacob. Thanks for sharing it!

It's also kind of incredible that we can predict earthquakes to the extent we even can.

Expand full comment

Earthquake prediction is a really complicated problem we still aren’t great at, and probably never will be. We are really good at determine where earthquakes happen though and what regions have the greatest earthquake hazards.

Expand full comment
May 20Liked by Andrew Smith

In antenna design work, the basic reference antenna against which you compared others is the isotropic radiator, a.k.a. the point source. The sun is a point source. A spotlight is a highly directional light source. Antennas do the same with radio waves.

Antennas can steer energy in certain directions and not in other directions. This is referred to as an antenna pattern in 3-space. This pattern of an antenna is often quantified versus the point source, and given in dBi or decibels above an isotropic radiator. It's a measure I use all the time in antenna system work.

Expand full comment
author

Neat! I love hearing the first-hand accounts of physics in action, Bobby.

Expand full comment

You explain this stuff well. Certainly better than the word-salad obfuscations that pass for "scientific explanation" in much of Hollywood now (and then).

Science fiction in particular explains what it can explain and speculates on what it can't. For example: in one of my books I have a brief explanation on how hydraulic fracturing ("fracking") works, but at the same time I also had a spaceship get destroyed by a fire raging inside it...

Expand full comment
author

Sci-fi is really science education when it's done right.

Also: thanks for saying this!

Expand full comment

How about some large scale agriculture? The harvest relies on the grain, hay, soybeans, etc to be ready at the same time. 🤔

Expand full comment
author

Good question! I'm not sure this would qualify as isotropic, but I'm also not sure. Is it isotropic because the "directions" are time?

Expand full comment

Another good question!?

Expand full comment
May 20·edited May 20Liked by Andrew Smith

I actually briefly thought of the Tesseract scene from Interstellar during your opening lines...except there were no balls in it. Nor was it a sphere. Come to think of it, I don't really know why I thought of Interstellar.

Expand full comment
author

You said "balls."

Expand full comment
May 20Liked by Andrew Smith

I know what I said.

Expand full comment