The longer path is the faster path

Why straight lines are slower than we think.

For most of my adult life, I’ve felt behind. It’s always taken longer than I expected to piece together what brings me joy.

But there’s a principle in physics, Fermat’s Principle, that I’ve been turning to when I’m feeling particularly behind:

Light takes the fastest possible route between two points.

This seems obvious enough when pointing a laser across the room. But it’s quite fascinating when you consider that it holds true when light travels through different materials (which it does at different speeds).

For example, consider a beam of light traveling from A to B through air and water. Fermat’s Principle states that the beam of light will bend when it hits the water so that it reaches point B in the fastest possible time.

The shortest geometric path, a straight line, takes more time because the light travels more distance in the slower water. Trying to maximize the distance traveled through the faster air also takes more time.

The fastest path is in between.

When I’m feeling behind, I’m often comparing myself to the straight-line path. But the path of one’s life travels through countless “materials”.

What if Fermat’s Principle is true in some way for our lives, too?

What if the optimal path from A to B isn’t a straight line?

What if the “longer” paths we find ourselves on are actually the fastest?

How a beam of light manages to find the fastest path is a topic for another day. But, I will say this: Light does so “accidentally”, without knowing the fastest path in advance.

In other words, light finds the fastest path simply by being and behaving like itself.

I like to think that’s true for us, too.

🤝 Stay in touch

I send an email several times a year with a handful of the most interesting things I’ve written or uncovered at home, abroad, and on the web.

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