In honor of Pi Day, today’s lunchtime photo comes a little early. This is a picture of Interstate 5 as you make the final descent into the San Joaquin Valley after crossing the Grapevine. Like pi, it seems to extend to infinity, going on forever and ever.

Not impressed? Sorry, it was the best I could do. I racked my brain for pi references I could make to any of the photos in my queue, but came up empty. So this is it.

By the way, today is also Albert Einstein’s birthday. He is, of course, famous for the definition of pi in his general theory of relativity, which he first wrote down while reviewing a patent application for a system of synchronized pie tins connected via telegraph wires:

This was a technical correction to Isaac Newton’s definition of pi, which occurred to him when he got bonked on the head by a falling apple:

In practice, Newton’s definition of pi is still used by working physicists today. Einstein’s definition is needed only for pies the size of the solar system.

BY THE WAY: Today is American Pi Day. In Europe, where they typically write the month first, 314 is April 31st, which is the day after April 30th, which is May 1st. Then there’s (American) Two Pi Day, which is on June 28. It’s even better than Pi Day because everyone gets two pies.

ALSO: Congratulations to St. Louis, which scored the coveted 314 area code back in 1947, and Marin County, which snagged the 628 area code just a few years ago.

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YOUR GIFT DOUBLES THROUGH FRIDAY

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In a climate where journalists face mounting pressure to back down, stay silent, or soften their reporting, Mother Jones refuses to flinch. We’re pushing back against intimidation and delivering fierce, independent journalism that holds power accountable—no matter who’s trying to silence us.

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