Solved cryptogram

Empty space has a measurable resistance to magnetism, and its value sets the speed of light.

Physics Facts, sourced to NIST.

Or go to the puzzle’s own page first.

What it means

A vacuum is not nothing. It has an electric property and a magnetic one, and together they determine how fast an electromagnetic wave can move through it. When Maxwell combined the two in the eighteen sixties the answer came out at the speed of light, which is how physics learned that light is an electromagnetic wave. The connection was one of the great surprises of the century.

The claim comes from NIST.

Nearby in the collection

The facts either side of this one.

  • NISTmedium, 73 letters
  • NISTmedium, 73 letters
  • NISThard, 77 letters
  • NISThard, 74 letters

About as hard as this one

Scored closest to it by the model behind our guide to solving cryptograms.

Every Physics Facts cryptogram · All fact collections

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