The-reference-he-used-to-this-effect-was-the-Earth -- Multiple sentences match

+ −

The reference he used to this effect was the Earth's magnetic field direction, which at that time was believed to be invariant.

+ −

The reference he used to this effect was the Earth's magnetic field direction, which at that time was believed to be invariant.

0.003 seconds.

Most text is available under the Creative Commons Attribution-ShareAlike License; additional terms may apply.