r/FlatEarthersOnly

Deutsche Physik Band 4, section 585. Here is what he actually wrote:

“Gravitation, like inertia, is a property of Energy and only of Energy in all its forms.”

He proposed that gravity between energies is mediated through what he called etheric accompaniments — and honestly acknowledged the mechanism cannot be described much further than Newton could in his time.

The book is publicly available on Archive.org in German. It has rarely been engaged with scientifically because Lenard’s N*a*z*i associations made his work politically untouchable after 1945.

That is a fact worth separating from the science itself.

His work was not formally falsified. It was set aside for reasons that had as much to do with politics as physics.

Whether his definition of gravity has scientific merit is genuinely unknown. It has not been properly evaluated.

Primary source: archive.org/details/PhilippLenardDeutschePhysikBand4

Draw your own conclusions.

Most people assume someone, somewhere, measured the curve of the Earth. They didn’t.

Every measurement of Earth’s shape starts the same way — on flat ground. A tape measure. A shadow. An angle. Local observations that are essentially flat and level.
A protractor measures angles. That’s it. It doesn’t tell you what’s creating those angles.

When Eratosthenes calculated Earth’s circumference around 240 BC he measured two things. A flat ground distance between Alexandria and Syene. And the angle of the sun’s shadow at each location on the same day.
From those two measurements he calculated a circumference.

The flat ground distance is the baseline. The sun angle is the protractor. The sphere is the conclusion he drew from combining them.

Not what he observed. What he inferred.
That’s worth sitting with. Every calculation of Earth’s shape follows the same basic pattern. Flat local measurements plus angular observations equals an inferred global shape.

The question worth asking is simple:

Has anyone ever directly measured the curve?