When an apple falls from a tree, we accept it has fallen.

We don't say "But you can't be 100% sure it won't fall sideways next time."

Some scientific questions have been answered thoroughly enough to move on.

Newton's law of gravity is one of them.

Vaccines not being a cause of autism is another.

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Cyclist · 46-50, M

Agreed on the vaccines point. Newtonian gravity, though, does not work for high gravitational fields. Even predicting the orbit of Mercury requires general relativity. But general relativity, too, has been proven to have amazing predictive power. As far as whether or not it’s reality, we still don’t know. So long as there are two independent ways of describing nature, general relativity and quantum mechanics, one or both could be an epicircle scheme.

ElwoodBlues · M

@Cyclist In an abstract philosophical sense, Newton has been supplanted by general relativity. However, Newton is still used by NASA and others for most calculations. Even though it's philosophically imperfect, its errors are smaller than most of the other errors encountered in practical space navigation.

Mercury's orbit precesses at a rate of about 574 arcseconds per century. This is a total of about 0.0016 degrees per century.

Cyclist · 46-50, M

@ElwoodBlues actually, the effects of general relativity in everyday life are very real. Much of modern technology would not exist without taking GR into account as more than just a philosophical concept, which it is not. Here are a few examples:
The most obvious example is GPS navigation. GPS works by measuring light travel time and time stamps among at least 3 satellites. Clocks on GPS satellites tick faster by about 38 micro-seconds per day. The difference in Doppler shift is about 0.21 meters/second. Over one day, the positions to each satellite would be off by about 6 miles, and the entire system would crash.
Another example is the worldwide synchronization of telecommunication systems. These systems can carry so much data in part because they know to very high precision when data are arriving in a new subsystem. Due to time ticking at different rates at different altitudes on Earth and in space, that requires a general relativistic correction. Slightly related, electricity transmission losses are minimized when AC currents are precisely in phase. 2 or more power systems can all be operating at 60 Hz, but if the phases of those cycles are not the same, combining th will cause losses. Over very large distances and altitudes, that again requires a GR corrections. NASA spacecraft also use GR corrections, for all the reasons discussed here. If GPS, in Earth orbit, would accumulate a 10 km error over a day, then imagine what it would be like for New Horizons traveling 10 years to get to Pluto.