Newton asks:
How strong is the pull?
Masses attract. More mass strengthens the force; more distance weakens it by the square.
F = Gm₁m₂ / r²
Gravity is a pull.
And a path.
Newton measures the attraction. Einstein changes the shape of the stage. Hold the experiment still and see both descriptions respond.
Shared experiment
Change one body.
Watch both lenses.
Every result comes from your inputs. The canvas uses a visual scale, while the readouts preserve the physical quantities and units.
SIMULATION RUNNING
Force9.82 kN
Acceleration9.820 m/s²
Orbit speed7.910 km/s
Orbit period84.35 min
Schwarzschild radius8.870 mm
Earth, through both lenses. Newton predicts a 9.820 m/s² acceleration at this distance. Einstein describes the same free-fall path as motion through curved spacetime. At Earth's surface, the Newtonian result is an excellent approximation.
One phenomenon
Two ways to read the motion.
Neither panel changes the experiment. It changes the question you ask of it.
Newton asks:
Einstein asks:
What path is straight here?
Mass-energy shapes spacetime. Free-falling matter follows the straightest available path through that geometry.
Gμν = 8πG Tμν / c⁴
Falling
A dropped object and an orbiting one are both in free fall. The orbit keeps missing the ground.
Weak fields
For planets, satellites, and everyday speeds, Newton's calculation is accurate and efficient.
Strong fields
Near black holes or at precision scales, curvature, clocks, and light paths matter.
Follow the path
Gravity does not switch theories.
Newton gives us the reliable shortcut. Einstein gives us the larger map. The shortcut emerges from the map when fields are weak and speeds are ordinary.
An orbit is a fall that keeps missing the ground.
A useful Newtonian picture
Keep the experiment, not just the answer.
Your report captures the exact setup, computed results, and the boundary between the two explanations.
Why distance changes gravity faster than mass
Read the explanation
Gravity Field Lab computes Newtonian force as G times central mass times probe mass, divided by distance squared. With its Earth preset and a one thousand kilogram probe, acceleration is about nine point eight two meters per second squared, and force is about nine thousand eight hundred twenty newtons. Double the distance from the center while keeping both masses fixed. The denominator becomes four times larger, so acceleration and force become one quarter as large. The source gives about two point four five five meters per second squared and two thousand four hundred fifty five newtons. The shrinking bar shows that quarter ratio. Now double only the probe mass from one thousand to two thousand kilograms. Force doubles to about nineteen thousand six hundred forty newtons. Acceleration stays nine point eight two because dividing force by probe mass cancels that factor. A heavier test object feels more force, but the computed field acceleration stays the same. The same code computes circular orbit speed and period, and the Schwarzschild radius. These numerical outputs are distinct from the animated orbit and curved grid, which are visual analogies. Switching the Einstein lens changes the drawing, not the Newtonian calculation. The page does not solve a relativistic trajectory; use the report to inspect the exact inputs and formulas.