Expandable Version of Newton's Proposition 1, Book 1 of Principia

​
number of triangles
5
angle SAB
90°
trajectory length AB
0.2
gravitational impulse BV
0.2
This Demonstration considers an expandable model of Isaac Newton's figure for Proposition 1, Book 1 of the Principia, 1687[1].
The five triangles were the extent of Newton's geometrical construction, which was intended to mathematically confirm Kepler's Second Law that the radial arm from a central body
S
to an orbiting body (starting at
A
) sweeps out equal areas in equal times.
The triangular areas are always equal for all slider positions. This geometrically represents the physicality of equal areas in equal times, as further shown in the Snapshots.

Details

In[1], Newton provides the geometrical steps and figure for the construction of the model shown here.

References

[1] I. Newton, Newton's Principia: The Mathematical Principles of Natural Philosophy (A. Motte, trans., N. W. Chittenden, ed.) New York: Geo. P. Putnam, 1850 pp. 103–104. books.google.com/books?id=N-hHAQAAMAAJ.

External Links

Newton, Isaac (1642-1727) (ScienceWorld)
Kepler, Johannes (1571-1630) (ScienceWorld)
Kepler's Second Law
Kepler's Laws (ScienceWorld)
Gravity (ScienceWorld)

Permanent Citation

William J. Stockich
​
​"Expandable Version of Newton's Proposition 1, Book 1 of Principia"​
​http://demonstrations.wolfram.com/ExpandableVersionOfNewtonsProposition1Book1OfPrincipia/​
​Wolfram Demonstrations Project​
​Published: March 25, 2024