Week 4: The Two Knobs Under Every Jump

Gravity and launch speed both change how high you go, but they don't feel the same, and the Gravity Lab lets you see why.

15 March 2027

Question#

Two jumps reach the same apex height. In one, gravity is low and launch speed is low. In the other, gravity is high and launch speed is high. Are these the same jump wearing different numbers, or do they feel different — and if they feel different, what number would you look at to prove it?

Prediction (skip if you’d rather just look)#

Before running anything: do you expect the time in the air to be the same for both jumps in the question above, given they reach the same height?

Experiment#

Open the Jump Lab, pick the Floaty preset (low gravity, low launch speed) and the Precise preset (higher gravity, higher launch speed), and run three immediate-mode trials of each. Log height and airtime for both. You’ll likely find their heights land in a similar range but their airtimes don’t — low gravity keeps you up longer for the same height, because gravity is what pulls you back down, and launch speed only decides how fast you left the ground.

Explanation#

Height comes from the balance of both numbers together — how fast you leave, against how hard you’re pulled back — so two very different pairs of values can produce a similar peak. Airtime, though, is set mostly by gravity alone: weaker gravity means a slower fall, which means more time to react, aim, and correct once you’re already committed to the jump. That’s the whole difference between “floaty” and “precise” as feelings, not just as labels on a preset button.

Task#

Using the Gravity Lab, hold launch speed fixed and run three trials each at two different gravity values of your choosing. Report height and airtime for both settings, and one sentence on which of the two numbers moved more.