Run · Relativity You Can Hold

Settle in title

Season 1 · Session 04

Relativity You Can Hold

Your phone's map only works because we corrected for bending time.

Prompt deck —

Use ↓ / ↑ to move between movements. → / ← steps the prompts. Space reveals on the wall.

Host notes, laptop only

Framing

We're not asking whether relativity is testable in principle. We're holding the test in our hands, and asking what it means that it works.

Opening question (Settle in)

What breaks if we ignore that satellite clocks tick at a different rate than ours?

The precise version (Watch)

GPS satellites orbit at approximately 20,200 km altitude and move at roughly 3.87 km/s relative to Earth's surface. Two relativistic effects operate simultaneously: (1) Gravitational time dilation (general relativity) causes satellite clocks to tick approximately 45.9 microseconds per day faster than ground clocks because they are higher in Earth's gravitational potential. (2) Velocity time dilation (special relativity) causes satellite clocks to tick approximately 7.2 microseconds per day slower due to their orbital speed. The net effect is that satellite clocks gain approximately 38 microseconds per day relative to ground clocks. Without correcting for this, GPS position errors would accumulate at approximately 11 km per day.

If it wobbles

Confidently wrong — Don't argue the microseconds. Ask, 'If satellite clocks kept the same time as ours, GPS would still drift 11 km a day. How do we know the correction is doing the work?'
Dead silence — Make it personal. 'Everyone here has trusted that blue dot today. It only points right because we corrected for bending time. Does that change anything?'
Runaway debate — Pull back. 'Hold the argument a moment. Let's agree on the measured number first. 38 microseconds a day, gained.'
Tipping into dogma — Name it. 'We're not here to defend a theory. We're noticing a fact engineers can't ignore, and sitting with how ordinary it's become.'

Wrap — close on (LOCKED)

How do you feel about this science and its understanding of reality?

Relativity You Can Hold

Facilitator hotkeys