the.com/gravity well
the universe's downward staircase, charging an exit fee paid in pure velocity.
means The region of curved space around a massive object where its gravitational pull dominates, so that escaping it requires more and more energy the deeper in you are.
from A pairing of "gravity" and "well" that arose in 20th-century physics and spaceflight thinking. "Gravity" comes from Latin gravitas, "weight, heaviness," from gravis, "heavy" — the same root behind "grave" and "grief." "Well" is the old Germanic word for a deep shaft sunk into the earth. The compound pictures gravity's pull as a pit: physicists often sketch a mass as a dimple in a stretched sheet, and "well" captures that downward funnel you must climb out of. The image gained currency with science fiction and the space age, when getting a rocket off a planet really did feel like hauling it up out of a hole.
- escape cost
- Earth charges 11.2 km/s just to leave
- black holes
- infinitely deep wells with no climb out
- slingshot trick
- probes steal planets' speed by skimming wells
- sun's pit
- 617 km/s to escape its grip
- time bends
- clocks tick slower deeper in the well
event horizon of m87 — black hole imaged in 2019, 6.5 billion solar masses, first photographed directly