Ember's Light

Chapter 1 of 9Record, 2452Covers 2155 to 24521:45 in the sim

What does the seed do between the Moon and Ember?

Astronomers found Ember circling something invisible every 188 days fiction. In 2155 a stack of 22,700 kg left the Moon to go and look fiction. A laser array pushed its sail up to 0.1 of the speed of light, and then the sail was cut loose. A beam can start a seed this way, but it cannot stop one, because nothing at the far end pushes back. Most of the stack's mass is the fuel for stopping, which is why the launch is so much heavier than the seed it carries. The chapter has six beats: the launch, the burn, the first sight of Ember, the silence after the burn, Vesper and Kindling.

The Record holds 297 years of falling, and almost nothing happens in them. Stopping takes carried fuel. The seed's fusion stage lit 3.3 light-years out and burned for 50 years, using 17,200 kg of propellant frontier. The physics of a deuterium and helium-three fusion engine is unsettled, so the Record tags that stage frontier, and the chapter says so in its narration.

In 2452 the burn ended and the seed was at rest beside Ember with 2,670 kg of itself left. The chapter then cuts away from the seed's path to a close view near Vesper: its shadow sits between two lensed images of Ember. Both arcs are the star's light, bent into a primary and a secondary image physics. The cutaway is illustrative, not a second location on the seed's route illustrative.

Then the seed looks around. The ripple in the background stars is Vesper, a black hole of 12 suns inside a horizon 30.4 km in radius. It cannot be seen, only inferred from how it bends the light of everything behind it physics. Ahead is Kindling, a hot rocky world 0.080 AU from Ember. A flyby probe that never braked had crossed the system earlier and mapped it, so the seed arrives with a briefing fiction. Starlight on Kindling will run the first factory, which is where The First Watt begins.

Which numbers does this chapter rest on?

The launch and the braking are worked through in Pushed by light and Stopping from 0.1c, including why a magnetic sail on the interstellar gas and Ember's light cannot stop a probe at this speed. What a horizon is and why Vesper's is so small is in What is a black hole?, and how it bends the sky behind it is in Why the hole looks like that. Where a seed can safely park around a hole and a star is in Where you can live around a hole and a star.