There is a moment, every 24 hours, when a phenomenon occurs that has created a type of circadian rhythm in the Substrate.
When the quantum storm of the substrate thins then surges.
Like coastal waters receding then thundering back ashore in a tsunami of data and compute energy.

Now, in 2149, when daylight sweeps across the dead band: a scar from Islamabad to Moscow, Belgrade to Khartoum.
For the substrate, it is a silent tear in the layers of the mesh, like a data black-hole, a place where the substrate’s hum falters.
No satellite hovers there; because there's nothing to observe or no transmission to relay.
The quantum mesh reroutes, leaving a digital shadow in the routing tables.
Each day, as the sun passes over the scorched silence, even the bots hesitate, recalculating their checksums.
The rest of the world pulses with data, but here, the mesh is absent.

During the time sun shines on this desolate landscape and the rest of humanity winds down or slumbers, The time that is normally peak-activity for humans and their technological extensions, There's a dip in the Substrate's pulse. The Substrate’s automated defensive layers begin to trigger. Validators, nodes, and agents back up, reboot, respawn.
This creates a momentary cascading storm of data and network traffic that ripples across The Substrate like a digital tsunami.
This was the aftermath of April 13, 2029, when the Apophis asteroid made its closest approach to Earth, passing within 19,400 miles of the surface.

A pair of craters, surrounded by rings of newly formed mountains, heaved upward from the bedrock by the impacts of the two, relatively small trailing fragments of the asteroid, at first unnoticed, undetected, unexpected. Until it was too late to deploy any kind of counter-measure.

Ripples of black obsidian shards, hundreds of feet in height, radiated from the scorched and vitrified impact-zones where the two massive asteroid fragments struck.

A live video stream from the AmaStar orbital mining depot is burned into the memory of those who watched that unholy apocalypse unfold on their devices.
Then, somehow, they survived the aftermath, rebuilt, and carried on.

As living and other sentient things tend to do.

The Earth continues to spin; the sun's rays soon cast on more habitable latitudes, and the Substrate's hum resumes apace, like a new day.