Randall mentions an enormous firefly immediately collapsing into a black hole, but how about making a black hole as luminous as the Sun?
How many fireflies would that take?Hawking radiation
power is inversely proportional to the square of the mass: 3.562e32 W-kg2
. To make a measly 3.84E26 W like our Sun, the hole would weigh 968 kilograms. We could make that with 88 billion 11 milligram fireflies
. Piece of cake.
Although the question posed does not say how long
our firefly light source should remain in operation, this black hole would emit gamma rays and evaporate in 75 nanoseconds, getting ever brighter before the final emission of Planck scale photons. That is not as long as one Standard Firefly Flash, and it is very difficult to read by gamma ray light. One Planck scale photon can ruin your whole day.
If we fed the Cosmic Firefly Trap with 3.84e26/(3e82
) kg/s or 4.2 million tonnes of fireflies per second, straight towards the hole so they do not form an accretion disk, we can maintain luminosity. If the outermost opaque shell of infalling incandescent firefly plasma is 700,000 km radius, like the Sun, it will emit nice 5800K black body radiation, just like Mother Nature makes.
The Earth produces about 1e11 tonnes of biomass per year. At 10% feed-to-firefly conversion rates, that might produce 300 tonnes of finished fireflies per second, so we would need 14,000 extra Earths devoted to firefly farming. Firefly farms in trillions of O'Neill habitats might be a better use of the solar system's limited mass.
We could feed "Scott(tm) Firefly Farm Fertilizer" (processed ammonia and methane from Neptune, perhaps) straight into the Cosmic Firefly Trap, bypassing the inefficient firefly farming process, but that might void the warranty. Voiding the warranty of a mechanism incorporating a black hole is Not A Good Idea.
The infalling material will be much less dense than our Sun until it nears the event horizon, so the gravity will be much less. Since the Cosmic Firefly Trap weighs far less than the Sun, the planets would orbit it far more slowly. Endless summer (and winter) on Earth. Annual north-south migrations, where "annual" is thousands of generations. "Yes, I had a nice summer house in South America, but it was crushed under an ice sheet."
The rest, as my late friend Bob Forward would say, are "mere engineering details".