Your Planet Shouldn't Exist

This terrarium is at the new California Academy of Sciences in San Francisco. By ascending a series of passageways one passes through all levels of a rainforest, from underwater to above the treetops. Hopefully we will build such domes on the Moon someday.

San Francisco State University is often overlooked in favour of those other colleges across the Bay. At SFSU Geoffrey Marcy and Paul Butler became the first extrasolar planet hunters. At first no one believed their findings, and they had difficulty getting published. Today science recognises hundreds of planets in other solar systems. Dr. Debra Fischer continues the planet hunt at SFSU today. (Disclaimer: Dr. Marcy also taught in Berkeley, and gave the writer an A in Honours Physics.)

From the time of Pierre Laplace, scientists have thought that planets coalesce from rotating disks of gas surrounding stars. New computer simulations by Joseph Barranco of San Francisco State University call this old theory into question. Using hundreds of parallel processors, Barranco made the first 3D simulations of planet formation. These more complex simulations introduced turbulence from Coriolis forces and vertical shearing. Because of these forces, early planets would have been torn apart. According to the simulation, our planet should not exist.

The old theory of planet formation has long suffered flaws. If particles collide at orbital speeds, they would ricochet rather than stick together. Small particles would need the masses of mountains to form planets. Planet hunters have also found many “hot Jupiters,” giant planets orbiting very close to stars. Under the old theory, such worlds should not form. Heat from the star would boil their surfaces and tidal forces would tear them apart. The old theory of planet formation needs something else to work.

The Big Bang may have created many billions of tiny Black Holes. They would have formed from quantum fluctuations grown large by expansion of the Universe. A primordial Black Hole would have the mass of a mountain, yet be smaller than an atom. Quietly orbiting in Space, they would be very difficult to detect. Tiny holes could be ubiquitous, even within our solar neighbourhood.

When our solar system was nothing but a cloud of gas, small Black Holes would have drawn the gas into their influence. The Black Holes were too tiny to suck everything up, but the tiny amount they did eat made the rest grow hot. Eventually a Black Hole would be surrounded by rock with a hot center. This was the birth of the planets.

If our Earth contained a tiny Black Hole, outward radiation pressure would prevent us from being eaten. Earth’s centre would be a whirlpool of charged particles surrounding the Black Hole. Radiation from the core would reach the surface as volcanic heat. If the Black Hole rotated, it would generate a magnetic field whose axis would not necessarily be parallel with Earth’s spin axis. Our planet behaves exactly as if it contained a Black Hole.