Cosmic Queries – Gravitons & Hyperspeed

What It Covers

Neil deGrasse Tyson and Chuck Nice tackle fan-submitted physics questions on StarTalk's Cosmic Queries Grab Bag, covering electricity generation via Faraday induction, graviton detection challenges, space-based solar power, galaxy collision mechanics, black hole light-bending optics, and relativistic invariance across 40 minutes of accessible astrophysics.

Key Questions Answered

• •Faraday Induction & Energy Generation: Every form of electricity generation on Earth — wind, hydro, geothermal, steam, nuclear — works by moving wires through a magnetic field, a principle Michael Faraday demonstrated in the mid-1800s. Solar photovoltaic cells are the sole exception, converting sunlight directly to electricity without any rotating turbine or mechanical motion involved.
• •Space-Based Solar Power: China is actively developing orbital solar arrays that would convert sunlight to microwaves and beam energy back to Earth. Unlike ground-based solar, space arrays positioned far enough from Earth experience no nighttime and no cloud interference, enabling continuous 24-hour energy collection — a strategic move to offset China's dependence on imported oil.
• •Graviton Detection Barrier: The graviton, the theoretical particle corresponding to gravitational waves, remains undetected because gravity is 10 to the power of 42 times weaker than electromagnetism. Current particle accelerators cannot reach the extremely low energy levels required to observe it. The photon-to-light-wave analogy provides the theoretical framework physicists use to justify the graviton's predicted existence.
• •Galaxy Collision vs. Universal Expansion: Nearby galaxies like the Milky Way and Andromeda collide because local gravitational speeds — roughly 200 miles per second — exceed the expansion rate of space at short distances. Only when cosmic expansion outpaces local gravitational velocities does separation occur. The Milky Way-Andromeda collision is projected approximately seven billion years from now.
• •Black Hole Optics — No Blind Spots: A black hole's extreme gravity bends light completely around its mass, meaning an observer positioned in front of a black hole simultaneously sees light from behind it. No vantage point exists from which the back of a black hole is hidden. This same principle explains why the sun appears above the horizon roughly five minutes before it physically rises.