Check out this audio journey into the center of a supermassive black hole posted to Science You Can Bring Home To Mom’s new YouTube Channel! Transcript and sources below.
Transcript:
[Intro Music]
A Journey to the Center of a Black Hole by Sav Miller
I don’t know about you, but personally, I want to be thrown into a supermassive black hole when I die. I haven’t gotten around to putting it in my will—I still have to work out all the legal details—but consider this a formal declaration of how I would like to be laid to rest. In fact, let’s imagine I am dead and you, my most trusted and loyal friend, have taken it upon yourself to bring my freeze-dried corpse to the nearest supermassive black hole—the black hole at the center of the Milky Way galaxy, Sagittarius A*.
[Music break]
Sagittarius A* is about 26,000 light-years away and over 4 million times as massive as our sun. The mass of a black hole impacts how much space its “darkness” takes up. In reality, the essence of the black hole, the singularity, takes up no space. It’s an area of infinite density where a mass approaching infinity is condensed into an area approaching zero. But what we observe when we look at a black hole isn’t the singularity. What we do see is a sphere of absolute darkness created by the singularity’s infinite well of gravity. This dark sphere is known as the black hole’s event horizon and once it is crossed, not even light can escape it. The event horizon of Sagittarius A* is estimated to have a radius of about 12 million km—about twice the distance between the Sun and Pluto (not that anyone cares about Pluto these days).
Unless Sagittarius A* is feeding on nearby gas, you will not be able to see the event horizon directly. Instead, as we approach the black hole from a distance, you will see space around it distorted like a funhouse mirror. Light from objects directly behind the black hole is smeared around the event horizon like a halo. The strong gravity of the black hole pulls on light moving away from the object and bends it towards you like an out of focus lens. Other objects around the black hole are duplicated, appearing identically inside and outside the halo. The overall effect, as we orbit closer to Sagittarius A*, is that the black hole seems to create a whirlpool of stars around it that spins against the backdrop of space.
[Music break and opening hatch sound effect]
As we orbit the black hole from a safe distance, you jettison my freeze-dried cadaver out towards Sagittarius A*’s waiting depths. You watch from the ship as my body sinks into oblivion, but instead something unexpected happens. From your perspective, my body moves towards the black hole at an increasingly slow pace. I appear to be stretched and contorted. Eventually, my body slows to a complete stop on the lip of the horizon. Printed on the surface like a hologram, you never see me cross the event horizon. Instead, the light coming off my body grows dimmer and redder until I disappear completely.
[Music break]
Meanwhile, as you contemplate whether I was vaporized or disintegrated, your ship tragically runs out of fuel and stops firing its thrusters. Forward momentum continues to carry you in an orbital path around the black hole, but you are now circling it like a drain. Every second brings you closer to the event horizon and certain death.
As you approach Sagittarius A*’s event horizon, the universe appears to recede behind you, like the light at the end of an increasingly long tunnel. It gets smaller and smaller, collapsing into a single dot of light that turns red, blue, and then disappears. On the other side of the event horizon, you are surrounded by complete darkness. Your ship is in weightless free fall. Your journey to the singularity is now inevitable. Even if you could somehow travel faster than light, what direction would you go? Darkness extends in every direction. If you were to use your ship’s instruments to tell you which direction gravity is highest, you would find that it increases in every direction. The singularity is all around you. It is inescapable. Inside the event horizon, time and space switch their roles. You are now suspended in time as space ticks relentlessly forward. The closer you get to the singularity, the stronger the difference in gravity gets between the bow and the stern of your ship. Eventually, the ship gets stretched and torn in two. Then, those pieces get torn in two. Your body gets stretched like spaghetti (literally “spaghettified”) until it breaks apart. Eventually, even your molecules get dismantled until you become a thin stream of atoms, hurdling towards the singularity. No one knows for sure what happens then. Maybe we are lost forever inside the heart of Sagittarius A* until it evaporates away completely. Maybe our atoms are extruded like toothpaste into a new dimension where they become the building blocks of new stars, planets, and lives. Of course, no one will ever know the truth. The information, like us, is trapped behind the event horizon forever.
Sources:
- Supermassive Black Hole Sagittarius A*, NASA. August 29th, 2013.
- Radius of event horizon calculated based on the Schwarzschild radius formula, Rs= 2MG/c2, and M= 4 million solar masses.
- Pluto’s Distance from the Sun, Universe Today. November 9th, 2009.
- Journey into a Schwarzschild black hole, University of Colorado Boulder JILA.
- Step by Step into a Black Hole, spacetimetravel.org. December 16th, 2004.
- The strange fate of a person falling into a black hole, BBC Earth. May 25th, 2015.
- What Would You See As You Fell Into A Black Hole?, Forbes. January 19th 2018.
- Nemiroff, Robert J. “Visual Distortions near a Neutron Star and Black Hole.” American Journal of Physics, vol. 61, no. 7, July 1993, pp. 619–32. doi:10.1119/1.17224.
- Death by Black Hole by Neil deGrasse Tyson. ISBN: 9780393350388. September 2nd, 2014.
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