Thanks to a new visualization created on a NASA supercomputer, we can now dive into the event horizon, the point of no return for a black hole.
“People often ask about this, but simulating these hard-to-imagine processes is the key to bringing the mathematics of relativity to reality,” said Dr. Jeremy Schnitman, an astrophysicist at NASA’s Goddard Space Flight Center. “It helps us connect this with real-world consequences in the universe.”
“So I simulated two different scenarios: one in which the camera, standing in for the daring astronaut, misses the event horizon and the slingshot recedes; This is a scenario in which your fate will be determined.
To create the visualization, Dr. Schnitman worked with scientist Brian Powell at Goddard Space Flight Center and used the Discover supercomputer at the NASA Climate Simulation Center.
It took about five days to generate about 10 terabytes of data and run on just 0.3% of Discover’s 129,000 processors. It would take a typical laptop more than a decade to do the same thing.
The destination is a supermassive black hole with a mass 4.3 million times that of the Sun, comparable to the monster at the center of the Milky Way.
“If I had a choice, I would want to fall into a supermassive black hole,” Dr. Schnitman said.
“Stellar-mass black holes, containing up to about 30 solar masses, have much smaller event horizons and stronger tidal forces, and can tear apart approaching objects before they reach the horizon.”
This occurs because the gravitational force at the edge of the object near the black hole is much stronger than at the opposite edge. Falling objects stretch like noodles, a process astrophysicists call spaghettification.
The simulated black hole’s event horizon spans about 16 million miles (25 million km), or about 17% of the distance from Earth to the sun.
A flat, swirling cloud of hot, glowing gas called an accretion disk surrounds it and serves as a visual reference as it falls.
The same goes for glowing structures called photon rings, which are formed near black holes by light that has circled the hole one or more times.
A starry sky background seen from Earth completes the scene.
As the camera approaches the black hole, approaching the speed of light itself, the glow from the accretion disk and background stars is amplified, similar to the pitch of the sound of an approaching race car increasing.
If you look in the direction of travel, the light will appear brighter and whiter.
The film begins with a camera located some 640 million km (400 million miles) away, and a black hole quickly fills the field of view.
In the process, the black hole’s disk, photon ring, and night sky become increasingly distorted, even forming multiple images as light traverses an increasingly distorted space-time.
In real time, the camera takes about three hours to fall to the event horizon, performing nearly two full 30-minute orbits along the way. But for those observing from afar, it will never get there.
As the space-time distortion increases as you approach the horizon, the camera’s image slows down and appears to stop in front of you. This is why astronomers originally called black holes “frozen stars.”
At the event horizon, even space-time itself flows inward at the speed of light, the speed limit of the universe.
Once inside, both the camera and the spacetime it moves through hurtle towards the center of the black hole. A one-dimensional point called a singularity, where the laws of physics as we know them no longer work.
NASA’s visualization shows a camera tracking a supermassive black hole, similar in mass to that at the center of our galaxy, as it approaches, briefly orbits, and crosses the event horizon (point of no return). Masu. Image credit: J. Schnittman & B. Powell, NASA Goddard Space Flight Center.
“Once the camera crosses the horizon, there are only 12.8 seconds left before spaghettification destruction,” Dr. Schnitman said.
From there, the singularity is only 128,000 km (79,500 miles) away. The last leg of this voyage is over in the blink of an eye.
In another scenario, the camera orbits close to the event horizon, but never crosses it and flees to safety.
If an astronaut were to fly this six-hour round trip, and her co-worker on the mother ship was far away from the black hole, she would return 36 minutes younger than her co-worker.
That’s because time slows down when you move near a strong source of gravity or at speeds close to the speed of light.
“This situation could become even more extreme,” Dr. Schnitman says.
“If a black hole were rotating rapidly, like the one shown in the 2014 movie, interstellar, she would return many years younger than the sailors. ”
Source: www.sci.news
