To solve the mysteries of black holes, a human being would only have to venture into one.
However, there is a rather complicated catch: a human being can only do this if the respective black hole is supermassive and isolated and if the person entering the black hole does not expect to report the findings to anyone from the entire Universe.
We are both physicists who study black holes, albeit from a very safe distance. Black holes are among the most abundant astrophysical objects in our Universe.
These intriguing objects seem to be an essential ingredient in the evolution of the Universe, from the Big Bang to the present day. They probably had an impact on the formation of human life in our own galaxy.
A person who falls into a black hole and stretches. (Leo Rodriguez / Shanshan Rodriguez / CC BY-ND)
Two types of black holes
The Universe is full of a large zoo of different types of black holes.
They can vary in size and be electrically charged, just as electrons or protons are found in atoms. Some black holes actually spin. There are two types of black holes that are relevant to our discussion.
The first does not rotate, is electrically neutral, that is, it is neither positively nor negatively charged, and has the mass of our Sun. The second type is a supermassive black hole, with a mass up to a billion times greater than that of our Sun.
In addition to the difference in mass between these two types of black holes, what also differentiates them is the distance from their center to their “event horizon,” a measure called radial distance.
A person who falls into a supermassive black hole would probably survive. (Leo and Shanshan Rodriguez / CC BY-ND)
The event horizon of a black hole is the point of no return. Everything that passes this point will be swallowed up by the black hole and will disappear forever from our known Universe.
On the horizon of events, the gravity of the black hole is so powerful that no mechanical force can overcome or counteract it. Even light, which moves faster in our universe, cannot escape, hence the term “black hole”.
The radial size of the event horizon depends on the mass of the respective black hole and is key for a person to survive falling into one. For a black hole with a mass of our Sun (a solar mass), the event horizon will have a radius of just under 3 km.
A person approaching the event horizon from a solar-sized black hole. (Leo and Shanshan Rodriguez / CC BY-ND)
In contrast, the supermassive black hole at the center of our Milky Way galaxy has a mass of approximately 4 million solar masses and has an event horizon with a radius of 7.3 million miles or 17 solar radii.
Therefore, someone who falls into a stellar-sized black hole will get much, much closer to the center of the black hole before passing the event horizon, rather than falling into a supermassive black hole.
This implies, due to the proximity of the center of the black hole, that the attraction of the black hole on a person will vary by a factor of 1 billion times between the head and feet, depending on what the free fall is.
In other words, if the person falls to the feet first, as they approach the event horizon of a black hole of stellar mass, the gravitational attraction of their feet will be exponentially greater. compared to pulling the black hole in the head.
The person would experience spaghetti and probably would not survive stretching into a long, thin, noodle-like shape.
Now, a person falling into a supermassive black hole would reach the event horizon much farther from the central source of gravitational attraction, meaning that the difference in gravitational attraction between the head and toes is almost nil.
Thus, the person would pass through the horizon of events without being affected, would not stretch into a long, thin noodle, would survive and float painlessly past the horizon of the black hole.
Other considerations
Most black holes we observe in the Universe are surrounded by disks of very hot material, which mostly include gas and dust or other objects such as stars and planets that got too close to the horizon and fell into the black hole.
These disks are called accretion disks and are very hot and turbulent. They are certainly not hospitable and would make the trip to the black hole extremely dangerous.
To get into it safely, you should find a supermassive black hole that is completely insulated and does not feed on surrounding material, gas, or even stars.
Now, if a person found an isolated supermassive black hole suitable for scientific study and decided to venture, everything that was observed or measured inside the black hole would be confined within the event horizon. of the black hole.
Given that nothing can escape gravitational attraction beyond the event horizon, the falling person would not be able to send any information about their findings beyond that horizon. His journey and his findings would be lost to the rest of the entire Universe of all time. But they would enjoy the adventure as long as they survived … maybe … 
Leo Rodriguez, assistant professor of physics at Grinnell College and Shanshan Rodriguez, assistant professor of physics at Grinnell College.
This article is republished from The Conversation under a Creative Commons license. Read the original article.