To solve the mysteries of black holes, one only has to dare to do so.
However, there is a rather complicated catch: one can only do this if the respective black holes are supermassive and isolated, and if the person entering the black hole does not expect to report the findings to anyone in the entire universe.
We are both physicists studying black holes, albeit at a very safe distance. Black holes are one of the most common astrophysical objects in our universe.
These intriguing objects appear to be an essential ingredient in the evolution of the universe, from the big bang to the present day. It probably had an impact on the formation of human lives in our own galaxy.
A person falling into a black hole and being stretched. (Leo Rodriguez / Shanshan Rodriguez / CC BY-ND)
Two types of black holes
The universe is littered with a large zoo with different types of black holes.
They can vary in size and be electrically charged, just as electrons or protons are in atoms. Some black holes actually turn. There are two types of black holes that are relevant to our discussion.
The first turn is not electrically neutral – that is, not positively or negatively charged – and has the mass of our sun. The second type is a supermassive black hole, with a mass of millions to even billions of times larger than that of our sun.
In addition to the mass difference between these two types of black holes, they also distinguish the distance from their center to their “event horizon” – a measure called radial distance.
Someone who falls into a supermassive black hole is likely to survive. (Leo & Shanshan Rodriguez / CC BY-ND)
The event horizon of a black hole is the point of no return. Anything that passes this point will be swallowed up by the black hole and disappear forever from our known Universe.
On the opportunity horizon, the gravity of the black hole is so powerful that no mechanical force can overcome or counteract it. Even light, the fastest moving thing 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 holes and is the key for a person to survive to fall into one. For a black hole with a mass of our sun (one solar mass), the event horizon will have a radius of just under 3 km.
A person approaching the horizon of a black hole with a song size. (Leo and Shanshan Rodriguez / CC BY-ND)
The supermassive black hole at the center of our Milky Way galaxy, on the other hand, has a mass of about 4 million solar masses and has an event horizon with a radius of 7.3 million miles or 17 sunbeams.
So, someone who falls into a star-like black hole will come much, closer to the center of the black hole before passing the event horizon, as opposed to a supermassive black hole.
Due to the proximity of the center of the black hole, it implies that pulling the black hole on a person will differ a factor of 1000 billion times between head and toes, depending on what causes the free fall.
In other words, if the person falls first feet, when they approach the event horizon of a stellar mass of black hole, the gravity on their feet will be exponentially greater compared to the black hole’s tug on their head.
The person will experience spaghetti identification and is unlikely to survive being stretched into a long, thin noodle-like shape.
Now, someone falling into a supermassive black hole will reach the horizon of the event far beyond the central source of gravity, which means that the difference in gravity between head and toes is almost zero.
Thus, the person would pass through the horizon untouched, not be stretched into a long, thin noodle, survive and float painlessly beyond the horizon of the black hole.
Other considerations
Most of the black holes we observe in the universe are surrounded by very hot material disks, mostly made of gas and dust or other objects such as stars and planets that have come too close to the horizon and fallen into the black hole.
These disks are called growth disks and are very hot and turbulent. They are certainly not hospitable and this will make the danger of driving into the black hole very dangerous.
To safely enter one, you need to find a supermassive black hole that is completely insulated and does not feed on surrounding material, gas or even stars.
If someone now finds an isolated, supermassive black hole suitable for scientific study and decides to go in, anything observed or measured on the inside of the black hole will be confined within the event horizon of the black hole.
Keeping in mind that nothing can escape from gravity beyond the horizon of the event, the person who falls would not be able to send any information about their findings back outside this horizon. Their journey and findings would be lost for the rest of the entire universe for all time. But they would enjoy the adventure as long as they survived … maybe … 
Leo Rodriguez, Assistant Professor of Physics, Grinnell College, and Shanshan Rodriguez, Assistant Professor of Physics, Grinnell College.
This article was published from The Conversation under a Creative Commons license. Read the original article.