The Buddha knows everything in this universe via his mind alone. Can I do the same? I want to know what is inside a black hole.
Please consider having a better look at MN 63. Here's an excerpt which might be relevant for you:
It's just as if a man were wounded with an arrow thickly smeared with poison. His friends & companions, kinsmen & relatives would provide him with a surgeon, and the man would say, 'I won't have this arrow removed until I know whether the man who wounded me was a noble warrior, a brahman, a merchant, or a worker.' He would say, 'I won't have this arrow removed until I know the given name & clan name of the man who wounded me... until I know whether he was tall, medium, or short... until I know whether he was dark, ruddy-brown, or golden-colored... until I know his home village, town, or city... until I know whether the bow with which I was wounded was a long bow or a crossbow... until I know whether the bowstring with which I was wounded was fiber, bamboo threads, sinew, hemp, or bark... until I know whether the shaft with which I was wounded was wild or cultivated... until I know whether the feathers of the shaft with which I was wounded were those of a vulture, a stork, a hawk, a peacock, or another bird... until I know whether the shaft with which I was wounded was bound with the sinew of an ox, a water buffalo, a langur, or a monkey.' He would say, 'I won't have this arrow removed until I know whether the shaft with which I was wounded was that of a common arrow, a curved arrow, a barbed, a calf-toothed, or an oleander arrow.' The man would die and those things would still remain unknown to him.
Buddhist meditation is about understanding misery and the way out of misery. Main aim is to get understanding of this process 4 Noble Truth.
You will get other insights in the process. I am not sure about whether you will get insights on what you are seeking. But this is a by product than a goal of Buddhist meditation.
The Therevada stand has been covered. The details of a black hole are metaphyiscal speculations, which in general discouraged, or at least set aside as irrelevant to the Buddhist path.
In Mahayana, in the 10 grounds of the Bodhisattva path, the first seven grounds mostly are paramitas, the 8 fold path, but the last three stages you become essentially a celestial Buddha with the same powers and abilities of pretty much any mythical god-- including omniscience. ref: http://en.wikipedia.org/wiki/Ten_Stages_Sutra
Now what one would wants to do with this Sutra is a different story-- on one hand, you can look at it as being literally true and spoken by a meditation master who saw this while meditating and therefore it has to be true.
(now entering my personal opinions) Or you can look at it some otherway-- I suspect the real point of the possibility of becoming a celestial Buddha was to emphasize how valuable & worthy it is to be enlightened, a way of encouraging Bodhichitta (the motivation to strive on the Buddhist path) in the readers.
Elsewhere in the Avatamsaka, readers are encouraged to study all sorts of topics including mathematics-- so astrophysics would be on the list-- although the value of academics in Mahayana Buddhism appears to be its value in being of use to others, less so the intrinsic value of just knowing a lot.
I do not recall any teaching where the Buddha is said to know what is inside a black hole. In fact Buddha specifically states not to spend time with contemplating the heavens. The Buddha focused his attention on the present moment, which rarely includes black holes.
We go beyond outward appearances or signs and come to "signlessness."At first, we think that the members of our family are separate from one another, but afterwards we see that they contain each other. You are the way you are because I am the way I am. We see the intimate connection between people,and we go beyond signs. We used to think that the universe contains millions of separate entities. Now we understand "the nonexistence of signs." -Thich Nhat Hanh, The Heart of the Buddha's Teaching
The Buddha knows everything in the universe because he understands interbeing. He undersands that everything is interdependent on each other thing. There is no separate independent black hole in the center of the galaxy that is separate then the keyboard I am using to type this response. The Buddha can look at this keyboard in front of me and see the trees, the sun, the people who designed and created this keyboard, the black hole in the center of the galaxy holding us all together, and even you and me.
The Buddha said, "Dear friends, I have seen deeply that nothing can be by itself alone, that everything has to inter-be with everything else. I have seen that all beings are endowed with the nature of awakening." -Thich Nhat Hanh, The Heart of the Buddha's Teaching
Are you sure that "The Buddha knows everything in this universe via his mind alone."? And if so, where do you know from?
If you want to know what is inside a black hole I recommend a textbook on general relativity like
"Thorne, Kip: Black holes and time warps".
A bit more speculative is
"Susskind, Leonard; Lindesay, James: An introduction to Black Holes, Information and the String Revolution. The Holographic Universe".
Susskind gives some information about the subject in his talk "Inside black holes" https://www.youtube.com/watch?v=yMRYZMv0jRE
Since the classical solutions of Einstein's field equations by Schwarzschild, Kerr and Kruskal we know a lot about the geometry of spacetime inside black holes. But the current conjectures about Bekenstein-Hawking entropy seem to me still a field of active research.
Nevertheless I assume that you want to know "everything" about black holes. Physics cannot fulfill this desire. But in my opinion, nobody can.
You have to practice to become a Buddha in order to reach your goal and not just a silent Buddha but a fully enlightened Buddha. A fully enlightened Buddha can know everything and anything he directs his mind at, e.g. The Four Imponderables or the black hole phenomena.
Yes, through proper (read Theravadin) Buddhist practice, an intellectual person, curious of many things will unwittingly, effortlessly gain understanding of many things about himself and the universe.
He can intentionally direct his prajna wisdom to any subject and understand it completely.
This is all I will share/write because there is so much information available. You can research the rest about the different types of prajna wisdom on Bill's meditationexpert.com site and most importantly cultivate mindfulness meditation (samatha) and vipassana. (When you have a question in your mind after stabilizing your mind through meditation, the answer will come--unless you crave the answer too strongly.)
On the other hand, if you want to experience whatever is in consciousness, Buddhism is a path to awakening consciousness. The problem is what you think is a black hole now stands in the way of your experiencing it in meditation. If you think of a black hole not as a vortex as it is often depicted, but as part of the dark matter and energy that scientists say compose 96% of the invisible universe. So Buddhism can lead you beyond the 4% of the visible to the 96% of the invisible and possibly unknowable by intellectual means. However consciousness has no such limits. So getting back to your question, if you want to study black holes scientifically, then other sites and practices would be better. On the other hand if your curiosity is even bigger to experience all there is in consciousness, then Buddhism offers you a way to get there. Meditation is the most likely tool you would want. Here is one type of meditation that you could practice http://zmm.mro.org/teachings/meditation-instructions/ If this seems suitable to you, then I would most definitely read a few pages a day of Shunryu Suzuki's treatise on meditation that goes even beyond concepts of Buddhism.
If you want just the meditation, mindfulness could be a useful practice: https://thebuddhistcentre.com/text/mindfulness-breathing
For whatever sincere reason you have to start practicing, I heartily endorse your entry. If it is right for you other doors will open. And in any case you will learn the most basic practice of being alive through being aware of the breath.
What buddha taught is know as the ultimate truth
He discovered way to out of the misery through that. Hinduism explains something about 6 chakras which controls the whole universe, they say that if you unlock the all the chakras you will gain access to ultimate truth.
It is said that budhha tried everything in the Dambadiwa or Simply India, but everything was useless then only he self discovered the ultimate truth.
The main excersise he did was Ana-pana-sathi, which concentrate on the breath.
You can't directly jump to this you have to go throught Samatha then Vidarshana to Anapanasathi.
One could practice meditation until arriving at the knowledge of what is inside a black hole. However, it is less clear how long such a meditation could take. Perhaps it may take a million years or more to reach such extended awareness.
Along the way, one's meditation may lead one to understand other things closer to home. Perhaps on the way one acquires awareness of why a teacher never replies to emails, or just exactly what is down in the crack between a car's seat and the center console, or where one's taxes go after they are sucked in by the IRS.
One may even become aware of why one wishes to acquire knowledge of black holes, and find that the answer to this question is even more valuable than knowing the contents of black holes in the first place. At this time, one could choose to set aside the search for such knowledge, and continue along a path of one's choosing.
The choice is always your own.
I think it is possible to know everything in universe by meditating. Our mind has many un-explored powers. The kind of visualization that we generate during our dreams while asleep is a demonstration of this. Ofcourse, that happens unintentionally but it is my firm belief that we can visualize anything intentionally by meditating on it. In the starting it would feel like we would be thinking of the topic of interest (black holes in this case) by LOGIC based on whatever we know of it but as we keep continuing our meditation on that subject, we will eventually reach a state of thoughtlessness. The first level of transformation which Buddha says will be that we will forget about our own body but still have a feeling that "I" am meditating of the "Subject". The second level of transformation which Buddha says will be that "Subject" is being observed. The third level of transformation will be that "I" am "Subject". I think when we reach to the third level, all the knowledge of the "Subject" will transfer to our mind and we will magically know everything about something alien like black holes. Hindu mythology gives a lot of examples that our "Rishis" knew about Astrology, electricity, magnetism just by meditation.
I think this is the only way to know the truth behind all science.
Mindfulness Buddhist practice is about what is in your experience and what is in harmony with your experiential reality as it is in the present moment. Experiencing reality like this as much as possible, through all the sense doors, moment by moment, with good morality and concentration, will soon turn mundane awareness of reality into something supermundane, something like experiencing the center of a blackhole but even more useful.