The overall concept of a black hole is the idea of “Trapping”, some can enter the black hole but cannot escape. Black holes exist due to gravity. Gravity is a universal force that makes everything attract everything else. If you put a lot of masses within the same region, then they will be pulled in from the attraction of a different mass, creating a black hole. The story of the black hole went through 4 iterations.
Iteration #1:
– Newton’s Law of Gravitation
– Newton’s Law of Motion
– In 1783 John Mitchell used Newton’s principles to come up with the idea of a dark star
– This came to a dead end because it isn’t considered a black hole due to Newton’s laws state that things can escape rather (not a black hole)

Iteration #2:
– Albert Einstein’s Theory of General Relativity in 1915
– General relativity is a consistent theory on its own, and this theory predicts the existence of black holes which trap anything that falls into them.

Iteration #3:
– Stephen Hawkings in 1975 still uses the idea of general relativity but adds the thought of quantum theory.
– a problem that comes up is the black hole paradox
– in this third iteration, we find that mass (or equivalently, energy) is not trapped, while information is either lost or trapped, depending on our assumptions about the endpoint of black hole evaporation.

Iteration #4:
– Gravity is described by a quantum theory of spacetime
– Matter is described by quantum theory as well
– the hole takes the form of a fuzzball, which traps neither energy nor information

I vaguely knew what a black hole was; a dense tiny ball of what I thought was anti-matter? It doesn’t seem terribly relevant because Dr. Mathur did an incredible job of breaking this incredibly difficult physics concept down to something that made sense to someone who has NEVER taken a physics class…

I found it really interesting that there was so much progress made on the topic of black holes by just one person. Though I did have a vague idea of what a black hole was, I had zero clue that this was the topic of Hawking’s research, and what presumably made him so famous. The man is more brilliant than I even thought – I was looking through the book he wrote with a colleague and my head hurt just looking at the calculations. It is so crazy to me that an actual human mind came up with this theory and had enough mathematical evidence to publish it. I imagine the feeling I had reading his book is comparable to the feeling that people had reading Newton’s book a couple centuries ago!

Another bit I found intriguing during Dr. Mathur’s talk was string theory. He briefly summed it up, but it kind of caught me off guard that he was teaching every bit of Hawking’s work and discussed how incredible it was that he had this breakthrough, but Dr. Mathur doesn’t believe it himself! How crazy is that? I found that maybe the emphasis was more on how genius Hawking truly was, not that scientists today are trying to prove him wrong.

I would love to visit the spot Hawking walked along on the river, maybe I can channel some of his genius for my midterm after break… (haha)

Since I was unable to attend the lecture, I read “What is a Black Hole”. I have zero background information on black holes, so this reading was very interesting. The first description of black holes using Newton’s law made sense and was easy to follow. The second description using Einstein’s theories was slightly more difficult to comprehend. In order to even begin to understand the third or fourth descriptions, I had to read them multiple times and look at the quiz. I still could not not explain them, but I could explain the issues with Hawking’s description and how the fuzzball theory remedied that problem. As I looked at the images that accompanied each description, I noticed that Einstein’s image looked familiar. I found it interesting that in popular media (movies/tv shows), Einstein’s theory of the black hole is used as a depiction, despite being disproved. I wonder if this is because it looks cool and is easier for the general public to understand (compared to the current fuzzball theory) or if there is simply a lack of knowledge in those who create science fiction works.

Dr. Mathur’s talk was very fascinating. I was first introduced to Stephen Hawking when I read selected chapters from his book “Black holes and Baby Universes and Other Essays”. I was so fascinated by his ideas about black holes. Dr. Mathur was able to explain black holes in a way his audience would understand. As Hawking is a little hard to understand at times, I really appreciated his talk. Another book I read by Hawking that is fascinating and I recommend everyone read is “Brief Answers to the Big Questions” published after his death. In it, he attempts to answer many of the questions humans and science have about the universe. It is divided into Why are we here? Will we survive? Will technology save us or destroy us? and How can we thrive?. In it he goes into the mechanics of black holes. I guess that is his way of defending his theory. Form Dr Mathur’s lecture, String Theory attempts to invalidate black holes and present a different solution. Because physics can’t have infinity as a solution.

To me, Dr. Mathur’s ability to so clearly and concisely explain astrophysics concepts was almost more amazing than the subject matter itself. I’ve known generally what a black hole is and that Stephen Hawking became well known in part due to his work on them, but why there might be black holes, how they functioned, and what Stephen Hawking’s research on them was weren’t questions I had thought much of. If I had, I probably would have assumed that these things would be completely beyond my understanding before Dr. Mathur’s lecture.

Dr. Mathur suggested that a “string star” model would work better at explaining how black holes work than Hawking’s model, where density could be infinite within a black hole’s event horizon anwhere, with a small enough radius and strong enough gravity, new particles could “pop” into existence. Whether they end up being true or not, these hypotheses were pretty fascinating to me.

I really enjoyed Dr. Mathur’s talk! I’m really glad he focused on black holes during his lecture because I’ve always been fascinated by the topic. I didn’t even realize that Stephen Hawking’s work revolved around understanding black holes better. The way that Dr. Mathur presented the information was very digestible, even though the concept can be hard to understand at first. His lecture reminded me of reading about different scientific discoveries in “A Short History of Nearly Everything” by Bill Bryson.

I appreciated that Dr. Mathur began the lecture by describing exactly what a black hole is and the different research being conducted on black holes leading up to Hawking’s involvement with Roger Penrose. Imaging Hawking walking around the lawns of Cambridge University while thinking about black holes made me want to visit such a historic place. I definitely have a better understanding of Stephen Hawking’s work, Hawking radiation, and the information loss paradox after the lecture.

After seeing Dr. Mathur on the OSU 150 Innovations page, I was very glad that he explained his research to us. I haven’t looked into string theory before, but Dr. Mathur’s description of his work sparked my interest. I was also blown away by his explanation of the photo of the black hole that we discussed in class!