# How to shorten this speech about BH?

• B
• avischiffman
In summary, the conversation discussed the topic of black holes and how they relate to the information paradox. Black holes are regions in spacetime with infinite density and virtually zero volume, and they emit Hawking radiation which causes them to "evaporate" over time. The information paradox arises when objects and their information fall into a black hole, and it is theorized that the information is stored on the event horizon and imprinted on the Hawking radiation. However, this raises questions about the conservation of information and the laws of quantum mechanics. Some physicists propose the Holographic Principle, which suggests that the information is not destroyed but rather represented as a 2-dimensional image on the event horizon. Ultimately, the conversation highlights the ongoing debate and search
avischiffman
Hi guys I am writing a speech for a school video and I have a maximum of 3 minutes, but I've written 4 minutes and 17 seconds worth of stuff.

I need help cutting the fat away giving me around 2 minutes and 45 seconds worth of stuff so that I can have some quick experiments and speak slower so it's easier to understand. If you guys could help me on cutting it down a bit that would be super helpful! Thanks!

Speech:
1. What are Black Holes? The information paradox is something that took scientists tens of years to understand, so let’s understand it in 3 minutes. Before we go deeper we need to understand what hawking radiation and a black holes are. Black holes are regions in spacetime with a core called a singularity with infinite density and virtually zero volume. The sphere that surrounds a black hole has a radius that can be calculated if you know the mass of the black hole. This is called the Schwarzschild radius, and surface area that surrounds the sphere is called the event horizon.
2. Hawking Radiation. Another key concept we need to understand is Hawking Radiation, and how it causes black holes to “evaporate.” Over time, the mass of a black hole decreases as it emits particles in the form of radiation. When a pair of virtual particles appear next an event horizon, one particle crosses and the other particle escapes. Therefore, to ensure that conservation of energy is conserved, a black hole loses some of its mass in exchange for the virtual particle.
3. What is information? So what is this “information”? In quantum mechanics, information is basically the arrangement of particles in a specific way. For example, if you arrange carbon atoms in a certain order, you get graphite. If you arrange those same atoms in a different way, you get diamonds. This is stored as what we call information, it’s kind of like if our universe was a giant computer storing everything as 1’s and 0’s. Picture a book. Now picture throwing it into a fire. It’s gone, right? Actually not really. If you could get back all the ashes and collect all the light and heat you could theoretically rebuild the book. The information of the book is not gone, it’s just hard to read.
4. The Information Paradox. Suppose say there was a black hole, and I threw a fish inside it. According to our understanding of the universe, the fish’s information should come out as hawking radiation, but instead we get nothing. Hawking radiation is like a giant cosmic eraser that wipes out information as the black hole evaporates, and when it finally dies it leaves no trace that any information was ever there. Sounds like we got an information paradox, and the journey for an answer has come up with numerous solutions, including that our universe may actually just be a hologram.

Is it too late to change the topic? This comes across much more like a parade of buzzwords than anything else, and in reading it, I don't get the feeling you understand what you are talking about - instead, you're parroting back popularizations.

martinbn
You have three minutes?
I wouldn't want to cover more than #1 and #2 in that time: what is a black hole and what is Hawking radiation.

I would also suggest a total re-write that considers your audience. No buzz words, just easy to swallow facts.

For example, "A black hole is a star of a certain size that has expended all of it's fuel."

D English said:
For example, "A black hole is a star of a certain size that has expended all of it's fuel."

I would alter this to "A black hole is formed when a sufficiently massive star has expended all of its fuel and collapses under its own gravity."

avischiffman said:
If you guys could help me on cutting it down a bit that would be super helpful!

I think it needs more than cutting down, it needs correction. First I think we need to understand what audience this is intended for. You say it's a school video; what grade level?

Mentors' note: This thread was initially posted to Cosmology and then moved to Quantum Physics. It touches on astrophysics and general relativity as well as quantum mechanics, but there's more QM in it than anything else which is why it's in Quantum Physics.

Is it too late to change the topic? This comes across much more like a parade of buzzwords than anything else, and in reading it, I don't get the feeling you understand what you are talking about - instead, you're parroting back popularizations.
That's true, Ill go back and reword a lot of it to make it look more like I understand and less like I'm just a parrot!
Nugatory said:
You have three minutes?
I wouldn't want to cover more than #1 and #2 in that time: what is a black hole and what is Hawking radiation.
The topic I chose was the information paradox and I didn't want to spend to much time on black holes and Hawking radiation but I thought it would be helpful to understand those two topics to understand the more advanced part.
D English said:
I would also suggest a total re-write that considers your audience. No buzz words, just easy to swallow facts.

For example, "A black hole is a star of a certain size that has expended all of it's fuel."
I think I'll rewrite it and try and add more visual parts to help people understand with less complicated words. Thanks!
PeterDonis said:
I think it needs more than cutting down, it needs correction. First I think we need to understand what audience this is intended for. You say it's a school video; what grade level?
Knowledgeable high school students - kinda like a science thing.

Keep in mind I am going to have a lot of animations and experiments to keep the audience engaged and whatnot. So for example if I say something like "a star fuses heavy elements", I'll have on the screen all the other heavy elements it fuses.

Thanks I'll take a look!

You're welcome. BTW, for speeches like this, are you required to have a bibliography page at the end or something where you list your sources that you used in putting the presentation together? Just curious.

Not required but I'll add a list of my sources. All of the animations will be done in after effects, it's pretty cool actually I'll post the video here when I finish it.

berkeman
avischiffman said:
Keep in mind I am going to have a lot of animations and experiments to keep the audience engaged and whatnot. So for example if I say something like "a star fuses heavy elements", I'll have on the screen all the other heavy elements it fuses.

That makes it more complex, not less. Visual aids need explanation. I think you're trying to pack a 30 minute talk into 3 minutes.

At the Toastmaster's Club (where they teach public speaking) they say that every speech needs a "so what" moment. "I said all this stuff, so what?" In other words, your planning should focus on what the audience gets from your talk, not what you gave. I don't think a high school audience would get much at all from what you wrote because there are too many hard words, and too many ideas in a short time.

May I suggest this, use the Wikipedia article on the information paradox as your source.
but write a speech about the human side rather than explaining the science. This very famous very smart physicist, Stephen Hawking, said something. Other famous physicists were horrified. Here is a quote that you can include in your speech.

Stephen [Hawking] claimed that “information is lost in black hole evaporation,” and, worse, he seemed to prove it. If that was true, Gerard [’t Hooft] and I realized, the foundations of our subject [quantum physics] were destroyed. —Leonard Susskind
The argument continues even today. Hawking is dead, but still people argue about it. The bad part about is that relativity and quantum mechanics are both very important. We don't want either of them to be ruined or proved false. The good part is that hard work on this difficult paradox may some day lead to advances in science that improve our understanding of both relativity and quantum physics.

By the time you say all that, and tell more about who those people are, the three minutes will be gone. Three minutes goes awfully fast when you're speaking.

What does the audience get from that? They learn that sometimes improvements in science come from scientists arguing with each other. Those high school students probably never thought about that, so they learn something useful from your speech. Tell them that in the last sentences of your speech.

Don't forget, after writing your speech, practice giving it over and over again until you can do it without any notes.

berkeman
avischiffman said:
Ill go back and reword a lot of it to make it look more like I understand and less like I'm just a parrot!

Just making it look like you understand isn't enough. You have to actually understand.

Seriously, if you are trying to present a topic that you don't understand yourself, you are doing your audience a disservice. It would be better to just stick to what you actually do understand, even if that means you can only cover a very limited portion of the desired topic.

avischiffman said:
Knowledgeable high school students - kinda like a science thing.

Ok. If the primary purpose is to give a quick overview of the information paradox, then I would allocate maybe a paragraph (meaning three or four sentences) each to what is a black hole and what is Hawking radiation. For Hawking radiation I would just stick to this:

avischiffman said:
Over time, the mass of a black hole decreases as it emits particles in the form of radiation.
I would not talk about the "virtual particles" description since that is at best highly heuristic and at worse misleading; you will find many, many threads here on PF discussing this. The most I would say is that Hawking first discovered that this radiation should occur based on adding quantum effects to the classical model of black holes that is given by General Relativity; that's why the radiation is named after him.

As far as the information paradox itself, I would not even try to define what "information" is in any detail; the accurate technical definition is not going to be accessible to your audience, and any attempt at a non-technical definition is going to be inaccurate. I would just give the gist of the paradox, which is that quantum mechanics says that information can't be destroyed, but the model of a black hole that comes from classical General Relativity plus the quantum correction that Hawking used to predict Hawking radiation says that, if we throw a quantum state into a black hole, the information in that quantum state gets destroyed when it hits the singularity inside. These two viewpoints, as they stand, can't be reconciled, so something has to give: the question is what.

I also would not mention the holographic principle, since it is only one of a number of proposed solutions to the information paradox, and there is not general agreement among physicists on which proposed solution is the right one. (I'm not sure how we could know what solution is the right one in any case without the ability to probe the relevant physical regime experimentally, which we do not have now and do not expect to have any time soon.)

PeterDonis said:
snip
I agree with all of it except for that part. I was thinking the holographic principle should be the main focus, even if it is all theoretical because it's a lot more interesting to talk about than the anatomy of a black hole. I think cutting away what information is, or just having one sentence about it is a good idea.

That's a good idea for the first two parts, so that I can get that part over quicker. Although, a lot of people will already know what those basic parts are because it's a kind of science fair sort thing at my school related to physics so I'm hoping people will have a basic grasp on black holes. I wish I had just one more minute :/

Thanks for the advice, I'll start working on a V2 of the script :)

avischiffman said:
I was thinking the holographic principle should be the main focus, even if it is all theoretical because it's a lot more interesting to talk about than the anatomy of a black hole.

It depends on what your goal is. If your goal is just to talk about interesting stuff without worrying about whether it's established science or just speculation, that's fine. I think it's still a good idea to be clear that the holographic principle is in the latter category, though.

avischiffman said:
it's a kind of science fair sort thing at my school related to physics so I'm hoping people will have a basic grasp on black holes

That depends on whether black holes are covered in your high school level physics curriculum. Are they?

PeterDonis said:
It depends on what your goal is. If your goal is just to talk about interesting stuff without worrying about whether it's established science or just speculation, that's fine. I think it's still a good idea to be clear that the holographic principle is in the latter category, though.
That depends on whether black holes are covered in your high school level physics curriculum. Are they?
Good idea I'll say that it's all theoretical and not proven yet at the end. Um also it's kind of a specialized science fair and most people are doing quantum things so I'd say they know "enough"

avischiffman said:
Not required but I'll add a list of my sources. All of the animations will be done in after effects, it's pretty cool actually I'll post the video here when I finish it.
The two latest video of spactime are exactly on that topic. But you'll need time dilatation to fit that in 3 minutes

anorlunda and avischiffman
Ok guys I reworked it a bit, probably not done yet. Keep in mind the visuals will help a lot for something like this.

Do you know what information really is? In physics, information basically means the arrangement of particles. For example, suppose we had some carbon atoms. If I arrange them in a certain way, we get graphite. Change the arrangements a little bit, and we get diamonds. This arrangement is what we call information, also known as unitarity, and in our universe, it is impossible to erase it. For example, if I burnt a book, and collected all the ashes and particles in the room, I could theoretically rebuild the book if I had the right machine because all the information of the book was never actually destroyed. According to quantum physics, information is indestructible.

Now suppose I had a black hole, and I threw that same book into it. Wouldn’t the information now be completely destroyed when it crosses the event horizon, the supposed point of no return, disregarding what I told you earlier that information can never be destroyed? If black holes could erase information that would violate countless laws in quantum physics and could rework most of our understanding of modern physics altogether. Stephen Hawking once made a bet that all information that fell into a black hole would be lost forever, because the arrangement of particles coming out would be completely random, the information of it scrabbled. It’s as if black holes are giant cosmic erasers that seem to erase information. Creating a problem known as The Information Paradox.

The Holographic Principle is a theorized solution to the paradox. Two physicists named Gerard T’ Hooft and Leonard Susskind realized that the horizon of a black hole was similar to that of a hologram. Whatever fell into a black hole would be a 3D image projected from the horizon as a kind of indecipherable hologram.

If you were to fall into a black hole, you would end up just being a projection from the event horizon. So what’s to say that we aren’t all just a hologram from the boundary of our universe? We could all just be stretched out versions of ourselves from the outside surface of our universe. Everything we know about our reality could be wrong. The math behind it says both versions are equivalent, and until we do more tests, for all we know we could just be a movie playing for some intergalactic aliens. So until then, thanks for watching.

I don't think you have the science right in paragraph one, and you certainly don't at the end when you talk about movies and intergalactic aliens.

Is it too late to change the topic to something you have a better grasp of?

atyy
What’s wrong with paragraph 1? Also I have 8 days left to finish and I think it’s s pretty cool topic, unless you have a cool idea? I’m open to other topics

avischiffman said:
What’s wrong with paragraph 1?

We can start here.

avischiffman said:
Do you know what information really is? In physics, information basically means the arrangement of particles.

No, no, it's not.

I'm not going to play this game, where you post something wrong and we try and fix it, and then you do it again and again and again. This is an exceedingly slow and inefficient (and often ineffective - there are many examples on PF) way to learn. It's also maximally annoying to those who are trying to explain things.

It's good that you are enthused. But you need to realize that having read some popularizations does not make you an expert, and that lack of expertise means that you will be making mistakes when explaining it to others. You really want to pick a topic you understand.

Last edited:
avischiffman said:
What’s wrong with paragraph 1?

You're giving too much detail about something that you don't have a detailed understanding of. (That's true of your entire post, not just paragraph 1.) You should just say that quantum mechanics has a property called "unitarity" (which is not the same as "information"--you say it is, which is incorrect), and that property means that in QM, information can't be created or destroyed. But our understanding of black holes says that information should be destroyed when an object hits the singularity (not the horizon--you say the horizon, which is incorrect). The apparent inconsistency between these two viewpoints is what is called the black hole information paradox.

avischiffman said:
I have 8 days left to finish and I think it’s s pretty cool topic

Thinking it's a pretty cool topic is not the same as having enough understanding of the topic to go into detail about it. You don't appear to have enough understanding to do that, so you shouldn't; you should stick to general, high-level statements like the ones I gave examples of above.

PeterDonis said:
You're giving too much detail about something that you don't have a detailed understanding of. (That's true of your entire post, not just paragraph 1.) You should just say that quantum mechanics has a property called "unitarity" (which is not the same as "information"--you say it is, which is incorrect), and that property means that in QM, information can't be created or destroyed. But our understanding of black holes says that information should be destroyed when an object hits the singularity (not the horizon--you say the horizon, which is incorrect). The apparent inconsistency between these two viewpoints is what is called the black hole information paradox.
Thinking it's a pretty cool topic is not the same as having enough understanding of the topic to go into detail about it. You don't appear to have enough understanding to do that, so you shouldn't; you should stick to general, high-level statements like the ones I gave examples of above.
We can start here.
No, no, it's not.

I'm not going to play this game, where you post something wrong and we try and fix it, and then you do it again and again and again. This is an exceedingly slow and inefficient (and often ineffective - there are many examples on PF) way to learn. It's also maximally annoying to those who are trying to explain things.

It's good that you are enthused. But you need to realize that having read some popularizations does not make you an expert, and that lack of expertise means that you will be making mistakes when explaining it to others. You really want to pick a topic you understand.

Hey guys I finally finished the video.
Check it out!

sysprog
Wow -- mad props kid -- my earlier post got deleted -- someone senior to me here said it included stuff that was wrong or at best misleading, and the moderatsia said it was not B level; anyway, for my part, I really like your presentation -- very nice work ...

avischiffman
sysprog said:
Wow -- mad props kid -- my earlier post got deleted -- someone senior to me here said it included stuff that was wrong or at best misleading, and the moderatsia said it was not B level; anyway, for my part, I really like your presentation -- very nice work ...
Thanks man! I spent hundreds of hours on this it’s nice to hear good words :)

What's done is done.

What's done is done.
I think it's often better to state explicitly what is meant than it is to anticipate statement recipient inference by use of an A=A type of statement form.

sysprog

## 1. How can I make my speech shorter?

There are a few strategies you can use to shorten your speech. First, consider eliminating any unnecessary information or details. Stick to the main points and prioritize the most important information. You can also try practicing your speech and timing yourself to see where you can cut out sections. Lastly, consider using simpler and more concise language to convey your message.

## 2. Is there a recommended length for a speech?

The ideal length for a speech varies depending on the context and purpose. Generally, a good rule of thumb is to keep your speech between 5-10 minutes. However, if you are giving a presentation or speaking at a conference, you may have a designated time limit to follow.

## 3. How do I know which parts of my speech to cut?

When trying to shorten your speech, it can be helpful to ask yourself if each section is necessary for conveying your main message. Consider if any information can be combined or if certain examples can be left out without affecting the overall impact of your speech. You can also ask for feedback from others to see if there are any parts that can be cut.

## 4. Can I still include personal anecdotes or stories in a shortened speech?

Yes, you can still include personal stories or anecdotes in a shortened speech. However, make sure they are relevant to your main message and are not too long. You can also summarize the main point of the story instead of going into too much detail. This will help keep your speech concise while still adding a personal touch.

## 5. Are there any tips for delivering a shorter speech effectively?

When delivering a shorter speech, it is important to be concise and to the point. Make sure you have a clear and organized structure to your speech, and practice beforehand to ensure you stay within the time limit. Use strong and impactful language to make your points stand out. It can also be helpful to engage with your audience through eye contact and gestures to keep them engaged and focused on your message.

Replies
0
Views
906
Replies
11
Views
2K
Replies
6
Views
1K
Replies
9
Views
2K
Replies
7
Views
998
Replies
4
Views
918
Replies
3
Views
1K
Replies
29
Views
4K
Replies
17
Views
2K
Replies
4
Views
1K