| | | | |

## Monday, February 27, 2012

### Black Holes and Elementary Particles: Part 2 (Math #63)

1. Fascinating concept and a radical "spin" on the equals sign. I struggle to visualise though how a massive black hole's mass could be reduced to that of a fundamental particle or am I completely missing the point?

1. Black Holes come in different sizes, so, as far as I understand it, there are ones that are extremely small (fundamental particle scale), however, a massive black hole's size would not be that small.

Here is an example I copied from wiki:

"A black hole the weight of a car would have a diameter of about 10−24 m (10 to the power of negative 24) and take a nanosecond to evaporate, during which time it would briefly have a luminosity more than 200 times that of the Sun."

2. Fascinating, I know this is getting of topic Cycho so feel free to kill the thread.

If black holes are created when a massive star's core collapses and becomes so dense that its gravitational pull keeps light from escaping, is it even possible to have a black hole with so little mass that it could be confused with a fundamental particle?

I can see how you hit a dilemma with the notion of equals and also how it's not simply sufficient to say A=B without considering the properties of the two. A notion not unfamiliar to object oriented software developers.

1. > "is it even possible to have a black hole with so little mass that it could be confused with a fundamental particle?"

This is the exact same question that lead me to make these two videos. I came across it when reading "The Elegant Universe" by Brian Greene. It blew me away in one sense, but also was able to consolidate a few thoughts/beliefs/facts/questions that I had across in my studies/research/hobbies.

The best way I was able to share my thoughts and my "dilemma", as you put it, was connecting black holes and elementary particles through the equal sign. Thoughts like this occupy my mind when I free up enough time to daydream.

I'm not a programmer so I'm not familiar with object oriented software development. Can you tell me when it is that you encounter this type of problem?

2. ps. I rarely kill threads. Only when they are way off topic and this definitely is not :)

3. In object oriented software development one can define an object say "Person" and associate properties such as gender, age, height. We can then create instances of object type Person but set their properties to different values. A test for equality of two Person objects would result in a negative if their respective properties differ but the objects themselves are both are a "type" of Person object.

So in your example we could have two instances of a Black Hole but with the same values for Rotation (was it), Spin and Mass and a test for equality would yield a positive result, but we couldn't determine if one was a fundamental particle as that property wasn't associated with our Black Hole object. The exact point you're making I think. I've never thought that deeply until now what it means to say one thing equals another in a mathematical context, does infinity = infinity :-)

Thanks for the reference to "The elegant universe" one to add to my reading list, assuming that is I don't need to be Dr Sheldon Cooper to understand it :-)

1. Thanks, Ivan. I can see how this works the same way - for very similar objects you would just have to have enough properties to be able to distinguish them, if that is what you wanted to do. Along the same lines as black holes and elementary particles, past their three main properties anyway.

As for infinity = infinity, that's a big questions. Check out the following documentary, "Dangerous Knowledge (TV 2007)". Great doc, one of my favorites.

As for the elegant universe, the first 3/4 is an easy read of sorts and in my opinion very accessible. The last 1/4, that was tougher :)