What Do Trees and Math Have in Common?

After watching "A Beautiful Mind," I got to thinking about how weird it would be to not be able to discern between reality and delusion. I started thinking about certainty. This got me to thinking about trees.

You have heard the old question:
"If a tree falls in the forest, but no one is there to hear it, then does the tree make a sound?"

I'm sure you've thought about this question at some point or another. It gets at the idea that we can't have complete certainty of something's existence (in this case, sound) without perceiving it ourselves.

In one of the discussion-based philosophy courses that I took, we talked about knowledge and certainty, and this same question came up. However, the professor changed it up a bit. He and a student in the class had the following discussion in class (a paraphrase):
Professor: "If tomorrow, at noon, humanity ceased to exist, then would mathematics also cease to exist?"
Student: "Yes, because mathematics is a creation of humanity."
P: "So are you arguing that all creations cease to exist when their creators cease to exist?"
S: "Uh, yah, I guess so."
P: "Ok. Tell me something. Is your great grandmother still alive?"
S: "No."
P: "When she passed away or ceased to exist here on earth, did your grandmother (her daughter) also cease to exist?"
S: "Ok, I see your point. But humans are different from things."
P: "Alright then, lets look at the creator of this building. Do you suspect that when he or she ceases to exist, that this building will consequently cease to exist?"
S: "No, I guess not. What I was trying to say is that math only exists in peoples' thoughts. When people cease to exist, so do their thoughts. Therefore so does math."
P: "What do you mean when you say mathematics exists only in thoughts?"
S: "Well, take the number 3 for example. The word 'three' and the symbol '3' are just constructions, created by humans for the purpose of explaining certain occurences in nature. So in essence '3' means nothing without a human to give the symbol significance."
P: "Oh I see. So you are not saying that the occurence, for which the symbol '3' was created, would cease to exist as a result of humanity ceasing to exist. Just the significance of the symbol '3' would cease to exist."
S: "Thats right."
P: "Lets look at a particular mathematical truth: 1+1 = 2 . So when humans cease to exist tomorrow at noon, the symbols '1', '+', '=', '2' would lose their meaning. But would the principal that underlies the sybols cease to exist. Lets look at another example: the standard gravity constant, 'g', which is used to explain the acceleration due to gravity on earth. Once again, when humans cease to exist, so does the significance of the symbol 'g'. But does that mean that gravity itself ceases to exist? Would the old rule of 'what goes up must come down' cease to exist?"

Would love to continue discussion on these questions.

Philosophical questions brought about by Vas

Several things were talked about today (or yesterday since it is 2:30am) during the discussion on Vas that I wanted to open up conversation on.
We talked very briefly about determinism v. choice. This is the subject of the Blog post "Are we robots?" that I posted two weeks ago. Basically, I was pointing out that determinism (choice is an illusion, everything is determined) seems to be the logical result if humans are purely matterial beings. I would love to continue the discussion that was sparked from this.
We also talked a little about altruism, selfless acts. Many people, not including myself, believe that altruism is impossible for human beings. Everything we do, we do for our own interests, some people think. This is a philosophical stance called egoism. People like Freud and Hobbes are convinced that humans are incapable of altruism. It was brought up in class that people act altruistically but they are really just after the good feeling associated with it. I find this to be a sort of jump in logic. Suppose that it is proven that there is some positive chemical effect in the brain associated with selfless actions. Association does not imply causation. How can one say the good feeling causes us to act selflessly? To assume that this is the only possible motive is begging the question, assuming the conclusion that someone can't have selfless motives.
Morality was also mentioned. This must have evolved along with conciousness and free will. This doesn't seem natural to me. How can right and wrong, good and evil exist if everything is simply material? If everything is determined by genes and neurons, then how can we say that any action is wrong or right. Choice must exist for morality to exist. And something beyond matter and energy must exist for choice to exist.
I would love to hear some of your thoughts on these things that I have been thinking about.

Sci-Fi is about ideas

Clive Thompson has an editorial in Wired Magazine on science fiction’s role in the world of ideas that I thought was an interesting coda to our conversation in class today.

From where I sit, traditional “literary fiction” has dropped the ball. I studied literature in college, and throughout my twenties I voraciously read contemporary fiction. Then, eight or nine years ago, I found myself getting—well—bored.

Why? I think it's because I was reading novel after novel about the real world. And there are, at the risk of sounding superweird, only so many ways to describe reality. After I'd read my 189th novel about someone living in a city, working in a basically realistic job and having a realistic relationship and a realistically fraught family, I was like, “OK. Cool. I see how today’s world works.” I also started to feel like I’d been reading the same book over and over again.

via Boing Boing