[SEQ RERUN] Reductionism

MinibearRex

Today's post, Reductionism was originally published on 16 March 2008. A summary (taken from the LW wiki):

We build models of the universe that have many different levels of description. But so far as anyone has been able to determine, the universe itself has only the single level of fundamental physics - reality doesn't explicitly compute protons, only quarks.

Discuss the post here (rather than in the comments to the original post).

This post is part of the Rerunning the Sequences series, where we'll be going through Eliezer Yudkowsky's old posts in order so that people who are interested can (re-)read and discuss them. The previous post was Qualitatively Confused, and you can use the sequence_reruns tag or rss feed to follow the rest of the series.

Sequence reruns are a community-driven effort. You can participate by re-reading the sequence post, discussing it here, posting the next day's sequence reruns post, or summarizing forthcoming articles on the wiki. Go here for more details, or to have meta discussions about the Rerunning the Sequences series.

Today's post, Reductionism was originally published on 16 March 2008. A summary (taken from the LW wiki):

We build models of the universe that have many different levels of description. But so far as anyone has been able to determine, the universe itself has only the single level of fundamental physics - reality doesn't explicitly compute protons, only quarks.

Is that my option 3? ETA: I still don't know what your point is. Try s/explaining/predicting in my previous comment.

ETA 2: The meaning of your original comment is what I really don't get. Eliezer is saying that reality consists of elementary particles, not elementary particles and other things. You don't seem to be disagreeing with this, but you're depreciating the proposition somehow. You say it's not predictive, but what is the significance of that? The fact that every natural number has a successor won't help you do arithmetic, but it's still true; and you really can do arithmetic with the larger axiom set of which it is a part. Analogously, the proposition that everything is made of elementary particles is not in itself very predictive, but it is a property of fundamental theories which we use and which are predictive.

Eliezer is saying that reality consists of elementary particles, not elementary particles and other things. You don't seem to be disagreeing with this, but you're depreciating the proposition somehow.

What I am saying is that this is irrelevant for higher-level concepts. You can make the same brain out of neurons, or, if you believe in upload, out of bits. It will have all the same cognitive processes, same biases etc. Knowing that the former can be eventually decomposed into subatomic particles adds nothing to our understanding of psychology.