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February 13, 2006

Sampling science

Three things that recently caught my attention in my web-trawling:

The first is newly published work by a team of MIT neuroscientists who study rats and memory. They discovered that the neurons in rat brains have an instant-replay behavior that kicks-in during the idle periods between actions. Except, this is not the replay that many of us experience just after learning a new task, when we play the events over in our mind sequentially. No, rats think about things in reverse and at high-speed!

D. J. Foster and M. A. Wilson Nature, advance online publication 10.1038/04587 (2006)

The second is a recent posting on arxiv.org by three Argentinian mathematicians on the quality of fits to power-law distributions using the standard least-squares method. Given my own interest in power laws, and my own work on statistical methods for characterizing them, this paper confirms what many of us in the field have known in practice for some time: least-squares is a horrible way to measure the scaling exponent of a power law. From the abstract:

In this work we study the condition number of the least square matrix corresponding to scale free networks. We compute a theoretical lower bound of the condition number which proves that they are ill conditioned. Also, we analyze several matrices from networks generated with the linear preferential attachment model showing that it is very difficult to compute the power law exponent by the least square method due to the severe lost of accuracy expected from the corresponding condition numbers.

And finally, although touch-sensitive screens are (almost) everywhere today, they are merely single-touch interfaces. That is, you can only touch them in one place at a time. Enter multi-touch interfaces (direct link to the video), developed by a team at NYU. Reminscient of the interfaces seen in Minority Report and The Island, in which table-top or wall-sized displays interact with users via "gestures". I can't wait until I can get one of these things.

posted February 13, 2006 04:34 AM in Scientifically Speaking | permalink

Comments

Posted by: Dave Bacon at February 13, 2006 04:55 PM