Simulating the Universe with a zBox

An anonymous reader writes "Scientists at the University of Zurich predict that our galaxy is filled with a quadrillion clouds of dark matter with the mass of the Earth and size of the solar system. The results in this weeks journal Nature, also covered in Astronomy magazine, were made using a six month calculation on hundreds of processors of a self-built supercomputer, the zBox. This novel machine is a high density cube of processors cooled by a central airflow system. I like the initial back of an envelope design. Apparently, one of these ghostly dark matter haloes passes through the solar system every few thousand years leaving a trail of high energy gamma ray photons."

Comments

theoretical background

[tengwar]

I wonder if anyone can answer a naive question for me. As I understand it, the solar wind consists of charged particles moving outwards from the sun. (a) Do these have a net charge? (b) If so, does this mean that there is a net movement of charge outwards from the galaxy?

The reason I'm interested is that a non-neutral charge distribution would tend to attract the outer part of the galaxy towards the centre more than would be expected from gravity alone, which is (simplistically) the evidence for dark matter / energy.

Re:Read the entire paper: astro-ph 0501589

[StupendousMan]

There are plenty of events and areas of study which aren't directly experimentally verifiable but which are considered science. Like evolutionary biology and big bang cosmology.

Both of which contain some testable statements (e.g. in cosmology, inflation predicts certain properties in the microwave background on specific angular scales), and some untestable statements. Scientists (ought to) ignore the latter.

Science is not as easy to define as most people (including most /.ers) like to imagine. If it were, the philosophy of science wouldn't be a very interesting discipline.

I'm a practicing scientist. I don't find the philosophy of science intereresting at all; it annoys me. I wonder what fraction of practicing scientists do enjoy the philosophy of science ...