An announcement on EurekAlert says that at least 10 to 30 percent of global warming measured during the past two decades may be due to increased solar output rather than factors such as increased heat-absorbing carbon dioxide gas released by various human activities. This has been claimed before. This is not to say that greenhouse gasses are off the hook, but it means that climate change models need to be adjusted accordingly. I would say another piece of evidence for increased solar output may have been found by the Mars Orbiter, where surveys show for three Mars summers in a row, deposits of frozen carbon dioxide near Mars' south pole have shrunk from the previous year's size, suggesting a climate change in progress (the Mars Orbiter report was also featured in this Slashdot submission).

The Washington Post has an article on the increased interest in fuel efficient cars after the recent hurricanes in the US and their affect on gas prices. It seems Toyota and Honda are struggling to keep up with demand, while GM and Ford have seen a serious drop in sales of large SUV's. Is this the start of a lasting change in the US market or is it just a knee-jerk reaction? What's the next car you plan to purchase?

In case anyone was wondering why we live in a universe with 3 infinitely long directional dimensions, Andreas Karch (University of Washington assistant professor of physics) and his collaborator, Lisa Randall (of Harvard) says it's because the natural evolution of universes (or more specifically the branes described in M-Theory) favor the eventual formation of a universe where you end up with either 3 or 7 infinite physical directions (the remaining dimensions shrink to a minuscule size). Other numbers of physical dimensions are possible, just not favored. An interesting note, the good professor implies that our universe actually contains many regions with different numbers of spatial dimensions at the same time; we just happen to live in a region that ended up with 3 spatial dimensions.

The announcement also implies that our universe is infinitely large and has big bangs happening inside it somewhere all the time. On the other hand, it has also been theorized that two branes colliding might have created what we call the universe.

Karch and Randall detail their work in the October edition of Physical Review Letters, published by the American Physical Society.