Sound in space

A lot of people may not know if there is actually sound in space or not. But among those in the know, it is a common belief that there is no sound in space. While this is true to the extent that it's unrealistic to hear all the sounds during a space battle you see in movies or on television, it is not quite true in the most strictest of senses. There is gas in space, albeit at such low densities and pressures that it would be essentially the same as a vacuum to life forms such as us, who are used to comparatively high-pressure atmospheres. And where there is gas, there can be sound.

Continue reading "Sound in space"

Blog carnivals

The Tangled Bank #116, the blog carnival for all things science with an emphasis on the life sciences, and the Giant's Shoulders #4, the blog carnival for classic science papers and other historical science tidbits, are up at Pro-science and second order approximation, respectively, with a mention of my own 137, my expose of the history of the fine-structure constant and its significance.

For lovers of all things space, the Carnival of Space #75 is up at the Lounge of the Lab Lemming with mention of my discussion of why dark matter doesn't just gravitationally collapse.

Skeptical readers can take a look at the 98th Skeptic's Circle on the Uncredible Hallq, including my article that we need not lose hope at the pervasiveness of medical quackery.

Exploring the heliosphere with IBEX


NASA's IBEX, the Interstellar Boundary Explorer, is a mission to explore the boundary between the heliosphere and interstellar space. The heliosphere is the region of space where our Sun reigns, swept out by the solar wind, while interstellar space is full of the interstellar gas and dust that pervades our galaxy. Another cool thing about IBEX is that it's a lightweight spacecraft launched on Pegasus, a small air-launched rocket.

But Pegasus is a dinky little rocket. Considering that the Voyager spacecrafts took almost three decades to reach the termination shock, and that it should take them a couple of more decades to reach the edge of the heliosphere, there's no way Pegasus could propel IBEX to the boundary in a reasonable amount of time. So it got me wondering just how IBEX is supposed to explore the heliosphere without actually getting there.

Continue reading "Exploring the heliosphere with IBEX"