Classical Cepheid Variables, commonly called Cepheids, are unstable stars larger and much brighter than the Sun which expand and contract in a regular way, taking anything from a few days to months to complete the cycle and the time taken to brighten and grow fainter again is longer for stars that are more luminous and shorter for the dimmer ones.

This remarkably precise relationship makes the study of Cepheids one of the most effective ways to measure the distances to nearby galaxies and from there to map out the scale of the whole Universe.

Last week while baking muffins with my son's preschool class, I set fire to the school. Okay, technically I didn't set it on fire—it was only butter smoke from the tin that set off the alarm, necessitating the entire school of a couple hundred kids filing out to the basketball courts while the fire department arrived en mass.

Anyway, after the holiday break my wife will be back for Wednesday cooking and I don't imagine Thanksgiving will be NEARLY so exciting. Besides, Leif was line leader that day, and he was really, very proud to lead the class evacuation.

The Nov 22 launch of the heaviest satellite known has everyone a twitter.   A Delta IV Heavy booster out of Kennedy put up NROL-32, a "classified spy satellite cargo for the U.S. National Reconnaissance Office".

It used to be that broader understanding of zoology meant intuitively that new species would be harder to find and so it followed that there would be fewer of them when found - that is the nature of rarity.

Now, because newer species are so rare, it is fashionable to label them nearly extinct even though they have just been discovered and so may not have been prolific any time in recent memory, or at all.  It can be a little numbing to the general audience. - when everything is rare, nothing is (see special snowflake).

I think there is something deeply wrong with our view of science. The word itself, Science (with a capital "S"), sits alongside other monoliths such as Religion, Art, Music, Literature, Politics and so forth that require constant defining just to ensure we're talking about the same thing. The problem with science is that we are taught a myth... and then complain when the myth is incommensurate with reality.

On paper, collaborations seem like a good idea because the costs for one agency or country are lower.  In reality, says a new analysis by the National Research Council, federal agencies should not partner in conducting space and earth science missions unless there is a truly compelling reason to do so and clear criteria are met in advance.

If you were a young person watching "The Empire Strikes Back" and saw Darth Vader clearly being more powerful than everyone else yet not being all that evil - and with Yoda telling Luke how much easier the 'dark side of the force' was, you may have wondered why more people didn't choose it.   Behaving badly required less effort and had no obvious repercussions; Han Solo was going to get the girl anyway and she turns out to be your sister.

Every magnetic material is divided into magnetic domains, called "Weiss domains" after physicist Pierre-Ernest Weiss, who predicted their existence theoretically more than a hundred years ago. In 1907, he recognized that the magnetic moments of atoms within a bounded domain are equally aligned. 

On Thanksgiving Day, it will be all hugs and football for many people, but inside their mouths one of the biggest wars of the year will be taking place.

Streptococcus mutans and other harmful bacteria get their own holiday feast and S. mutans gets to launch one of its biggest assaults of the year on your tooth enamel.  But you have soldiers on your side too, namely cranberries and even wine, say dental researchers at the University of Rochester Medical Center

A research team at the Yale School of Public Health has developed the first smartphone app for Lyme disease.  Lyme disease is caused by a bacterium, which spreads to humans through the bite of infected blacklegged ticks.

Using Global Position System, the application provides information regarding the abundance of infected ticks at the location of the user and a list of precautions one should employ to help avoid tick-bites. If bitten by a tick, the list gives step-by-step instructions and a 40-second video on how to remove the tick.