We don't know about yours but this holiday season, the homes of most scientists will be awash with even more coffee than usual. And that means coffee ring stains.

With the volume of science done in coffee houses (like Newton, who ate his meals in one every day) you'd think that anything about coffee, including coffee rings left behind from spillage, would be studied to death.

Not really.   In 1997, Robert Deegan and colleagues showed that the coffee ring pattern was due to capillary flow induced by the differential evaporation rates across the drop (1) but since then little has been done.    Sometimes science is practical instead of informational and 'just use a coaster' is enough.

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.

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