[The Gyrojet (A Failure in US Weapons Engineering)]

While the Gyrojet was clearly a failure on several levels, the idea of gyroscopically stabilizing rounds seems effective if it is implemented correctly. Has there ever been a new attempt at this technology, or was the concept abandoned altogether?

[Seeing the Distant Stars]

Kepler orbits about 40 miles or 65 kilometers away from Earth.  Since messages are sent using electromagnetic waves, it probably doesn't take long for data to reach Earth (not more than a few microseconds).  If anything, sending pictures might be slow because of poor signal strength, and because pictures tend to take up several megabytes of data.  Also, if the Kepler takes a lot of pictures in a short span of time, it may have a backlog of images to send due to the slow data transfer rate.

[Negative Kelvin?!]

They theorized it and then conducted an experiment to confirm their theory.

 

When it comes to normal substances with positive Kelvin temperatures, we define temperature as the average kinetic energy of the particles in the substance.  However, quantum physicists discovered that the energies of the individual particles vary greatly.  In a pot of boiling water, for example, only a few of the particles have high energies, while most still have low energies, even though to us the pot is painfully hot to the touch.  The distribution of energies in a substance is known as a Boltzmann distribution, and if you look at a Boltzmann distribution for any normal substance, you will see that most of the particles are clustered at the lower end of the energy scale, and only a few actually have high energies.

 

The German scientists, however, sought to create a new substance that essentially inverted the Boltzmann distribution.  This means that most of the particles would have high energies, while only a few would have lower energies.  In order to create an inverted energy distribution, they needed to enforce a maximum energy for the particles in the gas. Since the total energy of a gas includes its potential and its kinetic energy, they needed to place maxima on both energies.  To illustrate why, consider a set of balls on a hill.  At the top of the hill, the balls have a lot of potential energy, and therefore they want to roll down the hill and convert their potential energy to kinetic energy.  If the kinetic energy of the balls is already maximized, however, then the potential energy cannot be converted, so the balls stay at the top of the hill, and, amazingly, the system remains stable.  Using lasers and magnets, the scientists were able to induce maximum values on the potential and kinetic energies of the particles in the gas, and therefore they inverted the Boltzmann distribution of the substance.  Since the distribution was inverted, it makes sense to define the absolute temperature as negative, since the term "negative" implies an inversion or negation of something.

 

Hopefully this explanation helped.  I essentially condensed the explanation I found online.  If you want to read about this concept more in depth, or if my explanation didn't help, check out this article:

http://www.mpg.de/6776082/negative_absolute_temperature

[Stepping Stones in the Search for Dark Matter]

Here are links to the stories I found:

 

http://www.sciencenews.org/view/generic/id/349712/description/Dark_matter_detector_reports_hints_of_WIMPs

 

 

http://www.sciencenews.org/view/generic/id/349352/description/Cosmic_ray_detector_confirms_hints_of_dark_matter