When a feather or a plastic bag or almost anything light is placed in water, these items will generally float.  This is easy to understand if you think of water being more dense than the other item.  If you put something heavier in water, it tends to sink like a rock or a piece of metal but this doesn't fully explain how an iron ship can float.  All of these effects are accounted for due to a property all materials have known as buoyancy.

I received from Ravi Kuchimanchi, the author of a paper to be published in Phys. Rev. D, the following summary, and am happy to share it here. The paper is available in the arxiv.
Are laws of nature left-right symmetric? 

Besides being a giant triumph of theoretical physics and the definitive seal on the correctness of the Standard Model -at least at the energies at which we are capable of investigating particle physics nowadays-, the 2012 discovery of the Higgs boson by the CMS and ATLAS collaborations opens the way to new searches of new physics.

The Higgs boson is one more particle we know how to identify now, so we can now focus on new exotic phenomena that might produce Higgs bosons in the final state, and entertain ourselves in their search.
Neutrinos are among the more mysterious elementary particles in the universe: Billions of them pass through every cell of our bodies every second, yet these ghostly particles are incredibly difficult to detect, because they don’t appear to interact with ordinary matter.

Scientists have set theoretical limits on neutrino mass, but researchers have yet to precisely detect it.
"The era of the atom" is a new book by Piero Martin and Alessandra Viola - for now the book is only printed in Italian (by Il Mulino), but I hope it will soon be translated in English.
I used to post on this blog very abstruse graphs from time to time, asking readers to guess what they represented. I don't know why I stopped it - it is fun. So here is a very colourful graph for you today. You are asked to guess what it represents. 

I am reluctant to provide any hints, as I do not want to cripple your fantasy. But if you really want to try and guess something close to the truth, this graph represents a slice of a multi-dimensional space, and the information in the lines and in the coloured map is not directly related. Have a shot in the comments thread! (One further hint: you stand no chance of figuring this out).
On April 11th 2015 I delivered a presentation on the subject of Quantum Gravity in which I questioned the basic assumption that quantum is more fundamental than relativity.  Relativization is the name for the approach I propose.  In a nutshell let us try treating relativity as the more fundamental set of principles and make quantum field theory obey those.  The talk was well received.    There is still lots of work do on this and a lifetime to do it in, but the approach is now firmly not "crackpot".  Indeed as the money plot from my presentation shows this approach gets a very nice result for the behavior of black holes. 

The talk:

A very popular urban myth is that window glass is a liquid.  This apparently originated by the recognition that old European cathedrals had windows with the glass being thicker at the bottom than the top.  The actual cause of this is not attributable to gravity pulling the glass downward in a slump but rather the early window manufacturing techniques followed by a common practice of mounting window glass with the thicker side down. 

Temperature allows us to make a simple statistical statement about the energy of particles without having to know the specific details of the system.

How do quantum particles reach a state where statistical statements are possible? The result is surprising: a cloud of atoms can actually have several temperatures at once. 
Particle physics is so cool - you get to build huge detectors with a specific goal clearly stated in your letter of intents and technical proposals, but are then allowed to use them to study many other things.