When a mirror reflects light, it experiences a slight push but it is negligible in our everyday lives. Our furniture is not moving because due to radiation pressure of light, a 100 Watt light-bulb causes a radiation pressure that is only a trillionth (one part to 1000000000000) of the normal atmospheric pressure.
As yesterday in Italy was the equivalent of Labor Day, and today is a Saturday, with people around me exploiting the three-day rest for a recreational trip, I do not feel in a very productive mood, so rather than writing something original here I will exploit other people's work, pointing at what I found interesting or anyway worth my attention among the papers appeared on the Cornell Arxiv in the last few days, and other assorted material.
Detecting ionizing radiation does not mean that a disaster
has or will occur. Detecting radiation
is generally a good thing if the radiation is expected, intended or
natural. We and all living things on earth
are naturally radioactive. This is due
primarily to our requirement to have a healthy level of potassium and carbon in
our bodies (and these are both naturally radioactive).
"B.W. Lee also carries much of the responsibility for calling the Higgs boson the Higgs boson, mentioning repeatedly 'Higgs scalar fields' in a review talk at the International Conference on High-Energy Physics in 1972."J. Ellis, M.K. Gaillard, D. Nanopoulos, "An updated historical profile of the Higgs boson"
First collisions of protons at CERN's Large Hadron Collider are expected to start the first or second week of June. The LHC was restarted in early April after a two-year pause to upgrade the machine to operate at higher energies for a second three-year run . At higher energy, physicists may see new discoveries about the laws that govern the universe and SUSY diehards - physicists who support the hypothesis of space and time called SuperSymmetry - maintain hope new discoveries bolster them and change the current accepted theory of physical reality, the Standard Model.
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.
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.