Matter-antimatter asymmetry is one of the greatest challenges in physics - we know antimatter is out there, because it can be created at places like CERN, but the universe seems to be composed entirely of matter.
Theories predict that exactly equal amounts of matter and antimatter would have been created in the Big Bang. So where did all the antimatter go?
New research undertaken by the ALPHA experiment at CERN's Antiproton Decelerator (AD) in Geneva is the first time that the electric charge of an anti-atom has been measured to high precision. Measuring the electric charge of antihydrogen atoms is a way to study any subtle differences between matter and antimatter which could account for the lack of antimatter in the universe.
Today among the three top players -those in the money- at the Higgs challenge we see the appearance of Lubos Motl, whom I had signalled as a participant in an earlier posting. We all know that Lubos is a smart guy, but I doubted whether he would take this very seriously. However, it seems he is. As we speak he has submitted almost 100 solutions (you can submit up to 5 solutions per day, so that means having worked at this at least 20 days in a row).
In the clip below you see the top standers from the challenge site's leaderboard:
Two years ago, I expressed my doubts about the existence of a multiverse
(or at least it's portrayal by some cosmologists) in a blog post in this forum
. In the meantime, last March, the announcement about the discovery of gravitational waves got us perhaps closer to a multiverse--at least to one form of it, based on inflation. And then some problems with the Bicep data were discovered
For decades, physicists have searched for exotic bound states comprising more than three quarks.
In 2011, over 120 scientists from eight countries discovered strong indications for the existence of an exotic dibaryon made up of six quarks. Now, experiments performed at Jülich's accelerator COSY have shown that uch complex particles do exist in nature. This discovery by the WASA-at-COSY collaboration goes beyond what had been done before. Physicists were only able to reliably verify two different classes of hadrons: volatile mesons comprising one quark and one antiquark and baryons consisting of three quarks.
Space seems like an empty box that lives
through time. This can already be classified as a “better model”, as you can
see in the table below. However, this tacitly held model makes people wonder:
If I toss a coin and find myself with the result being “tails”, where is the other me, the one who
found “heads”, the other possibility which physics can no longer ignore, and which
good philosophy has always known to be equivalent?
Has a universe popped up
next door to this one?
If you’re flying in the vicinity of a black hole, seatbelts and a bumpy ride are really the least of your concerns, but we are in the world of the hypothetical, and the accepted wisdom among gravitational thinkers has been that spacetime cannot become turbulent.
An idea by the wizards at the Perimeter Institute is that such accepted hypothetical wisdom might be wrong.
The researchers followed this line of thought: Gravity might be able to behave as a fluid. One of the characteristic behaviors of fluids is turbulence – under certain conditions, fluids don’t move smoothly, they eddy and swirl.
Presto, let's put something on arXiv.
You are the first to arrive to a dinner party and must choose the table where to sit, relying on your past experience of how handsome members of the opposite sex (you're straight) usually choose their seat. You need to buy stocks based on past performances and trends. You travel to some distant location and would like to know what's the weather like there, but there is no forecast for that particular place. What do you do ?
Observations with the 1.6-meter telescope at Big Bear Solar Observatory (BBSO) in California, the most powerful ground-based instrument dedicated to studying the Sun, have resulted in the highest- resolution solar observations ever made.
They key issues in the discussion of the BICEP2 result center around the way BICEP2 accounted for dust in the foreground. They based their analysis on a presentation graphic which was shown at the April APS conference of 2013. This may have been a mistake. In the defense of the BICEP2 team, that graphic was the best data available at the time. A .fits file of this particular data from PLANCK did not exist yet. Never the less, it leads to reasonable questions about the validity of the result.
"After the 1974 London Conference, with its strong confirmation of the quark model, a general change of view developed with regard to the structure of hadrons. [...] the quark structure of hadrons became the dominant view for developing theory and planning experiments. A crucial element of this change was the general acceptance of QCD, which eliminated the last paradox, namely, why are there no free quarks ? The conjectured infrared slavery mechanism of QCD provided a reason to accept quarks as physical constituents without demanding the existence of free quarks. The asymptotic freedom property of QCD also provided a ready explanation of scaling [...].