Thursday, July 30, 2015

Report From 13 TeV

So far so good!

This report briefly describes the achievement of getting to 13 TeV collision energy at the LHC.

At 10.40 a.m. on 3 June, the LHC operators declared "stable beams" for the first time at a beam energy of 6.5 TeV. It was the signal for the LHC experiments to start taking physics data for Run 2, this time at a collision energy of 13 TeV – nearly double the 7 TeV with which Run 1 began in March 2010.

So far, they haven't been swallowed by a catastrophic black hole that is supposed to destroy our world. Darn it! What's next? Sighting of supersymmetry particles? You must be joking!


Wednesday, July 29, 2015

Weyl Fermions

This is a bit late, but what they hey....

Here is another triumph out of condensed matter physics experiment. This is the first reported discovery of the Weyl fermions, first predicted and now found in a Tantalum arsenide compound.

Another solution of the Dirac equation – this time for massless particles – was derived in 1929 by the German mathematician Hermann Weyl. For some time it was thought that neutrinos were Weyl fermions, but now it looks almost certain that neutrinos have mass and are therefore not Weyl particles.

Now, a group headed by Zahid Hasan at Princeton University has found evidence that Weyl fermions exist as quasiparticles – collective excitations of electrons – in the semimetal tanatalum arsenide (TaAs).

For those who are keeping score, this means that these condensed matter systems have, so far, detected Majorana fermions, and analogous signatures of magnetic monopoles.

And many people still think condensed matter physics is all "applied" and not "fundamental"?


Wednesday, July 22, 2015

The Standard Model Interactive Chart

Symmetry has published a webpage of an interactive chart for the Standard Model of elementary particle. It is almost like a periodic table, but with only the most basic, necessary information. A rather useful link when you need just the basic info.


Tuesday, July 21, 2015

Yoichiro Nambu

This is a bit late, but I will kick myself if I don't acknowledge the passing of Yoichiro Nambu this past week. This person, if you've never heard of his name before, is truly a GIANT in physics, and not just in elementary particle. His work transcends any field of physics, and had a significant impact in condensed matter.

I wrote an entry on his work when he won the Nobel prize a few years ago. His legacy will live on long after him.


Wednesday, July 15, 2015

Pentaquark Discovery - Here We Go Again!

I read with a combination excitement and skepticism of the report that LHCb may have seen not one, but two pentaquarks. The skepticism should be justified because previous claims of the discovery of such quarks have turned out to be false. Still, this one comes with a 9sigma statistics.

The LHCb team is confident that the particles are indeed pentaquarks that comprise two up quarks, one down quark, one charm quark and one anticharm quark. "Benefitting from the large data set provided by the LHC, and the excellent precision of our detector, we have examined all possibilities for these signals, and conclude that they can only be explained by pentaquark states," explains LHCb physicist Tomasz Skwarnicki of Syracuse University in the US. 

As always, and as with any other new and important claim, time will tell as more analysis and experiments are done. The public and the media, especially, need to understand that this is still a work in progress, as with any scientific endeavor.


Sunday, July 12, 2015

Space Coffee

It's amazing how much physics and engineering go into just getting the ISS occupants to have their cup of Joe while on board the space station.

They should just open a Starbucks franchise up there. It would have been easier!


Wednesday, July 08, 2015

More Physics Of Bicycles

I've already covered the topic on why a bicycle can be balanced easier when it is in motion many times in this blog. But here's another entry on this matter, this time it is a video from Minute Physics. Unfortunately, the explanation comes too rapidly for one to actually understand this simply by listening (you may have to play the video a few times).


Sunday, July 05, 2015

The Physics Of Your Vehicle Gas Mileage

While fuel prices are not as high as they were a few years ago, gas/petroleum cost is always a factor in our lives if we drive often.

This article reveals the physics of your vehicle gas mileage, and what may cause it to be better or worse than others. We can add this to another entry on this similar topic that I posted earlier.


Thursday, July 02, 2015

Don't Ask Siri To Divide 0/0

... unless you want a snarky remark about your personal life from her. You might get this response:

"Imagine that you have zero cookies and you split them evenly among zero friends. How many cookies does each person get? See? It doesn't make sense. And Cookie Monster is sad that there are no cookies, and you are sad that you have no friends."


So, have you tried any other math questions with Siri and got similar amusing responses? Do share!


Wednesday, July 01, 2015

100 Years Of General Theory of Relativity

This is a nice Nature Physics article summarizing the history of the General Theory of Relativity, especially on the historical verification of Einstein's idea.

If you have access to Nature Physics articles, you might also want to read the link in this paragraph:

Not everyone embraced the theory, though: in a Commentary on page 518 Milena Wazeck discusses the anti-relativist movement of the 1920s and uncovers an international network of opponents. Without any attempt at engaging in scientific argumentation, the refuters considered themselves “the last defenders of true physics”. Wazeck sees parallels with adversaries of Darwinism or anthropogenic climate change.

I suppose I shouldn't be surprised, but I continue to be amazed that human beings have such short memory, and how we continue to repeat the same things or the same mistakes that had been done before.