Physics

Okay, the riddle I posted two days ago  was indeed solved by theorists - albeit ones with good internet connections and smart search engines. The figure, pasted below for your convenience, is from the CDF collaboration, and it refers to a "famous" analysis - one of the few important measurements for which Run II at the Tevatron was considered a good idea (thank god that one sold with the funding agencies, because there were sooo many others that eventually paid off!). Now, despite being public, the particular figure has received relatively little attention, since another way of…

Recently scientifically 2.0 so topical Schrödinger's cat jumped into being in the 1935 three-part article (in German) in Die Naturwissenschaften, just at the end of part one: Man kann auch ganz burleske Fälle konstruieren. Eine Katze wird in eine Stahlkammer gesperrt, zusammen mit folgender Höllenmaschine … This is known in the translation(Translator: John D. Trimmer) which is found at http://www.jstor.org/stable/986572 or more conveniently at http://www.tu-harburg.de/rzt/rzt/it/QM/cat.htm One can even set up quite ridiculous cases. A cat is penned up in a steel chamber, along with the…

In a display of nonchalance that should teach us a thing or two, the ATLAS collaboration has put an end to the Easter Higgs Rumour (EHR), which brought the blogosphere in an excited state for at least a week, and experimentalists and theorists for even more time. They did so by publishing a very narrow-focused document, totaling less than five pages, where they discuss the backgrounds to Higgs boson decays in the diphoton final state. In the paper they do not seem to mention the EHR at all. It is just as if they were working at all these nice analyses they are doing, and at one point they…

My attempt at stimulating your curiosity with a scientific graph last time worked quite well, and I want to try it again. This time, however, you should not consider yourself eligible to participate if you are an experimental particle physicist (or in the process of becoming one). That's because I want to "lower the bar" a little, allowing non-experts in the game, and an experimentalist in HEP should recognize what this figure is quite easily. If you are a theorist, I am not sure -today's plot might be instantaneous for you to recognize, or not easy, depending on what you work on. I'll take…

As many of you know, I expressed here my strong doubts that the rumoured Higgs signal found by members of the ATLAS collaboration in the two-photon final state was due to a real particle, and went as far as to bet 2:1 against it (you can take the bet by just writing in the comments thread, but you must be a well-known individual who has a reputation in physics if you want to be taken seriously). Now Peter Woit, whose blog was the original recipient of the ATLAS leak, informs us that CMS appears to have leaked information to New Scientist, in the form of a internal document "shown" to them. I…

Thanks to all that read my previous post, “Sexy Standard Model Symmetries”. Most probably did not notice quite a few technical exchanges between David Halliday and myself. I was pretty darn sure I had a way to represent electroweak symmetry using quaternions. David was pretty darn sure I did not. Such exchanges can go on for some time, unless one party finally sees that they were in fact wrong on the facts. That doesn’t happen often. It did happen here, and I was the one who was wrong. This blog will go into my mistakes, and generate a few more animations which may open up new views. I have…

"There are 10^11 stars in the galaxy. That used to be a huge number. But it's only a hundred billion. It's less than the national deficit! We used to call them astronomical numbers. Now we should call them economical numbers." R. Feynman

Schrödinger’s cat is in a quantum superposition of two states, namely |Dead> and |Alive>. If we open the box and find the cat dead, where is the living one? You all know the answer: In the ‘parallel universe’ where I pull the cat out alive. Let me add a twist that only a true cat hater can come up with. In short, I will use quantum interaction to let the probability of observing a dead cat go to 100% without destroying the alive state. I pull only dead cats out and the alive ones have no parallel universes where I take them out of the box, thus they have nowhere to go when the box…

The big bang was given it's name by Fred Hoyle, in order to make the theory sound absurd.  He metaphorically called it an explosion.   In the mist of time most people even some scientist lost the metaphor part of that and thought of it as an explosion.  Others then stopped using the metaphor because it confused people.   This is more of an entry about the use of language than physics.  That said here is the shortest possible argument for why the big bang was not an explosion for anyone who needs convincing: Explosions are the free expansion of material from…

In his article “The World Is Not Woven From Real Stuff” Sascha Vongehr raised the important matter of quantum physics and our perception of the natural world. He argued that “the feeling that facts are just out there in a really existing world, is strictly wrong” and asked “However, how can a layperson best grasp that direct realism is wrong?” The reader was then taken through the mental exercise of considering how familiar objects such as billiard balls behave, that is, they lose motion. This was used to demonstrate that “real things” cannot be made of smaller things inside smaller things…