Physics

The only thing that might have saved a sequel like "Ace Ventura, Pet Detective, Jr."(1) was putting it in space. If you put ":In Space" at the end of anything, it gains instant credibility it might otherwise not have. (see The Muppets)(2) But some people, like Abraham Lincoln, don't need more credibility, they are already heroic.  So making Lincoln a Vampire Hunter is just showing off. And Albert Einstein doesn't need to go into space - but maybe his iconic formula, E=mc^2, does. In Einstein's Theory of Special Relativity, E stands for energy, m stands for mass and c stands for the speed…

That black holes radiate Hawking radiation (which should actually be called Unruh radiation) is almost established knowledge although it has not been experimentally confirmed.  The radiation, as of now, is founded on the consistency of the thermodynamics of, for example, black holes.  The radiation being also found around string theory black holes for example adds confidence.  However, somebody who falls into a black hole does not see the radiation! Could these kinds of quantum fluctuations differ from usual thermal radiation? Or are they the same, but also usual thermal…

"Given that a repeated series of trials is required, frequentists are unable to assign probabilities to single events. Thus, with regard to whether it was raining in Manchester yesterday, there is no way of creating a large number of `yesterdays' in order to determine the probability. Frequentists would say that, even though they might not know, in actual fact it either was raining or it wasn't, and so this is not a matter for assigning a probability. And the same remains true even if we replace `Manchester' by `the Sahara Desert'. Another example would be the unwillingness of a frequentist…

A popular hypothetical alternative to Albert Einstein's theory for the acceleration of the expansion of the universe does not fit newly obtained data on a fundamental constant, the proton to electron mass ratio, which may mean the need for a new direction in learning about accelerating expansion. To explain the acceleration of the expansion of the universe, astrophysicists have invoked dark energy – a hypothetical form of energy that permeates all of space. A popular concept of dark energy does not fit new results on the value of the proton mass divided by the electron mass in the early…

I am glad to see that the Higgs signal we have discovered last July continues to raise the interest of well-learned laypersons around the world. The confirmation this time comes from the fact that three readers of this blog have decided to challenge my bet that the two signals found by ATLAS in the gamma-gamma and ZZ decay modes, which presently have a discrepant measured mass, are no hint of two distinct resonances, but rather a systematic effect. The details of the status of ATLAS measurements of the Higgs boson are in this post, where I originally proposed the bet. I offered up to five $…

Occasional readers of this blog, I reckon, have time and again been left wondering what is the matter with these lower mass limits on new particles that physicists so copiously produce with their subnuclear physics experiments. How are they determined ? Why always lower mass limits and (almost) never upper limits ? And why do we care ? The fact is that whenever I set out to explain a new result from ATLAS or CMS (the two huge detectors collecting data from the proton-proton collisions delivered by the Large Hadron Collider -LHC in the following- at CERN) I invariably fail to provide all the…

It is with some delay that I decide to write about Aldo here. The reason is simply that after a house move I still have not been reconnected to the internet at home, and my absence from work for christmas holidays makes things even harder, and my presence online a sporadic break rather than a constant of motion. Aldo Menzione died a week ago. Those who have known him are surely very sad about this: besides the premature death, I think everybody liked him. Apart from being an excellent hands-on physicist, and among other things one of the true fathers of the silicon detector that helped CDF…

In classical physics, phase space trajectories give rise to flow-fields representing the dynamics of the system along its trajectories; they yield additional insight into a system's behavior. Quantum theory phase space trajectories do not exist because Heisenberg's uncertainty principle does not allow for the formation of sharply defined trajectories. But quantum physicists have not given up entirely on phase space, and so the study of the next best thing, the movement of quantum physics' phase space-based probability distributions, has actually boomed in recent years.  UK-based…

What is the farthest we can theoretically go? Would we ever be able to visit the galaxies shown in Hubble's Extreme Deep Field? Could we even travel beyond these and reach the edge of the observable universe? Suppose you are a googolionaire and money is of no issue. Suppose also that technology has evolved dramatically and that money will buy you the latest rocket technology capable of cruising close to the speed of light. Thanks to relativistic time dilation, for every year you age you would travel much farther than a light year. If you accelerate your rocket to higher and higher…

Hey smart gals, you know that there are two types of nerds:  The creepy type you want nothing to do with, and the one you would like to have a go at, because they are damn smart too.  But you need to tell them apart real fast, like before the wrong type becomes your stalker, which happens with hyperspace velocity!  And yes, the type you want is rare.    Gratuitous pic of perhaps smart woman for clicks   Here is the one question that you should ask straight away in order to find out immediately whether he is fun or RUN!   Ask him what he thinks about a) Time…