First of all, I must apologise for the fact that I haven't been updating my blog as much as I'd intended to over the past few weeks. As often happens, real life has gotten in the way, including (for example) my graduation. I can now officially carry the post-nominal letters BScAdv(Hons), although anyone concerned for my ever-inflating ego will no doubt be glad to hear that I have very little intention of doing so.
In terms of the blog, I'm currently working on a post on Fourier analysis and the following post will likely be on the physics of mechanical flight, by popular request. At the current rate I'm going that might not be for a while though!
In physics news, since my last news post some rumours have arisen that the BICEP2 results may not be as sound as initially claimed. Basically, Adam Falkowski has claimed that the BICEP2 collaboration have miscalculated the galactic foreground radiation by misinterpreting an image on a Planck collaboration slide, and their primordial polarisations can mostly be accounted for due to this error (a claim that the BICEP2 team strongly denies). A sceptical take on the rumour is provided by Sesh Nadathur, who argues that the issue has been blown far out of proportion. It will be interesting to see how things unfold in the coming months!
Showing posts with label News. Show all posts
Showing posts with label News. Show all posts
Thursday, May 29, 2014
Thursday, April 10, 2014
News (2014/04/10)
Two items of news to report this week (well, one and a half at least). The half-piece of news is that I'm working on a new blog post which will hopefully be posted some time next week (although it might take until the week after).
The real news is that the LHC has confirmed the existence of Z(4430), a so-called "exotic hadron". Hadrons are composite particles made of quarks (and held together by gluons). According to the quark model, hadrons can only form in one of two ways: a quark-antiquark pairing (known as a meson) and in a quark triplet (know as a baryon).
The most common hadrons in the universe are protons and neutrons which form atomic nuclei. Protons consist of 2 up-type quarks and 1 down-type quark ("uud") while neutrons consist of 1 up quark and 2 down quarks ("udd"). The names and details of quark types, which are known as "flavours", is not something I will go into here, as it is an interesting enough topic to deserve its own post (although a proper explanation for the layperson would need a little more than that I think).
The quark model is a simple one though and does not describe all of the dynamics permitted by quantum chromodynamics ("QCD", the part of the Standard Model that describes strong interactions). This leaves open the door for exotic hadrons which are not mesons or baryons. Z(4430) is one such exotic hadron.
It was first 'discovered' in 2007 (although 5-sigma confirmation didn't come until 2008) and has now been observed at the LHCb experiment at 13.9-sigma accuracy. This means the chances of the observation being a statistical fluke are $1$ in $1.579\times10^{43}$ (a very, very, very large number indeed). It is believed to be a tetraquark made up of 1 charm quark, 1 charm antiquark, 1 down quark and 1 up antiquark ("ccdu").
While perhaps not as exciting as, for example, the BICEP2 result recently, this confirmation is still a very interesting result and will hopefully spur on further developments in the search for exotic hadrons.
The real news is that the LHC has confirmed the existence of Z(4430), a so-called "exotic hadron". Hadrons are composite particles made of quarks (and held together by gluons). According to the quark model, hadrons can only form in one of two ways: a quark-antiquark pairing (known as a meson) and in a quark triplet (know as a baryon).
The most common hadrons in the universe are protons and neutrons which form atomic nuclei. Protons consist of 2 up-type quarks and 1 down-type quark ("uud") while neutrons consist of 1 up quark and 2 down quarks ("udd"). The names and details of quark types, which are known as "flavours", is not something I will go into here, as it is an interesting enough topic to deserve its own post (although a proper explanation for the layperson would need a little more than that I think).
The quark model is a simple one though and does not describe all of the dynamics permitted by quantum chromodynamics ("QCD", the part of the Standard Model that describes strong interactions). This leaves open the door for exotic hadrons which are not mesons or baryons. Z(4430) is one such exotic hadron.
It was first 'discovered' in 2007 (although 5-sigma confirmation didn't come until 2008) and has now been observed at the LHCb experiment at 13.9-sigma accuracy. This means the chances of the observation being a statistical fluke are $1$ in $1.579\times10^{43}$ (a very, very, very large number indeed). It is believed to be a tetraquark made up of 1 charm quark, 1 charm antiquark, 1 down quark and 1 up antiquark ("ccdu").
While perhaps not as exciting as, for example, the BICEP2 result recently, this confirmation is still a very interesting result and will hopefully spur on further developments in the search for exotic hadrons.
Thursday, March 20, 2014
News (2014/03/20)
I'm trying to post on my blog much more often this year than I used to, in fact as close to every week as I can manage. Unfortunately, the post I'm working on at the moment isn't nearly ready for publication, so this week I'm instead going to make a little news post, the first item of which will be the thing that I just told you (about the new blog post coming soon)!
The next item of news is not particularly new; last Friday (the 14th of March) was Pi Day. Pi Day is of course silly for a whole bunch of reasons (the main one being it's based on the completely nonsensical American dating system) so I've decided to introduce readers who may not be familiar with it to the concept of tau (τ). Tau has been proposed as an alternative to pi, and while I am not especially partisan on the matter I have to say I am somewhat sympathetic. Here is the case for tau laid out in the Tau Manifesto and for the sake of fairness a counterargument in the Pi Manifesto.
Finally, the real news comes in the form of the results of the recent BICEP2 measurements of B-mode polarisation in the CMB, easily the biggest news in physics since the Higgs was announced in 2012 and a major breakthrough for early-universe cosmologists. I will be able to do an explanatory post about the news if there's enough demand for one, but otherwise a lot of good explanations can be found around the place ranging from the somewhat simplistic to the slightly more technical. This is a very exciting time for fundamental physics and I expect to see some very interesting papers published in the next couple of years based on insights from this new data.
Finally, it isn't technically news, but if you haven't heard of them already, I strongly urge you to check out Brady Haran's science channels, especially Sixty Symbols (physics) and Numberphile (mathematics); I've subscribed to most of them on YouTube and they are absolutely fantastic.
That's all for this quick post, hopefully I'll have a considerably more in-depth number ready for next week! See you then!
The next item of news is not particularly new; last Friday (the 14th of March) was Pi Day. Pi Day is of course silly for a whole bunch of reasons (the main one being it's based on the completely nonsensical American dating system) so I've decided to introduce readers who may not be familiar with it to the concept of tau (τ). Tau has been proposed as an alternative to pi, and while I am not especially partisan on the matter I have to say I am somewhat sympathetic. Here is the case for tau laid out in the Tau Manifesto and for the sake of fairness a counterargument in the Pi Manifesto.
Finally, the real news comes in the form of the results of the recent BICEP2 measurements of B-mode polarisation in the CMB, easily the biggest news in physics since the Higgs was announced in 2012 and a major breakthrough for early-universe cosmologists. I will be able to do an explanatory post about the news if there's enough demand for one, but otherwise a lot of good explanations can be found around the place ranging from the somewhat simplistic to the slightly more technical. This is a very exciting time for fundamental physics and I expect to see some very interesting papers published in the next couple of years based on insights from this new data.
Finally, it isn't technically news, but if you haven't heard of them already, I strongly urge you to check out Brady Haran's science channels, especially Sixty Symbols (physics) and Numberphile (mathematics); I've subscribed to most of them on YouTube and they are absolutely fantastic.
That's all for this quick post, hopefully I'll have a considerably more in-depth number ready for next week! See you then!
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