The first experiments to be carried out by the Large Hadron Collider (LHC) at CERN are on the horizon. Some people are frightened by this historic particle accelerator, but the science community is abuzz with anticipation and excitement. Although some of the conditions of the Big Bang will be recreated, it is important to remember a second “Bigger Bang” will not be generated – although the LHC is powerful, it’s not that powerful!
There is a rich variety of experiments that will be carried out by a variety of LHC detectors in the 27 km circumference ringed accelerator. These experiments include ATLAS, CMS, ALICE, LHCb, TOTEM, and LHCf. All have their own specific goals, but a few possible discoveries stand out as being revolutionary for particle physics and cosmology alike. I’ve written a host of articles about the LHC and I have my own personal hopes for what could be discovered, but I’d be interested to get your views too… Continue reading “Poll: In Your Opinion, What Will be the First LHC Landmark Discovery?”
Wolf-Rayet (WR) stars are my favourite stellar objects bar none. Due to the excitement factor I find them even more interesting than black holes, pulsars and quasars. Why? Well, they are a significant period of a massive star’s lifetime making its violent, self-destructive death, possibly culminating in a supernova or gamma ray burst (GRB). WR stars blast out dense stellar winds creating a bubble of matter that completely obscures the star’s surface from any attempts at observation. They are also very noisy neighbours, disrupting binary partners and messing up huge volumes of space. If you thought a star might die quietly, the WR phase ensures this isn’t the case and astronomers are paying attention, making some of the most detailed observations of WR stars yet… Continue reading “Wolf-Rayet Star: My Favourite Stellar Object”
Could small, primordial black holes be efficient antimatter generators? It is well known that cool planetary bodies, surrounded by equal numbers of protons and electrons in thermal equilibrium, will eventually become positively charged. Why? Because electrons, with their low mass, have a higher velocity than the larger protons. Although they undergo the same gravitational acceleration, electrons are able to attain “escape velocity” more readily as the more massive protons get stuck in the gravitational well. The result? The planet has a net positive charge as more electrons, than proton escape into space.
Primordial black holes are thought to exist in our Universe (left-overs from the Big Bang), and although they may be small, they may influence ionized cosmic clouds in the same way, more electrons escape than protons left behind. However, should a threshold be reached, the extreme gravitational force surrounding the black hole could set up a powerful electrostatic field, kick-starting a strange quantum phenomenon that generates the electron’s anti-matter partner (the positron) from the vacuum of space… Continue reading “Are Primordial Black Holes Antimatter Factories?”
I’ve only just stumbled on this fantastic presentation Brian Cox did in Monterey, California in March this year explaining the stunning science behind CERN’s newest addition. I have followed the progress of the Large Hadron Collider (LHC) intently and I personally cannot wait until the accelerator is turned on. There has been much debate about the safety of the LHC and there have been some seriously nutty theories about the bad things that the LHC could (never) do. So, rather than waste any more time on the (impossible) negatives, let’s take a look into how the LHC is going to alter mankind’s view on the Universe forever with the help of Brian Cox at his best… Continue reading “Why is the LHC so Important? I’ll let Brian Cox Explain…”
By combining observations from a multitude of observatories, all looking at spiral galaxy M81, astronomers have taken a very close and intimate look at a supermassive black hole’s feeding habits. As supermassive black holes (of tens of millions of solar masses) and stellar black holes (of a few solar masses) exist in entirely different environments, astrophysicists were uncertain as to what supermassive black holes feed on. Stellar black holes eat away at the gas from companion stars, creating an accretion disk, generating a range of emissions as stellar gas falls into the disk. But where do supermassive black holes get their food? It turns out they feed off gas in the central region of galactic cores, generating similar emissions as their smaller stellar cousins. What’s more, this finding supports Einstein’s theory that all black holes, regardless of mass, share the same characteristics… Continue reading “Supermassive Black Holes are Not Fussy Eaters”
The hypothetical axion is a particle that might help scientists work out where the bulk of dark matter may be held in the Universe. So far, there has been much talk about the search for another type of hypothetical particle, the weakly interacting massive particle (WIMP), and little attention has been paid to the lowly axion. WIMPs are very appealing to scientists as proving they exist will help patch some holes in quantum theory. What’s more, WIMP detectors need to be huge, large volumes of underground caverns filled with hi-tech sensors and cleaning fluid – this makes for a cool funding proposal; think up and grand idea, explain that it will prove our understanding of the Universe and then receive a multi-billion $/£/€ cheque (it’s not quite as easy as that, but there are socioeconomic and political reasons for building such an awesome structure).
So how do you go about finding an axion? Surely this exotic particle will need an even bigger detector, especially as it has zero charge, very low mass and cannot interact via the strong and weak nuclear forces? Actually, a large WIMP-type detector would be useless for axion detection. Fortunately axions have a neat interaction with magnetic fields that can be detected with existing instrumentation. What produces the strongest magnetic field in the Solar System? This is where the Sun can help out… Continue reading “Is the Sun a Dark Matter Factory?”
There is a trend in astronomical observations to label strange and exotic objects with superlative names. Take “supermassive” black holes for instance. Yes they are more massive than intermediate black holes, bigger than stellar black holes, and in a whole different league to theoretical micro-black holes. But is the label “supermassive” an accurate description? Is it even scientific?
After reading a very interesting article written by Michael Gmirkin on “Incorrect Assumptions in Astrophysics“, I began to relate his investigation into the use of terms to describe astronomical phenomena with very expressive names. Terms like “super-massive”, “ultra-luminous”, and “beyond-bright” are mentioned by Gmirkin, perhaps leading astronomers to incorrect conclusions. Whilst this may be perceived as an issue amongst scientists, what if the media or non-specialist individuals misinterpret the meaning of these grand statements? Could it lead to public misunderstanding of the science, possibly even causing worry when a scientist describes a particle accelerator collision as “recreating the conditions of the Big Bang”? Continue reading “The Case of the Supermassive Black Hole, the Infrared Object and Perceived Accuracy of Science”
Scientists working with the Laser Interferometer Gravitational-Wave Observatory (LIGO) have announced their first land-mark discovery. LIGO was built to detect gravitational waves (as predicted by Einstein’s general relativity), but this discovery is actually about not detecting gravitational waves. Hold on, what’s all the fuss about then? This sounds like a null result, and in some ways it is. But on the other hand it may be one of the most important neutron star observations ever. So what has LIGO (not) seen? Continue reading “The Crab Pulsar is Probed By LIGO. Is it Really a Smooth Neutron Star?”
Wolf-Rayet stars are a violent and self-destructive phase of a massive star’s lifetime. This is the point at which they begin to die as a prelude to a supernova and black hole formation. Often, large nebulae can be found around these bright stellar objects (pictured), emitting strong ultraviolet radiation. As Wolf-Rayet (WR) stars continue to lose huge amounts of mass and deplete all their fuel, they become even more unstable, resulting in a huge supernova. Exploding WR stars have been linked with powerful gamma ray (γ-ray) bursts; in fact the largest, most distant GRB was observed on March 19th in the constellation of Boötes by NASA’s Swift Observatory and the Polish “Pie of the Sky” GRB detector. There is some evidence that this GRB was the result of a WR star/neutron star binary pair, but what would happen if a WR star is sitting close to an O-type star just as it explodes?
What with all the surprise activity of the Sun at solar minimum of late, I’ve found myself looking around the solar observation sites an awful lot more than I used to. During all the commotion back in 2003 when the Sun was blasting out record breaking X-ray flares one after another, I really didn’t think I could be surprised with anything else the Sun would do. That was until, very much unannounced, three sunspots rotated into view, blasting another X-ray flare into space… at solar minimum. The strange thing was, that these sunspots weren’t even from this solar cycle, they were from the previous one that ended some time around December 2007! And now we get a stunning, detailed view of more unexpected solar activity from the Solar Terrestrial Relations Observatory (STEREO), a hi-res video of dynamic coronal loops… Continue reading “Dynamic Coronal Loops as seen by STEREO (Video)”