It’s All Relative

Here's the picture of my pen you wanted to see.

I keep seeing references to relativity around me recently. It occurred to me that it’s a word with lots of different meanings, that is relevant to our lives on so many levels. What is relativity, really? It depends how you look at it.

Since the “discovery” of superluminal neutrino travel was announced, relativity has been a talking point in the media: will Einstein’s theories be proved wrong by these findings? It doesn’t look too likely at the moment. To reiterate, the measurement of the super speedy neutrinos is not “fact” – the OPERA experiment team posted their findings in a paper to the Arxiv to solicit ideas, opinions and follow-up experiments to try and explain their baffling observations. Not everyone turned out in favour of this publication strategy, and I use “publication” in the broadest sense and not in its peer-reviewed, journal-accepted kind, but I think it’s an open, responsible, and engaged approach to take when you’ve run out of ideas.

I think it’s likely that these results will be explained in a way that does not require reprinting thousands of textbooks. But in any case it’s good to remind ourselves that no theory, however firmly established, is above scrutiny. And with the Large Hadron Collider in full swing and some interesting developments in gravity research, our fundamental framework for understanding the physics of the Universe, from the Standard Model of particle physics to General Relativity and the Lambda cold dark matter paradigm, is facing some strong challenges.

Every measurement we make is relative to something – a standard. That standard must be known to a much higher precision that the quantity we’re trying to measure. In the end, most of our basic standards, which we adopt as measurement units, are defined in terms of the most fundamental quantities of nature we know – the speed of light, the energy levels within an atom.

[Read more...]

The cosmic ray signature of dark matter?

Detecting supersymmtric dark matter

Detecting supersymmtric dark matter

A very interesting paper was published in last week’s issue of Nature – I blogged about it before after reading the NASA press release. It’s wasn’t all that helpful without reading the actual paper but the cosmic ray – dark matetr link caught my attention.

Just today a conference paper (i.e. not peer-reviewed) appeared on astro-ph about some preliminary results from PAMELA – another cosmic ray detector that focuses on antiparticles (positrons and antiprotons). Recall that PAMELA was the source of some controversy earlier this year. Another paper on PAMELA data was posted on astro-ph back in October, it’s listed as being submitted to Nature so again, not reviewed yet. But perhaps another cosmic rays Nature paper soon, and there’s certainly a lot of buzz!

I had a read through these papers and some background stuff – it’s something I didn’t know much about and it’s very cool. Cosmic rays: inneresting akshually!

[Read more...]

Fundamental Physics work scoops the Nobel Prize

The Royal Swedish Academy of Science has just awarded the 2008 Nobel Prize in Physics to three theoretical physicists working in the field of fundamental subatomic particle physics. Read their press release here. Prof. Yoichiro Nambu of the Enrico Fermi Institute at the University of Chicago received half the prize “for the discovery of the mechanism of spontaneous broken symmetry in subatomic particles”; the other half went jointly to Prof. Makoto Kobayashi of the KEK Laboratory and Prof. Toshihide Maskawa of the University of Kyoto, both in Japan, “for the discovery of the origin of the broken symmetry which predicts the existence of at least three families of quarks in nature”. Congratulations to them and all their collaborators!

[Read more...]

LHC: Going Round in Circles

Going round in circles has never been so exciting as today at CERN, where a beam of protons has made it round the entire accelerator (27 km) for the first time. Yay!

The particles were travelling at a snail’s pace of around 30 kph, which is barely even a fraction of the final energy of 14 TeV they will hopefully achieve in around a year’s time.

The media interest is really great, particularly as particle physics has never been the easiest subject to get people excited about. Many of the media streams are pretty overloaded so it’s been hard to follow what’s happened.

There is a Twitter feed for the First Beam event.

The Guardian are blogging the event here.

The BBC’s updates are appearing here.

The Volkskrant has blog from Geneva in Dutch, by Prof. Bentvelsen from the University of Amsterdam and Nikhef.

LHC First Beam tomorrow!

On Wednesday 10 September the Large Hadron Collider, the long-awaited new particle accelerator at CERN on the French-Swiss border, will see its First Beam. This means that protons will be sent round the 27 km-long ring for the very first time, after more than 20 years of development work since its inception in the 1980s. Scientists around the world, including me, are really excited about this happening, as the LHC will be able to confirm or disprove our current understanding of particle physics, which totally underpins the way we see nature, from the very small to the very large.

The switch-on event will be webcast live here on 10 September @ 9 am CEST

If you want to know how it works, particle physicist-rockstar-all-around-lovely bloke Brian Cox explains it here.

The CERN LHC website lists some very cool facts and figures and all the info about the experiments that will take place around the beam.

The Guardian newspaper have been doing a whole series of pieces on the new accelerator – all collected here.