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.

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RB Editor’s Selections: Left-handed Life, Iceberg Songs, Disappearing Exoplanets and Redefining the Kilogram

Sarah KendrewSarah Kendrew selects interesting and notable ResearchBlogging.org posts in the physical sciences, chemistry, engineering, computer science, geosciences and mathematics. She blogs about astronomy at One Small Step.

[cross-posted from ResearchBlogging.org News]

Welcome to a new week, and a new instalment of physical sciences highlights.

  • The Universe and life is asymmetric: chirality of life. Why is life left-handed? This excellent in-depth post by The Astronomist describes in detail the problem of chirality of biomolecules, with words from a leading expert.
  • Death song of an Iceberg. Using seismometers, geologists can record the sounds made be icebergs as they grind against each other with the tides. This blog post on Now Hear This (“a site about sound”) discusses how such a recording has led scientists to find an iceberg graveyard in the Antarctic. The post contains an interesting video on this type of research, and a link to the researchers’ pretty dramatic sound recording.
  • The amazing disappearing habitable world? Exoplanet Gliese 581g was trumpeted as a potentially habitable exoplanet on its original discovery last year, causing a bit of a media frenzy – but its existence was soon after called into question when other scientists had issues with the analysis of the original data. Greg Fish discusses the latest efforts to single out 581g from the noise.
  • Redefining the Kilogram. Calibration is often considered a dull topic, but any scientist worth their salt knows it’s one of the most important concepts in scientific research. In this post, Ryan of A Quantum of Knowledge describes how research into a more precise determination of Avogadro’s constant could lead to a more scientific standard for the kilogram. In fact, the Royal Society is meeting today to discuss new definitions of measurement units based on fundamental constants. Interestingly, the kilogram is the only physical constant based on an actual physical artifact. Who knew?

As always, thanks for all the great writing!