Category: Changin’ the world
-
How fast could Usain Bolt have run the 100m?
You’ll probably have seen footage of “the greatest 100m performance in the history of the event” as Michael Johnson put it. But if not, here’s short description: In the Olympic final of the 100 metres in Beijing, the Jamaican sprinter Usain Bolt accelerated away from the field and then, with victory assured but with 20…
-
Orbiting observatory finds dark matter, but what kind?
The world of cosmology is abuzz with rumours that an orbiting observatory called PAMELA has discovered dark matter. Last month, the PAMELA team gave a few selected physicists a sneak preview of their results at a conference in Stockholm. Here’s the deal. The PAMELA people say their experiment has seen more positrons than can be…
-
Do nuclear decay rates depend on our distance from the sun?
Here’s an interesting conundrum involving nuclear decay rates. We think that the decay rates of elements are constant regardless of the ambient conditions (except in a few special cases where beta decay can be influenced by powerful electric fields). So that makes it hard to explain the curious periodic variations in the decay rates of…
-
How to measure macroscopic entanglement
If macroscopic objects become entangled, how can we tell? The usual way to measure entanglement on the microscopic level is to carry out a Bell experiment, in which the quantum states of two particles are measured. If the results of these measurements fall within certain bounds, the particles are considered to be entangled. These kinds…
-
The prophetic promise of category theory
When it comes to creating the final theory of everything, physicists have an ever broadening (and bewildering) choice of mathematical tricks with which to tackle the mysteries of the universe. A couple of years ago, random matrix theory cropped up as a potential framework for a new kind of science. And a fascinating idea it…
-
Schroedinger-like PageRank wave equation could revolutionise web rankings
The PageRank algorithm that first set Google on a path to glory measures the importance of a page in the world wide web. It’s fair to say that an entire field of study has grown up around the analysis of its behaviour. That field looks set for a shake up following the publication today of…
-
Quantum communication: when 0 + 0 is not equal to 0
One of the lesser known cornerstones of modern physics is Claude Shannon’s mathematical theory of communication which he published in 1948 while juggling and unicycling his way around Bell Labs. Shannon’s theory concerns how a message created at one point in space can be reproduced at another point in space. He calls the conduit for…
-
Push ‘n’ shove
The best of the rest from the physics arxiv: The NASA EPOXI Mission of Opportunity to Gather Ultraprecise Photometry of Known Transiting Exoplanets EconoThermodynamics, or the World Economy “Thermal Death” Paradox How the Surrounding Water Changes the Electronic and Magnetic Properties of DNA Traffic by Small Teams of Molecular Motors IceCube: A Cubic Kilometer Radiation…
-
Dark energy and the bitterest pill
It’s hard to get your head around dark energy, this universe-accelerating stuff that is supposed to fill the cosmos. Dark energy was invented to explain measurements that seem to show that the most distant supernovas all appear to be accelerating away from us. The thinking is that something must be pushing them away and…
-
First X-ray diffraction image of a single virus
X-ray crystallography has been a workhorse technique for chemists since the 1940s and 50s. For many years, it was the only way to determine the 3D structure of complex biological molecules such haemoglobin, DNA and insulin. Many a Nobel prize has been won poring over diffraction images with a magnifying glass. But x-ray crystallography has…