Month: August 2008
-
The black hole at the center of our galaxy
Is there a supermassive black hole at the center our galaxy, asks Mark Reid from the Harvard Smithsonian Center for Astrophysics in Cambridge. There sure is and Reid gives a good account of the evidence to prove it. How can astronomers be so sure? The first evidence began to emerge in the 1950s when the…
-
How big is a city?
That’s not as silly a question as it sounds. Defining the size of a city is tricky task that has major economic implications: how much should you invest in a city if you don’t know how many people live and work there? The standard definition is the Metropolitan Statistical Area, which attempts to capture the…
-
Carbon nanotubes sucessfully deliver cancer drugs (in mice)
“A holy grail in cancer therapy is to deliver high doses of drug molecules to tumor sites for maximum treatment efficacy while minimizing side effects to normal organs,” write Zhuang Liu and colleagues at Stanford University before revealing the results of experiments they have carried out with a material that has the potential to be…
-
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…
-
Sand ‘n’Sun (part 2)
More highlights from the physics arXiv this week: Injection of Short-Lived Radionuclides into the Early Solar System from a Faint Supernova with Mixing-Fallback Iron Behaving Badly: Inappropriate Iron Chelation as a Major Contributor to the Aetiology of Vascular and Other Progressive Inflammatory and Degenerative Diseases Quantum Algorithm Design using Dynamic Learning A Biophysical Model of…
-
Sand ‘n’ sun (part 1)
The best of the rest from the physics arXiv: The NuMoon Experiment: First Results The Role of Microtubule Movement in Bidirectional Organelle Transport Links Between Traumatic Brain Injury and Ballistic Pressure Waves Originating in the Thoracic Cavity and Extremities Testing the Dark-Energy-Dominated Cosmology by the Solar-System Experiments Shelf Space Strategy in Long-Tail Markets Image Steganography,…
-
The puzzling beauty of Abelian sandpiles
Pour real sand, a grain at a time, onto a flat surface and the result is a rather dull pyramidal shape. but in the mathematical world, the result is a little different. The image above is produced using a theoretical model called an Abelian sandpile model. It is produced by dropping some 200,000 grains onto…
-
Graphene quantum computers could be built with today’s technology
Is there anything graphene cannot do? The great graphene gold rush continues today with the news that graphene nanoribbon could be the key ingredient of the next generation of quantum computers. The trick with quantum computing is to use qubit-carrying particles that are easy to manipulate so that their quibits can be written and read,…
-
Solar systems like ours likely to be rarer than we thought
Astronomers, to their obvious delight, have discovered some 250 planetary systems beyond our own, many of them with curious properties. In particular, the discovery of several “hot Jupiters” gas giants that orbit close to their parent stars, challenges our theories of planet formation.The thinking is that gas giants can only form far away from stars…
-
The physics of skin vision
Most animals use optical systems to form images but a substantial number rely on optics-less cutaneous vision or skin vision. And while computer scientists have spent a good deal of time and effort trying to reproduce the former, how many will even have heard of skin vision? So a systematic investigation of this kind of…