February 2010 – Original Source: APS News, Volume 19, Number 2
January 1st brought not only a new year but an entire new decade. Usually in this issue, APS News looks back over the biggest news stories of the last 12 months. However, with the dawning of a new decade we wanted to take time this issue and highlight not just the biggest physics newsmakers of 2009, but the biggest physics newsmakers of the last ten years. These are the stories that may or may not have the most lasting physical significance, and may or may not have had the most impact within the physics community, but they represent the physics news that the public was reading and hearing about in the broader media over the last decade.
The Large Hadron Collider. With the potential to produce colliding beams of 7 TeV, it’s the most powerful particle accelerator in the world. With a circumference of 17 miles, it’s also the largest particle accelerator in the world. Costing upward of $6 billion to build, it is the most expensive science project in history. With millions of individual precision parts it is the most complex machine in the world. There are so many records associated with this modern marvel of science that it may also be the most superlative- laden physics story in history.
After almost fifteen years of development and construction, the accelerator was first switched on in September of 2008 with much fanfare. Just over a week later it suffered a critical malfunction when an electrical fault triggered a major leak of liquid helium, knocking more than fifty of its superconducting magnets out of alignment. Major repairs shut the collider down for over a year. However in November of 2009 it restarted, taking its time to warm up this time around. Now colliding particles at energies over 2.36 TeV, it is renewing its search for the Higgs boson.
The Decade of Carbon. Over the last ten years research into regularly structured carbon molecules has expanded tremendously, becoming one of the hottest fields in condensed matter. Carbon atoms arranged in hexagonal lattices have shown remarkable electronic and structural properties. Many in the field say that these materials are poised to revolutionize electronics over the next century. With careful manipulation carbon nanotubes and graphene can be used to create microscopic wires, diodes, semiconductors and more, shrinking electronics to unprecedented levels. At the same time these nanostructures are extraordinarily strong and with more development could be used to create materials of unprecedented strength. It’s even been surmised that nanotubes could serve as a tether that runs from the surface of Earth to an orbiting satellite for a proposed space elevator.
Negative Index of Refraction Materials. Tremendous advancements have been made over the last several years in creating meta-materials that can make objects seem to disappear. British scientists first theorized a way to make composite materials that divert light around an object in 2006. Since then, scientists around the world have been developing ways to engineer it. After first constructing a prototype that could redirect microwaves, a team at Duke University created a material that can redirect wavelengths from nearly the entire electromagnetic spectrum. All the while, the press has had a blast comparing the material’s ability to bend light to Harry Potter’s invisibility cloak, or to a Star Trek cloaking device, or to the Predator’s invisibility suit.
The Wilkinson Microwave Anisotropy Probe. The cosmic microwave background radiation is the leftover heat from the Big Bang that permeates the universe. The Wilkinson Microwave Anisotropy Probe’s mission (WMAP as it is better known) was designed to map the subtle variations in temperature in the background radiation. Launched in June of 2001, it carried instruments that could measure the cosmic microwave background information 40 times more accurately than its predecessor, the Cosmic Background Explorer Satellite (COBE). After a single year of observation, WMAP returned a map of the cosmic background so accurate, scientists were able to make precise measurements of the Hubble constant and the composition of the universe and were able to pin down the age of the universe at 13.7 billion years. Since then, WMAP has continued further to improve the accuracy of its measurements, and is scheduled to continue to operate until September 2010.
Quantum Teleportation. Taking advantage of the so-called spooky action at a distance inherent in quantum entanglement, physicists have been able to transmit quantum information from one system to another across macroscopic distances. The first such teleportation took place in 1998 at Caltech when two photons were entangled with each other. Over the next decade teams working all over the world moved on to magnetic fields and eventually entire atoms. In February of 2009 the team at the UMD/NIST Joint Quantum Institute announced they had been able to teleport information between two atoms separated by more than a meter. With any mention of teleportation, once again comparisons to Star Trek abound in the news media.
Quark-Gluon Plasma. For the first three minutes after the Big Bang, a strange form of matter known as quark-gluon plasma permeated all of space. Essentially a thick soup of high-energy quarks and gluons loosely interacting with each other, quark-gluon plasmas require such immense energies that they haven’t existed since the beginning of the universe. In February of 2000, CERN announced compelling evidence that they had finally recreated this exotic form of matter by colliding high energy lead ions into gold and lead targets. The resulting temperatures, over 100,000 times hotter than the center of the sun, were enough to dissolve the powerful bonds between the quarks and gluons inside some of the nucleons for a fraction of a second. The discovery was confirmed in 2005 by teams at Brookhaven’s RHIC, and will also be a major area of research at the LHC.
Gravity Probe B. Launched in April 2004 with much fanfare, Gravity Probe B carried onboard four spherical superconducting gyroscopes to measure the geodetic effect and frame dragging in general relativity. The four gyroscopes were touted as the most perfect spheres ever created, completely round with a variation of no more than the widths of 40 atoms. However after launch it became apparent that the coating on the spheres was less perfect, inducing subtle torque on the spinning spheres that threatened to ruin the entire experiment. The team persisted, painstakingly working to extract valuable data. At the 2007 APS April Meeting, the team announced that for the first time they had observed the geodetic effect in the data. However in May of 2008, NASA was forced to pull the plug on funds for the team. After contributions from outside sources including the founder of Capital One Financial and the Saudi Royal Family were secured, the team continued to work, cleaning up their measurement of the geodetic effect by a factor of seventeen as well as finally managing to detect frame dragging.
Light Stopped. In a vacuum, light is the fastest thing in the universe, travelling at nearly 300,000 kilometers per second. When it travels through other materials, such as water or glass, it slows down slightly. In 2001 two independent teams of physicists, one at Harvard, the other at the Harvard-Smithsonian Center for Astrophysics, actually stopped light altogether. The teams shone a coupling laser through a cloud of super-cooled rubidium atoms. The energy of the light beam was stored as an atomic spin wave within the excited atoms, which could be recalled at a later time. Since the first experiment, light has been effectively stopped and stored for up to 20 milliseconds.
Direct Evidence for Dark Matter. Astronomers tracking the movements of two colliding galaxies in the Bullet Cluster announced in August of 2006 that they had the first direct evidence of dark matter. By using computers to help model the movements of observable stars and gas in the collision, physicists were able to demonstrate that there was a substantial amount of mass that visual detection couldn’t account for. These observations only confirmed the presence of dark matter, not what actually might comprise the mysterious substance. Currently research teams around the world are hoping that specially designed detectors will soon observe an actual particle of dark matter.
Advances in Computing. High speed supercomputers are changing the way that modern physics is done. The world’s fastest supercomputers are now able to perform over a quadrillion calculations per second. Using these tools, biophysicists have been able to map complex biological structures like the human circulatory system or neural networks with unparalleled precision. Physicists are now able to calculate turbulence and fluid flows better than ever thought possible. Supercomputers are an indispensable tool for physicists, one likely to only become more important as time goes on.