So the web is buzzing right now over news that scientists have detected some subatomic particles moving faster than the speed of light.
Yeah, well, not so fast. Let’s think about this for a sec.
First, what happened is that they create these particles, called neutrinos, at CERN in Geneva. Neutrinos don’t interact with normal matter well, so they can pass right through the Earth as if it isn’t there. In a fraction of a second, some of them enter a detector called OPERA in Italy where they are recorded (pictured here). If you divide the distance between those two points by the time it takes for the neutrinos to travel, you get their speed.
And when the scientists did that, they find the neutrinos get to Italy about 60 nanoseconds faster than a photon would.
The thing to do is to look at where this claim might have gone awry. First, the timing is interesting. They claim a measuring accuracy of 10 nanoseconds, so 60 ns would be pretty significant. However, my first thought is that light travels about 30 centimeters in 1 ns, so they need to know the distance between the source and the detector to an accuracy of 3 meters. If they are off by 20 meters, then we’re done; that would explain the difference entirely. I suppose this depends on how they measured the distance and the speed of the particles, too. However, they haven’t published a paper on this just yet, so that’ll have to wait.
Also, as pointed out in a Science Magazine article, knowing the exact moment the neutrinos are created isn’t easy either. Mind you, 60 nanoseconds is 0.00000006 seconds, so they need a pretty good clock here. That page also says they used GPS to determine the distance, which could be off a bit.
Why the Faster-than-Light Neutrino Experiment May Be Wrong - [Link]
Engineers at the University of California, Berkeley, have shown that it is possible to reduce the minimum voltage necessary to store charge in a capacitor, an achievement that could reduce the power draw and heat generation of today’s electronics. Shown is a rendition of an experimental stack made with a layer of lead zirconate titanate, a ferroelectric material. UC Berkeley researchers showed that this configuration could amplify the charge in the layer of strontium titanate, an electrical insulator, for a given voltage, a phenomenon known as negative capacitance.
“Just like a Formula One car, the faster you run your computer, the hotter it gets. So the key to having a fast microprocessor is to make its building block, the transistor, more energy efficient,” said Asif Khan, UC Berkeley graduate student in electrical engineering and computer sciences. “Unfortunately, a transistor’s power supply voltage, analogous to a car’s fuel, has been stuck at 1 volt for about 10 years due to the fundamental physics of its operation. Transistors have not become as ‘fuel-efficient’ as they need to be to keep up with the market’s thirst for more computing speed, resulting in a cumulative and unsustainable increase in the power draw of microprocessors. We think we can change that.” [via]
Negative capacitance – one day soon - [Link]
Scientists at the University of Washington (USA) have developed a new type of transistor that uses protons instead of electrons for charge transport. It is intended to simplify the interfacing of electronic circuitry to the brains of living organisms, since protons (positively charged hydrogen atoms) and ions are responsible for signal transport between nerve cells. Proton-based transistors are therefore better suited to controlling and monitoring processes in the brain.
The researches discovered that the natural biomaterial chitosan, obtained from squid pens and crab shells, is a good proton conductor. They then used it to fabricate a transistor that can generate proton pulses. The prototype device is a field-effect transistor with a source, gate and drain, but it operates with protons. [via]
Novel transistor uses protons for charge transport - [Link]
Single molecule is tiniest electric motor ever @ New Scientist. – [via]
For the first time, an electric motor has been made from a single molecule. At 1 nanometre long, that makes the organic compound the smallest electric motor ever.
Its creators plan to submit their design to Guinness World Records, but the teeny motor could also have practical applications, such as pushing fluid through narrow pipes in “lab-on-a-chip” devices.
Single molecule is tiniest electric motor ever - [Link]
The memo, distributed to the senior technical staff, contained a ballot asking them to choose a name for a new device invented the previous winter – the semiconductor triode. Several options were presented, including my personal favorite, the Iotatron. [via]
In the end, the name “transistor” (“transconductance” + “varistor”) won out over all the others, but it’s still interesting to read the discussion of the other names. I love the note for “solid triode”:
This has the advantage of brevity, and is descriptive in the sense that the device may be explained by the physics of the solid state, and also that the active element is a solid rather than vacuum or gas filled. However, the word “solid” also commonly means sturdy, massive, rugged, or strong, which terms are contradictory to the actual physical characteristics of the unit.
How The Transistor Got Its Name - [Link]
Best viewed at 720p and fullscreen, this is truly spectacular. More from Universe Today: [via]
Newly reprocessed images from NASA’s STEREO-A spacecraft, allow scientists to trace the anatomy of a Coronal Mass Ejection in December 2008 as it moves and changes on its journey from the Sun to the Earth. Using a new technique, heliophysicists can now identify the origin and structure of the material that impacted Earth, and connect the image data directly with measurements at Earth at the time of impact.
The different views from left to right are at different scales. The yellow dot is Venus and the blue dot is Earth. Closer to Earth is a dial showing the solar wind density changes at Lagrangian point L1 where the ACE and Wind spacecraft recorded the event.
NASA Video: Solar Storm Enveloping the Earth - [Link]
The Higgs Boson – A one page explanation, read them all – they’re all good… [via]
What a great idea for a website. An entire list of things that are complex explained in one page and the best ones are chosen. We can think of a few dozen topics that could use this
In 1993, the UK Science Minister, William Waldegrave, challenged physicists to produce an answer that would fit on one page to the question ‘What is the Higgs boson, and why do we want to find it?’ Here are the winning entries!
The Higgs Boson – A one page explanation - [Link]
Pendulum Waves [via]
What it shows: Fifteen uncoupled simple pendulums of monotonically increasing lengths dance together to produce visual traveling waves, standing waves, beating, and random motion. One might call this kinetic art and the choreography of the dance of the pendulums is stunning! Aliasing and quantum revival can also be shown.
How it works: The period of one complete cycle of the dance is 60 seconds. The length of the longest pendulum has been adjusted so that it executes 51 oscillations in this 60 second period. The length of each successive shorter pendulum is carefully adjusted so that it executes one additional oscillation in this period. Thus, the 15th pendulum (shortest) undergoes 65 oscillations. When all 15 pendulums are started together, they quickly fall out of sync—their relative phases continuously change because of their different periods of oscillation. However, after 60 seconds they will all have executed an integral number of oscillations and be back in sync again at that instant, ready to repeat the dance.
Setting it up: The pendulum waves are best viewed from above or down the length of the apparatus. Video projection is a must for a large lecture hall audience. You can play the video below to see the apparatus in action. One instance of interest to note is at 30 seconds (halfway through the cycle), when half of the pendulums are at one amplitude maximum and the other half are at the opposite amplitude maximum.
Pendulum Waves - [Link]
Fermilab experiment discovers a heavy relative of the neutron… [via]
Scientists of the CDF collaboration at the Department of Energy’s Fermi National Accelerator Laboratory announced the observation of a new particle, the neutral Xi-sub-b (Ξb0). This particle contains three quarks: a strange quark, an up quark and a bottom quark (s-u-b). While its existence was predicted by the Standard Model, the observation of the neutral Xi-sub-b is significant because it strengthens our understanding of how quarks form matter. Fermilab physicist Pat Lukens, a member of the CDF collaboration, presented the discovery at Fermilab on Wednesday, July 20.
The neutral Xi-sub-b is the latest entry in the periodic table of baryons. Baryons are particles formed of three quarks, the most common examples being the proton (two up quarks and a down quark) and the neutron (two down quarks and an up quark). The neutral Xi-sub-b belongs to the family of bottom baryons, which are about six times heavier than the proton and neutron because they all contain a heavy bottom quark. The particles are produced only in high-energy collisions, and are rare and very difficult to observe.
Fermilab experiment discovers a heavy relative of the neutron - [Link]
When spy satellites peer down at you from over head, what can you do? Well, if your’re Thierry Legault and Emmanuel Rietsch you look back! The pair of enterprising Frenchmen have modified a consumer-grade telescope, added a small motor, hand-held controller and a video camera. The result is a do-it-yourself satellite tracker capable of recording the movements of America’s most secretive spacecraft.
Looking up at the spy - [Link]