ST. FRANCIS, Wis. (AP) -- The Milwaukee Bucks have lost their leading scorer.
The different sizes of the quarks represent their masses. A proton and electron are shown at the bottom left corner, for comparison.
Incnis Mrsi on Wikimedia Commons
Physicists have observed what they're confident is the first known particle with four quarks.
This isn't the first time the Belle detector, housed with the High Energy Accelerator Research Organization in Japan, has appeared to observe a four-quark particle, called a Zc(3900). This time, however, another particle accelerator, the Beijing Electron Positron Collider, confirmed the findings, Nature reported. There's only a 1 in 3.5 million chance that the observation is not true.
As Nature explains, current physics laws don't say that four-quark particles can't exist, but before the Belle observations, physicists only ever saw particles with two quarks and three quarks. Protons and neutrons have three quarks.
Check out Nature for more on the debate over how exactly the four quarks in the Zc(3900) are put together-and whether the particle represents a whole new building block of matter.
Researchers from American and French universities have discovered how to exactly map a room's shape solely by using a sense you wouldn't normally choose for this kind of task. Without sight or touch, this new technique can still reveal a room by using only the sense of hearing.
The system could fairly accurately be described as echolocation, just like bats use: it measures the time it takes for a sound to produce an echo at different points in the room. Essentially, what they've come up with is an array of microphones and an algorithm that picks up both the original source and its echoes. Our ears can't hear the tiny lags that make up the echoes in most sounds, but bats can, and so can this system.
From a single sound, they can reconstruct a room to within a few millimeters--provided the room isn't too complicated, at least for now. The system outputs a 3-D map, which until now could only be made with visual tools like LIDAR.
What could this be used for? Well, there are virtual reality possibilities--the Kinect, for example, might someday use audio as well as visual clues to more accurately map action. Or it could be used in forensics. A simple audio recording could reveal the shape of a room in which a crime was committed--a valuable clue to which we wouldn't have access before this.
The paper is published in the current issue of Proceedings of the National Academy of Sciences.