How to Fit 1,000 Terabytes Onto a DVD

DVDs and Blu-Rays don’t get a lot of respect from technophiles, because the optical disks aren’t able to store as much data as a typical hard drive. A team at Swinburne University in Australia could change that, by making it possible to store an entire year’s worth of video onto an optical disk. That could be good news for movie buffs but would also appeal to big data centers that who prefer to store the tremendous amounts of information they save in the least amount of space.

Storing data on conventional DVDs and Blu-Ray disk involves a single laser that burns a mark into the disk’s surfacing, changing its chemistry. The mark represents a 1 or 0, which is the basic binary language of all computer data. But because the marks can’t be smaller than a half the wavelength of the laser beam, there is a limit, to how many marks can be burned into the surface of a disk.

The Swinburne team, led by optoelectronics professor Min Gu, did something different. They used two lasers instead of one.

Each laser beamed a different wavelength of light onto the disk. The first one was in the near-infrared and created a spot of light, just like an ordinary DVD laser. The second laser beam was violet and partially interfered with the near-infrared beam in a way that ultimately shrank the spot burned into the disk. The technique shrank the size of the spot down to nine nanometers, enough to put 1,000 terabytes on a disk. For comparison, a Blu-Ray disk can hold 50 GB of data and a typical DVD holds about 4.7 GB of data.

The lasers are similar to those used in current players, so building a commercial version wouldn’t require any new technologies. Not too far in the future, the behemoth storage capacity of the Blu-Ray disk might seem as quaint as the 1.4 megabyte floppy disk.

Plans for an enormous telescope, equipped with a 3.2 billion-pixel camera, are ready for detailed designs, its creators announced on April 24. When built, the Large Synoptic Survey Telescope will take photos of every inch of visible night sky every week for 10 years in a kind of time-lapse picture that will provide scientists with unparalleled views of the universe.

The telescope’s research team, which received Critical Decision 1 approval from the U.S. Department of Energy, will now begin to make in-depth designs, a schedule and a budget. Department of Energy projects go through five critical decision stages, according to a department document posted online.

The telescope, known as LSST, is a long-planned and long-anticipated project, originally conceived in 1998. “It is tremendously satisfying to finally see this move forward to the point when we can begin to carry out the project,” a LSST project director, Steven Kahn, of the SLAC National Accelerometer Laboratory in Menlo Park, Calif., said in a statement.

The LSST will gather 6 million gigabytes of data annually, and its detailed images will teach astronomers more about dark energy, dark matter, near-Earth asteroids and the Kuiper belt, a region just beyond Neptune’s orbit where Pluto and other icy objects carve their paths in space.

It can also help researchers track asteroids that threaten Earth, according to the LSST’s website. All the LSST’s data will be publicly available, so “anyone with a computer will be able to fly through the Universe, zooming past objects a hundred million times fainter than can be observed with the unaided eye,” the site says.

Though the telescope was originally scheduled for completion this year, SLAC now says construction will start in 2014. Researchers have already started work on its 8.4-meter (27.6-foot) mirror and on preparing its construction site, atop the Cerro Pachón mountain in northern Chile.

3.2 Billion-Pixel Camera Telescope

Plans for an enormous telescope, equipped with a 3.2 billion-pixel camera, are ready for detailed designs, its creators announced today (April 24). When built, the Large Synoptic Survey Telescope will take photos of every inch of visible night sky every week for 10 years in a kind of time-lapse picture that will provide scientists with unparalleled views of the universe.

The telescope's research team, which received Critical Decision 1 approval from the U.S. Department of Energy, will now begin to make in-depth designs, a schedule and a budget. Department of Energy projects go through five critical decision stages, according to a department document posted online.

The telescope, known as LSST, is a long-planned and long-anticipated project, originally conceived in 1998. "It is tremendously satisfying to finally see this move forward to the point when we can begin to carry out the project," a LSST project director, Steven Kahn, of the SLAC National Accelerometer Laboratory in Menlo Park, Calif., said in a statement.

The LSST will gather 6 million gigabytes of data annually, and its detailed images will teach astronomers more about dark energy, dark matter, near-Earth asteroids and the Kuiper belt, a region just beyond Neptune's orbit where Pluto and other icy objects carve their paths in space.

It can also help researchers track asteroids that threaten Earth, according to the LSST's website. All the LSST's data will be publicly available, so "anyone with a computer will be able to fly through the Universe, zooming past objects a hundred million times fainter than can be observed with the unaided eye," the site says.

Though the telescope was originally scheduled for completion this year, SLAC now says construction will start in 2014. Researchers have already started work on its 8.4-meter (27.6-foot) mirror and on preparing its construction site, atop the Cerro Pachón mountain in northern Chile.