"It is finicky. Its what I decided to use to make the mirror. It's subject to tarnish, and oxidation, and corrosion.". And unlike the small-scale atomic deposition used in the electronics industry, this new machine--recently installed in a lab at U.C. 60-Second Science - 0 minute ago - By Christopher Intagliata, 60-Second Science - 20 hours ago - By Susanne Bard, 60-Second Science - November 18, 2020 - By Christopher Intagliata, 60-Second Science - November 17, 2020 - By Scott Hershberger, Divide and Conquer Could Be Good COVID Strategy, 60-Second Science - November 12, 2020 - By W. Wayt Gibbs, 60-Second Science - November 10, 2020 - By Mark Stratton, Funky Cheese Rinds Release an Influential Stench. And that's where the optics problem comes in. —and coat it with extremely uniform layers of transparent aluminum oxide, to protect against corrosion. Observations, Data, and Conclusions. The above text is a transcript of this podcast. After a pause for work on two other mirrors, the lab is in the process of grinding Segments 2 and 3. Drew Phillips, astronomer at University of California Observatories. Christopher Intagliata reports. Building a reflector telescope can be decomposed in 2 steps: make the mirror and build the tube/mount. Meaning you could coat all 500 mirrors of a state-of-the-art telescope—like the planned Thirty Meter Telescope—in a matter of months. Subscribers get more award-winning coverage of advances in science & technology. But silver's got problems too. Bounce that light around a few times in a telescope, and you lose valuable photons. —and do more science. The technique allows them to take a silver-coated mirror—and coat it with extremely uniform layers of transparent aluminum oxide, to protect against corrosion. It was 40"x40" and 0.75" thick. Casting a $20 Million Mirror for the World’s Largest Telescope More photons, he says, basically means more science about incredibly faint, distant objects. Scientific American is part of Springer Nature, which owns or has commercial relations with thousands of scientific publications (many of them can be found at, More reflective telescope mirrors allow astronomers to capture more photons. So Phillips and his team have borrowed a trick from the computer industry, called atomic layer deposition. Like silver, which reflects 97 to 99 percent of visible and infrared light, respectively. To study the heavens, it's all about the photons. [, When put to use, these better mirrors might allow astronomers to capture more photons… and shed more light. Here at the Mirror Lab, we finished making the first Giant Magellan Telescope segment in 2012. Shake well before pouring the grit on the mirror. [The above text is a transcript of this podcast. And mirrors aren't perfectly reflective. The traditional mirror coating, aluminum, reflects only about 90 percent of light. —literally—on faraway galaxies and stars. And unlike the small-scale atomic deposition used in the electronics industry, this new machine--recently installed in a lab at U.C. © 2020 Scientific American, a Division of Springer Nature America, Inc. Support our award-winning coverage of advances in science & technology. Because incoming light reflects off several mirrors before it comes out the business end of a telescope. "The throughput, the actual number of photons that are detected in the end in a modern spectrograph, you're doing good if you get thirty percent. Santa Cruz—is scaled up to coat mirror segments up to a meter in diameter. ], Scientific American Space & Physics is a roundup of the most important stories about the universe and beyond. Cutting it into smaller sections can be difficult but scoring it with a glass cutter and tapping the… Christopher Intagliata reports. Building a mirror for any giant telescope is no simple feat. This Instructable describe the planning, design, and par… In this post, we’ll talk about the first one which is the most time consuming but also the most interesting. Bounce that light around a few times in a telescope, and you lose valuable photons. [Journal of SPIE]. When put to use, these better mirrors might allow astronomers to capture more photons… and shed more light—literally—on faraway galaxies and stars. The sheer size of the glass, the nanometer precision of its curves, its carefully calculated optics, and the adaptive software required to run it make this a task of herculean proportions. "We in astronomy are always greedy. We want every photon we can collect." The technique allows them to take a silver-coated mirror. Homemade 12.5 Inch Dobsonian Telescope: How to build a 12.5 inch closed tube Dobsonian telescope. Take a plastic bottle (from drinks etc) 0.5 liters, add a few spoons of grit in the bottle and add 6-8 times the volume of water. The traditional mirror coating, aluminum, reflects only about 90 percent of light. So Phillips and his team have borrowed a trick from the computer industry, called atomic layer deposition. It starts to look like a telescope mirror :) The #400 grit is the finest size you will add with the teaspoon. More reflective telescope mirrors allow astronomers to capture more photons—and do more science. Santa Cruz, —is scaled up to coat mirror segments up to a meter in diameter. How to Make Your Own Telescope Mirror: [Fig 1] This is a large piece of glass a woman off Craigslist gave me. ", So you want the most reflective material for your mirrors. But the recent castings of the 15-metric ton, off-axis mirrors for the Giant Magellan Telescope forced engineers to push the design and manufacturing process beyond all previous limits.Read more: https://spectrum.ieee.org/video/aerospace/astrophysics/casting-a-20-million-mirror-for-the-worlds-largest-telescope