How about an identical-size Beryllium cube?

Post #401,803 by Ashton 5/15/15 4:19:01 PM Reply	How about an identical-size Beryllium cube? It might be a bluer hue, machined-smooth to same tolerances but the contrast, in-hand, should prove surprising to most. I find lots of pure-Elements fascinating to touch (omitting the usual unwise choices.) I have a flat Be sheet, a few mm. thick.. an amazing thing to most, as being so obviously "a metal". (Just don't ever imagine machining such 'at home', a top-lethal dust happens.)
Post #401,806 by Another Scott 5/15/15 7:00:02 PM Reply	Beryllium is a magical material. JWST mirrors: Webb Telescope's scientists and engineers determined that a primary mirror 6.5 meters (21 feet 4 inches) across is what was needed to measure the light from these distant galaxies. Building a mirror this large is challenging, even for use on the ground. A mirror this large has never before been launched into space! If the Hubble Space Telescope's 2.4 meter mirror were scaled to be large enough for Webb, it would be too heavy to launch into orbit. The Webb team had to find new ways to build the mirror so that it would be light enough - only one-tenth of the mass of Hubble's mirror per unit area - yet very strong. The Webb Telescope team decided to make the mirror segments from beryllium, which is both strong and light. Each segment weighs approximately 20 kilograms (46 pounds). The Webb Telescope team also decided to build the mirror in segments on a structure which will fold up, like the leaves of a drop-leaf table, so that it can fit into a rocket. The mirror would then unfold after launch. Each of the 18 hexagonal-shaped mirror segments is 1.32 meters (4.3 feet) in diameter, flat to flat. (Webb's secondary mirror is 0.74 meters in diameter.) Cheers, Scott.
Post #401,819 by rcareaga 5/16/15 2:43:29 PM Reply	a cube of astatine! Today's sermon is from Randall Munroe's delightful book What If?: We don't know what astatine looks like because, as Lowe put it, "That stuff just doesn't want to exist." It's so radioactive (with a half-life measured in hours) that any large piece of it would be quickly vaporized by its own heat. Chemists suspect that it has a black surface, but no one really knows. There's no material safety data sheet for astatine. If there were, it would just be the word "NO" scrawled over and over in charred blood. Our cube would, briefly, contain more astatine than has ever been synthesized. I say "briefly" because it would immediately turn into a column of superheated gas. The heat alone would give third-degree burns to anyone nearby, and the building would be demolished. The cloud of hot gas would rise rapidly into the sky, pouring out heat and radiation. The explosion would be just the right size to maximize the amount of paperwork your lab would face. If the explosion were smaller, you could potentially cover it up. If it were larger, there would be no one left in the city to submit paperwork to. This is lifted from an essay on the practical obstacles involved in building a representation of the periodic table consisting of cubes made of each of the enumerated elements. As you might gather, many of these obstacles are formidable. ironically,
Post #401,820 by Another Scott 5/16/15 2:50:04 PM Reply	:-)
Post #401,823 by a6l6e6x 5/16/15 3:12:40 PM Reply	If you briefly had a cube of such... you would have to kiss your astatine goodbye! :) Alex "There is a cult of ignorance in the United States, and there has always been. The strain of anti-intellectualism has been a constant thread winding its way through our political and cultural life, nurtured by the false notion that democracy means that "my ignorance is just as good as your knowledge." -- Isaac Asimov
Post #401,827 by gcareaga 5/16/15 8:01:07 PM Reply	Re: a cube of astatine! Theodore Gray's Elements uses the Uranium mineral autunite to represent astatine visually, but admits a low probability that an atom of At would exist at a given moment in such a small specimen. Gray says about an ounce of At exists on Earth at a given moment.

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