3-D printing isn’t just for toys and plastic models of your head. Witness a hot fire of NASA’s newest design for rocket engine injectors, 3-D printed to up performance in a way that traditional manufacturing of the parts couldn’t attain.
The agency, which tested the experimental injectors last month at Marshall Space Flight Center in Huntsville, Ala., used a type of 3-D printing called direct laser melting. To make the parts, a machine fires a laser at metal powder under the direction of a computer design program. This deposits layers of the metal one on top of the other until the part is complete.
NASA says the technique is letting engineers build the injector out of just two parts instead of the 163 formerly needed using traditional manufacturing methods.
At first glance, these probably come across as little more than hastily painted watercolor sketches of the moon. That’s precisely what they are, actually. Attractive, yes, but certainly not high art.
But hiding in their shadows lies a greater significance. The squiggled edges of that bleeding ink bear an observation that altered the heavens themselves. Or at the very least, our view of them.
The hand that traced these orbs belonged to none other than Galileo Galilei. They were included in his 1610 work Sidereus Nuncius (“The Sidereal Message”, which would make a great band name), the first scientific text based on telescope observations. To understand the significance of his illustrations, it helps to understand the world in which he drew them.
In 1610, cosmology, not that it had much to show for itself as a science, was still based on the ideas of Aristotle, who by this time had been dead for 18 centuries. So current! Copernicus’ observation that the Earth orbited the sun, first published in 1543, had begun to challenge Aristotelian supremacy, it wasn’t exactly a popular idea.
Aristotle’s cosmological beliefs were based on the idea that the heavens were made of a perfect substance called “aether”, and therefore the circular motions and spherical shapes of heavenly bodies were also perfect. Earth, he claimed, was inherently imperfect, as were all the things that existed upon it. Everything in the heavens was awesome, and Earthly matter was inherently “just okay”, even if its name was Aristotle. This was one of the reasons people found Copernicus’ claims so hard to swallow. The imperfect Earth among the perfect heavens?Heresy!
Enter Galileo and his humble 20x telescope, in 1609. At the time, in Aristotelian fashion, the moon, being of the heavens, was assumed to be a perfect sphere, its dark and light areas just splotches upon the billiard-ball-smooth lunar surface. I imagine it took Galileo about 7 seconds of lunar observation to realize that was not the case.
The terminator, that line that separates the moon’s illuminated face from its dark one, is jagged as a crocodile’s smile. I’ve seen it myself through modern telescopes, and I must say, it’s really something to witness how light and shadow break over a distant crater’s edge. Galileo painted this in his sketches above, inferring that the moon in fact had a rough and crater-marked face. This meant that not only was Earth not the center of the universe, as Copernicus had shown, but the heavens themselves were imperfect, just like Earth.
Scientists would go on to realize that the orbits of heavenly bodies were not perfect circles, nor were the bodies perfect spheres, and that everything up there is made of the same stuff as everything down here. It was either a huge demotion for the heavens, or a great promotion for Earth, I’m not sure.
Galileo’s SidereusNuncius also included newly detailed maps of the constellations and the mention of four moons of Jupiter (although detailed observations of those were still centuries away), but it was his drawings of our moon that bore the most impact on future astronomical science, realigning the heavens with a single stroke of the brush.
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Hi y’all! As you know…I’m a bona-fide bird nerd, particularly with conservation of coastal species, like shorebirds & seabirds. So two things very near & dear to me are, of course — birds & beaches!
South Africa’s gorgeous coasts support a large number of our beloved birds. They also are the fastest developing regions in the country (& the world!). We are seeing shorebirds disappear around the globe, and alarmingly fast (I’m talkin’ decreases like 40-60% of one of my favorites, White-fronted Plovers, in the W. Cape!), mostly due to habitat destruction and other human-caused issues. Since wildlife like shorebirds can tell us so much about the status of our coasts, finding effective conservation and awareness solutions is becoming incredibly urgent.
I’ve been offered a fantastic project for my Master’s (at Univ. of Cape Town, partnering with The Nature’s Valley Trust — a great South African environmental non-profit) to study endemic shorebirds in high-tourism coastal areas, using the research to balance human activity, reduce impacts of major threats, and keep our beaches healthy.
We’re backed by BirdLife South Africa, Cape Nature, Knysna Toyota, and local conservation & bird clubs as necessary research for the region(and the birds! and communities!).Now I need YOUR help to seal the deal.
Make sure to tag #ShareTheShores when sharing, so we can thank you for being awesome!
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This is where my (unpaid) blood, sweat, and tears have been focused this entire year (and there’s been a lot of all of that, phew)! I have been painstakingly working to gain the support make this happen — developing the project, networking with appropriate researchers, officials, and groups, applying for countless grants, awards, and sponsorships. I have put everything I possibly can into this, that is how important and necessary I absolutely know this is. PLEASE SIGNAL BOOST THE HECK OUT OF THIS!
This is the shape model of comet 67P/Churyumov-Gerasimenko. From the images taken on 14 July, the OSIRIS team has begun modelling the comet’s three-dimensional shape. The animated gif presented here covers one full rotation of the nucleus around its spin axis, to emphasise the lobate structure of the comet. This model will be refined as more data becomes available – it is still a preliminary shape model and some features may be artefacts.