A-Z GEMSTONES

Flame color guide of various materials combustion  

Vera Rubin, the groundbreaking astrophysicist who discovered evidence of dark matter, died Sunday night at the age of 88, the Carnegie Institution confirms.

Rubin did much of her revelatory work at Carnegie. The organization’s president calls her a “national treasure.”

In the 1960s and 1970s, Rubin was working with astronomer Kent Ford, studying the behavior of spiral galaxies, when they discovered something entirely unexpected — the stars at the outside of the galaxy were moving as fast as the ones in the middle, which didn’t fit with Newtonian gravitational theory.

The explanation: Dark matter.

Adam Frank, an astrophysicist who writes for NPR’s 13.7 blog, described dark matter by comparing it to a ghost in a horror movie. You can’t see it, he writes — “but you know it’s with you because it messes with the things you can see.”

Adam continued:

“It was Vera Rubin’s famous work in the 1970s that showed pretty much all spiral galaxies were spinning way too fast to be accounted for by the gravitational pull of the their ‘luminous’ matter (the stuff we see in a telescope). Rubin and others reasoned there had to be a giant sphere of invisible stuff surrounding the stars in these galaxies, tugging on them and speeding up their orbits around the galaxy’s center.”

Vera Rubin, Who Confirmed Existence Of Dark Matter, Dies At 88

The world’s smallest snowman is only 2.7 microns tall (for comparison, a human hair is 75 microns thick). To create it, scientists stacked 3 tiny silica spheres, added a nose and arms made of platinum, and cut the eyes and mouth with a focused ion beam. Source

Cristobalite, Hematite

SiO2, Fe2O3

Locality:

Caspar quarry, Bellerberg volcano, Ettringen, Mayen, Eifel, Rhineland-Palatinate, Germany

An interesting homoepitactic intergrowth from brown and black hematite  

Photo: Michael Förch

Cristobalite is a silica polymorph that is thermodynamically stable only at temperatures above 1470°C, up to the melting point at 1705°C, at atmospheric pressures. It commonly metastably persists or even forms at much lower temperatures in silica-rich volcanic and sedimentary environments. It can form crystals in cavities, probably vapour-deposited, or spherulites in obsidian or other silicic volcanics.

Hematite is rather variable in its appearance - it can be in reddish brown, ocherous masses, dark silvery-grey scaled masses, silvery-grey to black crystals, and dark-grey masses, to name a few. What they all have in common is a rust-red streak.

As a paleo-artist, one of my biggest pet peeves are prehistoric whales reconstructed not as whales but as sinewy, snarling, shrink-wrapped marine reptiles. It’s just not a plausible reconstruction, even if it’s highly speculative, and it paints an incorrect image in the public eye. Granted, this is a struggle I’ve exlpored in all forms of paleo-art and reconstructive illustration. But the whales have really been getting to me recently.

Here are some recontructions of Basilosaurus, if you don’t know what I mean (one by Karen Carr, the other by an artist I could not determine):

These snakey, reptilious reconstructions may stem from the fact that Basilosaurus, one of the first early cetaceans to be found, was believed to be a reptile when first discovered (hence the name). Maybe we simply haven’t fully shaken that mindset.

But still! Even the damn Smithsonian, which has such a wonderful collection of ancient cetaceans, is at fault in this:

Don’t even get me started on their recently-closed dinosaur hall. Thank the lord they’re finally renovating that dated piece of crap.

I have struggled to find a way to reconstruct these animals so that they are just a little bit more believeable. Up top I’ve done a really really quick sketch of Dorudon. I tried to not only make its body more streamlined and whale-like (because Dorudon has a lovely, almost but not quite modern-looking skeleton), but I also tried to give it markings similar to what we find on modern cetaceans for camouflage. Because hey, who’s to say they didn’t have ‘em? I tried to make them familiar but not directly copied from any modern species.

Aaaaand end rant.

The Titanoboa, is a 48ft long snake dating from around 60-58million years ago. It had a rib cage 2ft wide, allowing it to eat whole crocodiles, and surrounding the ribcage were muscles so powerful that it could crush a rhino. Titanoboa was so big it couldn’t even spend long amounts of time on land, because the force of gravity acting on it would cause it to suffocate under its own weight.

The origin of the universe was not by a singularity, since in a singularity, the laws of nature are not valid or do not exist,

The Clouds of Orion the Hunter https://go.nasa.gov/2n7rVh9

Andromeda Galaxy from Earth: