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A* Episode 13 
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Joined: Sat Aug 07, 2010 8:18 am
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Not art supply stores. The other places are the one's I mean. Artsy-craftsy decorator stores. They mostly sell frames, silk flowers, and seasonal junk, with a full spectrum of overpriced things for kids to do when its raining and self-contained projects for people with no artistic ability. Way back in a corner somewhere they sell really cheap brushes in plastic bags with names you have never heard of. (They also have name brands like Grumbacher and Liquitex that are never in the right category and usually overpriced for what you're getting. Don't buy those.) Look through the really cheap ones that have "sable brush" on them or on the package.


Mon Oct 03, 2011 3:12 am
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Ohhh I see! Hm yeah I know of one place like that in my neighborhood, I may have to check that out!


Mon Oct 03, 2011 2:28 pm
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Actually I think I may as well head over there now since I also need to get some kind of white board to put behind the paper I'm scanning and make sure the light doesn't get lost; this new scanner oddly enough has a *black* lining on the inside of its tray lid--I think this is so that you can easily make office scans by just plopping in a bit of paper of whatever size, and the preview function will be able to find the edges of the white paper against the black background and make a nice auto-select of just the paper area (which is slick), and then another default setting automatically washes out the paper background with straight white--pretty slick, and it's fine for just like scanning documents and stuff, but not for art scans where you need all the whites and blacks as clear as possible. So maybe they have some white board or something I can use as a backing board when scanning.


Mon Oct 03, 2011 2:35 pm
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Tally-ho ! Good hunting (or good digging) as the case may be !


Mon Oct 03, 2011 5:28 pm
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Score! Three "sable" and one wide "camel" brush for $1.99. And then I splurged on a twelve-pack of "natural hair" (human? dog? ant?) brushes for $0.99. ;)

Thanks for another good tip! (Speaking of tips, the tips on these are visibly messy, but nothing a snip here and there can't sorta fix I suppose.)


Mon Oct 03, 2011 6:37 pm
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Yay ! They're probably pretty decent brushes once you give them little haircuts !
Well, the "natural hair" could be any of a variety of hair or bristles, but really cheap and expendable if needed. Almost like an endless resource !
I really have a thing for those 59-cent white bristle brushes- like you find at Home Depot. The 1" brush does just about anything, with any kind of paint, finish or stain on any surface. If you think of doing large paintings this is the best brush you can buy....!


Mon Oct 03, 2011 7:11 pm
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I'm probably not gonna go big for a while, but that sounds like a good deal. :D


Mon Oct 03, 2011 11:07 pm
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I gotta go practice my ink work but I came across a supermassive science thing accidentally over the weekend so I'm gonna try to do that fast. Go!

The zig-zag shape of this 1997 Hubble spectrograph of the core of galaxy Messier 84

Image
image by NASA, Gary Bower, Richard Green (NOAO), the STIS Instrument Definition Team (source)

told scientists that the hot radiating gas at the galaxy's center was whipping around at 880,000 miles per hour within 26 light years of the core, and doing the math on that showed that there must be about 300 million solar masses at the center of it--a really big supermassive black hole (supermassive black hole Sgr A* at the center of the Milky Way is "only" 4 million solar masses).

Galaxy M84 is a lenticular galaxy, and I've talked about those fuzzy kinds of spiral galaxies before. Without clearly defined spiral arms, they can look a little boring (although I have some nice ones under that last link), and M84 isn't really an exception; here is it in visible light by Hubble:

Image
image by NASA (source)

On the other hand, if you look at it in other bandwidths, as done here with X-ray data from Chandra in blue and radio data from the Very Large Array in red (in front of a background seen in visible light by the Sloan Digital Sky Survey), it gets a little more interesting:

Image
image by: X-ray (NASA/CXC/MPE/A.Finoguenov et al.); Radio (NSF/NRAO/VLA/ESO/R.A.Laing et al); Optical (SDSS) (source)

In those wavelengths you can see huge lobes of hot gas being pushed out of the galaxy by the two jets coming off the poles of that big supermassive black hole at the center!


Tue Oct 04, 2011 2:21 am
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Brush and ink practice--my first real brush and ink painting, in fact:

Image

It's a preliminary version of a prospective guest art (you're probably not really supposed to show these at least until the other comic has them up, but hey then I wouldn't have much to put up today, so oh well hopefully they won't be too mad) for the webcomic Girls in Space, a whimsical, colorful science fiction romp starring a pack of feisty young women...in space. Quite colorful and worth checking out!

My attempt in no way does it justice...in fact it's quite an awful painting really, with terribly crude handling of the brush, backwards technique, and boo-boos everywhere, but believe it or not, it's miles better than my previous brush and ink attempts from a week ago, which were so reprehensible I couldn't show them to you at all. :o

That relative success is due in large part to having upgraded my materials; whereas before I was trying to work with synthetic brushes (da Vinci "Cosmotop Spin") and eh sorta regular ink ("Speedball"), this time I had on my side a da Vinci "Maestro" brush (size 3!) and Japanese "Sumi" ink; the Maestro, made by hand like this in Germany, totally blows away the synthetic brushes in terms of flexibility and precision, and the "Sumi" ink is just way blacker and easier to spread than the other stuff I tried--nice neutral grays when you use it in a dilute ink wash, too.

What also saved my bacon was liberal application of Dr. Ph. Martin's Bleed Proof White, which is essentially the "White Out" of the ink world, I guess. It was also a lot whiter than the old sketch pad paper I'm using for these practice attempts, so actually it maked for a pretty good all-around highlight, in addition to erasing some of my more glaring boo-boos. ... I'm gonna need to get a bunch more bottles of this stuff. It's fun to do stars with it, for instance!

~~~~~~~

Well yet again I accidentally stumbled across a bunch of neat science stuff today; still wanna get another ink practice piece in tonight so let's see how fast I can run these down:

- Seven supernovas exploded in the last 60 years (say that five times fast!) in galaxy Arp 220, in which two galaxies are actually colliding; this somewhat violent coming-together touches off a lot of starbirth--and death--activity as material from both galaxies comes together to form sudden high-density regions. All this activity has made it the nearest (at 250 million light years away) "ultraluminous infrared galaxy"--most of the energy reaching us is in the form of infrared light. Anyway, seven near-simultaneous supernovae in a galaxy is apparently a new record; it is estimated that a supernova occurs about every 25 years in Arp 220, whereas in the Milky Way for instance we only get one about every 100 years.

- I've posted a bunch before about Saturn's cool moon Enceladus and its ice geysers. The Cassini probe has continued to study these amazing phenomena, and found that not only do the ice crystals they emit rain down on Saturn, but they also coat Enceladus in a thick layer of snow--up to 300 feet deep in spots! I guess maybe that's what we can see in this cropped-to-fit-the-news-page version of one of those Enceladus images I posted before:

Image
image by NASA (source)

- The Atacama Large Millimeter Array, an international radio telescope installation being built in the high Chilean desert, has just begun to come online; although only about a third of its planned 66 7-and-12-inch radio telescopes are up and running now, it's already a world-class radio telescope by current standards. Radio telescopes read wavelengths that are much longer than those read even by infrared telescopes, so not only can they see really really old light from near the beginning of the universe--this light having been stretched to radio wavelengths by the subsequent expansion of the universe--they can also see right through fields of thick gas and dust that might block the vision of other telescopes; longer wavelengths are less likely to be blocked by such impediments because their "waves" vibrate back and forth less frequently on their journey, and are thus less likely to strike an obstacle like a gas molecular or dust particle (this is also why sunsets are red: the shortest, liveliest visible wavelengths are blue, so blue light from the Sun gets blocked more by the atmosphere--hits more stuff in the air--than red light from the Sun, so the Sun appears reddish when seen through a lot of atmosphere as it nears the horizon).

The array of linked radio telescopes, which will use computer coordination to work together to as one (or multiple, I guess, if they split up for separate tasks) massive telescope, will eventually cover a 16-km swath of the high desert! Here's a view of nineteen of the telescopes in place:

Image
image by ALMA (ESO/NAOJ/NRAO)/W. Garnier (ALMA) (source)

When complete ("by 2013"), it will be far and away the most powerful radio telescope on Earth, with a "spatial resolution of 10 milliarcseconds, 10 times better than the Very Large Array (VLA) and 5 times better than the Hubble Space Telescope." Radio telescope images tend to be kind of blobby rather than sharp and precise like visible light telescope images, but still, they can be very useful, and can be composited with light from visible and other wavelengths to reveal large-scale structures not otherwise apparent; that last photo of galaxy M84 that I posted yesterday, for instance, showed radio data from the VLA in red, illustrating giant lobes of hot gas shooting out from the supermassive black hole at the galaxy's center.

Speaking of supermassive black holes, the official ALMA press release (which has some typos that I'm trying to avoid) indicates that our galaxy's own supermassive black hole Sgr A* will be the subject of intense study by the giant telescope:

Quote:
26,000 light years from us in the center of our galaxy, sits Sagittarius A*, a supermassive black hole four million times the mass of our Sun. Gas and dust between it and us hide it from our optical telescopes. However, ALMA is tuned to see through the galactic murk and give us tantalizing views of Sgr A*.

Heino Falcke, an astronomer at Radboud University Nijmegen in the Netherlands, said, “ALMA will let us watch flares of light coming from around this supermassive black hole, and make images of the gas clouds caught by its immense pull. This will let us study this monster’s messy feeding habits. We think that some of the gas may be escaping its grip, at close to the speed of light.”

Go ALMA!

EDIT: I should mention that you can see the initial releases of ALMA radio images--of star-forming regions in the Antennae galaxies, superimposed on Hubble visible data--in that same press release. Here's one of the sharper ones, for instance.

- And then there's radium! I was looking up the element radium for a reason that I may tell you about later (>_>), and there's some interesting stuff in the history of its discovery and use! Radium is over a million times more radioactive than the element from whose decay it is obtained--uranium--and its hazardous nature was realized pretty early on; for instance, in 1900, two years after its discovery (by the Curies), famed French physicist (oops, there's another tongue-twister) Antoine Becquerel got an ulcer on the skin next to his waistcoat pocket after carrying a small ampule of radium in it for six hours. Yes Antoine, maybe you shouldn't do that! Radium takes most of the blame for Marie Curie's eventual death, too--she also observed getting an ulcer from it after carrying a sample around all day.

Still that didn't keep early industry from using radium in all kinds of things. Right up into the 60's in fact it was used for glow-in-the-dark watch dials; and in the 20's a lawsuit was filed on behalf of the Radium Girls--a group of watch painters working for the U.S. Radium Corporation, whose daily task was painting those little glowing dots on watch dials with radium paint

Image
image from Revised Work Plan, Volume 1 of 2, U.S. Radium Site, City of Orange, Essex County, New Jersey (source)

They were encouraged to keep their paint brushes nice and sharp (I'm using The Masters Brush Cleaner and Preserver for a similar purpose!) with their lips and tongues, and had fun by using the radium paint on their own faces to make glow-in-the-dark masks. :o This of course led to very bad medical complications such as radium jaw and, in some cases, death, although the exact number of deaths caused to the Girls isn't known; defending lawyers for the corporation blamed the Girls' illnesses on syphilis, implying thereby of course that they were scandalously loose women.

Radium is particularly nasty when it gets in the human body, because our body treats it like calcium (a lighter element in the same column of the periodic table), sending it to right to our bones, where its radiation can degrade bone marrow and mutate the cells. (And horrifyingly, early on it was used "in products such as toothpaste, hair creams, and even food items due to its supposed curative powers"!)

Fortunately, justice somewhat prevailed, and the five Girls who had filed the suit eventually won "$10,000 (the equivalent of $128,000 in 2010 dollars) and a $600 per year annuity while they lived, and all medical and legal expenses incurred." The case was also remarkable in that it was widely covered by the media; it led to a much greater public awareness of the dangers of radioactive materials, and "the right of individual workers to sue for damages from corporations due to labor abuse was established as a result of the Radium Girls case."

- Radium was also a key tool in the famed Rutherford experiment that led to the discovery of the atomic nucleus! In this 1909 experiment at the University of Manchester, alpha particles (consisting of two protons and two neutrons, just like a helium nucleus) radiated by radium were aimed at a thin gold foil surrounded by a circular sheet of zinc sulfide, which lights up when struck by an alpha particle; the idea was to measure the deflection of the radiation after it hit the gold foil.

According to the prevailing "plum pudding" atomic theory of the day, the radiation should have more or less gone straight through the foil, whose gold atoms were thought to consist of negatively charged electrons floating in a sea of positive charge. But quite to the contrary, the detection sheet showed that while most of the radiation went through, some of it deflected off at wide angles, even close to 180 degrees--right back at the radium source! Rutherford said of it

Quote:
It was quite the most incredible event that has ever happened to me in my life. It was almost as incredible as if you fired a 15-inch shell at a piece of tissue paper and it came back and hit you. On consideration, I realized that this scattering backward must be the result of a single collision, and when I made calculations I saw that it was impossible to get anything of that order of magnitude unless you took a system in which the greater part of the mass of the atom was concentrated in a minute nucleus. It was then that I had the idea of an atom with a minute massive center, carrying a charge.

~~~~~~

Man, that took a while. I've got to stop reading the internet!


Wed Oct 05, 2011 4:31 am
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The new tools seem to be working !
-Another way to get whites is to use resists that block out the ink. Rubber cement was always a quick way to get big white areas, but there must be better products than that available. I don't see why it wouldn't work to dot the heavens with stars...very quickly. Get a something like a toothbrush and spatter the "stars" first.
-If you have really good paper and a sharp knife you can also "shave" the paper to remove the unwanted dark part or just for general clean up.
Those photos yesterday of M84 were excellent, but I'm really wondering what the views of the center of this galaxy from Chile will be like. (I mean besides really neato keen!)


Wed Oct 05, 2011 5:53 am
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