As penance, here is a $65 mirror grinding kit, for a 4.25" mirror: http://firsthanddiscovery.com/...
To make your own Dobsonian, just add a diagonal and stalk, a cardboard tube, plywood, a bit of Ebony Star formica, and some teflon pads and miscellaneous hardware.
Derp. Yes.
This advice is almost exactly the opposite of "good". You might be interested to learn that James Dobson, of Dobsonian fame, specifically designed the telescope to be simple to construct and use. The OP talked about the moon and Saturn. Both of those objects are very easy to see with the naked eye, and therefore very easy to point an alt-azimuth telescope at. An equatorial mount or motor drive is actually harder for a beginner to use than just a simple push-to-go-to alt-az mount. And any motorized drive you could get for anywhere near $100 is just junk.
All that said, you probably won't find a new Dobsonian scope for $100. There are some inexpensive alt-az refractors for about $120 - the Orion StarBlast 70mm for example. It has a finderscope, an erect-image diagonal, and a standard 1.25"-diameter focuser and two eyepieces. Might be worth a peek.
Alternatively, if you are interested in really learning a lot about telescopes, you could build one, starting with grinding your own mirror. You might get that done for about $100 for a 4.25" reflector.
If I were personally going to use one of Tesla's patents in my business, I'd want a signed zero-cost GPL-like license agreement with Tesla. For example, Musk's good will is nice, but what if someone else were to acquire Tesla's IP?
From TFA:
Eris is just 2326 kilometers across—possibly smaller than Pluto, whose diameter is somewhere between 2300 and 2400 kilometers. The uncertainty arises because Pluto, unlike Eris, has air that complicates the interpretation of observational data.
...then what we have now are clearly leftovers.
Paleontologists have found 150-million-year-old dino tumors, see http://www.livescience.com/4013-dinosaur-tumor-studied-human-cancer-clues.html
The university is welcoming four renowned curators from Carnegie Museum into its classrooms to teach seminars and use the museum collection, which is considered one of the world's premiere displays of natural history artifacts, for demonstrations. Included in the collection is a 150-million-year-old fossilized dinosaur bone complete with a tumor.
I would not be surprised if there are even older amphibian tumor fossils out there somewhere.
Now get off my lawn
It's not the *cost* of the iPhone. It's the *black market resale value* that drives theft.
It's uncomfortable allowing a third party to be able to permanently brick your phone or other device, but if that were a commonly-used option, the resale value would quickly drop down close to zero.
As always - back up your data, and don't store important personal information on your easily-stolen device...
Well, it could be sedimentary rock layers. But volcanos can also cause layering - consult the oracle about "welded tuff" (example image from Idaho)
It's here. Let's deal with it.
but, to some physics, perhaps a bit boring.
Err, make that, "but, to some *physicists", perhaps a bit boring."
Possibly the most exciting physics news of the year. Although the detection of the Higgs boson was big, it mostly confirmed what existing theory predicted. Interesting, important - but, to some physics, perhaps a bit boring.
If further measurements continue to verify this effect, there are some very interesting new physics to discover.
How many sticks of dynamite would it take at 15 times per second, to eventually push the stated goal of 200MW into the power grid?
1 stick of dynamite == 2.1MJ, if you can believe Wikipedia
15 sticks per second == 32MJ/S = 32MW
200MW/32MW = 6.3 sticks of dynamite exploded 15 times per second.
This assumes 100% efficiency to electricity, of course.
Ya'll hear about the geometer who went to the beach to catch some rays and became a tangent ?
