Zixar

Steve: The easy test is to hold a magnet to it. If it's magnetic, odds are it's a meteorite.

Congratulations!

Jim emailed me and pointed out a couple of errors in my last post:

Plutonium was first syntehsized in 1941, not 1944, as I had stated, and it has been found naturally in at least two places.

Thanks, Jim!

It's U-235 that you need for fast-fission chain reactions. Either that, or plutonium-239. Since plutonium didn't exist on Earth until 1944, scientists had to extract the tiny fraction of U-235 from all the U-238 in order to make the first atomic pile, and the subsequent atom bombs. The good thing is, you can use some of the excess neutron flux from a U-235 fission pile to irradiate pellets of "depleted" uranium-238 and turn them into pellets of plutonium-239. (This is called a breeder reactor) Pu-239 works better than U-235 in power plants and nuclear weapons.

The other use for pure U-238 (the "depleted" stuff, from which the "hot/enriched" U-235 has been extracted) is for anti-tank bullets. Uranium is denser than lead, so it packs more of a punch. It is also pyrophoric, meaning it can ignite spontaneously upon contact with air. Depleted uranium bullets have a thin coating to keep them from pyrophorically igniting in the gun, or storage, but that coat doesn't survive the impact. The A-10 Warthog ground-attack aircraft has a 30mm cannon that fires these DU rounds, and is the best tank-buster going today.

Well, don't call the NRC yet. It's probably a sample of uranium ore (uraninite, pitchblende, or similar) and while it might elicit a tick or two from a geiger counter, odds are that the majority of the uranium in it is U-238 instead of the more active bomb material, U-235.

U-238 makes up over 99% of all the free uranium on Earth. It's a relatively stable atom, as fissionables go, having a half-life of about 4.5 billion years. It's primary decay mechanism is emission of helium nuclei, which we call alpha particles. A U-238 nucleus will spontaneously emit an alpha particle and turn itself into an atom of Thorium-234.

Alpha radiation is the least hazardous because it is the least energetic. It is easily shielded against, being stopped by a few sheets of paper, or your clothing. (It's beta and gamma radiation that you have to watch for, gamma especially.)

You are being pelted by more beta radiation from your monitor right now (electrons sneaking around the phosphor mask and hitting you in the face) than that little pebble puts out in an hour.

Remember the old glow-in-the-dark clocks? That was radium paint, which puts out a lot more radiation than your uranium does. Or your smoke detectors, which contain a speck of highly radioactive americium. You don't worry too much about those.

As long as it's in its box, and you don't swallow the thing, just keep it as a cold war souvenir.

God bless!

Zix

Thanks, I'm glad it was helpful!

Steve made a good point about lightning--it doesn't have to hit a power pole directly to knock out the electricity to a neighborhood.

Saw Men in Black II today.

Not really a contender for this particular award! (Oh, it was a good way to kill 94 minutes, but it'll be forgotten fast.)

Oh, one more thing about Minority Report. It isn't A.I. 2! While I liked A.I. (except for that really poor visual choice he made in the final hour of the movie) it was more of a test vehicle for what he had to do in MR. MR has a better plot and doesn't take as many annoying unnecessary detours as AI.

Yes, I was also pleased with The Bourne Identity, although I think the plot resolution was hurried at the end. I like Matt Damon and Franka Potente.

Minority Report would seem to be just a rehash of the 1976 movie Logan's Run from the trailers, but it really isn't. Now, it does start off as a seemingly-predictable run of the mill flick, but as the plot unfolds, you find that the characters you pigeonholed into the standard movie sterotypes in the beginning aren't anywhere near their holes at the end!

It's sci-fi like they used to make before Star Wars. (Of course, since it was written before Star Wars, that's sort of goes without saying...)

The Zeroth Law forces the temperature equilibrium in your definition just as I said, jackass. Two bodies placed in thermal contact come to the same temperature. Examine these links further:

http://www.physics.ubc.ca/~birger/boltzmann/node4.html

http://hyperphysics.phy-astr.gsu.edu/hbase...rmo/thereq.html

Even though I loved Spider-Man, my vote for best flick of 2002 so far has to go to: (drum roll please)

--==MINORITY REPORT==--

If you're sick of all the cookie-cutter blow-up-the-bad-guys sci-fi and want to see an intense, intelligent ADULT-themed near-future mystery, do yourself a favor and go see Minority Report.

Forget Close Encounters, forget Jurassic Park, forget E.T. (please!), and go see Steven Spielberg's best-ever science fiction film. None of the usual Spielbergian flaws here--no smarmy kids, no heavy-handed political correctness message, no over-the-top FX at the expense of the story. Don't let the previews fool you, this isn't more mindless sci-fi bubblegum. It provokes thought about a great many things, and skirts closely around paradoxing itself, a la "Sixth Sense". Watch carefully!

If you like Minority Report, you'll probably also like Alfred Bester's classic sci-fi novel "The Demolished Man", the first-ever novel to win the Hugo Award.

What are your votes for best flick so far this year?

The ultra-quick version: It's not exactly sunspots, it's solar flares that cause all the hoo-hah.

The long and boring version: Our sun is a typical yellow star, spectral class G5. It is a dull and boring star, as stars go, yet it's keeping everyone here alive with its heat and light.

Ol' Sol does this by being a constantly-exploding fusion reactor nearly a million miles across. Explosive reactions, being chaotic like they are, don't necessarily happen in neat little patterns. The mass of all that burning hydrogen keeps the Sun more or less round via gravity, else we'd have a bizarre mushroom-cloud for certain!

Now all the fusion that produces all the energy happens at the very core of the sun, 430,000 miles deep. It can take centuries for a single photon of light to ricochet itself out of the core and up to the surface. There's no guarantee where it will pop out, either, and this is the main reason for sunspots and solar flares.

While it's waiting to be fused into helium, a hydrogen atom gets pushed and shoved around by all its neighbors. Since temperature is really a measure of the average kinetic energy of all the particles in a given space, this naturally makes the little guy HOT. The more times it gets hit, the hotter he gets.

Okay, since all these collisions are completely random, there is a good chance that some regions of the sun will be quieter than others, and therefore cooler. Now, as any good thermodynamician ( ) knows, wherever there is a difference in temperature between two regions in thermal contact, there must be a directed energy flow from the hotter to the colder. (That's the Zeroth Law of Thermodynamics, for all you Junior Geniuses™ out there.) The hotter particles have more room to run around inside the cooler region, so the hot leaks over into the cold. Since all that energy from the sun has stripped the electrons away from the hydrogen nuclei, that energy flow is really moving charged particles around, positive protons and negative electrons.

Now, Krysilis was right, electricity and magnetism are very closely related. In fact, they are the heads and tails of the same quarter, so to speak. The very definition of electrical current is a charged particle moving through a conductor, and when any current at all flows through a conductor, a magnetic field is generated at right angles to the motion of the particle! Voila, electromagnetism! (Note to sudo, if he's reading this: This is how you objectively define the direction "right" if you're one of the radially-symmetric starfish people of Altair III. If you make a thumbs-up symbol with your right hand, with the thumb pointing in the direction of the current flow, the curve of your four fingers indicates the direction of the resulting magnetic field. If you do it with your left hand, it's backwards, so the hand that correctly models electromagnetic field/current interaction can be universally defined as the "right" hand. This is the magnetic Right Hand Rule, and now you're part of the evil geek conspiracy. Sorry, bud!)

Okay, back to the Sun. We have cooler regions and warmer regions, with charged particles moving between them generating electric currents and the concomitant magnetic fields to boot. We call the cooler regions "sunspots" because that's what they look like through a PROPERLY FILTERED telescope. Note well: if I ever catch any of you trying to look at the Sun through a telescope without a filter, I'll poke your remaining eye out too, just as soon as you've stopped screaming.

The cooler sunspots are darker because their photons have slightly less energy than the rest of the Sun's surface. Sort of a solar dim bulb, as it were. What you don't see through that PROPERLY FILTERED telescope is the huge magnetic tubes of force that result from all this moving charged solar plasma. And I do mean huge--you can drop the entire Earth into a small sunspot. These field tubes arc out of the sunspots and back into hotter spots on the Sun's surface. Since magnetic fields attract and channel charged particles, millions of tons of white-hot burning hydrogen plasma shoot up these tubes and crash back down into the Sun. (This is called a solar prominence.

Most of the time. Sometimes, the particles whooshing through the plasma tubes interfere with the lines of force that make the tube (remember, they're moving, and if they're moving, they're making their OWN magnetic field, which isn't necessarily lined up with the tube's field) and the tube collapses.

When the tube collapses, this HUGE loop of highly-energetic hydrogen plasma goes flying off of the Sun. Many times, towards US. (don't panic--happens all the time) This is called a solar flare. Without the magnetic containment, the particles start to move apart, colliding with each other less, and at different angles. When this happens, the particle collisions aren't strong enough to give visible light anymore, so they give off longer and longer wavelengths as the plasma loop cools and dissipates. This shows up on our doorstep 8-1/2 minutes later as a tremendous burst of radio-wave static. This static affects satellites, microwave telephone relay towers, radio and tv stations, the lot. Heck, turn on your AM radio and tune it to a distant station. Many of those snaps, crackles and pops you hear came straight off the Sun 500 seconds ago. (That's how long it takes light or radiation to reach us from the Sun.)

We're not out of the woods yet. While the radio static reaches us fairly quickly, there's still this huge blast of still fairly-energetic solar plasma particles swooshing through the 93,000,000 miles of space between us. Being matter, it travels quite a bit less than the speed of light, but it's still on its way. The flare ejecta makes it out to our neck of the woods in a couple of days or so. (Do the math--it's hauling booty, even if it isn't light-speed!)

No, we don't have to send Bruce Willis and Ben Affleck up in an impossibly-modified space shuttle to save our bacon. The Earth itself does it for us. Due to the Earth's make-up, our rotating molten iron core gives us a strong magnetic field of our own. The flare is blunted by our field, and the more energetic particles slam into our atmosphere and slow down into a harmless, yet spectacular display known as the aurora borealis, or northern lights. (Or aurora australis, the southern lights, if you're in the southern polar regions.) The stronger the flare, the farther south the aurora reaches. Canada and Alaska get auroras fairly often. It takes a Class-X solar flare to fire the aurora off down around Middle Georgia, but I am lucky enough to have seen it on one occasion. Very neat!

Okay, so what's the problem? Why do flares cause so much havoc? Back to moving charged particles, remember that electricity and magnetism are different manifestations of the same force, so their effects are reversible and interchangeable. Since we have a strong magnetic field of our own, what do you think happens when several million tons of charged particles slam into it? (Think it over for a second, the answer should be fairly easy...)

If a moving charged particle (an electric current) generates its own magnetic field, then a charged particle encountering a different magnetic field, must therefore generate an electric current in that field! Electromagnetic "sauce for the goose is sauce for the gander," so to speak. So, even though we're safe from being baked by Sun Plasma Pie a la mode, these chaotic solar droppings generate all sorts of weird eddy currents in our magnetic field, indeed, in the ground of our very planet!

This is how flares can disrupt power grids with surges and brownouts. It isn't so much being pelted with cosmic rays or gamma rays (flares generally aren't that strong), but all that copper in all those wires acts like a giant antenna to pick up these induced fluctuations. The sensitive electronics inside your PC don't like spikes or dips in their electro-diets, because spikes and dips correspond to the 0s and 1s of their binary language. A few flipped bits is all it takes to glitch a program or crash a computer.

Satellites get it hard because they don't have the atmosphere to protect them, and they are farther away from the Earth's center, so the magnetic field protects them less. This is partly why space stuff is so expensive--you have to design it to work in a rather hostile environment.

So that's the long and the short of it. There's one more thing that bears touching upon, and that is that you can actually SEE all this stuff if you have a very special, very expensive filter for your telescope. Normally, telescope solar filters cut out 99.9999% of the Sun's light, but they pass the rest of the spectrum across the board. This lets you see sunspots, but that's about it. If you splurge on a hydrogen-alpha filter ($2,000 and up) it passes only that very narrow band of red light from excited hydrogen. This is the light that all those prominences and flares shine in. Looking through a scope equipped with an H-a filter is one of the neater things you'll ever see in astronomy. Instead of a quiet white ball with a few dark spots on it, the solar surface comes ALIVE in H-a light. You can see the boiling turbulence of the plasma, see prominences snap off the surface and become flares--it's extremely impressive. I wish I could afford one! That's the nice thing about star parties--getting to look through all the other nifty equipment.

God bless!

Zix

I had a few moments to work on the ChatChek program, but apparently the GS Chat Room is not available at the old URL any more, so ChatChek is kaput at the moment, possibly forever.

Sorry!

Zix the Mostly-Itinerant

Actually, HopeRich has done most of the beta testing over the past year (she's currently the entirety of the installed user base) and has been on top of suggestions, etc.

I just have to find the most recent version of the source code, as the one I found yesterday was horribly broken. (Didn't work more than once...)

I'm not trying to be mercenary about this stuff, but considering the support issues I got over the Waydale CD Archive, (how difficult is it to put in a CD and read the ONLY file that shows up? Sheesh!) I doubt very seriously there'll be any more supported freebies.

The more I think about it, the less I feel comfortable charging a set price for the ChatChek program. There's a lot of unforeseeable support issues, and it's all tied closely to how beSeen runs their chatrooms. If those suddenly change, it will break the way the program works.

So, here's what I'll do: as soon as I get a reasonably-stable version updated, I'll see if Paw won't post it somewhere here. If he can't, I'll dump it onto one of those freebie web sites.

Download it, use it if you like. If you get a lot of use out of it, pay me whatever you think is fair for it. If you look at it once and throw it away, that's fine. If you use it constantly, but are struggling to make the mortgage payment, then keep your money, and God bless you.

Some folks call the shareware/honor system the "sucker system", but I can't think of a fairer way to distribute it.

God bless!

Zix

Guess I'll have to dust off the source code, then... Next question, what's a good pricing model?

a) My life is empty without that program! I'll mortgage my house!

B) Shareware programs rarely prosper when more than $20.

c) It doesn't matter what you charge, I'll just copy it off of whoever buys it first. It's not really stealing, is it?

d) What you do is, you put a big bucket out, ring a bell, and people will pay you to shut up.

Oh, definitely. The APOD page is a wonderful resource!

Just my luck...

The one person who would actually pay for it, and she's already got it...

Now we know why Zix will never be a millionaire!

(Note to self: Get the money FIRST, dumbass!)

God bless!

Zix

I ran across a program I wrote last year. It runs in the background and scans the chat room for your friends (or enemies, whoever you like to put in your list) When a friend enters the room, it pops up an alert box.

I used to use it a lot, then gradually forgot about it. A friend mentioned that it might be of some value to others.

What do you think?

a) Heck, I'd pay money for something like that!

B) I'd use it, but it's not worth paying for.

c) I don't use the chat room enough to have a use for it.

God bless!

Zix

Nah, Paw just has to approve all the picture uploads.

If you want a fun tool to play around with, go to www.space.com and download their free version of Starry Night. It's a computer planetarium (user friendly) and will let you play around with questions like this to your heart's content. (It's what I used to determine which constellations Earth would appear in from Mars and Venus.)

God bless!

Zix

Silly me... here's how it looks from 240,000 miles away. (really!)

Krys: No problem at all!

Earth is invisible from the surface of Venus--constant clouds of boiling sulfuric acid obscure the view. The surface pressure is 60 times that of Earth, and the temperature is in the hundreds of degrees.

From Venus orbit, however, Earth would be a brilliant blue-green star, currently in the constellation of Capricornus. Mercury would be slightly dimmer and to its left.

From Mars, Earth is too close to the Sun to be seen today, but would be in the constellation of Sagittarius. It would be about half as bright as Venus (Earth is on the opposite side of the sun than Venus right now. In 2003, Mars and Earth will again make their closest approach.)

Earth is quite visible from the Martian surface, unlike from Venus. The Martian atmosphere is thinner than the air at the top of Mt. Everest. When the sun sets on Mars, the twilight only lasts a few minutes. The night sky from Mars is spectacular, like nowhere on Earth. With hardly any atmospheric turbulence to look through, the sky would be deep, deep black, with the stars like little diamond pinpoints. Earth would be a slightly dimmer blue marble, since Mars is about 30,000,000 miles farther away from Earth than Earth is from Venus. It would not twinkle from Mars. The stars would only twinkle from Mars if there was a windstorm coming up.

Going farther out, Earth would only be visible from Neptune and Pluto if you knew exactly where to look, and a telescope would help.

Hope this helps!

God bless!

Zix

Nope, just a shrunk version of the new HST images. Maybe there's a hold on any attached file?

ignore please!

Safari Vista: The text of G_eer's "Passing of a Patriarch" is now available on the Grease Spot web site.

Click here to go to the first part: www.greasespotcafe.com/wa...c/pop1.htm

God Bless!

Zixar