kanzure

Personally, I really like the Death Star. As impractical and probably unrealistic as it is, the fact that it can destroy a planet in one shot makes it pretty kick ass. But alas (or rather, fortunately) it will probably remain science fiction.

Death Star? We're already working on it. It's completely practical, the only questionable item on the list is the supermassive laser.

- Bryan

I still have yet to understand why Tegmark argues there must be alternate universes. His mathematical reality interpretation is good as it is.

- Bryan

FYI- Cal BC typically requires AB beforehand. But if you want to gun it, just study like crazy and make sure you *know* each of the topics thoroughly. A good idea would be to memorize (or at least remember how to derive) 100 theorems in calculus, as well as differentiation and integration methods to go along with it. And trigonometric substitution techniques, that's important.

- Bryan

At first glance, it looks like a simple reaction that will make children happy, something like an explosion, not a serious nuclear reactor. The real deals are intense pieces of technology and engineering, you'd know one if you saw one.

- Bryan

*She* rocks. Did *her* links shared with you there answer your question?

Uh oh. She. Yes. I see I've been away for too long- curious, I am usually up-to-date on the "regulars" across the forums.

- Bryan

Paralith might know.

Indeed he does.

- Bryan

Hey all,

I am in search for some good mouse literature to read up on, such as taking care of lab mice as well as training methodologies or previous successes and so on. Where should I look or does anybody have a zip file of papers I can take a look at?

Thanks,

- Bryan

X-ray diffractometry? ;P

Let's take that answer seriously. I have some information on x-ray diffractometry, so go there and search for "XRD". Some of the resources include a mailing list and some tutorials, but I have not found any designs/schematics for XRD machines.

- Bryan

What environments are conducive to the construction of water in particular? Is there any statistical likelihood that there are large bodies of water in interstellar space? Sorry to hijack the thread.

- Bryan

I recently posted about "time before time" elsewhere, as well as on the existence of "time as a dimension".

The answer is: science has not yet determined this. The prevailing theory suggests that there exists some pre-big bang context where time existed already (see inflation).

Yeah, that is a good answer. Also, the problem with saying "time began" is that you are trying to use time to define time, since time allows for beginning and ends.

- Bryan

Computer science, in the sense of the study of computational abstraction and the mathematics of computation, is indeed an active area of development. However, I would be careful when saying "CS is programming languages," because technically that's not true unless you were wanting to make abstractions about all sorts of Turing-compatible languages, but I see that this is not what you are talking about.

I agree with pcollins, "What?"

- Bryan

How did you get to this number? What is the flux density on the surface of the earth?

Was not the flux density on the surface density of the earth, mind you. I was using this SVG image over at Wikipedia on cosmic ray flux versus particle energy and a conversation with a friendly particle physicist earlier this morning.

- Bryan

Edit:

The observed universe is a little bit bigger than that, about 1.3 X 10^10 lightyears .

Haha, so I was off by an order of magnitude. How much volume did I neglect? Probably enough for trillions of trillions of earths.

So I did some calculations of how large a detector would have to be if we wanted to capture the gamma photons at 10^11 eV (10^-8 joules). So if we wanted to capture 80 terajoules of energy, enough for an atomic explosion, by my calculations we would need much more than a trillion octillion square light years (about 10^88 square light years?) of our absorbent machine/substance.

Note that the observed universe is only 10^9 light years across. Thank you, Mr. Dyson.

- Bryan

As to actually implementing your ideas. You may want to check out the DIY 1000 watt wind turbine project. You will not be able to harvest the complete energy output of tornadoes and hurricanes, but you can at least get something out of it.

Edit- somebody said:

Tornadoes and hurricanes are way too destructive to harness any energy from them.

And I disagree. You cannot harvest the totality of energy, but the increased wind speed can be harvested to some extent, etc.

Re: cosmic rays. That's an interesting question. Gamma radiation is said to release more energy than other photons, so how big of a surface would we need if we wanted to harvest the power of gamma rays and get some stable energy levels? Would it have to be the size of the area of a city? Or maybe the size of our planet? Would we want to point the surface perpendicular to any particular area of the universe, to maximize the likelihood of hitting gamma photons?

- Bryan

So, I have done my research on the sorts of schools that I would like to apply to since it is just about time for me. Originally, I started with the list of 50 schools that had MD/PhD programs as sponsored by NIH, and then narrowed it down to those schools that had good chemical and computer engineering programs, or maybe experimental physics, etc.

However, recently I have found that I would much rather find those universities that bust paywalls. The importance of universities is not only the social environment wherein professors and other experts and peers can be contacted, but the library. These libraries with thousands of journals and tens of thousands of archived subscriptions are really awesomely important. Not to mention the online databases.

What schools are focused on busting these paywalls, like EBSCO, Science Direct, ACS, JSTOR, and all of the many other databases that Google Scholar crawls? What university libraries are the most well funded? Which schools are focused on providing information to their students, rather than enforcing nasty copyright violation policies? Not everything can be accessed through the Interlibrary Exchange after all, right?

BTW, this is a massive cross post, so check out my pub/portal for this thread on all of the other forums.

- Bryan

You're thinking of maybe a microwave gun, also known as the Active Denial System to the United States federal government.

Youtube.com video of a microwave gun

Homemade microwave gun tech video

How to make a microwave gun

High-power microwave system employing a phase-locked array of inexpensive commercial magnetrons (2006)

DIY microwave gun

etc.

Edit: Some more links, less related:

Giant review of microwaves

Microwave melting of metals

- Bryan

Hah, this reminds me of the heating copper thread over at chemicalforums.com ... but it's certainly not exactly related. How does the number of electrons flowing through copper per second influence what's going on? What does the picture look like?

Are the electrons being exchanged through the sea of electrons created by the conduction bands? Or are they following some definite path through the metallic structure that we should be aware of?

Many more questions.

- Bryan

I would say no, it consists of (among other things) our best (and ever improving) approximations of facts

Well said. Also, if we really wanted to we could include 'facts' as the set of true statements concerning formalized theories. Especially in the case of mathematical physics. Slightly relevant is this page re: the myth of the scientific method.

- Bryan

This reminds me of the Warning: gravity is "only a theory" page, and it's mostly for humor rather than anything factual. As for something with actual meat, try the Thiemann lectures on loop quantum gravity (2002). There's also the paper on the empirical foundations of relativistic gravity (2005).

Gravity as an effective field theory

Brief review of quantum gravity phenomenology

Hope this helps,

- Bryan

Hey, interesting. I am new to metal casting and playing with metals, so I am just going to help you out by linking to some resources that I have found. You may have added heat to the zinc as well as nearby air, so you might be unknowingly oxidizing the material sample. The zinc article at Wikipedia hints that you might be using the zinc oxide "American production" method. Oops? Just something you should check into.

Some resources on copper melting

Google bomb - "zinc furnace"- you might be the first guy to discuss this on the WWW

DIY pattern making and casting (slanted towards motorcyclists)

How to Cast Small Metal and Rubber Parts (2nd Edition) (Paperback)

Making your own materials for making your own molds

A trip to Radnor forge

Fun with molten metal

How to make a small gas furnace (I know, irrelevant, but it was still one of my many search results.)

DIY waterblock casting thread

Home metalcasting etc.

Home bronzecasting foundry

And finally, there's a list of zinc-related references here.

- Bryan

Hey, cool- a Mars thread. I can do this. Some weeks ago I posted on Slashdot re: getting off this rock, so there are some links there on this very topic, but are more organizational.

Also, there was a recent discussion on the Orion's Arm mailing list re: Mars and terraformation.

See the New Mars terraformation forum.

- Bryan

There are some simple chemistry poems here, and here are some more chemistry poems for each of the elements, which helps with memorization and is pretty cool when one becomes able to bust out with 20 lines of poetics on a final exam.

From the self-acclaimed page of "cheap" science quotes:

For me chemistry represented an indefinite cloud of future potentialities which enveloped my life to come in black volutes torn by fiery flashes, like those which had hidden Mount Sinai. Like Moses, from that cloud I expected my law, the principle of order in me, around me, and in the world. . . . I would watch the buds swell in spring, the mica glint in the granite, my own hands, and I would say to myself: "I will understand this, too, I will understand everything."

 

Primo Levi, The Periodic Table (1975)

"Hydrogen"

The real world is a jumble of awesome complexity and immeasureable charm. Even the inanimate, inorganic world of rocks and stone, rivers and ocean, air and wind is a boundless wonder. Add to that the ingredient of life, and the wonder is multiplied almost beyond imagination. Yet all this wonder springs from about one hundred components that are strung together, mixed, compacted, and linked, as letters are linked to form a literature. It was a great achievement of the early chemists — with the crude experimental techniques available also with the ever-astonishing power of human reason (as potent then as now) — to discover this reduction of the world to its components, the chemical elements. Such reduction does not destroy its charm but adds understanding to sensation, and this understanding only deepens our delight.

 

P. W. Atkins, The Periodic Kingdom: A Journey into the Land of the Chemical Elements (1995)

The chemists are a strange class of mortals, impelled by an almost maniacal impulse to seek their pleasures amongst smoke and vapour, soot and flames, poisons and poverty, yet amongst all these evils I seem to live so sweetly that I would rather die than change places with the King of Persia.

 

Johann Joachim Becher, Physica Subterranea (1667)

quoted in Paul Strathern, Mendeleyev's Dream: The Quest for the Elements (2000)

We began studying physics together, and Sandro was surprised when I tried to explain to him some of the ideas that at the time I was confusedly cultivating. That the nobility of Man, acquired in a hundred centuries of trial and error, lay in making himself the conqueror of matter, and that I had enrolled in chemistry because I wanted to remain faithful to this nobility. That conquering matter is to understand it, and understanding matter is necessary to understanding the universe and ourselves: and that therefore Mendeleev's Periodic Table, which just during those weeks we were laboriously learning to unravel, was poetry, loftier and more solemn than all the poetry we had swallowed down in liceo; and come to think of it, it even rhymed! That if one looked for the bridge, the missing link, between the world of words and the world of things, one did not have to look far: it was there, in our Autenrieth, in our smoke-filled labs, and in our future trade.

 

Primo Levi, The Periodic Table (1975)

"Iron"

But this is no longer the time for sprites, nickel, and kobolds. We are chemists, that is, hunters: ours are "the two experiences of adult life" of which Pavese spoke, success and failure, to kill the white whale or wreck the ship; one should not surrender to incomprehensible matter, one must not just sit down. We are here for this — to make mistakes and to correct ourselves, to stand the blows and hand them out. We must never feel disarmed: nature is immense and complex, but it is not impermeable to the intelligence; we must circle around it, pierce and probe it, look for the opening or make it. My weekly conversations with the lieutenant sounded like war plans.

 

Primo Levi, The Periodic Table (1975)

"Nickel"

The fact that alloxan, destined to embellish ladies' lips, would come from the excrement of chickens or pythons was a thought which didn't trouble me for a moment. The trade of chemist (fortified, in my case, by the experience of Auschwitz) teaches you to overcome, indeed to ignore, certain revulsions that are neither necessary or congenital: matter is matter, neither noble nor vile, infinitely transformable, and its proximate origin is of no importance whatsoever. Nitrogen is nitrogen, it passes miraculously from the air into plants, from these into animals, and from animals to us; when its function in our body is exhausted, we eliminate it, but it still remains nitrogen, aseptic, innocent.

 

Primo Levi, The Periodic Table (1975)

"Nitrogen"

... well, you asked for it. So fly now: you wanted to be free and you are free, you wanted to be a chemist and you are one. So now grub among poisons, lipsticks, and chicken shit; granulate tin, pour hydrochloric acid; concentrate, decant, and crystallize if you do not want to go hungry, and you know hunger.

 

Primo Levi, The Periodic Table (1975)

"Tin"

The world is a thing of utter inordinate complexity and richness and strangeness that is absolutely awesome. I mean the idea that such complexity can arise not only out of such simplicity, but probably absolutely out of nothing, is the most fabulous extraordinary idea. And once you get some kind of inkling of how that might have happened it's just wonderful. And . . . the opportunity to spend 70 or 80 years of your life in such a universe is time well spent as far as I am concerned.

 

- Douglas Adams

Though not in the form of poetry most are accustomed to, these still have that special poetic prose embedded in the sentences. And then there are all of those many science-related anecdotes, like when Planck was trying to get to his own lecture but was prevented entry because the receptionist thought he was too young to attend the lecture of highly valued Professor Planck, or Zues and his mechanical computers in his parents' kitchen, etc.

One last poem from Tesla:

I Haunted thee were the ibis nods,

From the Bracken's crag to the Upas Tree.

 

Nikola Tesla, November 4, 1934

 

"Fragments of Olympian Gossip"

 

While listening on my cosmic phone

I caught words from the Olympus blown.

A newcomer was shown around;

That much I could guess, aided by sound.

"There's Archimedes with his lever

Still busy on problems as ever.

Says: matter and force are transmutable

And wrong the laws you thought immutable."

"Below, on Earth, they work at full blast

And news are coming in thick and fast.

The latest tells of a cosmic gun.

To be pelted is very poor fun.

We are wary with so much at stake,

Those beggars are a pest—no mistake."

"Too bad, Sir Isaac, they dimmed your renown

And turned your great science upside down.

Now a long haired crank, Einstein by name,

Puts on your high teaching all the blame.

Says: matter and force are transmutable

And wrong the laws you thought immutable."

"I am much too ignorant, my son,

For grasping schemes so finely spun.

My followers are of stronger mind

And I am content to stay behind,

Perhaps I failed, but I did my best,

These masters of mine may do the rest.

Come, Kelvin, I have finished my cup.

When is your friend Tesla coming up."

"Oh, quoth Kelvin, he is always late,

It would be useless to remonstrate."

Then silence—shuffle of soft slippered feet—

I knock and—the bedlam of the street.

 

Nikola Tesla, Novice

While this is still on topic, let me link over to this page that details the construction of van de Graaff generators as well as many other subtopics. Also, there's the page on the simple homemade van de Graaf generator-- you may have to acquire a taste for soda since the design is slightly dependent on the packaging cans.

Some related information:

http://science.slashdot.org/article.pl?sid=07/05/28/034201 `"This month's issue of Symmetry, a magazine jointly published by SLAC and Fermilab, is featuring an article that points out the sometimes extemporaneous and unconventional solutions physicists have come up with in (and out of) the laboratory. From the article: 'Leon Lederman ... used a pocket knife, tape, and items on anyone's grocery list to confirm that interactions involving the weak force do now show perfect mirror symmetry, or parity, as scientists had long assumed.'"`

http://www.kk.org/thetechnium/archives/2007/03/bootstrapping_t.php

http://www.lindsaybks.com/dgjp/djgbk/index.html Dave Gingery

And any information on ores, extraction/purification techniques would be great.

- Bryan

Yesterday, I found Auerbach's Wilderness Medicine text, which is aimed towards producing effective medical professionals when in the outdoors-- past the confines of the hospital or university lab. So, whether the doc is in the forest, or in the middle of the corporate jungle, ideally some action could be taken to improve the well-being of the sickly, diseased, or injured.

Are there any books on wilderness chemistry? Not only would it be important to be able to check what elements make up potential food, but to show friends neat little tricks by quickly picking up dirt and a nearby miscellaneous object to ignite it, or show other cool phenomena, as well as the importance of understanding how to use the materials from the ground, such as ores, when we are not necessarily near our favorite sources of chemical information. This is, after all, how we started with chemistry in the first place. The difference being that we were in a (primitive) lab, and we could sit.

What would you include in a book on wilderness chemistry? What tools would be important to construct? Could anybody synthesize some pest repellant? Lots of ideas here ... guess it would be a step closer to answering what an 'ultimate chemist' should know.

- Bryan