Let's learn something new

[Tale]

I'm looking up wiki information on antihistamines when I become curious. Just how does one read this: http://en.wikipedia.org/wiki/Image:Chlorphenamine.png

I don't know how to read a molecular structure diagram.

 

Does anyone around here know? I'll spend some time today researching how and if nobody beats me to it I'll post later today.

 

And let's keep the thread alive with new questions and explanations. Not just explanations in response to questions, but any non-personal information you feel like teaching people about.

[Pidesco]

I used to know this, bot I don't really remember it, anymore.

 

I think the hexagons with the lines have CH2 on each corner, expect for the N whick is Nitrogen, of course. The double lines are double bonds.

 

 

 

In fact, I think the empty corners are all CH2, except for the ones with three bonds which should be CH. Nice to know it all comes back even after 10 years.

[Walsingham]

Way beyond me. Cool idea.

[Pidesco]

More info:

 

The hexagon to the right is a benzene, the hexagon with a nitrogen atom is a pyridine, and the bit on the left is a dimethyl, which is connected to the rest by a propane molecule.

[Walsingham]

More info:

 

The hexagon to the right is a benzene, the hexagon with a nitrogen atom is a pyridine, and the bit on the left is a dimethyl, which is connected to the rest by a propane molecule.

 

Do you have to know that in advance? Or is it somehow explained in the model itself?

[Pidesco]

The only one I didn't need to check was the benzene. The others, I had to check, although I should have known about the propane molecule.

 

Edit: Oh, and there's a sense to suffixes and prefixes. Like for example propane, propene, and propyne. Propane is all single bonds, propene has one double bond, and propyne has one triple bond.

Edited September 27, 2007 by Pidesco

[Walsingham]

[taks]

i've been involved with waaaaay too much "learning" lately so i cannot help, though i find the concepts about as interesting as i did when i took chem 5 in college (chemistry for engineers). moderately so. "my name is earl" has certainly perked things up a bit.

 

taks

[metadigital]

Does this help? "

 

Edit: monkeys attacked my keyboard.

Edited September 28, 2007 by metadigital

[Pidesco]

Wikipedia is for the weak.

[metadigital]

... And the literate. :ninja10:

[Tale]

Does this help? :yucky:"

 

Edit: monkeys attacked my keyboard.

Not as helpful as this:

 

http://en.wikipedia.org/wiki/Skeletal_formula

[Pidesco]

Not as helpful as me, you bunch of meanies.

[Walsingham]

Anyone interested in salvage engineering? It's similar to naval engineering, but deals primarily with the dynamics of damaged vessels.

[Tale]

I'm quite interested. Go on.

[Aram]

Anyone interested in salvage engineering? It's similar to naval engineering, but deals primarily with the dynamics of damaged vessels.

 

Hell no your life is boring.

[metadigital]

Did someone say dynamite?

[Tale]

I find myself curious about contract law, now! Just in general.

 

 

Later todayWhen I get a chance, I'll try to put something together regarding ADHD. I know it's a controversial subject in some circles and I even have personally known people who contest its existence.

[Tale]

Know what I'm fascinated by today? Special Relativity

 

When I was younger, I owned a set of scientific encyclopedias. It was a short set of encyclopedias that covered topics ranging from lasers and holograms, to relativity. Of course, those are just the three sections I was most fascinated with and read through several times at the time. So, I have some background knowledge on special relativity. I've been reading up more on it in wikipedia, when I should be working, and I feel like sharing it with you all. Some of you know of it, some of you probably don't, but it's doubtful too many here truly know what or why. Some of it's counterintuitive and that makes it difficult to wrap your head around at times. In fact, despite my interest in it, I won't be surprised if a few of the concepts I think I know, or at least think I'm familiar with, are wrong. And even if what I know isn't mistaken, there's no surety that I'll be presenting it accurately. But, here goes.

 

First off, I'd like to go over why special relativity is so difficult and counterintuitive. Einstein's Special Relativity takes the notion that observed motion is relative to the observers, Galilean relativity, and applies it to all laws of physics. As an example of Galilean relativity, if you are sitting still on the sidewalk and I were to move past you (ignoring friction), then from your position on the sidewalk I was moving and from my position, both you and the sidewalk are moving. According to Galileo and Einstein, both these points of view are equally valid. This is only slightly counterintuitive. In ways it may seem philosophical, because we're tempted to use the Earth to give us the frame of reference. Acknowledging that even it is moving through space, rotating along its axis, revolving around the sun, moving out from the center of the expanding universe, we have to discard this notion of the Earth as the definitive frame of reference for motion. Einstein takes this a step further and says that it doesn't matter if you're sitting on the sidewalk, driving by in a car, or hurtling through space in a rocketship going at 9/10 the speed of light, the physical laws of the universe are all the same.

 

So what? Big deal. It makes sense. Nothing difficult about that. Well, the problem is that it complicates what has been observed in regards to electromagnetic waves.

 

Several experiments attempted to measure earth's speed relative to a hypothesized medium through which electromagnetic waves travelled. This hypothesized medium, aether, was thought to be an absolute frame of reference. Unlike relativity, it was the only truly valid point of reference, always still, and everything else moved in relation to it. What's wacky is that these experiments ultimately showed a consensus that the speed of light does not change regardless of the motion of the observers.

 

What's so weird? Well, this has consequences. More on this when I post again.

[Tale]

So, what have we established? We've established now that the speed of light is invarient for all observers/reference points. This is included in the second postulate of the Special Relativity Theory (SRT). The first postulate, as we went over, is that for all frames of reference, the physical laws of the universe are the same.

 

Let us say that two objects moving through space are A and B. A is travelling at 1/2 the speed of light towards object B. A emits light. We might therefore expect the light emited by A to have a total velocity of 1 1/2 the speed of light. The second postulate of SRT says "NEIN!" The light emited by A is still only going the speed of light, c. However, according to an observer at A, the light emitted by A is also going the speed of light! This is weird behavior. If A was instead going 5 miles an hour and threw a softball 1 mile an hour, the softball would be going 1 mile an hour from the perspective of A, but 6 miles an hour from the perspective of B. It really wouldn't matter if A was going 5 miles an hour, 1/2 c, or 9/10 c, the difference in these two situations is that one is dealing with a 1 mile an hour softball and the other is dealing with the speed of light. But again, according to the first posulate of SRT, are they really that different? And now hopefully we see the complication.

 

The true difference in the 1 mile an hour softball and the speed of light in my examples is only a matter of scale. The same laws and effects are in play, the only difference is that the effect is unappreciable at the slower speed of the softball scenario.

 

I mentioned consequences of this earlier. There's more consequences to this and I'll be going over them in a bit.

Edited October 18, 2007 by Tale

[Tale]

And as an aside, and part of why I love this subject, I'm almost certain that I've already messed up somewhere and gotten something wrong.

[taks]

most schools introduce relativity in a first-course on atomic/nuclear phycics, aka a-bomb. if you're really that interested, i'd suggest taking it. however, you will need significant calculus and probably differential equations work (as well as the first couple classical physics classes) to understand a lot of the mathematics behind it all.

 

i agree, however, it is extremely counterintuitive and difficult to grasp in general. were i to go for another degree, this would be one of my options (the other being statistics, but my school does not offer any advanced statistics degree).

 

taks

Edited October 18, 2007 by taks

[taks]

oh, btw, on first glance i don't think you got anything wrong. what happens is that the velocities do not add linearly, though at slow speeds, much less than the speed of light, the linear approximation works fine, within any reasonable measurement error. at higher velocities, the linear approximation begins to diverge to the point that two objects approaching each other at the speed of light appear to be approaching only at the speed of light w.r.t. each others' view point.

 

oh, i say "velocity" rather than speed because velocity includes direction, but in a 1-D application it is immaterial.

 

taks

Edited October 18, 2007 by taks

[metadigital]

I guess the big-ticket achievement of Special Relativity is the codification of the speed of light as a finite, knowable and predictably static value irrelative to any other factor (okay, the medium through which light travels does affect its velocity, but generally people talk about the speed through a vacuum).

[Walsingham]

I think we need an equation function on the board. Anyone else agree?