Wednesday, October 24, 2007
Periodic Table of Desserts
Enjoy!
Wednesday, October 17, 2007
Geek Think: How Scientists Approach the World
Almost there, aren’t we? Congratulations. Now, at last, it is time to consider why you have been taking this class.
Two-tailed: Altering the reaction temperature will alter the reaction rate.
One-Tailed: The reaction will increase as the reaction temperature rises.
2. Water was prepared as follows:
a. Cold (~0°C): Four 1-in3 ice cubes were added to four cups of water and left for 15 minutes
b.
c. Hot (~100°C) Four cups of tap water were heated to boiling in a teapot
3. The glass was equilibrated to the desired water temperature by pre-filling with either ice water or hot water.
4. One cup of water at the appropriate temperature was placed in the glass. A 1-in3 ice cube was added to the “cold trials” to keep the water cold.
5. A single tablet was dropped from a 2-inch height into the vessel.
6. Time (in seconds) to complete dissolution of the primary tablet (i.e., the end of violent fizzing) was recorded.
7. Ancillary (“other”) measurements included observations on tablet motility and gas evolution.
| Temperature | ||
Trial | 0°C | 20°C | 100°C |
1 | 87 s | 47 s | 34 s |
2 | 100 s | 45 s | 33 s |
3 | 80 s | 49 s | 32 s |
4 | 66 s | 49 s | 32 s |
Mean | **83 | 48 | **33 |
SD | 14 | 2 | 1 |
The double asterisks (**) denote that the mean values for these two groups are significantly different from the mean value for the 20°C group, p < style=""> (Normally, statistical significance is assigned to an outcome if p <>
a. Cold (~0°C): Vertical at 45 to 50 s
Floated at 55 to 60 s
b.
Floated at 20 to 25 s
c. Hot (~100°C) Vertical orientation not seen
Floated immediately
a. Cold (~0°C): Many small particles and much foam cover most of the surface
b.
c. Hot (~100°C) No particles or foam remain
a. Cold (~0°C): Fine bubbles made from top of tablet, large ones from beneath
b.
c. Hot (~100°C) Myriad fine bubbles from entire surface of tablet, as well as elaboration of steam from upper surface
Tuesday, October 16, 2007
The Universe Within: Quantum Chemistry
Halfway there after today, folks. Hang in there.
Sunday, October 14, 2007
The Big Picture: Chemistry Gets Organized
One day down, four to go. Let’s rock on.
- Matter consists of tiny particles (atoms).
- Atoms are indestructible. In chemical reactions they can rearrange but not break apart.
- All atoms of a given element are identical in mass and other properties (true then, as isotopes had not been discovered).
- Atoms of different elements differ in mass and other properties.
- Elements combined into a given compound always react in a fixed ratio.
Saturday, October 13, 2007
Chemistry Experiment
Chemistry AS403 – Experiment
Chemical reactions proceed at a set rate, but the rate varies depending on many factors. Environmental conditions in particular have a major impact on the rate at which reactions may proceed.
You will be conducting an experiment with 3 tablets. Place one tablet in a glass of hot (but not boiling) water, another in a glass of ice-cold water, and a third in a glass filled with water that is at room temperature. Measure how long the fizzing continues in each glass after dropping the tablet.
Feel free to use the left-over Alka-Seltzer to sooth your heartburn....
Simulation on Public Policy
Chemistry AS403 – Simulation
Spring, 2019. The one bright spot in the usual atmosphere of political infighting and intrigue is public contentment with the austere homeland security policies that finally succeeded in interdicting illegal immigration across the nation’s 2000-mile southern border beginning in 2013. This success was achieved through the combined use of multiple electrified fences backed by solid concrete walls, with regular defoliation of the intervening no-man’s-land between the barriers using biodegradable herbicides.
In 2014, the
Despite the promise, a concern for the region’s population is the rising number of birth defects in infants and cancers in people of all ages. The problem has been smoldering for nearly three decades, but in the last five years the incidence has accelerated rapidly. The local economies are in danger of collapse as potential workers avoid relocation to the region while the incumbent population seeks to leave.
You are a member of a bilateral public policy commission tasked with identifying likely cause of the epidemic and pinpointing means by which the threat may be ended. Develop one or more hypotheses regarding the cause of the problem. Design the necessary tests to verify or negate the hypotheses, keeping in mind both scientific considerations and ancillary concerns (e.g., cost and international relations). Prepare a brief for delivery to the President outlining your hypotheses, proposed experiments (both initial and follow-up), and likely recommendations for dealing with the scenario.
Fundamentals of Chemistry, Day #1 Lecture Notes
Chemistry AS403 – Lecture 1 Notes: Fundamentals of Chemistry
Okay, let the good times roll. Today we cover the basic tools one needs to start taking a crack at chemistry.
Let’s start with VOCABULARY, some simple definitions that will put all of us on the same page as the game gets underway. In alphabetical order:
- Accuracy = closeness of a measured value to the true value
- Atom = the smallest particle of an element (Gr. atomos = “uncut”)
- Chemistry = a science that investigates the composition of materials and how their properties change by their environment
- Compound = substance combining fixed proportions of 2 or more elements
- Density = ratio of an object’s mass to its volume
- Element = a substance that cannot break into a simpler one
- Energy = a quality allowing an object to do work. The two main classes:
- Kinetic = energy in a moving object
- Potential = stored energy (which can be converted to kinetic type)
- Heat = energy that is transferred among objects with different temperatures
- Law = a broad generalization known by experimentation to be true for all people and all times
- Mass = the quantity (NOT weight!) of a given substance
- Matter = anything that occupies space and has mass
- Mixture = material combining variable proportions of 2 or more substances
- Molecule = Smallest particle of a compound
- Precision = closeness of repeated measurements to each other
- Property = characteristics unique to a given substance. Two types are:
- Chemical = trait that can change as a substance reacts with others
- Physical = trait that can be observed without changing the substance
- Specific gravity = ratio of a substance’s density to that of water
- Temperature = property proportional to the average kinetic energy
- Theory = a well-tested explanation of a natural phenomenon
- Weight = the force with which a substance is attracted by gravity
Once we have a common lingo, we need some other COMMON PROCEDURES. Chemists, indeed all scientists, use the following tools each and every day. The “Big Three” pieces in the tool kit are the International System of Units (SI), Significant Figures, and Scientific Notation.
The SI scheme offers standard units of measurement for seven basic quantities. The most common in the chemistry laboratory are for length (meter, m); mass (kilogram, kg); time (second, s); temperature (kelvin, K); and amount (mole, mol). The base units can be modified by adding prefixes and suffixes, the most typical of which are mega (106, M); kilo (103, k); centi (10-2, c), milli (10-3, m), micro (10-6, m), and nano (10-9, n). Conversion factors are used when necessary to convert between the various units. Examples for length and volume (with derived units of length cubed) include:
1 m = 100 cm = 1000 mm
1 m3 = 1000 L (where L = liter)
1 L = 1000 cm3 = 1000 mL
Significant figures are those which have been accurately derived by careful measurements. The number of significant figures in a measured value is equal to the number of digits known for certain plus one that is not totally certain. The higher number of significant figures, the greater the degree of precision.
Scientific notation is a shortcut for writing very large or very small numbers. In science, the standard use is to write numbers to base 10, using exponents. As an example, an electron (a very small subatomic particle) has a mass of about 0.000 000 000 000 000 000 000 000 000 000 910 kg. In scientific notation, this number is rendered as 9.10 x 10−31 kg. Simple rules for working with exponents allow scientists to manipulate numbers easily when working with minute samples and very rapid reactions.
Friday, October 12, 2007
Chemistry is Your Friend; Introduction Lecture Notes
Chemistry AS403 – Notes for Introductory Lecture
Breathe. Breathe again. Now, repeat after me: “Remain calm, all is well.”
Welcome to Purgatory, or as I like to call it Chemistry for the Scientifically Reluctant. In the next few sessions, we will take an all-too-brief tour through the wonders of the chemical world.
Why should you come along for the ride? Because your entire existence – body, home, street, community, Earth itself – rises and falls on the basis of the chemical reactions that occur around and within you. Chemistry is your friend, even if you feel that chemistry class is not….
We’ll start the tour with INTRODUCTIONS. Your tour guide/persecutor is Brad Bolon, professional science geek (experimental pathologist and medical writer). I get to torment you with chemistry because
(1) I am a reasonably adept apprentice-level chemist, having about 1000 hours of lecture and lab in the field during the course of my professional education, and
(2) the other topic for this course was physics, which causes my brain cells to short-circuit.
You know who you are (I hope).
The next introductory item is to define HOW SCIENCE FITS INTO THE “REAL” WORLD. “Real” in this context means “material” or “natural” or “physical.” We will approach this question as a scientist would, by constructing a theoretical model off which to bounce our subsequent experiments. Based on lots of years in college (13!) and living in this world (45), my model for gathering and using knowledge emphasizes several different epistemologies. (An epistemology is a system by which we know that something is true.) There are several different epistemologies with relevance to the modern world, and most of us use more than one in the course of our daily lives. Examples include Revelation (“God told me so”), Reason (“it just makes logical sense”), and Tradition (“we have done it that way in the past”). The main epistemology of modern science is Empiricism (“we did an experiment, and this is how the world works”). Put them all together, and my current model of the world looks like the picture above.
The next introductory topic is to ACING THE HARD SCIENCES. Success in studying science is not easy – it’s not called “hard” science for nothing! – but the goal is attainable. All it takes is self-discipline and a logical approach. I used a 7-step process in my own science education, and I still use it daily as in my work as a scientist. The 7 keys are simple, not rocket science:
(1) Read the textbook the night before class. Yep, I hate to break it to you, but science classics are almost always textbooks. The reason is that science builds on itself over time. In general, about 50% of the stuff printed in current science magazines will prove to be wrong a decade or two from now, while the principles in modern textbooks represent concepts that most scientists believe to be true. So why read the textbook before class? Remember, science builds on itself – in this case, by repetition. The more times you are presented with a concept, the better you will understand it and recall it.
(2) Annotate what you have read. Take notes in the margin of the book or on a separate sheet of paper. Ask questions. Write your own lecture. The act of writing helps your brain to better remember what you have read.
(3) Listen to the lecture. This key is simple, if you show up and maintain some degree of consciousness. It’s even easier if you have read the book before coming to class….
(4) Read the textbook a second time. Not to be a nag, but repetition is good when studying science.
(5) Do the homework. The professor did not dispense problems to you just to torture you. (That is just a side benefit.) The assignment was given because the only way to truly understand a scientific principle is to work with it.
(6) Read more stuff. Don’t just read the assigned pages in the textbook. Read ahead, or reread relevant pages from previous chapters. Look for other presentations regarding the same topic on the Internet. The idea is to give your brain as many different versions of a new principle as are necessary for the concept to finally penetrate.
(7) Repeat as needed. (Duh.)
The thing about science is that it really is hard. People don’t subject themselves to this degree of torture voluntarily unless they are geeky enough to really enjoy the challenge. Maybe you qualify as a science geek, maybe not. Regardless, don’t make the task more difficult on yourself than it has to be.
Star Trek Party!!!!
The Gardner's were kind enough to suggest that we have a Star Trek Party on Saturday evening starting at 8pm. We will be in the main classroom at GWC with a projector to watch the very first episode of Deep Space 9! This episode has some excellent stuff on how we humans view time as linear and how the fabric of space-time is bent and molded into a stable wormhole.
It is the best of physics theory and just plain fun to watch. Make sure to get here early so you get a good seat. I'll be bring popcorn and we'll have other finger foods as well.
I look forward to seeing you there!
Thursday, October 11, 2007
Lecture #5: The Properties of Light & Color
Time, Space and Light. Visible Light makes up such a small part of the spectrum, but there is still so much mystery and wonder about it all.
Question: Is a radio wave also a sound wave?
Answer: No, radio waves are part of the Electromagnetic Spectrum and sound waves are mechanical productions of air being pushed.
What is light? Technically, we don’t know. But we have some really fine theories that work well mathematically to give us close approximations.
Light is energy carried in an electromagnetic wave that emanates from vibrating electrons in atoms.
Visible light vibrates at a very high rate, some 100 trillion times per second (1014 Hertz). Light has an approximate speed of 300,000 km/s or 186,000 miles/sec.
UV light is responsible for sunburns due to its high frequency and clouds are semi-transparent to UV that is how you get burnt on a cloudy day.
Question: Why are lunar eclipses more commonly seen then solar eclipses?
Answer: The shadow of the relatively small moon on the large earth covers a very small part of the earth’s surface. Only a relatively few people are in shadow of the moon in a solar eclipse. But the shadow of the earth completely covers the moon during a total lunar eclipse so everybody who views the nighttime sky can see the shadow of the earth on the moon.
Light enters the human eye through the transparent cover called the cornea, which does about 70% of the necessary bending of light before it passes through the pupil. The light then passes through the lens, which is used only to provide the extra bending power needed to focus images of nearby objects on the layer at the back of the eye. There is also a spot in the retina where all the nerves carrying all the information exit; this is the blind spot.
The size of your pupils depends on your mood. Poker players have unwittingly given themselves away when they had a good hand by the size of their pupils!
Why is the sky blue?
A beam of light falls on an atom and causes the electrons in the atom to vibrate. The vibrating electrons, in turn, re-emit light in various directions. Light is scattered. This is known as Rayleigh Scattering. The shorter the wavelength of light the more light is scattered.
Why are sunsets red?
The lower frequencies of light are scattered the least by nitrogen and oxygen molecules, the primary component of our atmosphere. Therefore red, orange, and yellow light are transmitted through the atmosphere much more than violet or blue. Red, which is scattered the least, passes through more atmosphere than any other color.
Reflection and Refraction
Light interacts with atoms as sound interacts with tuning forks.
The Principle of Least Time – stated in 1650 by Pierre Fermat, Out of all possible paths that light might take to get from one point to another, it takes the path that requires the shortest time.
Index of refraction (n) = speed of light in vacuum divided by the speed of light in material
The Joy of Flames, Sound and Salt!
These two YouTube Videos are great for demonstrating classical physics in action using the mechanical form of sound. The fire one is terrific because it’s FIRE, man! The second one is lovely because it shows how the salt/sand is being made into fractals at higher and higher frequencies!
Rubin’s Tube: The Physics of Music
Seeing Sound, Geeks Make Art
Wednesday, October 10, 2007
Lecture #4 Notes: Electromagnetism
In current mainstream physics, a Theory of Everything would unify all the fundamental interactions of nature, which are usually considered to be four in number: gravity, the strong nuclear force, the weak nuclear force, and the electromagnetic force. The expected pattern of theories is:
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Electricity – is a general term for a variety of phenomena resulting from the presence and flow of electric charge
The inner ring is 3000km from earth
The outer ring is 15000km from earth
In spite of the earth’s protective magnetic field, many cosmic rays reach the earth’s surface. It is greatest at the poles because the particles do not travel across the magnetic field lines, but along the field lines and are not deflected. This creates the aurora borealis lighting in the sky caused by charged particles in the Van Allen belts striking atmospheric molecules.
Anti-matter:
First created in 1990 and has since been confirmed in it’s creation by multiple accelerators. Antimatter is currently the most valuable substance in existence, with an estimated worth of $300 billion per milligram. This is because production is difficult (only a few atoms are produced in reactions in particle accelerators) and because there is higher demand for the other uses of particle accelerators.