Summer Driving.....

PHYSICS HAS BEGUN AGAIN!!!!!!!!!!!!!!!!!!!!! Wow. Amazing how fast time flies. But, despite the fact that I was hoping to relax this summer, to little suprise of mine but to the dismay of my friends who also wanted to relax during summer, I saw Physics everywhere! One place where I saw Physics like crazy was here: driving..... Yes, I just got my permit this summer, took drivers ed, and have begun to drive. It has been a very interesting experience. First of all, I discovered that the "accelerator" really is an "accelerator;" I have had to constantly adjust the pressure on my foot because if i hold it in one place, thereby applying constant force, my speed keeps increasing, thereby surpassing the speed limit. Not good. I also have been having problems finding the correct amount of normal force to apply to the steering wheel while trying to let it spin back to strait after a turn so that it doesn't turn to quickly. Unfortunately, my hands tend to sweat whenever I even think about grabbing anything, so the coefficient of kinetic friction between my hands and the steering wheel is often changing. And then there's trying to figure out how much brake to apply while going downhill, and how much gas to apply to continue of a hill at a constant speed, where objects that I see in the mirrors really are, when do I turn to get into a parking space, AAAAAAAAAAAHHHHHHHHHHHHH!!!!!!!!!!!!!!!!!!!!!!!!!!! scary...... :-) Oh well, I'm beginning to get the hang of it. :-) Lots of Physics in driving, I've discovered. Now, if only driving could help me learn everything else firsthand, that would be cool, but I think I'm just about maxed out on multitasking while driving. I can learn everything else elsewhere. Go Physics!!!!!!! :-)

Last Physics B Blog :-(

Can you believe it? Physics is over. Part YEAH!, part :-(. But can you believe that I'm still seeing Physics everywhere? Of course, because it is! Well, on Friday night as I was drinking the last of my glass of water before I went to sleep, when I noticed a small black thing on the bottom of my glass (off the table, not in my water). However, when I drank enough water to pass below where the speck was, it moved. I suddenly though: "PHYSICS!" What I had just experienced was the refraction of light as it entered and exited different substances (air, glass, water, then air again). The picture above shows the refraction of light from an empty glass, but there was a huge amount of difference when the water was gone. The water must have caused the light to refract more than just the glass did (Snell's Law: N1sin(1)=N2sin(2)). It was a very interesting experience, reasuring me that I still remember something and that not everything has leaked out of my brain since monday afternoon, especially since I'm taking the Physics SAT on June 7. Hope that goes well.

Our AP exam was certainly an interesting experience; the multiple choice didn't seem bad, but that's what I thought last time (which didn't turn out too well). I hope I didn't make any horrible mistakes on free response, although I know that I did one problem wrong and was unable to correct more than a bit of it before time was called. Oh well, at least I defined my variables. :-)

But enough for Physics now. There are other finals to focus on now. And wasn't Junior Prom fun? :-) A nice way to close off AP exams (I took my last one on Friday afternoon, the last exam of all). Well, good luck to everyone, and I'll see you in AP Physics C next year, Doc! :-)

In the midst of all the AP's, Physics Final Exams, homework, and attempting to find time to sleep, I noticed a spontaneous bit of Physics the other day. In my windy Manoa home, where the bamboo bends nearly horizontally under some winds, I noticed that our closed front door (pictured above) was banging back and forth as far as the deadbolt lock (upper circle on the left) would let it. I then noticed the strong winds outside and realized.....Phyiscs!!!!!!!!!!! I decided that there were two possible explaination for this: one, the wind was pushing on the door, applying a force equal to the sum of (the masses of the air molecules times their acceleration), causing the door to accelerate inward until it hit the deadbolt; then when the gust of wind stopped, the door would return to its inital position from the force of the internal pressure in the house (F=PA). Scenario number two: the wind was not blowing into the door, but across it; therefore, by Bernoulli's Principle, the external pressure would decrease as the air velocity increased, pushing the door outward with the force of the net internal pressure, then returning as the wind speed decreased again. Or, perhaps, it was some of both, I'm not sure. But even the wind is a process of Physics; as a region of air increases in temperature, it expands in volume, decreases in pressure, and decreases in density, rising, making way for colder air to fill the void and creating wind. The opposite is probably true as well, and that's probably what happens in the valley at night. It sure makes for an interesting knocking noise while I'm supposed to be eating dinner or doing homework. :-)

Physics At Dinner

I know that this may look a little funny, but this was my parents' and my dinner (halibut with butter and rosemary). It was really good. While this may not seem very Physics like, I found myself relying on Physics to serve my dinner. When my dad first took the dish out of the oven, it was too hot to touch and I didn't have an oven mit so that I could steady the dish while I served myself. So I just used the one hand with the tool pictured. However, the fish was sticking to the pan, therefore making it hard to serve with only one hand. At first the dish didn't slide, then I felt that I was reaching the limit of static friction. Afraid that I would have to travel the five feet to get an oven mit, I tried different angles with the server, trying to find a place where the dish would neither slip nor spin. Eventually, I was able to serve my food without overcoming the maximum static friction force, although I was very close. I guess even though the dish is rather heavy (giving it a large normal force for a larger friction force), the fish was rather stuck. I also noticed other Physics connected with food and microwaves. When I heat up my lunch, which today was leftover spaghetti, I have to place a piece of wax paper over the top to keep it from splattering. This is because the water in the sauce turns to steam and, as it gets hotter, it expands (V1/T1=V2=T2 at constant pressure). If the reaction does work at constant pressure, the air is released from inside at a non-messy rate. However, if this is an isochoric instead of an isobaric process, the pressure rises with the temperature (P1/T1=P2/T2) and will eventually overcome the sauce's ability to contain it. At this point, the bubble explodes and sauce splatters all over the inside of the microwave, an occurence that is really hard to clean. That is the reason for the wax paper, unless, of course, you are like me and microwave food until it's cooked a second time, then sometimes the spaghetti explodes out the sides. That's always fun. :-)

Falling Cups

This was a weekend of scientific experiement and observation (as well as other forms of procrastination) for me. On Saturday morning as I searched for a sugary snack to eat while I tried to get some homework done before going shopping for prom dresses, I found a can of "all natural" 7UP in my fridge. When I poured it in my glass, I found that streams of bubbles were coming from the same points on the bottom no matter what I did to the glass (no, I didn't turn it upside down). I then hypothesized that there were small irregularities in those spots, as I remeber from Chem that bubbles form on irregular spots, at least when water boils. So I found a glass that my dad had dinked up the bottom by stirring liquid with a spoon and poured the other half of the can in, and found a noticable column of bubbles coming from the center with all the dinks. I have support!!!!! And this was before I really even got into my homework at all. But I know, that's Chem. Here's the simple but funny Physics encounter of the weekend. As my mom and I got home today (Sunday) and were unloading the car of our few purchases and other stuff, my mom brought up the cups of water we had been drinking. To make things easier, my mom stacked two of the cups one inside the other. She then forgot that there were two cups and took hold of the top of the top cup. Normally they would stay together because the static friction force on the two surfaces of the cups was enough to hold up the bottom cup. However, in this case, we did not drink all the water. Therefore, the weight (mg down) of the bottom cup plus the weight of the water was enough to overcome the maximum static friction force dictated by the coefficient of static friction of the cups, creating a net force pointing down. Thus, the cup slipped off, hitting the wood floor of our house with acceleration -9/8 m/s^2 (or g), not leaving a dink but resulting in a large puddle of water on our nice wood floor that had to be wiped up before it hurt the finish. The water splashed out of the cup, obeying the law of conservation of momentum, at least at first, giving the many water droplets large velocities in the same general direction to account for the large velocity and mass of the dropped cup. Thus with these large velocities, the puddle was large as well, for many dropplets flew far away. But no harm done, plus I got to explain to my mom the Physics involved. I felt smart. :-)

Oily Physics

Talk about a Physics packed weekend! I probably saw the most Physics during Family Fair at the game tents, as many of the games relied on projectile motion, especially the Lani Moo, baseball, blast-a-ball, and shoot-the-ring-onto-the-bottle games. However, a knowledge of the workings of momentum and energy are also in order for the plate/octopus dime toss and the floating glass dish + ping pong ball games, as too much energy in the projectile will make it bounce out and you will lose. :-( However, my blog this week is not about Family Fair; it's about the Arizona Memorial. Although I admit that this is perhaps not the best place to be thinking about Phyiscs, I happened to notice that oil was still leaking out of the ship, almost directly below the memorial. However, the first oil that I saw was not rainbow in color; it was white. I first thought that this must be very thin oil, too thin for there to be a phase shift in the two reflecting rays and have constructive interference at any certain color. After seeing a new drop of oil expand into a rainbow of colors and then become this ghostly white sheen on the water, I decided that I was correct. Above I've pictured something like what I saw. However, this oil also led me to another Physic note. Remember the sunglasses from last week? I wore them to Pearl Harbor and Fair. As I was looking at a particularly large area of rainbow, I saw a section in the middle that had no rainbow, appearing as the outside did behind my dark polarized sunglasses. I was curious why this occured and, preparing to try to find out, I picked my head up from a slanted position to strait. But in doing so, I got a better answer than taking off my glasses would have done. As I turned my head, the rainbow disappeared, leaving only the water looking slightly darker than usual, and the ability to see the dark black thick oil floating in the water. I guess the rainbow coming from the thin layer of oil must be polarized, otherwise this would not have worked. I wonder if it is just the light off the oil, or if most light off the water is polarized as road glare is, and that's why polarized sunglasses work so well?

Sunglasses at Night...Late Night

My, we know so much now, don't we? And we've finally hit the long, hard, month of review before the AP exam! Wow. In fact, as I was sitting and reading my online Physics book at my computer before this past test, I discovered some very interesting facts about my computer, and the way I found this out may seem a little strange. If you are wondering about my picture, no I did not just finish watching Blues Brothers or sitting at the beach. In fact, I was trying out my new sunglasses to make sure they were comfortable(I broke my old ones a while ago), with a very inquisitive look on my face. However, this fact combined with a small quirk of mine brought me some valuable Physics insight. Here's the quirk that some of you may have noticed: I sometimes sit with my head inclined to one side or the other, depending on what I'm doing. At this particular time as I sat at the computer and absentmindedly turned my head, I noticed something: the screen changed colors. Or actually it didn't change colors, but it got dimmer. I then remembered that my sunglasses were polarized. As I turned my head to the right, the screen got darker until it nearly disappeared. Then as I turned my head to the left, I found that the position of least change in light intensity occured at just about ninety degrees from the position of darkness. This was consistent with the design of polarized lenses, which have very thin dark bands running either vertically or horizontally depending on their purpose. Because of this, only the vertical or horizontal components of all light waves reaching the lens are allowed to pass through to the eye. Therefore, as I turned my head from the brightest point to the dimmest, more of each light wave was being blocked out until almost all of all light waves were blocked. I've included pictures (yes, I am writing this entry in the background) so you can see what I mean. Cool, isn't it? :-)

Hard Rock Cafe

No, this was not a spring break destination for me, although we did see one. I, as did many of my fellow band-mates, went to Japan over spring break on a great tour with a probably once-in-a-lifetime chance to see the cherry blossoms in full bloom in Tokyo. On our last day, the organization that did our tour treated us to a trip to Uyeno Park to see the many cherry trees there. Although my parents, friends, and I probably collected many hundreds of photos of the trees and blossoms, the one that caught my eye on this Sunday night was a picture my dad took of a sign in the subway station: "Hard Rock Cafe - Uyeno Park." This picture caught my eye for two reasons: one, the small Hard Rock Cafe in a Tokyo subway station was a funny sight, and two, the sign used neon lights to catch people's attentions. And it was these neon lights that caught my attention because of.....Physics! As we learned in Physics, these types of lights are made up of glass tubes filled with different types of gases per tube. When current is run through these tubes, some of the energy in the current goes to exciting the electrons in whatever gas is in the tube. These high-energy electrons then will fall back to their original energy states, releasing a photon of a certain wavelegnth depending on the stregnth of the current and the type of gas in the tube. Were the gas Hydrogen, the electron would be excited to an energy level, then fall back to n=2, corresponding to the Balmer Series and emitting visible light. Each element has different energy levels, therefore releasing different wavelegnths/colors of light corresponding to their emission spectrum. Therefore, there are four different types of gases used in these tubes, one for each different color. Oh no! This means Physics followed me, even on my spring break trip! AAAHHHH!

p.s. just kidding about the screaming :-)

Ripples in the Pool

On Saturday, my mom and I decided to go for a swim at the pool; since swimming season ended, I haven't exercised at all, unless you count our many exhausting but enjoyable band rehearsals, so I needed it. But as I was leisurly walking/floating back to the wall after trying some distance breastroke pulldowns, I thought to myself, "Hey, I wanna try making ripples like in Physics!" I then began playing with my fingers, hands, and the already ripply surface of the water to try to see the two circular waves converge and form higher troughs and peaks due to constructive wave interference, as well as regions of destructive interference. As the waves first began to expand outward, I noticed very large peaks forming, and then more formed, I saw the regions of destructive interference. Had I been able to freeze time and place a sheet of waterproof paper to record the heights at the convergence region parallel to the connection of the radii, I would have seen regions of both constructive (in a 180 degree phase difference with each other, as one peak hits with one trough on the other)and destructive interference. These regions would correspond to the light and dark regions of double slit interference with light as well. Wow, I guess there's one more reason to go to the pool on weekends: Physics in action! :-)

Mirage

In OPTI-GONE Int.'s contraption Mirage, two concave mirrors are placed one on top of the other, with a small opening at the top of one. This contraption forms a floating image inside this opening using the mirrored surfaces inside. After much consideration and learning about concave mirrors, the answer to why this works seems to lie in the focal legnth of the mirrors. When light enters the opening, it hits the object on the bottom, reflecting off the object and radiating out into the mirror region. In the cases of light rays like the ones diagramed, they will bouce a few times, hitting a mirror and refracting at the same angle of incidence, continuing until it either happens to exit the region, perhaps without even touching the object, or hitting the bottom mirror parallel to the principle axis. When it does, the light will then refract to the focal point, which for these mirrors is placed either inside the opening for the bottom mirror or at the center of the bottom mirror for the top mirror. This results in the fact that nearly all light will eventually converge on the focal point at the opening, creating an image to the human eye that should originate in what is actually thin air. The fact that the object sits on a mirror also results in an image of the image of the object on the bottom mirror appearing at the opening as well. Pretty cool!

Infinity Me's!!!!!

When I was little, I had a fascination with mirrors. I guess I liked Physics from a very young age! :-) I had three favorite things when it came to mirrors: two planar mirrors at right angles, two parallel planar mirrors, and three folding planar mirrors of the same size. In my travels through the various malls and dressing rooms of California and Hawaii, I found many instances of all three. But my favorite memory was of a particular dressing room in a department store here (I think it was JCPenny's). I was playing with my three reflections (we were identical quadruplets!) when I discovered that the mirrors, unlike other dressing rooms I had encountered, could move on their hinges and close to form a triangle, just big enough to fit me. :-) When I closed myself in this triangle, I noticed that I increased from quadruplets to quintuplets to sextuplets to septuplets, and so on, until there were infinity me's. However, we were not all in a big circle, there came a point where the number in the circle stopped increasing, and I noticed many other circles around me. It was fascinating. Now that I think back on this experience with some Physics knowledge, I realize what was happening. When I faced a corner, there was an image of me on each of the mirrors, and as I closed them, secondary and tertiary images began to appear as the mirrors reflected each other's light and their images. When the angle was as small as it could get in the triangle, the mirrors stopped reflecting new images. But there were also circles of images coming from the other two corners in the triange, showing me from different sides in the same manner. The mirror opposite each corner would then reflect the image of the circle of me's, then reflect the images of the images from the other mirrors, creating an infinite field consisting of three different orientations of me's. I tried to illustrate my fascinating experience from above(but not with all the reflections, of course!), adding in a pink bow so I could trace light rays. It was very fun. It's funny, I never got into curved mirrors when I was little. Maybe that woudl have been too complicated for me then. Oh well, I still enjoyed mirrors. I wonder where those mirrors are now...

Clicky Watches

A few summers ago when by uncle and cousin came to visit us from New Jersey, my uncle would sit in our chair by our computer and shake something that make a small clinking noise. Upon closer inspection, it was his watch. He said that it didn't have a battery, and that shaking it kept it going. At the time, I didn't understand what he meant, but I remembered this this past week as we explored electromagnetic induction; his watch must have had a magnet and a solenoid in it. The shaking sound must have been a magnet, moving back and forth into and out of the solenoid. The magnet's magnetic field would have turned the solenoid into a magnet, alternating the poles to repel then attract the magnet as it moved in and out respectively. The force of the moving magnetic field on the electrons in the metal solenoid would generate an alternating current, building up charge that would eventually go to power the battery. I'm not sure how the charge was stored, as capacitors only seem to be able to discharge charge (:-) )in large, fast, quantities that would probably do to the battery something similar to what happens to galvanometers when too much current runs through them (not a good thing).

However, I guess that the generated current is not that much, as my uncle still had to sit and conscienciously shake the watch; the natural motion of his arm wasn't enough, I guess. Great idea, but I wonder if it was more trouble that it was worth. (My watch has a regular battery :-) )

Cheryl Hayashi: "Spiders, Silks, and Me"

On Tuesday February 5, I attended the lecture by Cheryl Hayashi, describing her experience from high school graduation to finding her career passion to her present day research. At first, studying spider silk seemed like an obscure profession, but after her explanation of her road to this career, I not only found it fascinating, but was also inspired to finding my own passion.
She began her presentation by telling of her path from high school to finding her career; this section perhaps had the most impact on me, as I’m currently pondering what I want to do with my life and what classes to take next year. The fact that she found her life’s passion from a requisite class and a small part time job really says that anything is possible. It also encourages you to take every opportunity presented to you, for you never know what may turn out to be your life.
Aside from the inspiration, I also learned a lot about spider silk that I never knew before. I had known that silk was comparatively much stronger than many things we consider very strong, but I didn’t know just how strong that was until I saw the comparison. I was also surprised to learn of the many different types of silk that one spider can produce. And a hundred and fifty yards of silk from one spider! Wow. I hadn’t known there was so much to just spider silk alone; and as she said, one answer brings up ten more questions, like: I wonder what else there is to study that contains more than meets the eye? Perhaps one of those could be my passion. I’ll just have to wait and see.

Homework By Lamplight...

As I was sitting doing my Physics homework wondering what I should do my blog on, I began doing a sample problem about current, power, and resistivity. All of a sudden, it his me- I have a very close-at-hand example of all three of these: the lamp next to my computer. It has a bulb that contains two filaments, and the lamp is made in such a way that it can produce three different levels of light: one filament, the other filament, and both together. As I worked on problems pertaining to legnth of the resistor, cross-sectional area, resistance, power, and current, I began to wonder how the bulb worked from a Physics standpoint. This is what I have decided: there are two possibilities for this bulb. The first possibility (depicted above) is that each of the filaments have different legnths, but same cross-sectional areas. Since R=(coeff.)L/A, the filament with the longer legnth would have a greater resistance than the shorter one. Then since P=(I^2)R, and I(current) is the same for each of the filaments since the current comes from the same source, the power in the longer/higher resistance wire would be greater, resulting in more electron movement and more transfered energy to the filament's atoms, and therefore more light.

The second possibility was that the filaments have different cross-sectional areas but the same legnth. Then, since R=(coeff.)L/A, the filament with the smaller cross-sectional area would have the greater resistance. Then since P=(I^2)R, and I is the same for both, the power for the thinner filament would be larger, resulting in more collisions and more light.

There is actually a third possibility: the filaments could have both different areas and legnths. However, companies may want to save money by using the same wire, as well as try to increase the longevity of their bulbs by using the same thicker wire with different legnths. Or would they want to use the thinner one so that the thinner filament will break more quickly so consumers will have to buy more? :-)

Blue Sparks

Perhaps some of you who read my post a few weeks ago saw my mention of a large spark my dad created on our trip to Alaska. Well, here's more details.

If you have ever been somewhere dry, you know that static electricity is something to be feared. But on this trip to Alaska, we were staying in a hotel that required walking about twenty meters from our door to the elevator, all the way on carpet. One morning, my dad, being still a young boy at heart, decided to drag his feet along the carpet to see how much static/electrons he could accumulate. By dragging his feet, he accumulated extra electrons, giving himself a net negative charge, increasing with the amount of dragging. Having discovered that the panel on the side of the elevator was grounded, he slowly moved his hand towards the panel. However, he had accumulated so many electrons and potential energy that all of the excess electrons quickly left him for the grounded object, even before he touched it. The large discharge of potential energy, energy converted to kinetic energy for the quickly moving electrons, caused a visible spark coming from my dad's finger, quickly followed by an exclamation of "OUCH!" along with a slight jump. The electrons then probably were transfered to the ground, where they quickly spread out equalizing the charge, effectively canceling it out. Perhaps more electrons moved within the building back to the momentarily positively charged floor, so some electrons going to the ground ended up back in the building. But, like I said, the spark was a bluish color, and very bright. After that, my dad and I discovered that walking while rubbing our hands on the wooden handrail, as well as touching the elevator panel through our jackets, lessened the severity of the shock. I'm glad I don't have to do that on a regular basis. If we ever go back, I wonder if my dad will have learned his lesson, or if the young boy inside of him will prevail again? :-)

P.S. My mom was folding laundry once again (thank you, Mom!), when a sock which was held onto a shirt by static electricity from transfered electrons from the dryer came flying off when she shook it and landed right back in the pile without her noticing it. It was hilarious. :-)

Ions for your hair

Many years ago, my grandpa gave me a hairbrush for Christmas. However, this was not your ordinary hairbrush; this particular one claimed that it used ions to help your hair. It was called the "Ionic Hair Wand Pro," and if I recall correctly, it was supposed to make your hair more managable by causing it to tangle less. (At the time, I was about nine years old and didn't like to brush my hair...at all) Although I'm not sure it helped any, I was contemplating electric forces and charges when I remembered this brush. However, I had never known how it worked, but with my new-found Physics knowledge, I've formed a theory about how it works.

One of the parts of hair that makes it tangle is the outer part, which is make up of little plate-like flakes that can stick out and catch on other hairs' flakes, causing hair to become more tangled. So, my theory is this: the hairbrush sends out ions from a small vent in the middle of the hairbrush that come in close proximity to these flakes as the brush travels through the hair. When these charged particles approach the neutral flakes, they will cause them to become charged either by attracting electrons if the ions are positive, or by repelling electrons if the ion is negative (I'm not sure what the brush sends out). When it does this, the flakes will gain a charge, but they will also create an equal and opposite charge in the middle of the hair either by pulling electrons away from it, creating a positive middle, or by pushing electrons into it, creating a negative charge. Thus, the flakes and middle part of the hair will attract, because opposite charges attract with an equal and opposite force. This will then cause the flakes to lay down flat on the hair, keeping them from sticking up and keeping them from catching on to other hairs, causing the hair to be less tangly. Unfortunately, it didn't seem to work for me; however, that may have been more the fault of my lack of frequent conditioner use and my tendency to always wear my hair down (even in the wind). I wonder if it still works? I should try it out... :-)

Snap, Crackle, Pop!

No I'm not eating rice krispies, although rice krispie treats do sound good right now (although too sugary). Actually, as I was sitting trying to do my homework and watch TV at the same time, my mom was being very nice; she was folding my clean laundry, strait out of the dryer. Although I am very grateful as I know how long that takes, I don't usually pay attention unless I'm helping or I need to monitor the dryer so that my already-too-small-in-the-arms tops don't stay in too long. But as I was drawing polar coordinate graphs, I heard something very familiar: "rackle crackle crackle." I knew immediately what it was: it was my mom unsticking clothes from each other, held together by static electricity. But today, this sound was different, for I had read the assignment on electric charge, and I knew exactly what was going on. When the clothes had been tumbling around in the dryer, the electrons in the outer parts of these items would rub off, being transfered to the objects on which they were rubbing, such as the walls of the dryer, or other clothes. In this case, these two objects built up enough opposite charge to attract each other, since opposites attract. The forces that each exerts on the other are equal and opposite, as well as strong enough to hold them together. When my mom tried to pull them apart, the electrostatic forces fought back, keeping the items clinging together, even to the last clinging fibers which still point directly towards the other object. However, I believe the crackling sound has something to do with returning the charge to equilibrium, but I would have to read more. Oh also, just as a warning: if any of you ever go to some place dry,(my experience is from Alaska) don't drag your feet along the carpet, and don't go touching metal objects that may be touching the ground, because you almost certainly WILL get shocked. You should have seen the spark my dad created(it was blue).

The Thermodynamics of Baking

I love baking. However, I love eating the food even more than the work that goes into its preparation, so combined with my laziness and need to stop eating junk food after the extremely tasty month of December, I don't bake very often. However, last night my dad did that for me; he made a batch of very yummy biscuits (one of which is pictured here) that even though I had just eaten a large dinner and half a cinnabon I immediately dove into. (I need to learn some self control :-) ) But this morning while considering whether to eat another one, as well as pondering thermodynamics in daily life, I thought, "Hey! Biscuts are full of thermodynamics, at least the baking process anyway." When the oven is turned on, the coils producing the heat begin to heat up the air inside the oven by conduction, which then circulates by convection due to the differing densities between the warm and cool air, eventually bringing the entire oven up to temperature. The heat is prevented from escaping by the walls of the oven which, I would guess, are covered with a high specific heat material and/or a material that is designed to reflect the infrared waves from the hot air and heating coils. Then when the biscuits are put in, they begin to heat up by conduction as well. However, the outside will heat up faster, as it has more contact with a larger heat source than the inside does. Then when the outside begins to cook and get hard, it doesn't allow for the expansion of the biscuit anymore as the temperature goes up, turning an isobaric process into an isochoric process. However, that means that as the temperature of the inside rises, the pressure builds. But the outer layer isn't strong enough to contain the pressure, so it splits and releases the pressure, allowing the inner contents to expand once more, just like this biscuit started to do, but the picture's not good enough to see it very well. But sorry, there can be no more pictures of that biscuit to show the split; notice that the biscuit is sitting on a cutting board. It was eaten with strawberry preserves soon after that picture was taken. Yum!