The Magic of Mirrors

This post is about reflection. Ha! There's double meaning there! Reflection on the year because these are from homecoming week and reflection literally! Reflection occurs when light bounces back from a surface. We see objects in mirrors and other reflective surfaces because light bounces off of the object and into our eyes. Reflective surfaces are not the only things that light bounces off of. We are able to see because light bounces off of all objects and into our eyes. We perceive color because certain wavelengths of light are absorbed and reflected by materials. Light that is absorbed is not seen, while light that is reflected is seen. White is all of the colors of light (red, green, and blue) being reflected back, while black occurs when all of the colors of light are absorbed, the absence of light. Now that I have explained a little about how we see, let's get back to the pictures. Not all of these pictures show totally reflective surfaces, i.e. the last picture with images of Gavin, me, and Jon on Gavin's tinted car window. We are actually able to see inside the car, as it legally should be, therefore all of the light is not reflected back from the window, and neither is it fully absorbed. Clear glass doesn't reflect or absorb color, light simply passes through, but because this window is tinted, some but not all of the light is reflected, which is why we can basically see ourselves, or rather, our images. And what's also interesting is the fact that our images are not merely on top of the reflective surface as I and many others previously thought, our images are actually the same distance away from the reflective surface as we are, but BEHIND it. And another maybe even more fascinating thing we learned about mirrors is the fact that the distance between an object and a mirror does not affect the amount of the object that is reflected back. This is not obvious in these pictures, but is when you try it out for yourself. The only thing which makes it appear as though the size of the image is changing is your angle from it and the amount of other objects you are able to see when you move toward or away from the mirror.

Reflections are truly fascinating and make many optical illusions possible. Before this last section I never realized how magical mirrors really are. Thanks, Physics! :)

Oh How I Love You, Red, Green, and Blue

Here is a picture of Erika and me in Times Square in NEW YORK during spring break. Erika and I stayed with Erika's cousin for about a week, and I would have been lost without both of 'em. However, in Times Square it's kind of hard to get lost if you pay attention to the huMONGOUS, brilliantly lit signs and billboards. I chose this picture because, well one, Erika and I just look so cute with our umbrellas and boots, and more relevantly, two, because of the lights! I'm not exactly sure if these signs and billboards are made out of LEDs or not, but I do know that when the ball dropped in Times Square last year they used LEDs which are much more efficient than regular incandescent light bulbs. Although I don't know if these are LEDs behind us in the picture, I would surmise that the colors are created like those on a computer screen. The pink background behind "OH BOY" would be made with the three primary colors of light: red, green, and blue. On the computer screen, they are arranged exactly like that, "red, green, and blue," but in tiny blocks which, at each frequency of the lights creates a unique color. Each light color (red, green, blue) has 255 frequencies, which can blend to make more than 16 million unique colors that our eyes perceive. The pink would be a high frequency of red, maybe almost the maximum 255, a relatively low frequency of green, less than 100, and a surprisingly high frequency of blue, around 200. It is truly amazing how our technological world is colored by red, green, and blue, all because of the way we, as humans, perceive light.

"We Represent the Lollipop League"

Cutting the balloons off of their ribbons.

Cutting slits to make inhalation faster.

End products of our music videos.

This weekend we went to Nicole's baby shower where there were super fun games, good food, and of course, balloons decorating the place. So, of course, as teenagers, Elysia, Erika, Laurie, and I sucked up some helium and made our voices squeaky. Up until this past week I wouldn't have thought anything of it, other than pure fun, but now, after a week of learning about sound, I realized that it's physics! We get such squeaky, high pitched voices because the air around our vocal cords is changed by the helium gas which is lighter than our usual oxygen/nitrogen blend that we use when we talk/sing. The lighter helium gas causes the natural resonance of our vocal tract to change, creating a faster vibration, which results in a higher pitch than normal. Too much inhalation of helium can be dangerous, i.e. making breathing hard, but a little bit once in a while is (hopefully) innocuous. In these brief moments where we were under the influence of helium, we managed to make a few music videos, the one above was the best one, I wonder if that was really how they got the Lollipop League to sound like that...?

Electric Meter

Work It, Jesse!

I know that this journal entry is a week late, but I hope these videos will make up for it. Here we have Jesse making himself happy...by creating current and light! The big coils of conductive wire were attached to an ampmeter, and when Jesse moved the coils in and out of the horseshoe magnet a current was created that we could see on the ampmeter, and also in the bulb that apparently lit up for a brief moment. The change in the magnetic field inside the coil as it moved in and out of the space between the poles of the horseshoe magnet induced an emf that caused a current. This phenomenon is called "motional electromagnetic induction: Moving a wire through a magnetic field induces an emf." Current flows because "the motion of the wire causes the electrons in it to be moving in a magnetic field, and the magnetic field exerts a force on the moving electrons that is directed along the wire." The faster Jesse moved the coil in and out of the magnet, the more current he produced. Alex couldn't do it because he didn't have as much energy as Jesse did. Jesse was apparently able to create enough current to make the tiny bulb light up, but I was recording so I didn't get to see it :( . There are four factors which affect the emf:

"1. The strength of the magnetic field. The stronger the field, the greater the change in field strength as the loops move by, and the greater the induced emf.

2. The speed of the wire relative to the magnetic field. The faster one passes by the other, the greater the emf.

3. The area of the loops. The greater the area enclosed by each loop, the greater the emf.

4. The number of loops of wire. Increasing the number of loops increases the total area through which the field passes. This, too, increases the induced emf."

I hope you found the videos entertaining and the entry informative! =)

Sorry it's so late, Mr. Kohara. :)))

Baking Time!

Once again, I only just realized that we had a physics journal due over this long, three day weekend. Luckily, I didn't realize this at 11:30 pm like I usually do, and I had some time to look through all of my pictures. I don't know where my camera charger went, so I couldn't take any new physics pictures, shucks. However, I noticed a baking/birthday theme in my pictures and decided to go with it! I looked at our online textbook, and found that heat is thermal energy transferred between objects because of a difference in their temperatures. Energy flows from the object with the higher temperature (the hot oven coils) to an object with a lower temperature (the dough for cookies, cakes, or cupcake mixtures). This heat (measured in joules by physicists) causes the dough to rise, and we get the yummy treats you see up there! I think most of them were yummy, I'm not sure about Julia's cake with the real flowers, toothpicks, foil, and what looks like toothpaste on it, though. But it's the thought that counts (thanks Julia!).

The Power of the FORCE (fields)

Once again, I realized at a very late point in time that we had a journal due this weekend. Searching through my pictures and racking my brain for new concepts we learned in physics, I came upon a birthday candle from Elysse Tom's birthday at California Pizza Kitchen when we were in 9th grade or so. I just went to another birthday dinner tonight with a similar singular candle in celebration of the birthday girl's special day, however, I did not take a picture of it as I did here. In any case, as I came upon this picture I remembered when we talked about force fields in class. When Mr. Kohara turned on the light bulb in class, there was a definite "glow" around the glass of the bulb, which we identified as the light's force field. Even when we could no longer see the tiny rays of light emitting from the bulb, they were still there, going on forever and ever.

So that I would keep with the pattern of my other journals, I tried to look for a number of other pictures to show an example of force fields. I came upon one where I was taking random pictures at Chili's, and one of them happened to be of the various lights, torches, and neon signs that Chili's has. I'm not sure if the "glow" is a result of the force field, or of a slightly shaky camera, but I thought this was an example. Another picture which I really liked was the first picture, which is of a scoreboard of an 'Iolani against, perhaps, Punahou game, in which we won! This must have been a basketball game, it was probably 3 years ago or so. In this picture, the rows of lights making up the numbers on the scoreboard have force fields which can be seen by the various red and green glows being emitted from the numbers.

Good thing I take pictures of such random things! And GREAT thing I take physics so I can analyze them so thoroughly! =D