The last thing you will ever see

This weekend I performed my sword kung-fu for my lion dance group and apparently had pictures taken of me while I performed. In this picture you see here, my blade acts like a plane mirror as it reflects the light of its side. Polished metal acts like a mirror because it reflects the light of objects straight back to them. It is not a perfect mirror because the light it reflects back is intensified by the light from the sword's surroundings. As the objects' lights hits the sword they return at the same angle they hit the sword at, and unfortunately that some stray light rays hit the sword so that the angle it leaves is the same is in the same direction as the primary object's eye.
These stray light rays from surrounding light sources are what causes cameras and eyes to see a glare. Since the sword reflects its own light and the light from light bulbs, flashes, and other objects, it creates a glare that tends to blind opponents until it is too late for them to block.

The Physics behind Kiss Me Kate

This weekend was the culmination of work for the cast, crew and pit of the spring Musical Kiss Me Kate. AS a member of the crew it was my job to make the magic of the show happen for the cast to shine in their full glory. For some of the times that required being on fly rail (the part of the theatre that manually pulls in and out the drops that come onto stage.) Now mind you I shared this task with a less experienced whiny senior. But the physics for moving the these set pieces remain the same on the stage or above. On the stage there are the two big rolling pieces which require a Strong force to overcome static friction of the wheels. The wheels make the job a lot easier because they have a smaller static coefficient and can glide across the floor quicker in the dark.

The second part of the theatre magic is in the fly rails. These thousand pound drops experience a large weight force and have a lot of potential energy being raised about 20 meters up.

To assist with lifting these beautiful drops, we have a combination pulley system assisted by weights. A combination pulley system is comprised of a stationary pulley and a movable pulley, which in this case has weights on it to decrease the weight we are actually pulling. Since there are only one complete set of pulleys, we halve the difference between the weight of the drop and the weight of the weights. The overall force we had to move is supplied by the rope via tension to life the drops in and out.

This is the magic of the theatre.

The Current of a class

This past test was on Direct current of a circuit. Now If you think about it a class in doc!'s room is considered a complicated circuit, namely pd. 7. A complete circuit needs a power supply or a battery to give it energy. Going with the Classroom metaphor the power supply would be doc! and the energy would be physics. With every circuit there are the light bulbs that light up, people who get it,
and those that don't, stupid.

Now the light bulbs will have varying amounts of resistance, some will get it faster than others, and varying current since the ones in the back would usually have more resistance. Each row would be a series of bulb in parallel with the other rows. The back rows would receive more current because of its higher resistance, but everyone would receive the same amount of volts because we are all on the same wire (classroom). Some people would also act as capacitors where they will store all the information and then release it when the test comes, our class has a lot of capacitors because capacitors need to be recharged after each test.

Images protected for anonymity. This all makes sense if you think about it.

Chinese New Years

This past week end was Chinese New Years and being a lion dancer I was out 13 hours of the day. Some of the minor physics I observed a lot this weekend is the concept of work. Work is the term used to describe the amount of force used over a distance. Distance is rate x time so the amount of work I completed this weekend is Force x rate x Time which was a really fast rate and for a really long time.

Another offspring of the same concept is the change in potential energy of lion dancers. We performed a lot of tricks and routines this weekend that involved acrobatics and jumping. One of the better examples is the use of the jong or pole jumping. AS the performers increase in height of the poles, their potential energy goes up proportionally to the amount they went up. So if they were to fall from the 6 feet pole as from the 2 foot table, they would have 3 times the amount of energy went they hit the ground.

Tension save us all

This past week was one heck of a week. The Cheryl Hayashi lecture on Thursday got me started thinking about the tension. The wide medley of spider silks that exist have high durability (because its near impossible to break up silk strands) and able to pick up lots of tension. As I was sitting through the lecture and quite a bit after wards I started seeing how high tension material is need in this world. She explained how silk could be used for bullet proof vests to tennis rackets. But the best place I learned from her lecture was the amazingness of tension. At Lyon Arboretum on Saturday, yes 3 days thinking about same principle, we had to do extreme weeding.

AS you can see from how much stuff we need to pull out of the ground it was made even more fun by the sheer verticalness (not a word) of the cliff. As I pondered how to pull out the non-ferns, non-grass, and no-tea leaves, I realized that maybe nature already found a perfect combo of tension. Since it was found in spider silk, I prayed that roots had the same principle, so I climbed the mountain using natural fibers to pull me up. And it worked, although I fell down and slid 20 feet, and I was able to rest against a tree (that also had to be cut down)and ponder why physics was stuck in my head that long? Seriously Doc why? whyyyyyyyyyyyyyy?

By the way this is what the cliff looked like and the ground about 20 fet behind me

Card House

This weekend was another Chinese New Year performance weekend for me. 6 more weeks till I can drop dead and work more for school. Anyways I was staying at a disclosed location with my friends in Chinatown and was really bored. They were playing some kind of shooting game and I found a deck of cards. Since I don't know how to play solitaire and playing other cards games by myself and figuring out which hand will win grew tiresome, I started building a house.



As you can see in the picture the card house only goes up so far because of potential energy. As each card layer increases in height, the next layer on top will have that much more potential energy since PE=mgh. The tower eventually fell, because of the higher potential energy of the cards on top and the second law of thermodynamics, which states the entropy of the universe is the same or increasing. The highest level of the card fell into its more entropic state and leaving me forced to build another card tower (Note: I build card tower because Chinese people do not build card pyramids, we build tower-like pagodas)

When a sword meets the spear

This weekend officially marks the start of the Chinese New Years celebration on the chinese calender. Yay and boo. Yay because its about 8 weeks worht of partying and eating (great after the American holidays!). But it is boo because as a lion dancer the majority of my next the next two months will be lion dancing, sometimes whole days at a time. If anything this would be considered my tird sport season because the amount of time i put into this will conflict horribbly with everything else. Well enough of my pain time for physics.
Today's post is about what happened while I was practicing my sword/spear dueling set. I was teaching it to someone else the sword pat of the routine this weekend and hoping they will learn the set. I would normally play the spear part,but I know both. So as I was going through the set, actually about five to six strikes in, the sword is suppose to do an upper block against the spear's strike coming down. But the person who I was practicing with, needless to say is kind of lacking certain gray matter, whipped the sword out as a strike and came in contact with the wooden part of the spear. Normally you would never block a spear strike with a sword stike for two reasons. One the strike will dull your sword. Two the spear could break off and end up hurting you. No one was hurt, but the large amount of force behind the small area of the blade ended up combing with the initial strike of my spear ended up damaging the shaft. The resulting pressurenearly snapped the poitn right off.

This demonstrates first hand with physics why you neve block with the blade.