Physics FTW!

Phun

2008-05-12T14:06:00.000-07:00

I just found Phun the other day. It's a free open-source, cross-platform 2D physics simulator that makes you want to pick up blocks, or maybe crayons, and learn more about the way things fall and move under pressure. Written by a Swedish graduate student, the program teaches concepts of restitution and friction. Having the physics exam made me think of this.

http://phun.cs.umu.se/wiki/Download

Good luck on the exam everyone!

Iron Man

2008-05-04T10:45:00.000-07:00

Finally one of my favorite comic book heroes has come to the movies. I highly recommend watching this movie. It definitely strays from the norms of the brawns of most superhero movies and has moments of clever dialog.

Its a cool movie. And the hero, Iron Man aka Tony Stark is a scientist. Although the science and physics involved in Iron Man may seem farfetched, according to New Scientist much of the technology is closer to reality than we may think. One such example is the superhero exoskeleton. The suits that Stark builds give him super human powers but nowadays some teams have built exoskeletal legs that can transfer weight to the ground and make objects like backpacks seem lighter.

One of the coolest things about Stark's suit is not its strength but its ability to fly. Stark zooms to Afghanistan to stop warlords killing a group of poor villagers. This is also a technology being researched by such projects as SoloTrek that was capable of flying 200 km.

The way Stark manages to build his suit is due to the assistance he receives from his artificial intelligence. Stark's robotic helper doesn't always correctly guess what he wants but as real-world software grows evermore sophisticated, modern technology is making such science-fiction seem possible. He also also a 3d software program with a tactile interface.

Perhaps one day we will see these technologies realized. Have a nice rest of weekend.

Bow

2008-04-28T02:05:00.000-07:00

I recently, and sadly, broke my violin bow. As my violin teacher once pointed out, the bow is crucial, some bows can get as expensive as millions of dollars which is more than most of the expensive violins. A bow makes the sound, and everything about the bow influences that sound. The weight, camber, balance point and materials all make a difference to the sound and my ability to play.

So when I broke my wooden bow I was worried. Thankfully my good friend loaned me his carbon fibre bow. Although the material is extremely strong and resilient (I'm not worried at all about breaking it) it is not the same as a good wooden bow (which are usually made of pernumbuco wood or brazil wood.) The different density gives the carbon fibre a different resonance. There's a saying in french, L'archet, c'est le violon. The bow is the violin. And although the new bow is quite nice it doesnt make the same sound as my old bow which relates very wholly to physics.

Have a nice rest of weekend, i.e. something like 30 minutes of it left.

Earth Day

2008-04-21T22:42:00.000-07:00

Tomorrow is Earth Day. I'll probably forget to wear green and brown, but nevertheless I'll try not to forget what earth day is all about, and that it really shouldnt be just one day when i remember the environment.

But earth is also the setting and playground for so much physics. It's where we find all those situations with friction and kinematics etc. But more relevant to saving the environment and safeguarding a pristine (ish) earth for our generations and future ones is energy. We all know that ancient fossils of all types eventually became the petroleum that gets pumped out of the ground. But it seems that some people forget that we're past the half mark of world supplies, or are just too greedy to realize that we need alternatives.

Oil is great stuff. I wouldn't be surprised if eventually this time we're living in is called the Age of Petroleum because it made our industrial modern world possible (and comfortable). However, I hope future generations don't call this the Golden Age of man because we end up going down hill from here. Oil is great, but limited and temporary.

In physics we discussed energy efficient engines and even watched a video at the beginning of the year about the electric car. I also recently read an inconvenient truth by al gore. Sadly, he recommends that we use energy efficient bulbs at the end. I don't he thinks that we can do much better or more drastic stuff. Take ethanol for instance. Not only does it has 1/3 the energy of oil but it requires a lot of farming to get to that point.

We need reform in terms of the environment. Sure businesses will complain and people can argue that people in China and India will just take our places as polluters. But a spark of true and big change is the only solution to stop destroying the earth.

The Island of Stability

2008-04-14T01:54:00.000-07:00

Although everyone else has moved on from nuclear physics I got thinking about how an "island of stability" was mentioned in chem last year. There was a chart in the reading that showed as the masses of elements got greater and the ratio of neutrons to protons grew ever larger the stability rapidly decreased.
According to wikipedia, Glenn T. Seaborg for whom seaborgium is named after, first proposed the idea of super heavy elements that would be stable. (unlike elements like seaborgium itself which has only lasted one hour or element 118, ununoctium which only lasts 0.89 ms.)
Although the half lives of elements in the island are uncertain. Some physicists think they are basically short, only minutes and days long. However, some theoretical calculations indicate that their half lives may be long (some calculations put it on the order of 109 years). It is possible that these elements could have unusual chemical properties, and, if long lived enough, various applications (such as targets in nuclear physics and neutron sources). However, the isotopes of several of these elements still have too few neutrons to be stable.
Perhaps in our lifetimes we will see the "shores" of this island reached, with a radical application ready. Anyways, I'm tired, have a nice 30 minutes of sunday left everyone.

Arthur C. Clarke

2008-04-06T18:51:00.000-07:00

Sadly, the few days before we all went off to spring break, a time that seems so long ago, no one mentioned a word about Arthur C. Clarke. The visionary writer died on March 19 at the age of 90.

I'm sure that many of us saw the epic Stanley Kubrick film 2001 based on Clarke's short story the sentinel, but in addition, Clarke also drew up the first plans for artificial satellites in 1945, at a time when space and communications seemed to be wholly unrelated. I indeed watched 2001: a space odyssey and the sequel, then read the following two books, all of which I really enjoyed. I've read a bunch of his other stories including Childhood's End.

But aside from being an amazing writer, Clarke was a scientist. Through his books so many people's minds have been opened to science but better yet, they have been exposed to doing the impossible.
Here are Clarke’s Three Laws: published in his Profiles of the Future

1. “When a distinguished but elderly scientist states that something is possible, he is almost certainly right. When he states that something is impossible, he is very probably wrong.”

2. “The only way of discovering the limits of the possible is to venture a little way past them into the impossible.”

3. “Any sufficiently advanced technology is indistinguishable from magic.”

His visions and optimism certainly have inspired many including myself. These visions have in turn helped bring about his predictions into reality. From a wholly unrelated play, South Pacific, comes an entirely appropriate quote, "How you gonna have a dream come true, if you don't have a dream".

Far from being my favourite science-fiction author he still grabbed my attention with his sweeping overviews of what the future holds. He made the impossible look so feasible, and its more of this attitude that is needed to give dreamers hope of making dreams into reality.

And so ends my pitifully unworthy tribute to a great man, Arthur C. Clarke. A man who helped to inspire exploration in us all of the world around us and of the world inside ourselves. I hope his visionary optimism of the future lives on in scientists and others around the world. Have a nice weekend everyone.

The End of Cosmology

2008-03-16T23:16:00.000-07:00

A 100 trillion years from now the last stars will fade out and the only lights will be a few dim black holes and the artificial lights of civilization, at least according to the latest issue of scientific american.

There are 400 billion galaxies in our universe. And one decade ago cosmologists made the discovery that the universe's expansion is accelerating. One day the skies will be empty (if earth gets through the next 100 trillion years..). In the future the universe will look like a puddle of stars and then drop completely out of view. The article also brings up the issue of what evidence from the past we could have already lost.

This obviously relates to physics because of things that we study like light and optics. Light is fast (ha) but the distances in the universe are unimaginably immense. In addition one must wonder how to deal with a vast universe in terms of Newton's theory of universal gravitation because theres just so much matter.

But in relevance to human society it still has implications. No human will be around 100 trillion realistically speaking. But like Copernicus 500 years ago, these discovery change our attitude towards the earth and the universe. We are incredibly small to put it bluntly. And the universe itself is neither constant nor eternal.

Grand implications indeed to think about. Have a nice weekend everyone.

The Opti-Gone Mirage

2008-03-09T21:48:00.000-07:00

What a fantastic trademarked name.. ha. and what an awesome photo!..

thank goodness we had a day to think about this. But i think i now have the general idea. The insides of the mirage generator is lined with a reflective surface. The top and bottom act as two concave mirrors. Thus, the object at the bottom is at the focus point of the top mirror. Light rays go through the top mirror focus from the object, and reflect parallel down to the bottom mirror. These light rays reflect towards the focus of the bottom mirror, which is opposite the one at the bottom, therefore producing the illusion that there is an object where it is not.

have a nice rest of the weekend everyone!

Galerie des Glaces

2008-03-03T00:22:00.000-08:00

The hall of mirrors is immediately what came to mind. It is a hallway full of mirrors in the Palace of Versailles just outside of Paris. Sadly when i was there it was being partially renovated. But at least i got to see some of it!
When two mirrors are placed parallel to each other the images made by each mirrors gets seen by the parallel and so on. This means an infinite number of images in the mirrors.
One can almost imagine Wilhelm I being proclaimed Kaiser..
The hall is quite elegant and so many mirrors increases the ambient light as well.
Anyways, can't write much more, have a nice remaining weekend everyone! Something like an hour and half of it.

Transformers:More than Meets the Eye

2008-02-24T19:58:00.000-08:00

Sadly, my valley loses power more than any place i've ever been. Even where my grandparents live in Southern Taiwan, during a freaking hurricane for god sakes, keeps its power more regularly. Yes, I can say with near certainty that I lose power roughly one every 1-2 months.
But why? To my chagrin i really don't know. But i have my hunches. It's probably some transformer at the base of my valley or some place in the electrical substation that blows out.
So transformers... (insert robot joke here) they transfer the low current high voltage to be stepped down into more manageable electricity for homes and/or different areas. They have coils of different number of turns to allow alternating current (because it produces a magnetic flux) to either be stepped down or up.
The number of turns multiplied by the change in magnetic flux over the time it takes will give the voltage.
So why do they fail so often in my valley (assuming that they are even the problem)? Maybe overload, faulty parts, or maybe its the weather that can get to them, i have no clue.
Anyways, have a nice weekend everyone, and yes so far i've had power this whole weekend, nice!

Dr. Hayashi's Talk

2008-02-10T20:01:00.000-08:00

I was duly impressed with Dr. Hayashi’s ebullient and contagious optimism. Not only did she clearly liked talking to her audience, but immensely liked her work as well. But what truly struck me was her remark on education. I agree that what this country needs are more thinkers. Maybe not just scientists, but people that have the minds of scientists: clear and open minds. As I have probably mentioned before, China’s politburo is composed almost entirely of scientists; China is a technocracy. Concerned less with power they send the country in a forward and future looking path.
On the other and more ominous hand Muslim countries hardly make any impact on the world’s affairs. Although there are over a billion Muslims only two have ever won a Nobel Prize, in addition, one of these winners, a Pakistani, was barred from speaking in his native land. Today’s situation is a far cry from the golden times of early Arab rule during which Muslim Arabs led the world in scientific progress, a time when the rest of Europe was in the Dark Ages.
What went wrong? Invasions and Turkic peoples certainly destroyed the progress Arabs had made but there were also fewer people like Dr. Hayashi. When thinking becomes conservative and closed people will and can suffer terrible conditions.
This is why it was very encouraging to hear Dr. Hayashi speak so eloquently and passionately about spider silk. I know that people must question the reasons why scientists pursue these stretches of science when there is no apparent impact on people (for instance creatures on the ocean floor or in the far reaches of space). Nevertheless, there are indeed some very potentially profound and interesting applications for spider silk. One day there might be spider silk factories churning out either biological or synthetic silk to make incredibly strong materials. Her work compares to the fantastic qualities of the Spiderman comic. Like Spiderman, Dr. Hayashi’s work has the quality to be significant in people’s lives.
When scientists, like Dr. Hayashi, look for answers they open minds. All of a sudden there are many more paths to take. If only our politicians in the world had the training that Dr. Hayashi had. Scientists gather to figure out more about the genome, build the ISS, and test out CERN when the world’s politicians can’t come to terms with anything. Science is optimism; it is the general mood that things can be changed for the better. And optimism is something sorely needed in today’s world of gloom and doom.
Personally I feel that it made me realize that being open-minded is a golden quality. She had no idea what she wanted to do and it was by chance she had the opportunity to get into spiders. I just hope I have the same luck in finding equally golden opportunities.

Aqua Script

2008-02-03T19:41:00.000-08:00

I just saw this system of displaying moving text and images using falling drops of water. Its called "Aqua Script" and reminded me of the physics that we have already done and will soon do. It is 2 meters long with a number of magnet-valves that can expel single water-drops on demand. It creates a virtual floating billboard effect and requires a computer to coordinate the timing and speeds of each water droplet to simulate the text made the water drops. So kinematics are definitely required to make this project a reality.

But furthermore this is an example of something interdisciplinary, or at least something in between art and science. So now I'm going to find some super bowl commercials to watch since I missed the game. Enjoy the weekend everyone!

Static Shock

2008-01-27T23:10:00.000-08:00

Well every once in a while I go to Costco out in Hawaii Kai. Ever since I was a kid I've feared static electricity, sure, the everyday static won't kill you but it sure can be a surprise and even painful. But the humidity is much lower in Hawaii Kai than where I live and it makes the situation ripe for memorable shocks.

When I walk across floors whether they are carpeted or tiled I pull many electrons from the floor. This creates a surplus on my body. When I come into contact with an object that has fewer electrons i.e. my car door the electrons extra on my skin jump across to balance things out. As a result theres a shock. Well I don't what else to say but enjoy the remaining weekend everyone!

wah wah

2008-01-20T22:53:00.000-08:00

Well im glad exams are over :)

Anyways i was fortunate enough to get a new amp this weekend with a whole bunch of digital effects. I suppose sometime during the rest of the course I'll learn about how the sound waves are transformed into new and completely different sounds. However all amps have some kind of speaker. A loudspeaker that is and thats where electromagnetism comes into play.

The first one was patented in Bell's telephone. And in 1878 it was improved upon by Siemens. Now i think i can understand the roots of these truly vaunted companies. It involves a magnet and compressing air to create vibrations. Soon i hope we'll delve deeper into the understanding behind all these electromagnetic machines. this will be continued i hope! Enjoy the rest of the weekend everyone!

The Dead Sea

2008-01-07T00:18:00.000-08:00

During my trip I traveled north from the Red Sea (Eilat) through the Negev, to the Dead Sea. Then we stayed a night at the Ein Gedi Oasis. It is actually a kibbutz (agricultural (although now often replaced with hitech) commune) with a spring. Kibbutzs are interesting because although they never accounted for more than 7% (i think) of the whole population of Israel so many important figures had once been part of one. Israeli food really disagrees with me, perhaps it is kosher. It is quite bland and i often had the same view on Judaism, but I think i have had a much better brush with it. That would be another blog topic or 10 haha.

anyways Ein Gedi and the Dead Sea. The beaches were made of salt, coming from Hawaii it is quite the phenom! However, it was cold as heck. haha Dante's inferno comes to mind when i say cold as heck. anyways i hadnt the courage to go in the water but my brother sure did. And sure enough you can float! its amazing, ill have to go back in summer times. obviously the amount of salt in the water makes the water so dense that one can float. and in the future it will be saltier as the Jordan River gets more and more diverted. and wow the Jordan river valley was quite the agricultural beast.

Why the World is Not Flat

2008-01-02T22:40:00.000-08:00

Why the World Isn’t Flat

I’m glad we had to read this book because I had read it early, but only the 2nd edition. The book is a very entertaining read, even on the second time. For everyone, you should pick up the NYT and read some of his articles. Or perhaps some of his other books like the Lexus and the olive tree or aside from globalization, from Beirut to Jerusalem (which my gf just gave me). He has clever diction and often gets to the heart of some our times most pressing issues.
Friedman puts it directly to us the reader. Most his audience I assume is American. No longer do we have the overwhelming advantage of dominance in the world’s markets, as that will longer be the case. Of course as of now America is still undoubtedly singularly still the greatest nation the world has ever seen. However, as Friedman points out over time the importance of these huge groups such as nations and corporations is decreasing and that of the individual is increasing.
The effect this will have on me is that I will soon be facing increased competition from not just my peers around me but those of my peers from around the globe. As people right now are experiencing in the United States this can mean jobs will be lost or gained as opportunity presents itself. I feel that the best way to deal with the flat world is to adapt. It is just like survival of the fittest where animals that cannot adapt go extinct. On a better note I just read an article about the continuing success of kiwi breeding in New Zealand!
I appreciate Friedman’s keen sense of simplicity in laying out his ten flatteners. Open source is the greatest in my opinion. There is the ever-present conflict between customization and standardization. Open source projects make it possible for individuals (like me!) to develop software. Open source can successfully compete with big companies as well (Linux etc.). Open source also means greater opportunity for everyone in open source politics, culture and much more. Globalization has the chance to transfer power from the few to the many!
Nevertheless I’m sorry to say that there are so many problems in taking every word of his book entirely seriously. Sure, I need to hone a varied and important set of skills to remain “irreplaceable”. But the globalised world is not here yet. To think this way can lead to folly. Since Friedman gives many “stories” and examples in his book here’s one in addition: a little over ten years ago Coca Cola rebranded itself as going aggressively global and emphasized that there would be no distinction between international and domestic. So they set huge growth targets, focused on a few megabrands, and underwent a load of centralization and standardization. Well, I admire Coca Cola a lot, my dad worked for them for a little while in Brazil and said there were an incredibly future oriented company, buying up land for later use and setting plans for far into the future. As Steve Jobs said, the consumer doesn’t tell you what they want, you tell them what they want. Nevertheless, this plan terribly backfired and I believe they lost something like $100 billion in market value. Oops. Haha. Well that’s unfortunate. So now they are setting more realistic goals and diversifying. They’ve learned a lot from Japan, where if you’ve ever been there they have a huge assortment of products. I’m sure you’ve heard about entering the vita-water sectors as well. The lesson learned here is that globalization is not finished and not even close.
In fact, most of the technological advances that have made the world a smaller place have only served to increase local ties. Sure information, people, money etc can move quicker and to basically anywhere. But the world is only starting to truly benefit from globalization. Take the web for instance; you should be connected with the whole world when you get on. But don’t you end up chatting mostly with close friends and emailing cross-country. We are more wired but it does not mean that we are any more “global”.
From the business investment standpoint most fixed investment is internal. “Our investment knows no boundaries” is what companies say. But if you’ve looked at where investment comes from it’s a largely domestic thing. Politically we are not yet global citizens. If you ask people what they are they’ll respond with a nationality or ethnicity. Parochial ties are so strong. Some people I’ve met won’t even say a country but give me a region like Bavaria or Catalonia. These are reasons why even on the smaller scale such as the EU (haha not so small maybe) globalization has taken a hit. Someone said if globalization were given a vote in the United States today it would lose. We have the Mexicans, Britons have the Polish, the French have Algerians, Germans have Turks and the list goes on and on.
I truly believe in the flattening of the world. But the amount of exaggeration that people have used in describing globalization is ridiculous. Friedman talks about a world where distance, geography, and language don’t matter. But my god they do!
Even when all are in common it does not mean a flattening in its entirety. Look at the Canada-US border. The biggest bilateral trade in the world and yet there is more trade between provinces in Canada than between states of similar size and distance. Obviously some people care about these boundaries are artificially as they are. When you look at trade figures I am shocked, not by the huge numbers, but by the small numbers. There’s still a huge amount of international trade however don’t get me wrong.
But I mean, globalization is occurring but is far far far from complete. In fact, policies are very fickle as well. I remember a picture on the cover of the Economist, in 2006 or something, of the future of globalization showing a beached wreck see it? haha its probably of the Aral Sea, what a calamity. Anyways... I guess I feel pessimistic because of the sub-prime crisis this year. Who knows what will happen. Policies are as capricious as the wind. And an election is coming up! Oh no… haha as decreasing numbers of votes turn out Americans find themselves with fewer leaders and choosing between as Nader said, between Tweedle Dee and Tweedle Dum.
As the world flattens, as it looks like it will in the coming years we might find many more Americans without jobs. After all, many of them are overpaid for jobs that others who are more tenacious and determined could do for much much less. Luddites destroyed machines in the past for taking their jobs. Nowadays theres lots of violence against the minorities that can take jobs. But its survival of the fittest right?!
In the future we will experience more shocking news. Jobs will be lost and gained. Economies will plunge and soar. People will be put in poverty and some will become richer than anyone has ever been. This years election will come and go. Gas will be become more expensive. Maybe the next google will come around. There is global warming. And hopefully mankind doesn’t destroy itself in the process.
I guess some people at this point, after reading Friedman’s book or whatever, will be wondering how to be on the upside prospering in spite and because of all these things. How to prosper and be the next Bill Gates and how to change the world! Well you need skills that no one else can utilize as well as you. You’ll need friends in high places and friends to keep you sane. And heck, Friedman doesn’t go to lengths on this, but you’re gonna need some luck because regardless of a flat world or not, the world is changing.
And yet. What I wonder is whether you’ll be happy. Is what really matters the end result? Because if that’s true, then you might as well be dead.
But anyways. Happy new year to all!!! Heres to a prosperous, educational, satisfying, fun, and happy 2008! *clinks glasses* (btw it was handed to us by a Macedonian waiter who works for a Turkish chef whose company of restaurants is owned by a Frenchman whose investment parters come from China, Korea and Japan selling Argentine meat to markets in India and Mexico. The connections go on and on and on, but at least the glass is made in the USA).

Sound

2007-12-09T19:30:00.000-08:00

Guitars may be played acoustically, where the tone is produced by vibration of the strings and modulated by the hollow body, or they may rely on an amplifier that can electronically manipulate tone. The above clip is an example of the electric guitar being played by Tom Morello who has a distinct way of playing with multiple effects. Although it must seem like he has a dozen different pedals to make all these sounds that should be coming from a synthesizer he uses only a wah, whammy, and delay. The killswitch is important too to cut off sounds. He makes the guitar sound like anything but a guitar at some times.

I learned a bunch of other things about the guitar. And about my violin as well. Such as the bridge, to me it seemed somewhat useless. But instead the main purpose of the bridge on a guitar or violin is to transfer the vibration from the strings to the soundboard, which vibrates the air inside of the instrument, thereby amplifying the sound produced by the strings. Well thats pretty important.

Oftentimes i wish i had an electric violin to play around with the various effects. If i did i would have a violin without much of a body. It would have pickups however. Pickups are attached to a guitar/violin that detect (or "pick up") string vibrations and convert the mechanical energy of the string into electrical energy. The resultant electrical signal can then be electronically amplified. And in regards to the whammy bar, it allows me to modulate the pitch moving the bridge up and down.

Very interesting chapter on sound. Especially since its such an inescapable part of our lives. Yet, such an enjoyable part.

Excuse me while I kiss the sky!

2007-12-02T23:44:00.000-08:00

Yes. Hey Joe! I love how Hendrix plays his strat upside down because he's a lefty. His strings even sound different too.

I can't wait for chapter 17 on sound. I couldn't bear rehash the simple harmonic motion that we just covered. I guess all i've got to remember is the usage of conservation of E total. Actually, we've to rememeber everything we've covered right?

Next week ill try to attempt explain different techniques and stuff using physics. Fun fun :) In the meantime however, im sick.

Bungee Jumping!

2007-11-25T01:38:00.000-08:00

So that's a short on bungee jumping at the original bungee jumping site in Queenstown, New Zealand with an introduction by a bungee company.

If the spring action on the bungee cord wasn't dampened then this would be an example of simple harmonic motion. However, no one would be able to stop, so that wouldn't be good for advertising. The motion is periodic, as it repeats itself with intervals in a specific manner; it is described as being sinusoidal, with constant amplitude. A motion with frequency f has period = 1/f. Thus if there was a period of 4 seconds the frequency would be 0.25 hertz.

Okay well that's it from me. I'm going to enjoy the rest of my thanksgiving break. There really is so much I have to be thankful for and I should be thankful year round.

The Challenger Deep

2007-11-19T01:14:00.000-08:00

My homepage for Safari is a random page on wikipedia. I'll say that 40% I find a useless irrelevant page like one on some unknown district in India or in Minnesota. However, the other times I can find true gems and oddities (Vang Stone or Australian Senate election of 1967). This time though I found something that correlates with my work in physics and fluid motion.

The Mariana Trench is the worlds deepest oceanic trench. It goes down to a maximum 11 km down. This makes it the deepest location on the surface of the earth's crust. It is located where the Pacific plate is subducted beneath the Philippine plate. In 1960 the bathyscape(similar to a spherical shape so as not to be crushed by the intense pressure) "Trieste" reached the bottom with two men. The gauge presure of the seawater at the bottom is 1030kg/mcubed times 9.8m/s squared times 11000m. This is equal to 111034000 Pascals. This is over a thousand times greater than the atmospheric pressure we experience at sea level! It is almost scary to imagine the sheer darkness and fear one would experince being at that depth, although life persists even at that depth (foot long flounders and shrimp).

So now I've gone from space to the depths of the ocean. Hauntingly but beautifully, physics is omnipresent.

Eleven Flights More :(

2007-11-10T23:59:00.000-08:00

Mission STS-120 was a space shuttle mission (Discovery) to the ISS that was launched on October 23 and landed this Wednesday the 7th. Sadly however, I was reminded that only eleven more missions will be flown by the space shuttle program until its decommissioning in 2010. On a better note the ISS is one more module closer to completion as the Harmony module (a US module built in Italy as part of a joint ESA-NASA deal) was attached; it is a habitat module, and repairs were also performed.

The ecape velocity needed was 11200 m/s this escape velocity does not depend on the mass of the space shuttle although it may require more or less energy depending on the payload of the space shuttle. The space shuttle escaped earth gravity to enter into a LEO or low earth orbit to meet with the ISS at about 320 km above the earths surface. The value of g at this height is GM over (r + 320km)squared. However, since this is at such a low (comparatively) orbit the value of g here is nearly the same as on the surface. The weightlessness is caused by the effects of freefall.

2007-11-04T16:53:00.000-08:00

Heres a video that made me wonder what the initial angular acceleration of the system with the Tundra truck would be if my family's four door sedan was placed on the other side of the seesaw. Assuming the whole seesaw is 70m long then the Tundra truck would be at 25m from the fulcrum while on the otherside my family car would be 35m away from the fulcrum on the right side of the seesaw. The video states the truck is 10000 pounds (4535.9 kg) while my car is probably around 4000 pounds (1814.3 kg) and the mass of the seesaw is probably 10000 pounds (4535.9 kg).

First, inertia of the system would be needed. I = (truck)mr^2 + (car)mr^2 + IS
By substituting values for the variables and I of the seesaw is 1/2ML^2 one finds that the system's moment of inertia is equal to 6909614.2 kg*m^2.

Now net torque is found by adding the torques of the car and the truck. Which is 488990 N*m.

Σt = iα and so angular acceleration is 0.0708 rad/s^squared. Its kinda slow but it makes sense when dealing with large masses that are nearly equidistance from the fulcrum.

In the video it is clear the initial angular acceleration is much larger when only the truck is on the seesaw at a great distance from the fulcrum.

Fly Gundam!

2007-10-27T21:36:00.000-07:00

I was watching an episode of 0080: war in the pocket. I noticed the space colonies were rotating. The different sections had different rotational speeds.

With further research I found out that many of these colonies are called O'Neill cylinders. One the first designs was "island one" a sphere with a diameter of 1.609km (804.5m). So to find the velocity at which the colony would have to rotate is using F= m(vsquared/r) to get 88.8 m/s. Another design calls for a cylinder rotating in different sections at different speeds. There is even an outer ring that rotates at various speeds for farming. In Gundam, the cylinders probably rotate way faster than 88.8 m/s since the rotation is too fast (for visual effect). Interestingly, in Rendezvous with Rama the object being explored also seems to be an O'Neill cylinder except without the mirrors and windows (needed for light).

These cylinders would need to be placed at Lagrange points. These points would allow a colony (only affected by gravity) to remain stationary between two objects, say the moon and earth. <> wikipedia includes some ways to calculate the five Lagrange points. This is demonstrative of center of mass, it being essential. However this is no longer a uniform circular movement since the objects take elliptical paths.

A large problem that confronts space exploration is the effect that radiation in space will have on colonists/explorers. At the scale of the O'Neill cylinder however, the air and the steel (perhaps another metal) hull will be sufficient protection.

Personally I can't wait for space colonies.. there's just something so enticing about space.

Conservation of Momentum

2007-10-21T22:29:00.000-07:00

Admittedly this video isn't that cool. By the way, I hope the other embedded video works now.

However, this is an example of (variation upon) newton's cradle. It's better than showing you the one on my desk. Here, momentum is conserved. When one ball is pulled back and allowed to hit the stationary balls the momentum is transfered to the ball on the opposite side and it moves. Here the balls (of same size and mass, and same plane of movement) are involved in an elastic collision. The KE is not changed to anything else. I also see this concept in the bowling ball return. When there is a line of bowling balls and a ball comes back and hits the series of balls only the last ball moves away. So anyways, happy rest of weekend everyone.

Joon Lee!

2007-10-14T18:55:00.000-07:00

The other day the car I was ridiing in got hit by another car. Although Hawaii state law is handy with its "no fault" clause it was obviously the other drivers fault. Turning onto a one lane street and signalling, the other driver (Joon Lee) sped up to pass and crashed into the front right of the car.

Now the car door hardly opens, however, I feel pity for the other car which seemed to sustain even more cosmetic damage. Fortunately nobody was hurt although my neck felt a little stiff.
I feel what helped reduce the effects of the minor collision were the "crumple zones" on the car. Although the impulse of the collision is the same, it increased the duration it took the other car to have the collision and thus reduced the average force. Thank goodness for that. Happy rest of weekend everyone!

Rube Goldberg FTW!

2007-10-07T22:20:00.000-07:00

I'll have to say that Rube Goldberg contraptions are awesome.

In what is basically an interactive physics program, Garry's Mod, one can simulate different physics (gravity, even static and kinetic friction) but heck, to put it bluntly, nobody talks about Gmod in those terms very often. But! when you're messing around with Rube Goldberg contraptions very minute differences can make something go amiss.

So here's a video that I really like. Everywhere there are examples of physics. I like the part at the end where the crates slide down a massive ramp. The people at the end are encountered by a massive load of kinetic energy because satrting from higher up means more potential energy and we all know for conservation PE + KE = KE +PE, although I wonder if the creator had to reduce some friction on the ramp. Well anyways, this is some fun fun stuff (to me at least :p). The only limit is imagination! (ha what a hackneyed phrase)

Get a New Car

2007-09-30T22:54:00.000-07:00

It seems everyone is having car problems as of late. Goodness knows why... Both of my family's cars have needed repairs and two of my friends have also had car problems. I'm starting to suspect that the repair places don't the greatest jobs either. Oh well.
On to the physical part! Going over on the H3 yesterday (I rarely go on H3 actually) I saw something that caught my eye. An old rickety brown car from what seemed to me was the 70s was really close to another car. Since we were going roughly 70 mph (112 kph) I thought, "whoa". As we started to pass the pair on left lane I realized the two were attached by a thick gnarled rope. And no, I didn't think about a picture unfortunately so the picture I do have doesn't explain the hilarious/interesting side to what I witnessed.
The rope wasn't at any angle so I figured why not calculate some work? If the car ahead was pulling the other car with a force of 15000 Newtons then over 1km 15million joules of work were needed. And I'm sure the distance was much much longer.
I'm glad that guy got someone to pull his car because a lot of work is involved. Not to mention the change in angle because of hills and the friction on the tires. And now imagine what life would be like without cars... It'd be like Virginia in 1732, rivers and poor roads (hah I'm writing a paper on Washington's formative years).
Happy rest of weekend again! Happy next week too everyone!

Post Two!

2007-09-23T21:15:00.000-07:00

Mid quarter has just passed! I'm that much closer to the end of year :) yet... I'm enjoying it all right now. For those who took Asian Studies last year, one has to enjoy the journey!
I moved my television from one floor to the other. It wasn't particularly easy work either. Sitting on its stand I first had to slide it off (with my brother's help of course, who am I, the Hulk?) and I overcame static friction to get the TV off the stand and hanging in the air. I estimate that the TV is about 70 pounds, which is roughly 32 kilograms. So thats about 314 Newtons of weight downward I was fighting with. If I had slid the TV along either the carpet or wood floor the coefficient of friction would have differed, if there was no friction then i could have pretty easily dragged the TV nearly anywhere (although stairs are different, that thing is an awkward object to move).
Well hopefully next weeks entry isnt so mundane :p oh well happy rest of weekend all!

Wait, hold on... cue the elevator music

2007-09-16T19:05:00.000-07:00

Hey everyone, Happy weekend! If physics were an elevator... it'd be 88 floors in reach and some little kid just pushed every button. Good thing I have my laptop though! I can thankfully still access my physics book.
So elevators. Something as mudane and as simple as an elevator still has so many physical principles. That's something I appreciate about Physics; it, more than the other sciences is right there in front of your eyes.
Now I'll never ride an elevator the same way again. So there are essentially three situations when one is in an elevator: zero acceleration (when speed is constant or the elevator car is at rest), upward acceleration, and downward acceleration. At zero acceleration the opposing forces (Fnormal and Fgravity) balance each other out and the rider (me I suppose) feels no change in my weight.
During upward acceleration however, the normal force is greater the force of gravity (which doesn't change) and one feels heavier. The opposite is true for downward acceleration when the normal force is less than gravity and one feels lighter. The same principle using the equation from Newton's second law applies to other "weightless" situations like roller coasters.
Which brings me to why there isn't a theme park here in Hawaii? Every physics student would have to go on it!
Now I got to do better on quizzes! Short term Sean goal! Physics FTW! Kikaida!

Post Number One!

2007-09-08T02:09:00.000-07:00

I look forward to a wholesome year of physics! I'm gonna break down problems into little acorns and so bit by bit solve them like a squirrel saves each acorn for the long winter. There is nothing to fear but fear itself!