Using the Speed of Light

I wrote this as my final for physics class. I spent a lot of time on it so I thought I'd put it on here. That way more than one person reads it! Enjoy :)

Using the Speed of Light

Katie Showalter

May 10, 2012

How fast is fast? Humans top out at 27 mph. To reach orbit, rockets must achieve speeds of 17,500 mph. What about 670 million mph? This is the fastest known velocity in the universe, and it is believed nothing can surpass it. This is known as the speed of light.

 Over the centuries, measuring the speed of light has proven to be a great challenge. Galileo was the first to attempt it in the early 17th century. He and his assistant took lanterns and stood on hills one mile apart. Galileo flashed his lantern and as soon as his assistant saw it, he was supposed to flash it back. In theory, it was a good idea. They would measure the time it took to go there and back, divide by two, and end up with miles per hour.

It did not work. Light travels much too quickly to be measured in this manner. What was needed were extremely long distances, hundreds of millions of miles to be exact.

In the 1670s, careful observations of Jupiter’s satellite Io were being made by Danish astronomer Ole Roemer. He found that Io makes a complete orbit every 1.76 days. Because of this, Roemer expected to be able to predict the exact position of Io at any point in time. He was wrong. At times, Io would be ahead of itself, and at others, behind. There was no known reason why the satellite should behave this way. The only thing Roemer noticed was that Io seemed to be ahead of its orbit only when Jupiter and the Earth were close, and farthest away when Io was behind.

Roemer eventually realized that when it was behind, he was viewing Io in the past. In the time it had taken light from Jupiter to reach Earth, the satellite had moved forward. Io was still following its precise orbit; it just didn’t appear to. This revelation marked the first point in history where scientists began to predict that light did not appear instantaneously, but rather that it had a velocity.

Using the speed of light became very important to Albert Einstein, the 20^th century German physicist who wrote the two theories of relativity. His first theory, special relativity, creates a link between space and time. Space is three-dimensional, meaning it can move forward and back, up and down, and left and right. Time is one-dimensional, only moving forward. Added together, time and space create a four-dimensional object called the space-time continuum.

Einstein said when mass moves at a high enough speed – say a spaceship traveling at half the speed of light expressed as .5c - its time seems to differ from mass moving at a slower speed such as the Earth. Because the spaceship is covering much more space much more quickly, its time actually slows down relative to Earth time. Also, the length of the high speed objects appears to be much shorter because it is covering a huge amount of space at a time. Once again this is only a relative difference, hence the name relativity. For an observer on the spaceship, time and length of mass appear to be normal.

This behavior of space and time is only evident at velocities close to the speed of light. As a result, no one has ever observed it before directly. However, experiments performed have confirmed its truth. Space and time are perceived differently for those objects moving at near the speed of light. And so, Einstein proved space and time are not absolute.

Special relativity did not explain everything, however. It only applied to objects moving in straight lines. This means it is in a vacuum - such as space -  and is not acted upon by outside forces like gravity, making it a special case. Einstein released a theory on general relativity ten years later. This theory stated that gravity can have an affect on space and time as well as motion.

Einstein found that as a particle approaches the speed of light, its mass increases. This makes it impossible to accelerate an object to velocities close to the speed of light because the more mass it contains, the more energy it needs to accelerate. It is impossible to increase any sort of mass to the speed of light because its mass would then become endless. Since the net applied force is equal to the rate of change of momentum and the work done is equal to the change in energy, it would take an infinite time and an infinite amount of work to accelerate an object to the speed of light. Using his famous equation E=mc², this can be explained. Energy is measured in Joules, and one Joule is kg-m²/s². The speed of light squared equals m²/s². Mass in kg is necessary in the equation to balance it out.

Because there are two sides of an equation, matter and energy can change into each other. All mass has kinetic or potential energy, and energy can only act on mass. One cannot exist without the other, and they must always be equal. Einstein’s equation says energy due to motion is proportional to the mass increase expressed by the speed of light squared. He interconnected energy and mass just as he connected space and time.

Light has a constant speed in the vacuum of space without the influence of gravity. In the presence of mass, light slows. The larger the mass, the slower the velocity of light. Keep in mind, this change in speed is only at a distance. Someone under the same influence of gravity as the light will see it as traveling at its normal speed.

This complicated idea can be explained in another way. In 1904, Einstein was riding home from his office in a streetcar. He looks behind him and sees the large clock in a tower. He then imagined what would happed if the streetcar suddenly took off at the speed of light. Einstein realized the tower clock would appear to stop since light announcing its change would never reach him. However, his own watch would keep normal time. To someone standing underneath the tower, both the street car and the new time would shoot off at the speed of light at exactly the same time.

Through this revelation, Einstein realized time can tick at different rates throughout the universe depending upon how fast one is moving. One second on Earth is not the same as one second on the sun or on Pluto. The faster one moves, the more time slows down.

Einstein also showed the speeds add in an unknown way. Say a spaceship traveled at 80% the speed of light. Now say Einstein shot a bullet in the same direction, once again at 80% the speed of light. Using Newtonian principles, the bullet should be traveling at 160% the speed of light, a physical impossibility. Einstein proved this wrong.

In everyday events, Newtonian physics works perfectly and with no flaws. But people in the world do not reach the speed of light. This is the main reason why it took 200 years to find the first correction to Newton’s laws.

Newton’s most important discoveries explained how motion can only change with time. He showed the force that pulls an apple to the ground is the same that controls the tides and the same that keeps the planets circling the sun. However, while he could show how gravity works, he could not explain why.

For Newton, both space and time were absolute. Space was a fixed, infinite, unmoving entity against which absolute motions could be measured. Newton also believed the universe was pervaded by a single absolute time that could be symbolized by an imaginary clock off somewhere in space. Einstein changed all this with his relativity theories and once wrote, "Newton, forgive me."

The universe is 13.7 billion years old; however, the visible universe spreads a distance of 47 billion light years. So how is it possible that scientists can see stars and galaxies at distances that shouldn’t even exist? And how can they see light from galaxies 47 billion light years away when it has only been traveling for 13.7 billion years? Well, for starters, they do exist; but to fully explain, a theoretical substance called Dark Energy must be defined.

Scientists have no idea what could possibly be causing this massive expansion. Eventually three theoretical explanations emerged.  One contains a discarded part of Einstein’s theory of relativity called a cosmological constant. Another mentions an energy-fluid that fills space. The last suggests something wrong with Einstein’s theory of gravity and looks for a new theory that can explain both gravity and the field causing cosmic acceleration. No one knows what the correct explanation is, but the solution has been named Dark Energy.

Dark Energy is the driving force in the expansion of the universe. It is a recent discovery that acts in opposition to gravity. As the Dark Energy pulls mass farther and farther away from other objects, the gravitational pull upon each other decreases. Because over time less and less gravitational force holds the galaxies in, the pull of the Dark Energy increases. As a result, everything in the universe is expanding with exponentially positive acceleration.

Einstein was the first to realize empty space was not nothing. The first property discovered is that it is possible for more space to come into existence. Einstein’s earliest version of gravitational theory contained a cosmological constant. It said space can possess its own energy, and as more space comes into existence, more energy would appear. Of course, this completely undermined the both the laws of the conservation of matter and energy. This is why it was discarded as soon as it was proposed.

Scientists looking back found a related explanation that comes from the quantum theory of matter. This states that empty space is full of particles that continually form and disappear. Physicists then tried to calculate how much energy this would give empty space. However, the answer came out too big. Much too big. Ten to the 120^th power too big.

The second theory of what Dark Energy is that it is a dynamical energy fluid or force field, similar to gravity. This fluid fills the entire universe, but its effect on expansion is opposite that of matter and normal energy. Another name for this fluid is “quintessence,” so named for the Greek philosophers who thought this was the fifth element.

The last possibility is that Einstein’s theory of gravity is incorrect. This assumption would cause a huge upset in the world of science. This affects not only the expansion of the universe, but also the way known matter in galaxies and stars behave. Scientists are baffled at how to find a new theory that will correctly explain the movement in solar systems as well as Einstein while also explaining the expansion of the universe. The only way to find out is to collect more data.

Scientists are sure that the universe spreads 47 billion light years from Earth. Obviously they cannot travel this far, nor can they send instruments out these distances. However, they can study the light that reaches the Earth. Light coming toward the earth appears to have a bluish tint, and light moving away seems red. These colors can build upon themselves, much as sound waves from a train whistle build from the Doppler effect. As they pass the earth, they change tints, much like the train whistle changes pitch.

Scientists are sure of these distances because of the tint of their light. The redder the galaxy, the farther away they are.

If Dark Energy continues to accelerate its pull at this rate, eventually today’s observable galaxies will no longer be visible. Even though the light is heading in our direction, the Dark Energy will pull it away at speeds greater than the speed of light. These galaxies will still exist, but it will be impossible to see them. From Earth, the only light left in the night sky will be the moon.

Recently, last year in fact, researchers in Italy stunned the scientific world by announcing they had broken the speed of light. Their experiment called OPERA showed that tiny particles similar to neutral electrons called neutrinos could accelerate to speeds faster than that of light.

Because of skepticism, these scientists challenged others to repeat their experiments, and all reached the same results. Each time, the neutrinos arrived 60 microseconds faster than light would have.

However, a new batch of researchers arrived. These scientists wanted to measure the energy left over in the neutrinos after they arrived. They believed moving at this speed would cause the particles to lose most of their energy because they should have begun to spray out pieces of themselves similar to the way light photons spread in all directions.  In the end, the particles had exactly the same amount of energy. It turns out the timing mechanism on the Large Hadron Collider,  - the enormous machine at CERN in Switzerland capable of accelerating particles to massive velocities - was off just a hair. As of today, nothing known has broken the speed of light.

The greatest controversy brought about by traveling at the speed of light is time travel, or even time itself. What is time? Does it have a beginning or an end? Can it only move in one direction? These million dollar questions can never seem to be answered satisfactorily.

Many believe time travel is possible, especially into the future. Because the faster one moves, the more time slows down. This also means the body ages more slowly. A person who travels near the speed of light can go deep into space, then return to find Earth thousands of years in the future. Time travel into the past would require moving beyond the speed of light, however; and according to Einstein, this is a physical impossibility.

Many scientists have proposed ideas for time machines. These actually are physically possible even if they are not yet practical for humans at this point in time. The worst humans can do is to say something will never happen. Lord Kelvin, president of the Royal Society in 1895 once said, “Heavier than air flying machines are impossible.” Science has proven him wrong.

It is amazing what something as seemingly simple as light can do. Most humans in the world take it for granted. However, the problems solved by studying and using the speed of light is incredible. There are so many mysteries left to unravel; and it is left up to those who will step up to the challenge of explaining the universe to the coming generations.

Bibliography Page

"Dark Energy, Dark Matter - NASA Science." NASA Science. N.p., n.d. Web. 7 May 2012. <http://science.nasa.gov/astrophysics/focus-areas/what-is-dark-energy/>.

"Einstein's Relativity." Astronomy Notes. N.p., n.d. Web. 11 May 2012. <http://www.astronomynotes.com/relativity/s2.htm>.

"Faster-Than-Light Discovery Raises Prospect of Time Travel | CERN Neutrino Experiment | Time Travel Potential & Barriers | LiveScience ." Science News – Science Articles and Current Events | LiveScience . N.p., n.d. Web. 6 May 2012. <http://www.livescience.com/16207-faster-light-discovery-time-travel.html>.

"Measuring the Speed of Light." University of Colorado Boulder. N.p., n.d. Web. 8 May 2012. <http://www.colorado.edu/physics/2000/waves_particles/lightspeed_evidence.html>.

Moskowitz, Clara. " What Is Dark Energy? | Space.com ." Space and NASA News – Universe and Deep Space Information | Space.com . N.p., n.d. Web. 11 May 2012. <http://www.space.com/6619-dark-energy.html>.

"Speed of Light." Speed of Light. N.p., n.d. Web. 6 May 2012. <http://www.speed-light.info/>.

"Speed of Light.." Speed of Light. N.p., n.d. Web. 7 May 2012. <http://www.speed-light.info/speed_of_light_12000.htm>.

This is something I entered in a writing contest. The title was supposed to be My Kansas Shoes Were Made for Walking, and this is what I wrote. :)

The Sunflower State, the Heartland, the Breadbasket of the United States. These are nicknames given to the great state of Kansas, and become extremely proud of in the process.

My little town of Alexander is the oldest in Rush County. Some may know that it was originally a trading post on the crossroads of the Fort Hays and Fort Dodge trail. The post was built on the north bank of Walnut Creek in 1869 where it served as a refuge for travelers. Surrounded by a stockade, it was well protected from outlaws and Indians.

The first pair of shoes I remember were a couple of pink cowgirl boots. Wearing these, my mom and I would walk through my tiny hometown of 70 people, visiting neighbors, getting to know just about everyone, and having just about everyone know me.

We moved to the farm a couple years later, and just about every inch of that place has been tread upon by either myself or my four younger siblings. We play cowboys and indians, build forts, hide Easter eggs, and in the evenings walk through the rows of trees that form the shelterbelt, protecting our cattle and our house from the blustery Kansas winds. We run through the pasture, hide in the tall grass, and hike out to the cherry tree growing on the opposite end. We even walk to the end of the road to get the mail, we’ve been over it all.

For ten days every June, six members of my family walk through the wheat stubble to reach our designated machinery. My dad, grandpa, and I on a combine, my brother and sister on their grain carts, and my uncle on his semi. The mothers watch as the five youngest cousins step fast to keep up with Daddy, or Uncle Adam, or Grandpa while they pack up the supper eaten on the side of the road.

Life would not be complete without a ride with Dad on the combine. Hours seem like minutes as he explains how the machine works, how the wheat progresses from simple sprouts to a waving sea of gold, and the journey the grain embarks upon from the field to the dinner table. It’s crazy how these simple explainations seem to always contain a lesson about life.

Years ago, my great grandma started the tradition of bringing supper to the harvest field. As a young child, I looked forward to our little picnics on a dusty dirt road in the shade of a tractor. Today it is a means of taking a thirty minute break from the long hours in the harvest field to spend a bit of time with my family.

My tennis shoes are made for running. Be it volleyball, basketball, cheering, softball, or track, my shoes have taken me hundreds of miles all while staying close to home. Plenty are still covered in red dirt, scuff marks, or have holes peeking through the sides. A definite rule is a pair of shoes must be completely worn out before it is necessary to buy new ones.

My highschool of 40 students hasn’t had much success in sports for the last few years, but the bond of teammates is stronger than the pain of losing. Walking onto the court with hands tightly held to honor the flag during the national anthem shows we are proud of our country, our state, our town, and our school.

In March, my shoes took me around and around the Ness City track, in honor of those fighting and in memory of those who lost the battle with cancer. This is the first year Relay for Life was held during spring break, and while pretty cold, everyone was provided fuzzy socks to keep feet warm and toasty.

This Relay was the third I have ever attended, and was also the most difficult. My aunt lost her battle with breast cancer in September, making this the first Relay I have attended without her. In the past, I would walk laps throughout the night with friends. This time, I took in a couple laps alone. It is amazing what a little quiet time will do for the spirit.

This April, my shoes took me all the way to the Kansas pillar at the WWII memorial in Washington, D.C. Talk about the trip of a lifetime! As a guardian on Honor Flight, I was accompianied by a very special person. My veteran’s shoes also took him to D.C., though they carried him very slowly. But while his feet were slow, his tongue was quick. He shared countless stories from his 88 years of life, all of which I will never forget.

While D.C. was amazing, and the change in scenery was incredible, I’ve got to say I was glad to come home. There’s something about life on the prairie where I can see for miles, where I can watch the grass wave in the wind, where I can see every single star in the night sky.

The world is filled with wonderful and beautiful places. Someday perhaps I will get to visit them, perhaps not. But for now and forevermore, I’m proud to call Kansas, the Heartland, the Sunflower State, my home.

Summer 2012

This morning I realized there are only two Mondays left of school (after today of course). This is crazy. It doesn't seem like the end of school.
I also realized this is my second to last, last two weeks of school! Even crazier. It seems like I just started high school and all of a sudden I'm going to be a senior.
I decided this year must have gone so fast because I seemed to be so busy. I played volleyball, basketball, participated in track, cheerleading, band, vocal, school play, journalism, FFA, FBLA, and KAY.
I can definitely say I'm ready for a bit of a break... of course I won't stay down for long. My summer is filling up fast, and I've gotta say I wouldn't want it any other way :)

Singing! :)

Our first music contest is this Tuesday held in Macksville. Since this completely snuck up on me, I have not memorized my vocal solos yet...... Problem? Yes. But I have a plan.

Drum Roll Puhhhlease!

I decided I would find people singing these songs on YouTube and listen to them on repeat! Awesome right? Well I think so.

My first song is Come To the Fair by Helen Taylor. It's pretty corny, and something only judges at a music contest would sing, but that's fine with me. The only thing that is slightly irksome is the people in this video sing "Hey Ho" as opposed to "Hi Ho." But honestly if this is the only thing I have to complain about in life then mine must be pretty good.

My second song is titled "Panis Angelicus." It is written in Latin. We sing a different version of this song in church but I think both are equally pretty. The weird thing is the translation I know of means "Holy and Living Bread." However, this translation is "Heavenly Manna." I guess it's basically the same thing.

I think I'm pretty awesome most of the time, especially at singing but this gal totally humbled me. She's amazing and definitely my new idol.

So anyway I have five days to learn both of these songs. I'm a little worried about the Latin one, but I'm confident I can do it. Now our band on the other hand........ Ha. Let's just say it's going to be interesting!

Our music instructor gave Kate, Tori, and I a new band trio yesterday. Yesterday. And just in case you didn't get that the first two times, he gave it to us YESTERDAY. This gives us two days to practice together and honestly that is next to nothing. The best rating you can get at a music contest is a 1, and I have never received anything lower than a 2. At this rate we are going to get a 5, and I will cry. (Maybe not literally....well on second thought, if that happens I probably will.)

For the most part, I'm looking forward for Tuesday. I've beaten the odds for a long time in the whole music scores department so I shouldn't complain. All we can do is our best. :)

The End! 

Grammys 2012

I didn't watch the Grammys last night (my dad wouldn't let me) but I did hear that Adele won a whole ton of awards including pop vocal album, album of the year, record of the year, best pop solo performance, song of the year, and short-form music video.

That's pretty amazing if you ask me, and while she isn't my favorite, congrats to her.

I also noticed that the Disney movie Tangled won a grammy for best song written for visual media. I pretty much love that movie, and the song that won the award is on my ipod playlist! :)

Favorite Superbowl Commercial

Last night was the Superbowl, and while many people watch the games, there are others who watch only for the commercials. There were many funny, serious, and enjoyable commercials, however, my favorite was the movie trailer for the Hunger Games. This movie is released to theaters on March 23, and this preview was the first to air on TV.

Hunger Games Movie Trailer :)

It is very likely that not very many people saw it on TV. It was toward the very beginning, before the game even started. I'm pretty sure I only noticed it because I was looking for it!

When The Ice Melts

There are some things words cannot describe. The deep feelings of love felt by a mother for her child, the care and protective nature instinctive in oldest children for their younger siblings. The initial attachment only grows as the years pass, even when the adored child is now resting in peace.

The most daunting moment arrives as the baby is lowered into the ground. The mother’s face is eerily calm, starkly contrasting the distress and grief apparent in the previous weeks. No tears fall, the eyes stare without seeing, yet she would give anything to deaden this moment, to make it go away, to join her breathless babe.

Hot tears of shame roll down the oldest child’s face. Through no fault of his own, his brother is dead. He failed to protect, failed to lead, failed to support. He will never get the chance. A small whimper escapes his lips as the sorrow, pain, and guilt becomes too much to endure.

The father is doing his best to comfort his children, grasping his wife’s hand in his own, hiding his pain. The youngest child wraps her little arms around his sturdy leg, understanding that he is hurting more than he shows. The tiny gesture becomes too much, and he finally succumbs to his sorrow.

Those watching are unable to handle the awfulness of it all. The tears of the father causes widespread sympathy for the defeated family, the tragedy becoming more real with every passing moment.

Inevitably, months pass. The novelty and sadness felt by spectators soon becomes a distant memory as it was destined to be. However, the pain never leaves the family.

The most unbearable moment comes when it snows. The thought of the helpless child lying in the cold, unforgiving earth alone without love or comfort becomes too much. The mother becomes desperate, begging and pleading for her child to be returned to her. Happiness felt by others becomes intolerable as the winter drags on.

As time somehow passes and spring arrives, the torturous pain lessens. Never disappearing, and never far from thought, but acceptable, bearable. When the ice melts, the hurt is still present, but so is the knowledge that one day, they will meet again. When the ice melts.