Hello I am Katy Wilson and I am taking AP Physics (with calculus) at Fayetteville High School in Faytown, USA. I created this page, which has truth, for my teacher, D. A. Young. You can email him your questions at dyoung7@prodigy.net .

 

 

Honey, I shrunk DAY!

 

Length Contraction is a very small, but very significant subject in the realm of physics. This website deals with the idea that length is not dependent on how long something actually is.

 

Linkth is relative, so is spelling

 

The contraction of length can be explained like this…

From Earth, if DAY was moving extremely fast, he would look like he shrunk. From his point of view, the fast-moving Earth and the rest of space seems to shrink!

 

 

for those who arent so hip on animations

 

 

EXAMPLE PROBLEM: How fast would DAY have to be moving to fit in a hypothetical closet in space that has a length of 140 centimeters?

    L moving = L proper x b       

     b= (1- v2/c2)1/2

 

learn about Lp

 

 

L proper is the initial length of DAY, which is approximately 170 centimeters.

 

 

So here goes…    140 cm = 170 cm * (1- v2/c2)1/2

 

                            19600/28900 cm = (1- v2/c2)

 

                            -c2 * (19600/28900 – 1) = (- v2/c2) * -c2 

 

                            c * (1 – 19600/28900)1/2 = v

 

                                                                                              .57c = v

 

One of those fill in the blank websites

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 


But you know what’s funny…DAY thinks the closet is getting smaller because that’s what he sees, how strange!

                           

 

 

For more fun with length contraction, visit these great places to be:

Animations

Einsteins theory of special relativity!

these cars go fast

 

 

 

History of the sport:

 

Newton considered everything to be absolute, as did everybody else at the early time that I’m talking about. Many believed that light was a wave that moved through space, called ether. Ether had no matter, yet it co-existed with matter. Two guys, namely Michelson and Morley, did an experiment to try to prove the velocity is relative and it failed (or so they thought). After all that didn’t work out their buds in the service, Fitzgerald and Lorentz, both came up with the idea that length may be affected by motion. Simultaneously they came up with the Lorentz factor (1/[1-(v2/c2]1/2), but they did not know why length was affected at certain velocities. Then of course Einstein starts thinking and realizes that “hey this is great!” He studied time dilation and how it affects length contraction. He got an understanding of all this relativity stuff and proposed it to the big guys. He got it to what we now know today!

 

Sources:

http://webs.mn.catholic.edu.au/physics/emery/hsc_space_continued.htm#history 

http://www.softcom.net/users/greebo/einstein.htm