Fryeburg Academy Physics

I would be willing to guess that most of you are on Facebook and/or MySpace and/or Twitter and/or Live Journal and/or , and any number of other social networking sites.  Some of you may even have your own blog, and at the very least I assume everyone uses email.  Many people use these communication methods to share photos, websites, pages, links, etc with friends (and complete strangers too), and with the diversity of webpages these days there can be some frustration with links not being pasted correctly.  Take for example the address I have copied here:

http://blogs.discovermagazine.com/badastronomy/2009/01/27/i-for-one-welcome-our-new-squirrel-overlords/

If you care to count, that thing is 103 characters long.  There’s a lot of information there: the hosting site (Discover Magazine), the name of the blog (Bad Astronomy), and the full title and date of the post.  There are a lot of windows where that won’t fit, and some email programs will actually truncate it or move to a new line, or take some other such inconvenient action.  

Which is why URL shortening utilities are useful.  I’ve come across two recently: one can be found at http://tinyuRL.cc, and the other is http://is.gd.  Go to the webpage, copy your desired link into the box, hit enter, and what comes out is something much shorter.  The two links below were made for the same page listed above (remember the 103 characters?).  In the first case it was shortened to 20 characters, in the second to 17. 

http://tiny.cc/VJJJb

http://is.gd/hp8p

Clicking on either link will take you to exactly the same page as above (which I recommend you read because it’s funny), and the shorter URLs also have the advantage of being able to track visitor statistics and stuff.  Just something to keep in mind when you have a link to share with your friends.

A recent post involved a guy who is, to put it nicely, an idiot.  I’ll let you read about it and watch the video, and see just what do you think about his claims.  

This post is about some real science now, and the author lists ten reasons Earth must be round.  Not exactly of course (it’s an oblate spheroid, remember?), but definitely not flat.  Just in case there was anyone doubting that.

When human beings first left Earth in 1961, a completely new viewpoint of the planet was discovered.  Astronaut and cosmonaut photos from orbit were something people had never seen before, and they were, quite simply, stunning.  Since then, permanent satellites and observatories have been launched, and with programs like Google Earth, satellite images are available to the general public.  I bet many of you (maybe all?) have looked for satellite pictures of your house; I certainly have.

The Big Picture from the Boston Globe has a series of pictures taken from orbit, and they are amazing.  What do you think?

I came across this video on YouTube at some point last year, and I find it a very sad example of how ignorant some people can be.  After some study of Universal Gravitation, every point he makes can be easily explained and refuted.  His points about science can be explained anyway, I have no comment on his treatise about Britney Spears and Miss Minnesota drinking fermented fish guts.

I encourage you to leave some comments about his videos, if you can stand the insanely incorrect logic with which he responds.  If you get in a comment war with him, I’d love to hear about it!

All right, it’s time to face the facts.  The United States is one of a very few countries that still use a measurement system other than metric (or SI).  This is bad for two reasons: first, the system we use is clumsy, inconvenient, obscure, and inefficient.  I mean seriously folks, what is your height in barleycorns, digits, spans, or cubits?  Off the top of your head, how many feet are in a league?  True the league isn’t used much, but how many feet are in 1 mile?  Now how many feet are in 6 miles?  Quick, quick, no calculators!  I don’t know either.

The second reason this is bad is that we consider ourselves a world leader, but refuse to measure things the same way as everyone else.  It’s one thing if we’re trying to be distinctive and lead the way to a better system, but the reality is that we’re holding ourselves back and clinging to an outdated and impractical way of doing things.  

Metrication is the process of converting to the metric system, and it was begun in the United States around 1975.  It was plagued with poor planning (optional implementation over 10 years) poor funding (the advisory board was disbanded in 1981), and resistance from the public, and it eventually died out.  I think it’s time it comes back.

The Details

Therefore, I’m going to offer an opportunity for extra credit.  I want you to write and mail a letter to either or both of our US Senators from Maine (Olympia Snowe or Susan Collins).  In this letter, I’d like you to explain what’s wrong with our current measurement standards, why the United States would be better off using the metric system, and some suggestions for how it might be implemented.

The due date for this assignment is the end of the school day on January 20 (the first exam day) and it will be worth an extra 15-point homework assignment.  In order to get credit, you must bring me a paper copy of your letter in a stamped, addressed, but unsealed envelope, and I’ll drop it in the mail for you.  If you mail the letter yourself without showing it to me, you will not get credit!

Your letter should be respectful and polite, but your point should be clear.  Your letter should not be anonymous, so sign it and be sure to include your return address.  Use the address of any of the senators’ regional offices (Portland is closest), and please share with me any response you may receive.  

If you are not one of my students and have somehow found this blog, I encourage you to participate as well!  Obviously I can’t give extra credit if you’re not in my class, but together we can change the world!  Or the country at least.

Did it seem to you that 2008 would just never end?  Not to me; the year just flew by.  That’s interesting, because 2008 was longer than normal years for two reasons.  First, it was a leap year, which means that February had a 29th, giving the year a total of 366 days instead of the usual 365.  This happens because one rotation of the Earth doesn’t take exactly 24 hours, it’s a little under.  To correct for this we’ll occasionally add a day to the calendar, usually every four years, though it’s really quite a bit more complicated than that.  Click this link for a quite detailed description of leap years that might make your head spin.

In addition to messing with February, scientists decided that something else needed to be done to screw up 2008.  Turns out that not only does it take not 24 hours for the Earth to rotate once, it doesn’t rotate at a constant rate!  Things like the gravitational pull of the Moon and Sun change things.  Those objects pull on huge bodies of water (oceans) and cause them to slosh back and forth like water in a bucket.  This sloshing is the tide, and the friction between the water and the sea floor helps to slow the Earth’s rotation ever so slightly.  It’s imperceptible over small periods of time, but after a while it adds up.  

The result is that the rotation of the Earth, which is one way we have of measuring time, and atomic clocks, which is another (less variable) way of measuring time, are going at slightly different rates, so from time to time we’ll correct one of them.  It’s a lot easier to change the calendar than to speed up the rotation of the Earth, so that’s what we do.  At the very end of December 31, the clocks read 11:59:58….. 11:59:59…… 11:59:60…… then it rolled over to 01:00:00 on January 1.  

My favorite science blogger The Bad Astronomer goes into a lot more detail about the extra 86,401 seconds in 2008 on this post and a (followup post), and you might find that interesting.  He’s also the one who was so energetic about the pronunciation of kilometer that many of you chimed in on early in the year.  (Wow, four pingbacks from a single post!  Must be a record of some sort.  I’m just trying to get my little blog noticed by the big boys.)

I don’t think the revelers noticed at Times Square, but then again they probably didn’t account for that when the ball was dropping.  So I hope you used your extra second productively; I very much enjoyed my extra million microseconds of sleep (I was already in bed).