Fourier Analysis – Done By A Machine With Gears and Levers

Fourier analysis allows your cell phone or MP3 player to transmit your voice and play music without needing huge reel-to-reel tape recorders to store all the sounds and without using enormous amounts of bandwidth. It’s now done electronically, by clever mathematical algorithms that are encoded on the tiny microchips inside your computer or cellphone or iPod or whatever.

The general idea is you take a complex wave-front and you turn it into an infinite series of sine or cosine waves. Believe it or not, it actually makes the data much simpler!

A very simple example. This weird shape

2 COSINES SUMMED

is merely the sum of two cosine waves:

cosines

And all of the music you hear (eg a clarinet, which might look like this on an oscilloscope)

clarinet

can be deconstructed into a whole lot of sines or cosines

 

About 40 years ago, I did some Fourier transforms by hand in a calculus class. It was time-consuming, but very, very cool.

A full century ago, Albert Michelson had to do a whole bunch of Fourier transforms for some astronomy task. It was too time-consuming to do by hand, so he built a machine with gears, levers and so on to do it for him.

It’s a super-cool analog (as opposed to digital) computer — and there is a fellow who shows you exactly how it works!

His presentation is in four parts. Start with this one, the introduction.

Published in: on November 18, 2014 at 5:23 pm  Leave a Comment  
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American Teachers are Chewed Up and Spit Out by the System

There is no way for anybody to keep up with all the excellent news articles and commentary showing how completely screwed up the American educational system has become — with the billionaires running the system mostly to blame.

Here are two such articles:

http://www.americanthinker.com/articles/2014/11/american_public_schools_chew_up_teachers_and_spit_them_out.html

and

http://badassteachers.blogspot.com/2014/11/our-martyred-brothers-what-43-missing.html

Published in: on November 18, 2014 at 3:49 pm  Leave a Comment  

You need to watch “Last Week” with John Oliver

John Oliver is one of the funniest, and most serious, people on TV. In my opinion, he is a better comedian and anchor than Jon Stewart of the Daily Show where he more or less got his start, tho Stewart (and Steven Colbert) are both quite good.

You can watch his shows on YouTube at this link. I don’t agree with everything John Oliver says or with his approach*, but he’s both funny and serious at the same time, as I said before.

==================

* For example, with the bit on gambling, it wouldn’t hurt to show that in blackjack, the average payoff is  negative  3% but for the lottery it’s negative 37%, which is a lot worse. In other words, if you are playing blackjack in a casino, on every bet of $100, on the average, you get back $97, losing $3. With a state lottery, if you bet $100, then on the average, you get back about $63, losing $37. It is very difficult to find any game of chance with worse odds than the lottery. In fact, we math teachers have a little saying: The Lottery is a tax on those who don’t learn anything about probability. And there’s this.

 

Published in: on November 18, 2014 at 2:47 pm  Comments (3)  
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Two VAMboozlers down, but many more to go

Two of the foremost promoters of the junk science known as VAM (Value-Added Measurements) have just resigned, one in Tennessee and one in Louisiana: Kevin Huffman and John Ayers.

Yay! But there are several dozen more who need to be fired across the country as well.

(Huffman is the ex-husband of the notorious liar and self-promoting former chancellor of DC Public Schools, Michelle Rhee, who is now selling fertilizer. Huffman was once chosen by the pro-EduDeformer Washington Post editorial board as its main educational pundit.)

Audrey Beardsley has the details on her blog, VAMboozled.

 

A Scathing Review of Joel Klein’s Book on New York Public Schools

Gary Rubenstein has a guest post that gives a devastating review of the many lies and inconsistencies in the recent book by Joel Klein, the recent chancellor of New York City Public Schools. It’s a bit long, but worth reading. Here is the URL:

http://garyrubinstein.wordpress.com/2014/11/18/guest-post-a-review-of-joel-kleins-new-book/

Is Class Size or Social Promotion the Main Problem?

Leonard Isenberg argues that large class sizes are not the main problem in Los Angeles public schools, but rather the fact that large numbers of students have been socially promoted without understanding the basics of whatever course they supposedly passed. As a result, they become disruptive, he says. A quote:

What causes disruption and no learning in the vast majority of overcrowded classrooms in LAUSD is not the size of the class, but rather the inability of socially promoted students to understand what their teacher is talking about, so that they can be productively engaged in their education. They neither have the language, math, science, or other prior grade level standards mastery necessary to having any chance of achieving anything even remotely resembling productive classroom engagement.
 
In an LAUSD of the 1950s and 1960s when I went to school, classes were often over 30 and up to 40 on a regular basis. What was different then was that the students in any particular grade were predominantly at grade level and capable of being engaged by their teachers, because they hadn’t been socially promoted, which has now become the rule at LAUSD for far too long.
Your thoughts?

Jack Berman Fights an Endless War for the Rich and Powerful

Richard Berman is better at twisting public opinion in favor of the rich and powerful than anybody else alive. He gave a speech to the Wesern Energy Alliance, explaining how he gets people confused about whether fracking or global warming and climate change, or labor unions, or increasing the minimum wage, are good things or not — even though the entire audience was quite aware that the public as a whole hates oil industry executives.

One of the people in the audience recorded the secret speech and leaked it to the New York Times. You can read the NYT article on it here.

Berman is a major sleaze-bag, and so is his friend Jack Hubbard, who also addressed the group.

Here is the link to the transcript of his speech, and I append a few quotes from the transcript:

From Rick Berman on keeping their funding sources secret:

rick berman

Jack Hubbard explains how they spend lots of money digging up nasty stuff to discredit anybody they disagree with. He starts off explaining how he will soon be attacking a liberal Colorado congressman named Jared Polis.

jack hubbard

Published in: on October 30, 2014 at 7:41 pm  Leave a Comment  
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A Revised and Corrected Ad for Koch Industries

Jon Stewart and the Daily Show made a few corrections to an advertisement extolling the enormous Koch corporation — one of their sponsors (sort of). It’s a hilarious and factual improvement on the original ad. Definitely worth watching at the Daily Show, which you can find here. Also, read the Rolling Stone expose of the Koch brothers. These are not nice guys, and they really are attempting to purchase our entire government….

Here is the text of the revised advertisement, if you don’t feel like waiting for the video to load:

We’re Koch industries — not just an energy company.

We’re in your food and in your pants and in your home.

If there’s a way to monetize your thoughts, we’ll find it.

All while backing seventeen shadow organizations to buy elections from Pennsylvania Avenue to Main Street.

You won’t always see our names on our campaign ads, because the politicians we own say that’s OK.

With our heartfelt devotion to fossil fuels, we make your planet warmer and your water more flammable, while lubricating your birds and rearranging your polar bears.

We can’t raise your little girl for you, but we can hand-pick her school board and approve her textbooks. And when she lands her first job, we’ll be fighting to reduce the miminum wage. Because we actually believe it [raising the minimum wage] could lead to Naziism.

Yeah. Naziism. We’re that [expletive deleted] out there.

Koch industries: the next generation of robber barons, bending the democratic process to our will since 1980.

Oh, and our brother David likes ballet.

By the way, the Koch brothers were not pleased by the Rolling Stone expose, so they fought back. They couldn’t actually deny any of the facts, but they still got nasty. You can read the response by the author to their criticisms, here.

Published in: on October 30, 2014 at 6:59 pm  Comments (2)  
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Charter School Fraud and Abuse

This article in Salon talks about how many charter schools are merely a way for grifters to scam the public and make off with a ton of money… It’s based on a report you can read here:

http://integrityineducation.org/charter-fraud/

 

 

On fighting back against Arne Duncan, from ‘Busted Pencils’ blog;

An excerpt from a call to arms:

We [college departments of education - gfb]are now going to be responsible for the test scores of children that end up being taught by our graduates. In other words, if my son fails and his teacher was your student, it’s now your fault! And if you don’t make the changes needed to help your students “teach” my son how to do well on his standardized tests you, your department, your school, and/or your college will be slapped and eventually shut down. …

Remember NCLB? Yeah, some of you complained and some of you even managed to turn it into a productive line of research. And what was it that you complained about and what did all that research reveal? You complained that testing would not do anything to the achievement gap, that the curriculum will narrow, that the “least among us” would be hit hardest, and that linking student test scores to teachers and schools was problematic. Then after years of conducting research you found out that all of your complaints were substantiated. The achievement gap still exists, public school children now receive little to no instruction in the arts or the humanities, the children of poverty are bearing the brunt of this misguided ideological attack on public schools and value-added measures of teachers are extremely unreliable and the public reporting of these statistics causes harm to all involved with public education. 

It is our turn to join with the children, parents, teachers and public schools. All across the country there is an “Opt Out” movement occurring. Parents are refusing to allow their children to take standardized tests (hereherehere), teachers are refusing to administer the tests, administrators are speaking out against the negative consequences associated with the tests, and some schools have actually stopped administering the tests. 

What should we do? How should we respond? Who’s willing to be the first teacher educator to say: “No. I opt out too. I will not abandon everything I know about children, teaching learning and schools. I refuse to take part in a rigged political system designed to dismantle public education and thwart democracy.”

Isn’t it our turn to tune in and “opt out”?

I’ll ask again three years later:

Teacher education colleagues are you ready to organize and speak truth to power?  

Can we move beyond simply complaining about Duncan and the reformers?  

Can we look within the profession and demand that our leaders not offer “anxious” compliance?  

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