Who's tracking you on the web? Find out with Collusion.

There is a new add-on for your Firefox browser called Collusion. I just downloaded it and installed in on my computer.  Collusion generates a network diagram of the website you visit and other sites from that one.  All of them collect information about you and share that information. Collusion a way to see who is tracking you.

Here's a snippet from my visit to Contentions, a political blog.

You can see the blog itself in the center.  What I didn't know, but now I do, is that Contentions shares my visit to them with 23 (count 'em!) other sites. Whoa! That's a lot of sites that know about me that I don't necessary want to having anything to do with them.  Some of these sites may be innocuous, but some are tracking me to use that information to make money or generate ads.  With the Collusions diagram on a tabbed page (you simply click on the Collusions icon on your Firefox toolbar at the bottom of the window) you can put your mouse over any node to see what the node is. Also, Collusion gives you information on

It's not clear to me what to do about this, but the first step is to know that there's a problem. Collusion is showing us the problem.

Here's some of what Collusion reports on my visit to Contentions (with a cut and paste just below):

"When you visit commentarymagazine.com, it informs the following websites about you.

• google.com
• doubleclick.net
• addthis.com
• turn.com
• afy11.net
• openx.net
• wtp101.com
• revsci.net
• adnxs.com
• yieldmanager.com
• quantserve.com
• mathtag.com
• invitemedia.com
• jewishideasdaily.com
• contextweb.com
• scorecardresearch.com
• nrelate.com
• rfihub.com
• vizu.com
• advertising.com
• pointroll.com
• gwallet.com
• serving-sys.com"

Some of these sites I know about, and some I don't know about. But for all of them, I had no intention of telling them about myself. Yet, with a click to one site, these others know about me. That's scary.

Courses for Everyone

What do Stanford University, Princeton University, University of Pennsylvania, and University of Michigan have in common?

For one thing, these top tier schools now offer courses on-line and for free. If you haven't seen this before, click on the link and take a look at what's available. There are humanities, computer science, health care, and economics courses, to name a few subject areas.

I took the cryptography course taught by Dr. Dan Boneh and it was excellent. The course website has the slides for the lectures (pdf format and as a PowerPoint file) available for downloading. The videos can be watched (and saved!) in various formats.  In fact, in one video format, the video will pause so that the student can respond to a question in a box on the screen. The student can press a button to see if his answer is correct or not.  It's a great way to interact with the lecture (limited though it is) and keeps you involved with the material.

After a  week of lectures (usually about 5-hours, maybe less, of viewing time) there is a homework assignment. The homework was mostly multiple choice with a few fill in the blank answers. You can save the assignments as you do them and once you've completed the assignment, you submit it for immediate grading. The homework comes back with your answers graded and with comments about the answers you selected. Thus you learn why you were right (let's say you guessed the answer!) and why you may have been wrong.  The homework was due about a week, I think, after the material end date.  If you submit the homework after the due date, you lose 50% of the points.

At the end of the class there was a 13-question final exam with a two-week time period to complete.

Based on the one class I took, I signed up for three more. The cost is zero but there is a commitment of time and it's not small. Plus, the course goes week after week so there's a commitment of continual participation. Still, you have a chance to learn new topics in your home or office with no travel required.

The course was not as good as a traditional lecture. You can't ask the professor questions and you hear and see the lectures on your own without the benefit of peers nearby. There is a discussion forum and I found that useful to clear up ambiguities in the homework. But that's all I used them for; I think other students probably made greater use of the forums.

I encourage you to take a look at the courses, and if you find one to your liking, sign up. You have nothing to lose and can gain new knowledge in the comfort of your home or wherever you are.

Blogging again

Dear Friends,

It's been a bit since my last post but I'm ready to begin posting again.

My time was committed to other activities over the past few years and I didn't have the opportunity to write here. But that commitment is completed and I have more free time to write. I intend to do just that.

So, come back here soon and look for more posts and interesting tidbits of science and engineering.

David

From Best of the Web on the Wall Street Journal Opinion web page

You know how scientists are always doing medical experiments on rodents? It turns out those studies have real-world applications, as this Associated Press story suggests:

A flight crew checking the cabin of a Qantas plane before takeoff found rats in a compartment holding medical equipment, grounding the plane for more than a day, a spokeswoman said Thursday.

Crews did a visual check of the plane Tuesday afternoon and found no more rats or any damage. The rodents had been in a cabinet holding a defibrillator.

It was really cute when, just before applying the electric shock, one of the little fellas squeaked "Clear!"

Found: Missing Mass

A 22-year-old Australian university student has solved a problem which has puzzled astrophysicists for decades, discovering part of the so-called "missing mass" of the universe during her summer break.
Undergraduate Amelia Fraser-McKelvie made the breakthrough during a holiday internship with a team at Monash University's School of Physics, locating the mystery material within vast structures called "filaments of galaxies".
Monash astrophysicist Dr Kevin Pimbblet explained that scientists had previously detected matter that was present in the early history of the universe but that could not now be located.
"There is missing mass, ordinary mass not dark mass ... It's missing to the present day," Pimbblet told AFP.
"We don't know where it went. Now we do know where it went because that's what Amelia found.

Bedbugs: They're Baaack

After a half-century of relative inactivity in the U.S., bedbugs returned in the late 1990s. Nationwide, 95 percent of pest-control companies have treated an infestation in the past year. A decade ago, it was just 22 percent.
In the 1940s and ’50s, liberal use of DDT and other insecticides all but wiped out the pests. Scientists hypothesize that the few that survived proliferated—females can lay up to five eggs a day, and 500 during a lifetime—and passed along pesticide-resistant traits. Millions of bedbug generations later, scientists are finally zeroing in on how, exactly, bedbugs made their comeback.

 Do your best not to get 'em.

By the way, I call this little fellow "Andy."

The Touch of the Master's Hand

I found this poem mentioned the other day and thought it worth posting. Enjoy.

It was battered and scarred,
And the auctioneer thought it
Hardly worth his while
To waste his time on the old violin,
But he held it up with a smile.
"What am I bid, good people", he cried,
"Who starts the bidding for me?"
"One dollar, one dollar, Do I hear two?"
"Two dollars, who makes it three?"
"Three dollars once, three dollars twice, going for three", But, No,
From the room far back a grey haired man
Came forward and picked up the bow,
Then wiping the dust from the old violin
And tightening up the strings,
He played a melody, pure and sweet,
As sweet as the angel sings.
The music ceased and the auctioneer
With a voice that was quiet and low,
Said "What now am I bid for this old violin?"
As he held it aloft with its' bow.
"One thousand, one thousand, Do I hear two?"
"Two thousand, Who makes it three?"
"Three thousand once, three thousand twice,
Going and gone", said he.
The audience cheered,
But some of them cried,
"We just don't understand."
"What changed its' worth?"
Swift came the reply.
"The Touch of the Masters Hand."
And many a man with life out of tune,
All battered with bourbon and gin,
Is auctioned cheap to a thoughtless crowd
Much like that old violin.
A mess of pottage, a glass of wine,
A game and he travels on.
He is going once, he is going twice,
He is going and almost gone.
But the Master comes,
And the foolish crowd never can quite understand,
The worth of a soul and the change that is wrought
By the Touch of the Master's Hand.

---

"The Master's Hand" was written by Myra Brooks Welch.

Physics: Not all it seems to be

The range of phenomena physics has explained is more than impressive; it underlies the whole of modern civilization. Nevertheless, as a physicist travels along his (in this case) career, the hairline cracks in the edifice become more apparent, as does the dirt swept under the rug, the fudges and the wholesale swindles, with the disconcerting result that the totality occasionally appears more like Bruegel’s Tower of Babel as dreamt by a modern slumlord, a ramshackle structure of compartmentalized models soldered together into a skewed heap of explanations as the whole jury-rigged monstrosity tumbles skyward.

A physicist notes the inconsistencies and holes that exist in this study of nature.

Worth reading the whole thing.

Great slide show: How to tear down a nuclear power plant

Click on the link above to see a great slides show of the Fukushima Daiichi nuclear power plant destruction and work to stop the reaction.  

The finger of God

Tuition costs: Dependent on your major

The University of Nebraska--Lincoln is considering charging engineering majors more than, say, English majors.

[T]he proposal is expected to allow UNL, for the first time, to charge more tuition for some undergraduate programs than for others.

It would be a watershed departure from the concept that all Nebraska resident undergraduates should pay the same tuition for their degrees — currently $198.25 per credit hour — no matter what they study.

UNL previously dipped its toe into this water, however, by enacting a $40 per credit hour fee for engineering classes in 2007. Unlike traditional laboratory fees often charged for certain classes, the fee was not directly linked to a specific classroom expense.

At first glance, this almost makes sense. If students major in a field that costs more to teach, then perhaps it makes sense to charge more for the education. Engineering requires more lab work, more equipment, and maybe better teachers. So, perhaps students should pay for that. English, on the other hand, does not require particular facilities, at least not like those of engineering.

But, if you read the article, university costs are not the issue, at least not by major. The thinking is that an engineering student would make more money upon graduation and could therefore be charged more for his education. The proposed scheme is not based on university costs by major, but rather university costs in total and then those costs are skewed based on expected salaries.

Seems to me that an engineer could argue for a lower price if he promised to take a low paying job. Silly, isn't it?

PHD comics: The grand unified theory

While the video from PHD comics doesn't say it explicitly, what we're starting to see is the connection between cosmology and particle physics.

Physics who study the heavens are now interacting with physicists who study the nature of matter. For years, these were separate endeavors with little in common. Now, the scientists are finding common ground.

You heard it here: These collaborations will yield the Grand Unified Theory!

Watch the video, it's worth a few minutes.

Bing versus Google

Earlier today I needed to convert 6-inches to that distance in the units of meters. Search engines are known to perform computations. Here's what Bing provided:

which is terribly wrong. A meter is about 3-feet, so 6-inches, at 1/2-feet is about 1/6-meter or 0.17-meters.

I tried Google:

and got the right answer.

So, what's up with Bing?

Update: If I type in Bing: "6 inches to meters" I do get the right answer. So, what's the difference between "6-inches to meters" and "6 inches to meters" other than the dash after the 6? And, this is cute, for Google, the dash in the search terms, doesn't even return a wrong answer; rather I get no conversion.

Seems weird to me, but maybe I'm missing something.

Here are two graphics from the Wall Street Journal for Saturday, February 12, 2011. They each show top countries for either exports (right) or imports (left) for the United States. Note how nicely the data show current rankings of each country and their historical position in 1990 and 2000.

What is more, the relative volume of each country is porportional to the colored (gray, really) bars.

The graphs are easy to understand and allow the viewer to make comparisons quickly and accurately.

I think this is a marvelous example of how data can be displayed for meaningful interpretations.

Sonar cloak

Illinois professor Nick Fang developed a two-dimensional acoustic cloak that makes objects in the center invisible to sonar and other ultrasound waves.

Cloaking is no longer scientific fiction.

Solar cells on toilet paper

Researchers have developed a working solar cell that can be put on toilet paper.

In the figure here, the solar cell is flexible enough to be folded into an airplane. A video at the link shows a video of the folding and that the cell does produce a current when illuminated.

Atomic weights: Your results may vary

Seems that elements can have a range of atomic weights. Why, well because:

Some elements have more than one stable (nonradioactive) isotope—variants of the same substance, but with different numbers of neutrons in their atomic nuclei that alter the mass. (The element's identity is determined by the number of protons.) In those cases the atomic mass listed on the periodic table has traditionally been defined as an average depending on how common each isotope is in nature. But that average is not the same every place on Earth, or in every situation. Just as radiocarbon dating can place a substance in time, isotopic analysis can also pinpoint its location.

So, now instead of carbon listed as being 12.0107 atomic mass units with a measurement uncertainty of about 0.0008, it has an official atomic weight of [12.0096; 12.0116], where the brackets and semicolon indicate an interval of atomic weights. The interval doesn't reflect an uncertainty in measurement precision but rather a real variation of atomic weight from substance to substance. Only 10 elements will have these new intervals, because the others have at most only one stable isotope or because upper and lower bounds have not been quantified.

Speaking of atomic weights, let me recommend the book The Joy of Chemistry: The Amazing Science of Familiar Things . I should say more later, but for now this is a great book to give a layperson a good overview of chemistry. And it includes experiments you can do at home with common household items.

Invisibility: Now available

The idea of invisibility has always intrigued people from the Invisible Man to stealth airplanes. Now, there's a new cloaking material that can actually hide objects.

Two independent groups have now achieved this feat [of invisibility], by building transparent 'carpet cloaks', made from calcite crystals, that lie over the object to be hidden.

Carpet cloaks render covered objects invisible by bending light rays as they enter the cloak and then when they exit it -- after they have bounced off the hidden object. The light is deviated in such a way that the rays seem to have been reflected directly from the ground underneath the object -- as though the object was not there.

Seems that special crystals can bend the light rays to hide the object.

That's pretty neat.

Cross breeding: Good or Bad or Both?

The headline reads:

"Arctic ice melt may promote cross-breeding, further imperiling endangered animals"

Sound ominous. Danger lurks ahead. Or does it? Within the news article we find this:

[I]nterspecies sex brought on by the melting Arctic ice could lead to the extinction of many endangered Arctic animals, the scientists said in an article published in the journal Nature.

Bad news, indeed.

Although Arctic species rarely interbreed, many are capable of doing so. In 2006, a bear with a patchy white-and-brown coat was shot in the Canadian Arctic. Scientists suspected — and DNA-typing later confirmed — that the animal was a polar-grizzly hybrid, a creature known variously as a "pizzly" or "grolar bear."

And last year, what appeared to be a hybrid of two whales — a bowhead whale and a right whale — was spotted in the Bering Sea.

Well, it's bad news if the cross breeding actually happens, which is rare. But is there a glimmer of good news? Let's see...

Even though hybrids can often be healthier than either of their parents (a phenomenon termed "hybrid vigor" by scientists), this is often a temporary advantage, said coauthor Andrew Whiteley, a conservation geneticist at the University of Massachusetts. The offspring, should the hybrids be fertile, are generally more sickly.

Nope. Hybrids are bad news (save for hybrid cars, I guess).

Wait, not so fast because:

Cross-breeding could also bring positive results, Allendorf said. However, he seconded Kelly's call-to-arms. "The most important point is … collecting the samples now so we can see if this happens in the future. If we don't, in the future we'll have no way of knowing if this is something new or has been there the whole time."

The conclusion: We just don't know if cross-breeding is good or bad. It so rarely happens that scientists have to make a study just to recognize it if it does happen. Forget about studying the effects when cross-breeding does occur. To see the effects, there would have to be lots of it, not just a single example, by the way.

What's most interesting is that cross-breeding, if you believe science, is another term for evolution. Evolution, the story of the genesis of man, and every living organism on our planet, is all about cross-breeding, mutation, survival, and adaptation to the creature's environment. Here's a possible deduction: If cross-breeding is bad, then so must be evolution.

I've always wondered why scientists, who support evolution in theory, why they don't like evolution when they see it. If cross breeding happens it would be golden opportunity to study evolutionary effects. The article hints at that, and only at the end. In reality, if science gets a chance to see this happen, it's a distinct step forward for evolutionary theory.

Poop: It's not all the same

Think your poop (or pooh, as my daughter says) is not worth a thing? Think again.

Go to the link and see that doctors are now transplanting poop with good bacteria into bowels that lack those bacteria. The transplanted poop helps the recipient digest food and cures a possibly deadly form of diarrhea.

So, if you have good poop, you are lucky.

By the way, if you are taking antibiotics, the drugs may not only kill the bacteria that caused your infection, but they can also kill the good bacteria in your colon. The good news is that once you stop taking the antibiotics, the good bacteria show grow again and your colon returns to normal. The bad news is that without those good colon bacteria you could suffer diarrhea. Be sure to ask your doctor about it.