Friday, September 27, 2013

Kitchen Experiment: Magic Ketchup

What would your little minds think if you told them that they could make a pack of ketchup float and sink at their command while it was sealed inside a one liter bottle? I know, they'd tell you that that was impossible! Lucky for you, you can work with them to prove them wrong and teach them a little about buoyancy and density in the process. Sounds like a win-win to me.

So let's get started! Here's what you'll need:
  • 1 liter plastic bottle
  • Ketchup packet from a fast food restaurant
  • Salt (using Kosher salt will keep your water from become foggy)
Here's what you'll do:
  1. Remove all labels from the plastic bottle and fill it to the top with water.
  2. Add the ketchup pack to the bottle.
  3. If the ketchup packet floats, you're ready to move on to step four. If the ketchup packet doesn't float and starts to sink, skip to step five.
  4. For the floating ketchup packet, simply screw the cap on the bottle and squeeze the sides of the bottle hard. If the ketchup sinks when you squeeze it and floats when you release it, you're in business and ready to show off your magical powers! If it doesn't sink when  you squeeze the bottle, try a different ketchup packet or a mustard or soy sauce packet.
  5. If the ketchup packet sunk when you put it in the bottle, add around 3 tbsp. of salt to the bottle and shake it until the salt dissolves.
  6. Continuing adding sale a few tablespoons at a time until the ketchup packet is just barely floating at the top.
  7. Once it's consistently floating, make sure the bottle is filled to the top with water and then cap it tightly.
  8. Now squeeze the bottle. The magic ketchup should sink when you squeeze the bottle and float up when you release it. If you get really good, you can get it to stop in the middle of the bottle!
So how does it work? What' behind the magic? This entire experiment revolves around two things: buoyancy and density. Buoyancy describes whether objects float or sink and density deals with the amount of mass in an object. Adding salt to the water adjusted its density and got the ketchup packet to float. There is a little bubble inside of the ketchup packet and, since we know bubbles float, this bubble is what keeps the packet from sinking. But when you squeeze the bottle, you put pressure on the packet that results in  the bubble getting smaller and the packet becoming more dense. Thus, it sinks. When you release the pressure the bubble expands, the packet becomes less dense and more buoyant and floats back to the top.

To take this experiment to the next level, try answering these questions:
  1. Do different food packets (ketchup, mustard, soy sauce, relish, mayo, etc.) have the same density?
  2. Does the temperature of the water affect the density of the ketchup packet?
  3. Does the size of the bottle affect how much you have to squeeze to get the packet to sink?

Monday, September 23, 2013

Zombies & STEM: Coming to a Classroom Near You

Photo courtesy of STEM Behind Hollywood
When all else fails, turn to the undead, right? For many teachers trying to boost student interest in STEM, that's exactly right. Thanks to a new program created by the National Academy of Science and Texas Instruments, teachers now have STEM lessons based on zombies, superheroes, space and forensics to present to their middle and high school students. It looks like the undead could be exactly what the suffering subjects need to bring them back to life.

I know what you're thinking: the concept is too far-fetched to work. Maybe not. STEM Behind Hollywood begins their four-part activity with zombies and a hypothetical virus infecting humans. As reported in Forbes last week, in the part of the activity, students can observe a zombie's behavior and deduce that something is wrong with the cerebellum, the part of the brain that controls walking. From there, they can work to understand how a healthy brain works and reverse engineer a zombie brain.

STEM Behind Hollywood is hoping for what all STEM initiatives have hoped for in recent years: a boost in curiosity and excitement about STEM careers. The Department of Labor estimates a 17 percent jump in these fields by 2018, so the fact that teen interest among them is declining is hard to hear.

Nonetheless, the new program seems to be staggering in the right direction. STEM Behind Hollywood is available to teachers and students on a free TI-Nspire software trial, but those who purchased the graphing calculator get the software included at no extra charge. There's also an iPad app.

After going live on Aug. 8, the program has already seen 2,300 downloads and the zombie program is underway to go live later this fall with other developed themes. Texas Instruments is in works to extend the program through 2014.

To read more about the program, what else is our there like it and to see commentary from the president of Texas Instruments and educators implementing STEM Behind Hollywood in their classroom, check out Emily Canal's full report

Wednesday, September 18, 2013

Research Shows Men & Women Do See Things Differently

We all know men and women think differently. Who's judgement is normally better - well, that's up for debate. Nonetheless, recent research suggests that opposite genders really do see things differently - particularly when it comes to colors.  In this month's issue of Headline Discoveries, Joe Giacobello reported that women are better at distinguishing among subtle color differences, while men have greater sensitivity to fine detail and rapidly moving, distant objects.

So let's get down right brainy. Scientists say that there are high concentrations of androgen - the male sex hormone receptors - in the visual cortex of the brain, which is responsible for processing images and explains their sensitivity. 

When it comes to knowing colors, women are who you want to talk to. Isreal Abramov and his research team at CUNY's Brooklyn College conducted a series of visual tests on men and women at both the high school and college level. Among other things, Abramov and his team found that women detected tiny differences between yellows that looked the same to men.

So why do men and women see differently. Can it really all be attributed to hormones in the brain? Not exactly. As stated in Headline Discoveries, a possible, but highly speculative explanation for why the sexes see different is for evolutionary advantages. Back in the hunter-gatherer societies, the males needed to see predators or prey in the distance while women had to detect subtle color differences while scouring for edible plants. An interesting perspective id we do say so ourselves.

To read the full article and to check out follow up questions that can be used for classroom discussion, click here.

Tuesday, September 10, 2013

STEM Interest Among Teens Declining?

CBS News reported yesterday that STEM interest among teens is actually declining. This may seem strange given the economy's current state and the difficulty finding a job many members of the younger generation are facing, but experts at the Partnership for a New American Economy project say that there will be a shortfall of 230,000 qualified advanced-degree STEM workers by 2018.

At a time when most buzz about STEM and the initiatives in place to make it more exciting and relevant in today's schools is positive, this comes as a total downer. As stated in the CBS News report, the Partnership for a New American Economy project's Junior Achievement USA and ING U.S. Foundation teamed up to survey 1,025 teens about their career plans. This is the 12th year that they have conducted the survey, and nearly half of the students ranked STEM and medical-related fields as their top choice. Forty-six percent sounds encouraging, but that is a 15 percent decline from the 2012 survey, when 61 percent of students considered STEM their top choice.

So what's happening? Where is the disconnect between efforts being made to make STEM the go-to choice for student interest and actual student interest? Are U.S. students just simply more interested in other fields than they are STEM fields?

As CBS explains, regardless of whether there is a shortage, the first step in developing a deeper American talent pool is bolstering student interest in STEM fields. The question now: how are we going to do that?

It appears we may to go back to the drawing board, reevaluate current initiatives and efforts and implement some changes.

Check out the full CBS News report for detailed commentary on the topic and more information.

Monday, September 9, 2013

Telling Whiskeys Apart Scientifically

PopSci reported earlier today that food science researchers at the University of California at Davis have been studying different whiskies to determine whether they can tell them apart, scientifically. Though determining the difference between a Scotch and Irish whiskey isn't as easy as determining the difference between Scottish and American English accents, the university's research director Thomas Collins explained today at the American Chemical Society's annual meeting that they're well on their way.

As reported by PopSci, Collins said, "Right now, we can do a pretty good job of separating, for example, Scotch whiskies from bourbons and other American whiskeys and also Canadian and Irish whiskeys. When you narrow it down into whiskeys from a particular region, the process gets a little more difficult because they're more similar to each other," Collins explained during the talk which was recorded by the American Chemical Society

In the future, Collins hopes that he and his team can relay to distillers best practices that make for the best whiskey. Right now, distinguishing one whiskey from another is all about chemical reactions! The major chemicals that Collins' team uses to tell whiskeys apart include some that come from grain, some from the fermentation process and some from the wood barrel in which whiskey ages.

To find out how many concentrated chemicals are used to determine any two given whiskeys from one another or to figure out how many whiskeys Collins and his team analyzed, read the full PopSci report.

Friday, September 6, 2013

'Science' Moving on Up as Most Important School Subject

There's good news for all you science lovers out there: a new Gallup poll finds that three times as many Americans now say science is the most valuable school subject (MVS) than did so more than a decade ago. As reported by LiveScience on Mashable, science bumped out history for the third spot behind No. 1 math and No. 2 language arts as the school subject that has been most valuable to Americans' lives. This is exciting news!

In the new Gallup poll conducted earlier this month (Aug. 7-11), 12 percent of respondents mentioned "science/physics/biology" as the MVS. In the same poll conducted in 2002, a mere 4 percent felt the same way.

Interestingly enough, it appears that education and gender played a part in affecting people's answers. Respondents who had high levels of education were less likely to choose math as the MVS. Likewise, men were more apt than women to give math the top spot - 40 percent versus 28 percent, respectively. Men were also more likely than women to choose science as most valuable.

The poll results are based on phone interviews with a random sample of 2,059 Americans, ages 18 and over, from all 50 U.S. states and Washington D.C. Results were weighted so they were nationally representative. Further, respondents were allowed to look back at their entire education when gauging the value of subjects, including elementary all the way through postgraduate school.

For more information on the poll results and to see specific excerpts and statements from the Galllup statement, check out the Mashable article. The importance of science is making a name for itself and we're moving in the right direction!

Tuesday, September 3, 2013

Pass Rate on Math & Science AP Tests Rise

In an article published by McClatchy last week, Renee Schoof reported that the pass rate on rigorous Advanced Placement tests went up by 72 percent last year at high schools that took part in a National Math and Science Initiative program that trains teachers and gives students extra help on Saturdays.

The proof is in the puddin'. That being said, with statistics like the one above, what could possibly be argued about the initiative other than it's working for U.S. students? The article elaborates and states that the program has been especially helpful in boosting success for girls and minority students - groups that initiative CEO Sara Martinez Tucker says have been under-represented in advanced math and science classes.

Supporters, participants and teachers involved in the initiative's training says that the program raises expectations. It looks as though when teachers are stepping up their game in the classroom, students feel inclined to do the same. Why the program hasn't made its way on to more campuses is practically shocking.

Last year. the initiative was in place in 462 schools in 18 states, about two percent of the nation's schools. It will be added in schools in Mississippi, Tennessee, Pennsylvania and Arkansas this year. Each participating school receives the extra support for three years at a cost of $500,000 per school. Some districts receive funding as a grant from the group, which gets support from foundations, corporations and the U.S. Department of Education. 

The program began five years ago and has improved the pass rates on the AP tests every year! Read more about the program and how its pass rates on math and science AP exams stack up against national averages in Schoof's full report on McClatchy.