Johnson County Science Cafe

Dark Matter, Dark Energy, and the Accelerating Universe

Speakers: Bharat Ratra, cosmologist in the KSU physics department
Date: April 9, 2013

Time: 6:30 pm

Location: Coaches Bar and Grill, 9089 W. 135th Street, one block west of 135th and Antioch, south side of 135th St.

Dark energy is the leading candidate for the mechanism that is responsible for causing the accelerating expansion of the universe. (The observational discovery of the accelerating
cosmological expansion was recently honored by the award of a Nobel Prize.) I will describe the data which persuade cosmologists that (as yet undetected) dark energy and dark matter are by far the main components of the energy budget of the universe at the present time.

Dr. Ratra’s area of research is Cosmology and Astroparticle Physics. He develops models for the large-scale matter and radiation distributions in the universe, testing these models by comparing their predictions to observational data, including the uneven distribution of the cosmic microwave background radiation, and the mass correlation function. 

For more information:

Summer Modeling Workshop Opportunity

Subject: National Science Education Leadership Association / 50 Modeling Workshops nationwide this summer: HS physics, chemistry, biology
Date: Fri, 15 Mar 2013 09:08:37 -0700
NSELA colleagues:
Please forward this to your high school science teachers, and also to listservs for science teachers in your state or area. — Jane Jackson, Arizona State University, Tempe.

Fifty Modeling Workshops in high school physics, chemistry,  physical science, and biology will be offered in summer 2013, in many states. Modeling Workshops are peer-led. Modeling Instruction is designated by the U.S. Department of Education as an Exemplary K-12 science program.

Some sites offer stipends, usually for in-state teachers.  Graduate credit is available at some sites. Pre-service teachers and TYC faculty are welcome too.

Biology Modeling Workshops that are open to teachers nationwide will be in
* Dallas Texas (June 5-21),
* near Chicago (June 17-28),
* southern New Jersey near Philadelphia PA (July 29-Aug. 16).

For information:
Most workshops are described at .

* Modeling Instruction is of documented success in physics and chemistry. See also two accounts of success in 8th grade math and 9th grade integrated physics/algebra in high-poverty urban schools, at

* The pcb sequence shows even better success than the bcp sequence; see Tim Burgess’ collection of research evidences at

Johnson County Science Cafe

Comets Big and Small

Speakers: Fred Bruenjes, Fred is an electrical engineer by day and amateur astronomer by night.
Date: March 19, 2013

Time: 6:30 pm

Location: Coaches Bar and Grill, 9089 W. 135th Street, one block west of 135th and Antioch, south side of 135th St.

Fred Bruenjes will present a talk about comets, their makeup, how
they alter history, and how we can observe them. He will share the story of how
he found his own comet (read about it at, and how we can observe the bright comets coming this year.

Following the talk and the skies cooperating, we will move upstairs to the roof and look at the currently visible comet, Comet Pan-Starrs.

Fred’s interest in astronomy was sparked when Halley’s Comet returned in 1986. As
an accomplished astrophotographer, Fred’s images have been published by
Astronomy Magazine, Sky & Telescope, Disney, APOD, Reuters, and many others. He
founded Moonglow Technologies, an electronics firm dedicated to developing
cutting edge astronomical products for the professional and amateur community.
In 2009 Fred began a systematic search for comets in the northern hemisphere in
his spare time in cooperation with the Stargarden Foundation. In 2012 he
discovered comet C/2012 C2 (BRUENJES).

For more information:

Inquiry in Action – DNA Isolation

I know that many of us are familiar with isolating DNA using a salt solution and an alcohol layer.  The most common procedure uses strawberries, and we see oodles (a technical term) of DNA.  The students can even go so far as to pull the precipitated DNA out of solution and place it in a necklace.  The whole procedure is a cool way to introduce DNA, but I would urge everyone to consider looking to this lab with an inquiry eye.

I asked my students, if that procedure can isolate DNA… then what has DNA?  We have a short list of various samples:  animal cells (we used human buccal cells but chicken liver also works), plant cells (strawberries), fungus cells (mushrooms), and a soil sample.  We attempted to isolate DNA from each sample and answered our question.  Still not a terribly remarkable lab.

What made this experience post-worthy was what the students did from here.  A group of boys in my last hour turned to me with about five minutes left in their class period with a revelation, “Mr. Ralph, this means we need to run a sample of bacteria to confirm our hypothesis.”  They had hypothesized that all cells have DNA.  I was caught so off-guard that I had to take a moment to formulate an answer.  They weren’t even doing a lab report for this lab, and their notes were only for use on the quiz.  I told them yes, that is the next reasonable step.  They asked if it was even possible, and I quickly described how they could grow bacteria in a broth culture.  They then could centrifuge the sample and attempt DNA isolation from the pellet.  They wanted to know if they could actually do it, and they would even come in outside of class.  I couldn’t believe it.  Of course you can!

I had no idea if it would work or not, but what the heck.  The students were true to their word and came in before school three days in a row to get their results.  Sure enough, it worked like a charm and their hypothesis was confirmed.  I plan to make this a “scripted” extension for the lab next year.  As so often happens, students come up with some of the best ideas when given the chance.