Strategies to ensure learning

I find teaching basic science to non-science majors challenging, which leads to my trying new approaches.

In a sense, our Sunday planetarium shows throughout the school year have a similar audience, beginners who are interested in new ideas, but not being overwhelmed.

In teaching today’s students, many have a bottom line mentality (What’s in it for me?) and often are so overscheduled that they cut corners with their study time.

So it’s important to develop strategies that insure the most learning in the scheduled class time.

One approach is hand-on, where students work with the objects, measuring devices and verify laws or principles which they accept more readily as it’s based on their experience.

Another approach is “discovery” where students are given a minimum of directions, have to come up their own strategies of what to do and then draw conclusions on what they have discovered.

The problem with both above strategies is they limit the ideas and concepts per hour of class.

Both approaches de-emphasize reading and listening as a way to learning.

The “discovery” method is how most students learn how to play video games; those with a lot of confidence in this approach can learn quickly, while others are puzzled and give up.

But there is a great deal of difference between mastering a video game and understanding the functions of organs in a human body.

So there are plenty of reasons not to abandon traditional teaching; greater efficiency in covering a greater variety of ideas in the time allotted, less dependence on providing specialized equipment and space for the students to use during class time and more adaptable to larger class sizes.

One of the best ways to help students retain new ideas is through models (relating the size, time durations of objects, events with familiar objects and time events).

If students reflect on these models after class, then there can be some gain in learning for motivated students.

One model to convey the relative size of parts of an atom is the baseball model.

An atom has two main regions; the electron cloud that makes up nearly all of the space in an atom and the tiny nucleus that contains nearly all the mass (in protons and neutrons) of the atom and whose positive charges keep the electrons in the electron cloud (by attraction of unlike charges).

If we could enlarge the atomic nucleus to the size of a baseball, then the electron cloud would extend out several tenths of a mile beyond the baseball stadium, where the farthest parking spaces (for fans’ cars) are found.

Another model illustrates the size of our solar system (where the planets, bigger asteroids and Kuiper Belt objects all move around the sun).

If we could shrink our solar system into a coffee cup, then our galaxy would stretch across the North American continent.

Another model is the Cosmic Calendar devised by the late Carl Sagan to help grasp the timing of key events in our universe’s development.

If we could compress the entire history of our universe into a 12 month calendar, then on what date would the Earth form?

On what date did the dinosaurs rule the Earth? When did Homo Sapiens Sapiens (modern humans) first arise?

Since the universe is 13.7 billion years, each month correspond to 1 and 1/7 billion years, each day about 38 million years, and each hour about 1.6 million years.

On the Cosmic Calendar, the Earth and sun formed in early September, the Dinosaurs ruled Earth as late as the early morning hours of Dec. 30 and modern humans appeared at 11:57 p.m. on New Year’s Eve (Dec. 31).

Moon and Friday the 13th

Tonight the evening moon appears close to the bright star Regulus (marks the heart of Leo, the Lion).

A little to the left of Regulus is the planet Saturn, shining steadily.

On Monday and Tuesday evenings, the moon appears half full, offering the best views of its craters and mountains through binoculars and telescopes.

On Thursday night, the moon appears near Spica, Virgo’s brightest star.

This Friday is the only time this year we have a Friday the 13th.

We can have up to three Friday the 13ths in a year (14 or 15 years in a century).

The 13th of a month falls on Friday more often than any other day of the week, due to the first of a month occurring on a Sunday more often than any other day of the week.

Correction to last week’s column: The amount of petroleum humans have extracted up to now is a trillion barrels; a trillion is a million times a million with 12 zeroes. To the British, a billion is a million x a million, not the trillion that we in America use.

Call Bob Doyle at (301) 687-7799 to request a free planetarium/Exploratorium bookmark (shows and tours resume on Sept. 7).