Category: science in public

Sunrise, Sunset, and Moving Swiftly Through the Days

January 31, 2010

A new month in a new year and it’s gone by far too quickly. I thought I’d close out the lengthening days of January by sharing some interesting sources of information. The pick for today is the NOAA Sunrise/Sunset Calculator, developed by some talented former colleagues. It is a resource used by people in all walks of life—from scientists and sky watchers to film makers and event planners—and a great way to explore what’s going on in terms of the number of hours of daylight received in a day.

According to the calculator, at 40 degrees latitude in the approximate middle of the mountain time zone, the apparent sunrise on January 31 is 7:09 a.m. and apparent sunset is 5:19 p.m. What’s “apparent” sunrise, you ask? Let’s use this graphic from the solar calculator Help Guide (really guys, great work putting this resource together!) to illustrate:

schematic showing reflection of visible light by atmosphere
Gases in Earth\’s atmosphere refract visible light from the Sun.

Earth’s atmosphere refracts (or bends) incoming light from the Sun. Because of that refraction, we see the sun “rise” shortly before it actually crosses the horizon. Likewise, we see the setting sun for a short time after the sun has actually “sunk” below the horizon at the end of a day. (If this part sounds like desperation from a person eager for any at all additional daylight, well, consider that mid-latitude winters sometimes just seem…long.) Apparent sunrise and sunset times are different than actual sunrise and sunset times, adding just that little bit of additional time to the number of hours of daylight in a day.

The nice thing about the end of January sunrise and sunset times is how they differ from the dark, dark days of December. Did we talk about the solstice on December 21? On that day, the apparent sunrise was at 7:18 a.m. but the sun was gone a full 40 minutes earlier, at 4:39 p.m. For those of us desperate enough to grab those few minutes based on apparent sunrise and sunset, 40 minutes seems quite a cause for celebration, or at least acknowledgment. Go ahead, play with sunrise and sunset times for your location, and check out what happens at the summer solstice too.

Earthquake Education

January 13, 2010

First, if you’re inspired to help those in Haiti, please see this list of organizations compiled by CBS News. This tragedy teaches us lots of things, about life, and the human condition, and vulnerability, especially as it relates to this planet on which we live. And sticking with the idea of linking teachable moments with topics on this site, today let’s consider plate tectonics and its relation to where and how people live.

Plate tectonics refers to the movement of Earth’s crustal plates. Earth’s surface, or lithosphere, is composed of about 12 of these plates, which can move next to, over, under, toward, and away from each other.

graphic showing tectonic plates and boundaries

All of these tectonic movements can cause earthquakes or volcanoes, and the infamous Ring of Fire is marked by the boundaries of the Pacific Plate with the North American, Nazca, Australian, Philippine, and Eurasian plates.

The January 12, 2010, earthquake in Haiti resulted from a break on the southern fault zone between the Caribbean plate and the Gonave microplate. While this area is not one of the more active earthquake zones on the planet, major earthquakes have occurred, often with devastating results. The January 12 event occurred on a “strike-slip” fault—one in which adjacent plates are moving against each other. Strike-slip events tend to be shallow and can therefore produce violent shaking over a sizeable area. According to the U.S. Geologic Survey (USGS), the magnitude 7.0 earthquake caused strong and very strong shaking in Haiti, with moderate shaking in the Dominican Republic and weak or light shaking as far away as the Bahamas.

plot of shaking intensities for January 12 earthquake

Tuesday’s earthquake reminds us of something we sometimes forget: that oftentimes the regions we don’t consider vulnerable to earthquakes are indeed places where major destruction and loss of life can occur. Where could the next big one happen? Scientists have identified several places where geology and population combine with potentially dangerous results. A few of them are viewable here.

Fun with Snow

December 15, 2009
snowflake stamps from the United States Postal Service
The United States Postal Service released these snowflake stamps in October 2006.

Do you remember the year the United States Postal Service offered stamps with photos of lovely snowflakes? Those were by far my favorite holiday stamps to date, and one of the things I liked best was that USPS included some information about the images. For example, the stamps show three stellar dendrites and a sectored plate, each having its own unique characteristics, like every single snowflake out there. Nature. Is. Cool. You can view the original images, and learn more about the uniqueness of snowflakes and how to identify snowflake types, at this site by Cal Tech’s Kenneth Libbrecht, who photographed the snowflakes.

With the Northern Hemisphere winter solstice occurring in less than a week, I thought it would be a good time to pass along some experiments to let you have fun with snow. Check out this article by NCAR scientist Peggy LeMone and this one also. Ideas for a science fair project, perhaps?

And if you’re in the U.S. and want to report your snow (and other precipitation) measurements, check out the Community Collaborative Rain, Snow, and Hail Network (CoCoRAHS) —it’s a great citizen science opportunity.

The State of Science Knowledge, and Water on Earth & Moon

November 20, 2009

demographic breakdown of science knowledge survey results

This Science Knowledge Quiz from the Pew Research Center first entered my radar when Ian over at AstroBlog posted about it back in August. Even then, I knew it was destined to become blog fodder here at ScienceSpeak, and at last I am returning to the topic.

Ian’s correct: the questions are quite easy and the very large percentage of people who couldn’t correctly answer them is somewhat disheartening. However, because keeping up with and blogging on the science literacy topic can oftentimes be disheartening, I’m going to try to look at the bright side here. About 44% of people answered at least 9 of the 12 questions correctly, and that includes quiz takers with a high school education or less. I suppose it’s difficult to consider less than half of population receiving a passing grade as something other than bleak, but when it comes to recent scientific advances, news, discoveries, etc., sometimes you have to wonder, how *would* people know? It’s not covered in the media, or only very superficially covered in the media, and that’s a whole other topic (one covered very well in the book Unscientific America. Indeed, it’s almost enough to make a person not want to blog.)

So where are people supposed to learn about science? Well, in school, of course, but what if it’s been decades since you were a student? And what if you didn’t pay attention in science class? There’s this idea that if we keep putting the information out there, people will find it somehow. But those of us embarking on this experiment can testify that only people looking for the information will find it.

If you take the quiz on the Pew site, you can see the demographic breakdown of results, by question. There’s a clear age differential for some of them. Only 30% of people over age 65 correctly answered that an electron is smaller than an atom, for example. (Of course, electrons were discovered in the late 1800s, so age can’t be considered an excuse.) Just over 50% of all quiz takers correctly identified how stem cells differ from other cells, which is sad considering that stem cell research is something that has been politicized and so is often in the news, but again, how often do news anchors or politicians or even the researchers themselves actually address what a stem cell is?

Oh, it’s difficult. Maybe the only bright side is that there’s so much room for improvement. So I am going to begin posting scientific facts for my readership, and perhaps those who seek out the information will find it. Then, if they are someday surveyed on science knowledge by the Pew Research Center, they’ll perhaps be able to earn a passing score. If nothing else, maybe they’ll get darn good at getting that green pie in Trivial Pursuit.

For today’s simple science lesson, in honor of water just having been discovered on the Moon (yes, make a note of that, people!), let’s learn about water and the planet Earth. You can find some useful materials here and here. And if you want to learn more about how valuable water on Earth is becoming, look here.