Tag Archives: Sun

3 Things You Need to Know About the Eclipse

You may have heard about the solar eclipse that will be happening on August 21st. For just a few minutes, the moon will be in front of the sun, blocking its light and casting a shadow over parts of the earth. What do you need to know about the solar eclipse?

  1. This is rare

Solar eclipses occur on the Earth about once every 18 months. That might actually sound pretty frequent, but there is also a lot of Earth. The shadow path from an eclipse is about 70 miles wide, so if you were to camp out in a lawn chair and wait from one eclipse to another, it would take (on average) about 360 years! This technique for observing this phenomenon is not recommended.

However, if you are captivated by the idea of seeing a solar eclipse, it doesn’t have to be a once in a lifetime event if you are willing to do some travelling. The motions of the earth and the moon are very predictable, so scientists have already figured out when (and where) eclipses will be for a very long time. The map below is an example of these predictions. As you can see, North America will see its next solar eclipse in 2024!

Eclipse    2. It’s not totally happening everywhere

This very much goes along with point number one. This particular eclipse will be sweeping the nation from Oregon to North Carolina. That path, known as the path of totality, is where the sun will appear to be completely covered but the moon. However, that doesn’t mean that if you are in another location like us, you’re totally out of luck.

Eclipse 1

Other areas will be experiencing a partial eclipse during this time. This awesome app will show you what you can expect from the eclipse in your location. At AstroCamp, we will definitely be checking out the eclipse even though we are almost 700 miles from the path. However, it’s important to have proper protections or techniques when viewing the eclipse, which brings us to point number 3.

The app linked above also has the time of the eclipse. At its longest, the eclipse will last 7 minutes, so don’t be late!

    3.  The dangers of staring at the sun

You have probably heard that it’s not a good idea to stare at the sun. As you have probably noticed, the sun is very bright. Having the moon block out half or more of the sun may seem like it makes it safe to look at, but it doesn’t!

Eclipse glasses are a piece of safety equipment used to view the sun. These glasses block out 99.997% of the light from the sun to make it comfortable and safe to view. Wearing these glasses around in a brightly lit room, the wearer literally can’t see anything. They are close to being complete blindfolds, until the sun comes into view. This cannot be emphasized enough: without these glasses, you should not be looking at the sun!

If you don’t have these glasses, you are not out of ways to view the eclipse. Through a very simple crafts project, you can view a projection of the eclipse on the ground or another screen. All it takes is getting a piece of paper (construction paper works well as its a bit sturdier) and poking a hole through the center. Then, by angling the paper towards the sun and looking at the small point of light in the center, you can view a projection of what is going on with the sun and the moon.

Here in Idyllwild, the sun will be 62% covered. However, due to the sun’s immense brightness, it won’t look dark outside. In fact, if you were to look at the sun (DON’T), it wouldn’t look any different. If you want to see what is happening with the sun, strangely, the best thing to do is look down. Try to find and look at the shadows from any small openings, like a hole made with your fingers, or those made from the leaves on a tree, you will notice something interesting: All of the shadows have little eclipses in them!

Eclipse 3

Survival Skills: Science Style

Light travels incredibly fast. In a vacuum, it speeds along at nearly six trillion miles per hour. Ever notice how your feet look distorted when you wade in the water, or how a straw seems to be cut in half where it enters a full glass? When light travels through a medium, it slows down. When a collection of light rays crosses from one material to another (from water into air, for instance), the change in speed warps the image.

StrawSmall

This warping effect can appear random, as in the case of rippling water, or it can be well-organized. We often take advantage of light’s transition between air and glass, for example, to bend images in a useful way. A magnifying glass works by taking a small image and spreading it out over a large area. What happens when you use it backwards– put a large cross-section of light in, then focus it down to a tiny point?

SunBurn

Try this with the sun as a light source on a warm day, and you’ll find that the visible light and heat at the focus point are intense enough to burn wood!

Written By: Caela Barry

Earth Day & the Greenhouse Effect

Since today, April 22nd, is Earth Day we decided to take a look at one of the most important phenomena on our planet: the greenhouse effect. The greenhouse effect is when some material – like glass, plastic, or the gases in our atmosphere – allows visible light to pass through it easily but traps heat. Without the greenhouse effect, the average temperature on Earth would be a chilly -2℉, but with its help we can instead enjoy a comfortable 57℉. Too much greenhouse effect, on the other hand, and a planet could end up like Venus, the surface of which can reach a whopping 800 degrees!

 Greenhouse Effect diagram

In the video, we harness the greenhouse effect and the power of our sun to heat water. The black background of the solar water heater is very good at absorbing the energy contained in the sunlight. It then re-emits this energy as infrared radiation, or heat. This heat becomes trapped by the plastic cover, warming the interior of the solar heater. When cold water is passed through the pipe it collects the heat that has been gathered from the sun, emerging from the other side 70℉  warmer than it went in! 

Below you can see the same thing as in the video, but in infrared! Infrared light allows us to see the temperature of everyday objects, instead of their normal color. Then, the infrared camera produces what is known as a false color image, changing it back to visible light. Since we can’t see in the infrared, it wouldn’t do any good without this step. At the bottom, it shows which temperatures correspond to which colors. This is constantly updating depending on the hottest and coldest objects in view.

Greeenhouse in Infrared

We can see another example of this effect using our solar ovens.The only difference between the two is that one of them has the cover open. The oven without the cover has only heated up to about 140℉, while the covered oven is able to achieve a temperature of 280℉. When it comes to keeping you warm, or even sun baked treats, the greenhouse effect has got you covered!

Ovens Arrows

Sources and Additional Information:

Earth temperature with and w/o greenhouse effect: Intergovernmental Panel on Climate Change Fourth Assessment Report. Chapter 1: Historical overview of climate change science – http://www.ipcc.ch/pdf/assessment-report/ar4/wg1/ar4-wg1-chapter1.pdf
Greenhouse effect image: http://www.globaled.uconn.edu/teachers_climate/images/greenhouse_effect.jpg

WELCOME TO OUR ASTROCAMP BLOG

We would like to thank you for visiting our blog. AstroCamp is a hands-on physical science program with an emphasis on astronomy and space exploration. Our classes and activities are designed to inspire students toward future success in their academic and personal pursuits. This blog is intended to provide you with up-to-date news and information about our camp programs, as well as current science and astronomical happenings. This blog has been created by our staff who have at least a Bachelors Degree in Physics or Astronomy, however it is not uncommon for them to have a Masters Degree or PhD. We encourage you to also follow us on Facebook, Instagram, Google+, Twitter, and Vine to see even more of our interesting science, space and astronomy information. Feel free to leave comments, questions, or share our blog with others. Please visit www.astrocampschool.org for additional information. Happy Reading!

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