# Newton’s Law of Cooling

One of Newton’s famous contributions to physics was his work in thermodynamics — the study of heat and energy flow. He developed a physical law that showed the proportional relationship between heat loss and the temperature difference between an object and its surroundings: Newton’s Law of Cooling. Despite its name, it can be used to show how an object will cool or heat in its surrounding.

It’s worth mentioning that heat and temperature are two separate — but related — values. Heat is a measurement of the total kinetic and potential energy stored in the molecules of an object, while temperature is a measurement of the average kinetic energy. Heat depends on the speed, the number, and the type of molecules. So while a cup of coffee may have a higher temperature than something like an iceberg, the iceberg is made up of so many molecules that it has more heat, and thus more energy.

Nevertheless, heat and temperature are related. As an object gains heat, its temperature will also increase. When talking about Newton’s Law of Cooling, it can actually be rearranged to create an equation to show the temperature as a function of time.

Where Ts is the surrounding temperature, T0 is the initial temperature of the object, and k is a constant.

This equation looks pretty confusing, but all it essentially means is the temperature of an object will decay (or increase) to match the temperature of its surroundings. The change will happen quickly at first, but it will slow down as time goes on.

This theory allows scientists and engineers to correctly predict how certain materials will behave in different conditions. These types of calculations are done for anything from insulated coffee mugs to space rockets. They can then safely manufacture these to prevent any damage or harm.

Written By: Scott Yarbrough

# What is a CCD Telescope?

During our Space Night, you’ll eventually find yourself in an area with tools that allow you to look at the beautiful night sky. Each station has its own set of binoculars, Dobsonian telescope, and either a Celestron or Meade telescope mounted on an electric motor. But in the center of the telescope area sits another type of telescope. This telescope has the ability to take images of objects that are too dim for our eyes to see. This is our CCD telescope!

At first glance, there’s not much different about it. It’s a little bigger, its mount is different than the others, but instead of an eyepiece attached to the end of it, there is a special camera mounted to the front. This camera has computer cables that allow it to be controlled by a special laptop, and it can take photos of very dim space objects.

The CCD chip is a very sensitive device. It can count individual photons (particles of light) as they hit the sensor and then convert them into electrons. The more a particular area is struck by photons, the more electrons it will generate. This electrical signal is what gives us our image.

While looking through a telescope with an eyepiece, our eyeballs are doing the equivalent of taking many images every second. The telescope helps us see dimmer objects than we’d normally perceive, but there’s nothing we can do about taking longer exposures with our eyes. The CCD camera changes that. It can keep its sensors on for a long amount of time, gathering and collecting light for thousands of times greater than our eyes can.

The CCD onboard the Kepler Space Telescope. Credit: NASA

These telescopes are used all around the world by amateur and professional astronomers. They can also be found beyond our planet in space telescopes like Hubble or Kepler! These devices allow us to view faraway objects and help us unravel the mysteries of our universe.

Written By: Scott Yarbrough

# Oxidizing Metals vs Organic Materials

When certain metals reach a high enough temperature, they can catch fire. What’s happening here is similar to what happens when wood ignites. The material captures oxygen from the surrounding air and binds it in a reaction that gives off heat and light. This reaction is the fire that we see.

We define “organic material” as any carbon-based object. It doesn’t necessarily need to be alive to be organic, but many organic compounds are alive, or were at some point. When an organic compound like wood burns, the oxygen in the air is bound to the carbon atoms found within the material. This releases carbon dioxide and carbon monoxide. Additionally, elements like hydrogen will also react with the oxygen, forming water vapor. These gases are what cause the smoke to rise from the wood. Small bits of unburnable material are left as ashes.

In pure metals, however, there are no carbon atoms. As the metal heats up and oxidizes, the oxygen is mostly being bound directly to the metal itself. In fact, this means that the oxidized metal will weigh more than the starting metal. Since very little material is being emitted as smoke or ash, the majority of the metal is being converted to its oxidized form, seen in the equation below.

2 Fe(s) + O2(g) —> 2 FeO(s)

These reactions don’t have to happen quickly, though. Oxidation happens at slow speeds in metals and organic materials. If you’ve ever seen rust forming on the surface of iron, that’s oxidation  — producing the same material as when it’s burned. Composting — the act of letting organic material decompose to create fertilizer — is also a form of slow oxidation. As bacteria breaks down the organic material, heat and energy are released as the material absorbs oxygen.

These examples of slower oxidation are found all around us. Even though they may not be as dramatic as a fire, they still play an important role in our universe.

Written By: Scott Yarbrough

### 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!