Last week in our discussion on energy, we briefly mentioned that plants are able to convert the sun's energy into plant mass, now let's look at that process, called photosynthesis, in better detail.
Photosynthesis: a Chemical Reaction
The illustration above shows a simplification of what is happening in the natural world involving photosynthesis. We see that the energy from the sun's light (photons) creates a chemical reaction that combines (synthesizes) Carbon dioxide (CO2) and water (H20) to create some form of carbohydrate sugar (CH2O)n and leftover Oxygen (O2).
We list the equation out below, so that you can see the overall process. In our balanced reaction, we see that glucose (C6H12O6) is our representative of a carbohydrate. The important thing here is that the byproducts of this process are extremely important for life on Earth. We have to ingest carbohydrates and oxygen to have energy to live. When our bodies metabolize carbohydrates like glucose, we oxidize sugars to release energy for physiological movement (putting our bodies in motion). The byproduct of this process is CO2 which can then be stored again during photosynthesis.
For a more in depth look at the various types of chemical reactions, check out the Khan Academy video series.
Bringing It All Back Home
Again, what does this have to do with technology? Last time, we saw that when fossilized carbohydrates (hyrdocarbons--CnH(2n+2)) are burned, stored energy is released in the form of heat. That energy is converted into electricity that powers our electrical devices. The photosynthesis of hydrocarbons is the foundation for our electrical power.
For plants to continue to grow, they need balanced access to the key components of photosynthesis: water, sunlight, and Carbon dioxide (other elements like Nitrogen, Phosphorus and Potassium are crucial as well as you shall see later this summer). That balance is the basis of all gardening and agriculture. There are quite a few resources out there to help people find that balance and make their garden the most productive.
Check out these tech resources to balance light and watering in a garden and experience photosynthesis with a deeper understanding:
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The Genesis of Energy on the Sun
Constant complex atomic reactions (nuclear fusion reactions, for extra credit ) are taking place on our sun called Proton-Proton chain reactions. During these reactions, Hydrogen (H) atoms are combined together to create isotopes of Helium (He). See the image below (note: MeV denotes megaelectron volts, a measure of electric energy). The result generates electricity that radiates all the way to Earth. The resulting He isotopes undergo more atomic reactions that involve Beryllium and Lithium, further resulting in a release of energy. The sun's energy is radiated to Earth in the form of electro-magnetism.
In one form or another, the energy that you use comes from the sun's electro-magnetic ray. The food that you eat transforms the sun's energy during photosynthesis and uses it to create mass (e.g. glucose sugar in plants) storing energy that your body uses when you consume and digest your food. The stored energy is also passed to your body when you consume fish and animals that eat plants.
So What Does this Have to do with Technology?
The energy that you use to power devices like your phone, TV, and computer also originates in the sun. Depending upon where you live in the world, your main source of electrical power varies. The main sources of fuel that we use in KY are coal power and natural gas (to power our homes and charge battery powered devices) and petroleum-based gasoline (to power our transportation).
Coal and oil are fossilized versions of plant and animal matter that have undergone extreme heat and pressure for millions of years. Energy in the form of heat is generated when we burn those substances, and we use that to generate electrical energy (for more on this, stay tuned for the post on Copper). So when you use your computer to update your status or play a video game, the energy that is needed to power the device originates in the Hydrogen and Helium reactions on the sun.
Alternative Ways to Harness the Sun's Energy
Since there is a limited amount of fossil fuels left on Earth, scientists have been designing alternative ways to harvest energy from the sun's rays.
The most direct way is through solar-powered energy which can be divided into two categories. First, passive solar energy harnesses just the heat given off from the sun's rays and concentrates that energy to heat water or a greenhouse, etc. Second, scientists use photovoltaic panels to actively transform the energy in the sun's rays into electricity that can be used to power batteries.
Biofuels, like bio diesel are made from low-cost, mass produced sugary plant substances like sugar cane, corn and soy. The sun's energy is stored in the plant's sugars and is distilled into a purified ethanol and used to power machines and automobiles.
Onyx Photovoltaic Estimation is a cool, free app that uses your phone's screen to estimate the amount of power that a photovoltaic panel would generate at any location.
There is a diverse world of alternative energy that is constantly changing due to technological improvements. Here's a cool app to keep you up to date from Renewable Energy World:
(Montage of alternative sources of energy: wind, hydropower, and photovoltaic cells)
Here's an extra credit question for your Teen Summer Reading activity point: how are wind-powered and geothermal electricity also forms of the Sun's energy?
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Next week (June 1) marks the beginning of LFPL's summer reading for kids and teens and the themes for each are science-related: 'Build Your Brain' and 'Reading is Elemental' (respectively). For the entirety of summer reading we are going to look at a variety of science subjects on the teen blog.
For this post we are going as far out as we can possibly go: outer space! Below are several free resources to explore the entire universe:
Resources for Viewing the Night Sky
Google Earth (View>Explore>Sky, Mars, Moon) is a great place to start finding your place in our universe. Users can view pictures and find links to educational resources directly from a 3D map. Look at terrain features for Mars and take a virtual tour of the Apollo landing mission on the moon.
Stellarium will create a realistic view of the night sky in real time for any location on Earth. View constellations from all over the world including many different cultures.
Celestia is a 3D space travel simulator that allows you to travel through their extensive collection of astronomical bodies. View close ups of planets from our solar system and see the interactions of all objects at any point in the universe's history. Both NASA and the European Space Agency (ESA) utilize Celestia for outreach and public education.
WorldWide Telescope was developed by Microsoft and displays a 3D map of the universe taken from the Hubble telescope and nearly a dozen Earth-bound scopes. Download the Windows client or use the browser-based viewer.
Skychart (Cartes du Ciel) lets you turn your computer into a planetarium by mapping and labeling planets, stars and constellations. Overlap photographs to get a closer look at each object.
Aladin is a great tool for researchers that lets you browse through maps, images and dozens of databases of scientific research.
Louisville Astronomical Society - Since 1931, the LAS has been gazing and educating Louisville on our solar system and beyond. They offer monthly public star viewing at their Urban Astronomy Center located at E.P. Tom Saywer Park.
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Some of you may be wondering, 'so how do the pros do it?' This week we will explore that question and give you the tools that you need to make and distribute your own apps.
Now that you have had a bit of time to key around with different programming languages, let's talk about what to do with the skills that you have begun to develop. We will discuss putting your skills to work through computer and mobile app development, but keep in mind that your skills are not limited only to building apps.
Apps are typically self-contained programs that perform a series of tasks related to the same overall function. Apps all have some sort of graphical user interface (GUI)--which is a fancy way of saying the buttons on the screen that the user pushes and the content being displayed.
Operating systems for devices have evolved to include easy access to a marketplace (Apple App Store, Google Play, and the growing Windows Store) rich with free and low-cost apps.
There is currently quite a bit of free software available designed to create apps for a variety of marketplaces, and the software is aimed at professional developers and hobbyists alike.
Though development varies across platforms, the basic concepts are all the same. Each platform has a specific set of tools called a software development kit (SDK) for creating apps. Those tools usually include the following: code editor, interface builder, frameworks (prefab code libraries), code debugger, a simulator that gives you a live test of your app, and some way of measuring how your app performs on a specific device.
To integrate all the tools, programmers utilize an integrated development environment (IDE). It may be helpful to think of the SDK as the tools necessary for building an app, and the IDE functions like the workbench keeping all the tools together and at close reach.
Many apps also require an application programming interface (API) to communicate to an operating system, a database, or some other piece(s) of software.
Below is a list of resources broken down into three popular development platforms Android, iOS, and Windows. Getting started can be a bit tricky, so I have included getting started resources and tutorials. The image above features an infographic detailing the general workflow for building an app. In the tutorials below, you will find similar charts more specific to your needs.
MIT App Inventor - this browser-based IDE runs on Java and is a great to start. Tutorials found here.
Eclipse IDE and Android SDK (Bundle) - a more robust IDE from Eclipse
Building Your First App Tutorial - get started with installing and developing with this tutorial
iOS Developer Center - sign up and start making iPad, iPod and Mac apps
XCode - Apple's IDE and programs are written in Objective-C
ManiacDev - a one-stop for new and professional developers alike with libraries and tutorials
Visual Basic Express - Microsoft's IDE and apps are typically written in C# or C++
SQL Server Express - Microsoft provides you with a free database engine to power your apps
C# Tutorials - to get you started making apps with VS
MDSN - Microsoft's developer network with all the resources you need
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Computer code is all around us and powers every electronic device. As an exercise for those who may have never seen a code before, hit F12 (Internet Explorer), Ctrl+U (Firefox and Chrome), or Cmd+Opt+U (Safari) to see the source code for this webpage.
In an increasingly digital age, learning computer skills is a fundamental necessity, and learning programming is like learning the language. Learning to code has never been easier, and everyday more resources are popping up to teach you how. Currently, there is a high demand for programmers in the job market. This post is dedicated to giving you some of those resources.
Learning to Code
Python is a great place to start programming. This scripting language is expressive and easy to understand. The Python community has come together to create tons of libraries and tutorials to get you started and beyond.
Scratch is a graphic programming language that teaches users the basics of object-oriented programming (OOP). This program was created by MIT and teaches you to create games and animations. Check out Learn Scratch to get started. Teachers interested in including Scratch into curriculum may be pleased to note the 'Lesson Plans' section.
Alice Developed by Carnegie Mellon University, Alice is similar to Scratch and teaches users OOP in a 3D environment through the use of storytelling.
Happy Nerds Want more? Happy Nerds has put together a fairly comprehensive site with more resources for learning to code for various platforms.
SmallBasic is based on Microsoft's .NET programming language. The SmallBasic language editing software (called an integrated development environment, IDE) allows you to break problems down into small steps and test each one along the way, in other words: teaching you how to think like a programmer.
The library has a Code Club for teens who are interested in learning more about coding and meeting others who share the same interest. Click Here for more information.
Click here to check out programming books that the library has in its collection.
Check back next time for part two where we teach you the skills to design and implement your own computer and mobile apps.
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