The angle that the reflected light makes with a line perpendicular to to the mirror is always equal to the angle of the incident ray for a plane (2-dimensional) surface.
We’re going to play with how light reflects off surfaces. At what angle does the light get reflected? This experiment will show you how to measure it.
This simple activity has surprising results! We’re going to bend light using plain water. Light bends when it travels from one medium to another, like going from air to a window, or from a window to water. Each time it travels to a new medium, it bends, or refracts. When light refracts, it changes speed and wavelength, which means it also changes direction.
Most people know not to shine lasers into sensitive places like eyeballs, but very few people can tell one laser from another. The truth is that not ALL lasers are dangerous, and there are different classifications of lasers. The most important information you need about laser safety is printed right on the laser itself.
Basic Laser Guidelines for Safety:
1. Never look directly at the beam source, or aperture
2. Never point the beam at another person
3. Always be mindful of where a “bouncing beam” will land due to reflection
This set of experiments will show you the properties of light, including optics, diffraction, transmission, reflection, wavelength, intensity, and so much more. You’ll discover how light travels in a straight line, how light can turn a corner, split into several beams, and why objects can appear dark even when light is shining right on them.
If you hate long division like I do, then this lesson will be very useful in showing you how to make the most out of your division tasks without losing sleep over it. It's easy, quick, and a whole lot of fun! If you haven’t already mastered your multiplication tables, make sure you have one handy to refer to as you go along.
If you don’t have the patience to do multiplication on paper for every single math problem that comes your way, then you’ll really enjoy this math lesson! You’ll be able to multiply one and two digit numbers in your head, which you’ll be able to use when checking your answers on a math test, or just whenever you need to multiply something quickly when paper’s not around.
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In school, you are trained to solve math problems on paper, at a desk. The problem with that is, for most people, math problems don’t usually come with a desk or a pencil. They pop up in the checkout line when paying for groceries, figuring out your gas mileage at the pump, or when counting calories at a restaurant. Learning how to solve math problems in your head is an essential everyday life skill, especially if you don’t want to be ripped off in money transactions.
This math lesson is so easy that one night, I wound up showing it to everyone in the pizza restaurant. Well, everyone who would listen, anyway. We were scribbling down the answers right on the pizza boxes with such excitement that I couldn’t help it – I started laughing right out loud about how excited everyone was about math - especially on a Saturday night.
Here is the list of materials for doing ALL the experiments in the entire Unit 20 section on atmosphere and geology.
How many of these items do you already have? We’ve tried to keep it simple for you by making the majority of the items things most people have within reach (both physically and budget-wise), so you can pick and choose the experiments that fit with what you’d like to do. Since the lessons for Earth Science require very different materials, we’ve keep them in two separate itemized lists for you.
Here’s how to use this shopping list: First, look over the list and circle the items you already have on hand. Browse the experiments and note which ones use the materials you already have. Those are the experiments you can start with. After working through the experiments, your child might want to expand and do more activities. Make a note of the materials and put them on your next shopping trip OR order them online using the links provided below.
We’ve tried to keep it simple for you by making the majority of the items things most people have within reach (both physically and budget-wise). Are you ready?
Shopping List for Unit 20: Earth Science Click here for Shopping List for Unit 20.
NOTE: Radio Shack part numbers have been replaced. Click here for full chart.
Lesson 1: Atmosphere
Lesson 2: Geology
Mineral & Rock Samples (These are the ones we used in the videos, but if you have your own collection, use those!)
Supplies:
We’re about to dive into a comprehensive course that teaches the big ideas behind rocks, minerals, and the science of geology. Soon you’ll learn how to burn coal, fluoresce minerals, chemically react rocks, streak powders, scratch glass, and play with atomic bonds as they learn how to be a real field geologist.
Today, you’ll learn what to look for in a broken mineral. There are different names for the types of breaks that a mineral can experience. You’ll need to ask a few important questions during your investigation, like, “What is the difference between mineral cleavage and fracture?”
Your goal is to identify samples according to their reactivity with acid. Minerals that react are called chemical rocks, and minerals that don’t are called clastic rocks. Some chemical rocks contain carbonate minerals, like limestone, dolomite, and marble which react with the acid.
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Clastic rocks come in very different shapes and sizes, but they all have a few characteristics in common. A clast is a grain of sand, gravel, pebble, etc that makes up a rock. Clastic rocks look like they are made up of fragments of other rocks.
Bituminous coal (also called black coal) is a soft, black organic sedimentary rock that contains 85% carbon. It’s a lower grade than anthracite coal, which contains 93% carbon. Bituminous coal can either be dull or shiny, whereas anthracite is hard and shiny. Lignite, a lower grade than bituminous, is a crumbly, black type of coal that only contains 72% carbon.
Density can be found by weighing an object and dividing by the volume of the object, and for geologists, is the same thing as specific gravity. Water has a density of 1, which means that 1 gram of water takes up 1 cubic centimeter of space. Specific gravity is a number you get when you divide the density of an object by the density of water, which happens to be 1 gram/cm3.
Fluorescent minerals emit light when exposed to ultraviolet (UV) light, usually in a completely different color than when exposed to white light. UV is invisible to the human eye, and is the wavelength of light that is responsible for sunburns.
A magnetic field is the area around a magnet or an electrical current that attracts or repels objects that are placed in the field. The closer the object is to the magnet, the more powerfully it’s going to experience the magnetic effect. Nearly all minerals that are magnetic have iron as a component.
Out of all the kinds of sedimentary rocks, limestone makes up 10% by volume. People have used limestone in architecture like the Great Pyramids, castles in Europe, and in early 20th century buildings like banks and train stations. Today we use it as white filler in toothpaste, to build roads, make tiles, in cosmetics, and added to breads and cereal as a cheap source of calcium.
Popcorn rocks are different than regular dolomite samples because they have a lot more magnesium inside. This was first discovered by a geology professor in the 1980s who was dissolving the limestone around fossils he was studying in his rock samples. When he placed samples of this type in the acid to dissolve, it didn’t dissolve but instead grew new crystals!
Today we’re making polyurethane foam, which looks a lot like pumice in that it’s lightweight, porous, and cream colored. Polyurethane is a polymer that is used to make a variety of products, including seat cushions, insulation panels, seals and gaskets, roller coaster wheels, escalator rollers, carpet underlay, and wheels for skateboards.
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Field trip time! Today you get to sift through sand and excavate your rock samples right on your own desk. This inexpensive set of rock samples contain pieces of not only fossils and gems, but true minerals and rocks also, so take your time and follow the video instructions carefully.
We’re going to use a laser pointer and a protractor to measure the microscopic spacing of the data tracks on a DVD and a CD. The really cool part is that you’re going to use an interference pattern to measure the spacing of the tracks, something that you can’t normally see with your eyes.
Interference is what happens when waves smack into each other. When the waves collide, if the two highest or two lowest points of the waves are lined up, then they add together to form a larger amplitude which is seen as a bright spot of light. However, if a peak and a trough line up, then they cancel each other out and there is a dark area in the pattern (see the dark spaces in the line?).
This lab is a physical model of what happens on Mercury when two magnetic fields collide and form magnetic tornadoes.
You’ll get to investigate what an invisible magnetic tornado looks like when it sweeps across Mercury.
Materials
Using the position of the Sun, you can tell what time it us by making one of these sundials. The Sun will cast a shadow onto a surface marked with the hours, and the time-telling gnomon edge will align with the proper time.
In general, sundials are susceptible to different kinds of errors. If the sundial isn’t pointed north, it’s not going to work. If the sundial’s gnomon isn’t perpendicular, it’s going to give errors when you read the time. Latitude and longitude corrections may also need to be made. Some designs need to be aligned with the latitude they reside at (in effect, they need to be tipped toward the Sun at an angle). To correct for longitude, simply shift the sundial to read exactly noon when indicated on your clock. This is especially important for sundials that lie between longitudinal standardized time zones. If daylight savings time is in effect, then the sundial timeline must be shifted to accommodate for this. Most shifts are one hour.
Scientists do experiments here on Earth to better understand the physics of distant worlds. We’re going
to simulate the different atmospheres and take data based on the model we use.
Each planet has its own unique atmospheric conditions. Mars and Mercury have very thin atmospheres, while Earth has a decent atmosphere (as least, we like to think so). Venus’s atmosphere is so thick and dense (92 times that of the Earth’s) that it heats up the planet so it’s the hottest rock around. Jupiter and Saturn are so gaseous that it’s hard to tell where the atmosphere ends and the planet starts, so scientists define the layers based on the density and temperature changes of the gases. Uranus and Neptune are called ice giants because of the amounts of ice in their atmospheres.
Materials
Today you get to concentrate light, specifically the heat, from the Sun into a very small area. Normally, the sunlight would have filled up the entire area of the lens, but you’re shrinking this down to the size of the dot.
Magnifying lenses, telescopes, and microscopes use this idea to make objects appear different sizes by bending the light. When light passes through a different medium (from air to glass, water, a lens…) it changes speed and usually the angle at which it’s traveling. A prism splits incoming light into a rainbow because the light bends as it moves through the prism. A pair of eyeglasses will bend the light to magnify the image.
Materials
Today you get to learn how to read an astronomical chart to find out when the Sun sets, when twilight ends, which planets are visible, when the next full moon occurs, and much more. This is an excellent way to impress your friends.
The patterns of stars and planets stay the same, although they appear to move across the sky nightly, and different stars and planets can be seen in different seasons.
Materials:
Kepler’s Laws of planetary orbits explain why the planets move at the speeds they do. You’ll be making a scale model of the solar system and tracking orbital speeds.
Kepler’s 1st Law states that planetary orbits about the Sun are not circles, but rather ellipses. The Sun lies at one of the foci of the ellipse. Kepler’s 2nd Law states that a line connecting the Sun and an orbiting planet will sweep out equal areas in for a given amount of time. Translation: the further away a planet is from the Sun, the slower it goes.
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How do astronomers find planets around distant stars? If you look at a star through binoculars or a telescope, you’ll quickly notice how bright the star is, and how difficult it is to see anything other than the star, especially a small planet that doesn’t generate any light of its own! Astronomers look for a shift, or wobble, of the star as it gets gravitationally “yanked” around by the orbiting planets. By measuring this wobble, astronomers can estimate the size and distance of larger orbiting objects.
Doppler spectroscopy is one way astronomers find planets around distant stars. If you recall the lesson where we created our own solar system in a computer simulation, you remember how the star could be influenced by a smaller planet enough to have a tiny orbit of its own. This tiny orbit is what astronomers are trying to detect with this method.
Materials
It just so happens that the Sun’s diameter is about 400 times larger than the Moon, but the Moon is 400 times closer than the Sun. This makes the Sun and Moon appear to be about the same size in the sky as viewed from Earth. This is also why the eclipse thing is such a big deal for our planet.
You’re about to make your own eclipses as you learn about syzygy. A total eclipse happens about once every year when the Moon blocks the Sun’s light. Lunar eclipses occur when the Sun, Moon, and Earth are lined up in a straight line with the Earth in the. Lunar eclipses last hours, whereas solar eclipses last only minutes.
Materials
A meteoroid is a small rock that zooms around outer space. When the meteoroid zips into the Earth’s atmosphere, it’s now called a meteor or “shooting star”. If the rock doesn’t vaporize en route, it’s called a meteorite as soon as it whacks into the ground. The word meteor comes from the Greek word for “high in the air.”
Meteorites are black, heavy (almost twice the normal rock density), and magnetic. However, there is an Earth-made rock that is also black, heavy, and magnetic (magnetite) that is not a meteorite. To tell the difference, scratch a line from both rocks onto an unglazed tile. Magnetite will leave a mark whereas the real meteorite will not.
Materials
You are going to start observing the Sun and tracking sunspots across the Sun using one of two different kinds of viewers so you can figure out how fast the Sun rotates. Sunspots are dark, cool areas with highly active magnetic fields on the Sun’s surface that last from hours to months. They are dark because they aren’t as bright as the areas around them, and they extend down into the Sun as well as up into the magnetic loops.
Materials
Have you ever wondered why the sky is blue? Or why the sunset is red? Or what color our sunset would be if we had a blue giant instead of a white star? This lab will answer those questions by showing how light is scattered by the atmosphere.
Particles in the atmosphere determine the color of the planet and the colors we see on its surface. The color of the star also affects the color of the sunset and of the planet.
Materials
What comes to mind when you think about empty space? (You should be thinking: “Nothing!”) One of Einstein’s greatest ideas was that empty space is not actually nothing – it has energy and can be influenced by objects in it. It’s like the T-shirt you’re wearing. You can stretch and twist the fabric around, just like black holes do in space.
Today, you will get introduced to the idea that gravity is the structure of spacetime itself. Massive objects curve space. How much space curves depends on how massive the object is, and how far you are from the massive object.
Materials
You’re going to use a compass to figure out the magnetic lines of force from a magnet by mapping the two different poles and how the lines of force connect the two. A magnetic field must come from a north pole of a magnet and go to a south pole of a magnet (or atoms that have turned to the magnetic field.)
Compasses are influenced by magnetic lines of force. These lines are not necessarily straight. When they bend, the compass needle moves. The Earth has a huge magnetic field. The Earth has a weak magnetic force. The magnetic field comes from the moving electrons in the currents of the Earth’s molten core. The Earth has a north and a south magnetic pole which is different from the geographic North and South Pole.
Materials
A binary system exists when objects approach each other in size (and gravitational fields), the common point they rotate around (called the center of mass) lies outside both objects and they orbit around each other. Astronomers have found binary planets, binary stars, and even binary black holes.
The path of a planet around the Sun is due to the gravitational attraction between the Sun and the planet. This is true for the path of the Moon around the Earth, and Titan around Saturn, and the rest of the planets that have an orbiting moon.
Materials
One common misconception is that the seasons are caused by how close the Earth is to the Sun. Today you get to do an experiment that shows how seasons are affected by axis tilt, not by distance from the Sun. And you also find out which planet doesn’t have sunlight for 42 years.
The seasons are caused by the Earth’s axis tilt of 23.4o from the ecliptic plane.
Materials
If you could stand on the Sun without being roasted, how much would you weigh? The gravitational pull is different for different objects. Let’s find out which celestial object you’d crack the pavement on, and which your lightweight toes would have to be careful about jumping on in case you leapt off the planet.
Weight is nothing more than a measure of how much gravity is pulling on you. Mass is a measure of how much stuff you’re made out of. Weight can change depending on the gravitational field you are standing in. Mass can only change if you lose an arm.
Materials
Telescopes and binoculars are pretty useless unless you know where to point them. I am going to show you some standard constellations and how to find them in the night sky, so you’ll never be lost again in the ocean of stars overhead. We’re going to learn how to go star gazing using planetarium software, and how to customize to your location in the world so you know what you’re looking at when you look up into the sky tonight!
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We’re going to do a chemistry experiment to simulate the heat generated by the internal core of Neptune by using a substance used for melting snow mixed with baking soda.
Calcium chloride splits into calcium ions and chloride ions when it is mixed with water, and energy is released in the form of heat. The energy released comes from the bond energy of the calcium chloride atoms, and is actually electromagnetic energy. When the calcium ions and chloride ions are floating around in the warm solution, they are free to interact with the rest of the ingredients added, like the sodium bicarbonate, to form carbon dioxide gas and sodium chloride (table salt).
Materials
Greetings and welcome to the study of astronomy! This first lesson is simply to get you excited and interested in astronomy so you can decide what it is that you want to learn about astronomy later on.
We’re going to cover a lot in this presentation, including: the Sun, an average star, is the central and largest body in the solar system and is composed primarily of hydrogen and helium.
The solar system includes the Earth, Moon, Sun, seven other planets and their satellites (moons) and smaller objects such as asteroids and comets. The structure and composition of the universe can be learned from the study of stars and galaxies. Galaxies are clusters of billions of stars, and may have different shapes. The Sun is one of many stars in our own Milky Way galaxy. Stars may differ in size, temperature, and color.
Materials
Helioseismology is the study of wave oscillations in the Sun. By studying the waves, scientists can tell what’s going on inside the Sun. It’s like studying earthquakes to learn what’s going on inside the earth. The Sun is filled with sound, and studying these sound waves is currently the only way scientists can tell what’s going on inside, since the light we see from the Sun is just from the upper surface.
Molecules are vibrating back and forth at fairly high rates of speed, creating waves. Energy moves from place to place by waves. Sound energy moves by longitudinal waves (the waves that are like a slinky). The molecules vibrate back and forth, crashing into the molecules next to them, causing them to vibrate, and so on and so forth. All sounds come from vibrations.
Materials
Jupiter not only has the biggest lightning bolts we’ve ever detected, it also shocks its moons with a charge of 3 million amps every time they pass through certain hotspots. Some of these bolts are cause by the friction of fast-moving clouds. Today you get to make your own sparks and simulate Jupiter’s turbulent storms.
Electrons are too small for us to see with our eyes, but there are other ways to detect something’s going on. The proton has a positive charge, and the electron has a negative charge. Like charges repel and opposite charges attract.
Materials
On a clear night when Jupiter is up, you’ll be able to view the four moons of Jupiter (Europa, Ganymede, Io, and Callisto) and the largest moon of Saturn (Titan) with only a pair of binoculars. The question is: Which moon is which? This lab will let you in on the secret to figuring it out.
You get to learn how to locate a planet in the sky with a pair of binoculars, and also be able to tell which moon is which in the view.
Materials
If you want to get from New York to Los Angeles by car, you’d pull out a map. If you want to find the nearest gas station, you’d pull out a smaller map. What if you wanted to find our nearest neighbor outside our solar system? A star chart is a map of the night sky, divided into smaller parts (grids) so you don’t get too overwhelmed. Astronomers use these star charts to locate stars, planets, moons, comets, asteroids, clusters, groups, binary stars, black holes, pulsars, galaxies, planetary nebulae, supernovae, quasars, and more wild things in the intergalactic zoo.
How to find two constellations in the sky tonight, and how to get those constellations down on paper with some degree of accuracy.
Materials
Let’s see how much you’ve picked up with these experiments and the reading – answer as best as you can. (No peeking at the answers until you’re done!) Just relax and see what jumps to mind when you read the question. You can also print these out and jot down your answers in your science notebook.
Let’s see how much you’ve picked up with these experiments and the reading – answer as best as you can. (No peeking at the answers until you’re done!) Just relax and see what jumps to mind when you read the question. You can also print these out and jot down your answers in your science notebook.
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Let’s see how you did! If you didn’t get a few of these, don’t let it stress you out – it just means you need to play with more experiments in this area. We’re all works in progress, and we have our entire lifetime to puzzle together the mysteries of the universe!
Here’s printer-friendly versions of the exercises and answers for you to print out: Simply click here.
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Let’s see how you did! If you didn’t get a few of these, don’t let it stress you out – it just means you need to play with more experiments in this area. We’re all works in progress, and we have our entire lifetime to puzzle together the mysteries of the universe!
Here’s printer-friendly versions of the exercises and answers for you to print out: Simply click here.
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Today you get to sort and identify as many rocks as you can as you test for streak, hardness, fluorescence, color, magnetism, chemical reactions, and more with this unique set of rocks. You may have to do a little research on the ones that are not yet familiar to you!
Although urine is sterile, it has hundreds of different kinds of wastes from the body. All sorts of things affect what is in your urine, including last night’s dinner, how much water you drink, what you do for exercise, and how well your kidneys work in the first place. This experiment will show you how the kidneys work to keep your body in top shape.
When high energy radiation strikes the Earth from space, it’s called cosmic rays. To be accurate, a cosmic ray is not like a ray of sunshine, but rather is a super-fast particle slinging through space. Think of throwing a grain of sand at a 100 mph… and that’s what we call a ‘cosmic ray’. Build your own electroscope with this video!
The Moon appears to change in the sky. One moment it’s a big white circle, and next week it’s shaped like a sideways bike helmet. There’s even a day where it disappears altogether. So what gives?
The Sun illuminates half of the Moon all the time. Imagine shining a flashlight on a beach ball. The half that faces the light is lit up. There’s no light on the far side, right? For the Moon, which half is lit up depends on the rotation of the Moon. And which part of the illuminated side we can see depends on where we are when looking at the Moon. Sound complicated? This lab will straighten everything out so it makes sense.
Materials
Do you have thick or thin hair? Let’s find out using a laser to measure the width of your hair and a little knowledge about diffraction properties of light. (Since were using lasers, make sure you’re not pointing a laser at anyone, any animal, or at a reflective surface.)
Does it rain on the Sun? The answer to this is yes, however, it is not water that falls but very hot plasma. On July 19, 2012, there was an eruption on the Sun that produced a massive burst of solar wind and magnetic fields and released into Space. This eruption also produced a powerful solar flare. After that, a phenomenon known as coronal rain occurred. Corona Rain occurs occurs when hot plasma in the corona cools and condenses in strong magnetic fields, usually associated with regions that produce solar flares. The plasma condenses and slowly falls back to the solar surface.
The electrons, protons and ions in the rain is forced to move along the magnetic loops of the Sun’s surface. As a result, this bright flare highlights matter glowing at a temperature of about 50,000 Kelvin. The entire coronal rain lasted about 10 hours.
Video Credit : http://apod.nasa.gov/apod/ap130226.html
Numbers that are not fractions or decimals, are called integers. Numbers like: 2 and 144 and 299,792,458 (that’s the speed of light in meters per second) are all integers!
Integers can be positive or negative. If the number is greater than zero, like 4, 16, 25… then it’s a positive integer. Negative integers are -15, -42, -1 million.
It’s important to know how to handle both positive and negative integers because they come up all the time in algebra. You probably already have experience in working with positive and negative decimals and fractions, so now let’s do a quick review so you can make sure you’ve mastered the basics.
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“CQ, CQ.. calling CQ 20 meters. This is KJ6ZFH calling. Kilo Juliet Six Zulu Foxtrot Hotel in San Luis Obispo calling CQ 20 meters. Hello CQ, CQ, CQ 20 meters. This is KJ6ZFH calling. Kilo Juliet Six Zulu Foxtrot Hotel in San Luis Obispo calling CQ 20 meters and standing by for a call.”
What is all THAT?
Well, it’s a “ham” radio operator calling out to anyone listening on a special radio frequency (the 20 meter band) inviting them to answer and talk. It’s a fun and exciting hobby for those who love electronics and meeting new people from all over the world. Plus it’s an ideal hobby for students because it’s inexpensive (there’s no on-going cost once you’ve bought your radio, unlike a cell phone plan), provides a huge amount of learning opportunities from geography to electronics to foreign language, and it’s just plain cool.
Amateur radio has been around for a long time (since 1912), so you never know who you’re going to make contact with when you put out a call. A friend of mine actually talked with the King of Jordan once… no kidding!
You can even connect with astronaut hams on the International Space Station (see the image on the left… notice her hair?) Suni Williams is using the space station’s radio module to communicate with kids on earth. There’s really no limit to what you can do once you learn the fundamentals.
I’m going to outline the basics of amateur radio so you can really get a feel for what it is, why people still love it, and what it’s really like out there in the air. Let’s start with the first thing people always ask me, which is: “What is CQ?” “CQ” means “calling any station”. Calling “CQ” takes about 20-30 seconds to say clearly, and includes the call sign (KJ6ZFH) several times, including phonetically (Kilo Juliet Six Zulu Foxtrot Hotel). Also includes the location information so the listener knows exactly who and where the caller is.
The videos on this page were created by Tyler, and his call sign is N7TFP. He’s extremely passionate about amateur radio, and he has created several videos on the hobby that I thought you might enjoy, including a peek at his radio shack. The “shack” refers to the place you do your “hamming”, usually in a shed or room where all your radio equipment is located. Some hams operate from their homes, others wire up their vehicles with portable radio stations, some hams set up a separate building in the yard, and a few had to be sneaky about hamming, especially if their housing development or family didn’t approve of their rooftop antennas. In fact, I know of one ham that was so desperate to continue his hobby, despite his wife’s objections that he stashed his radio equipment in a tiny closet and figured out a way to use the metal rain gutters as his antenna!
Let’s take a look at how a ham operator works:
If you’ve got your Amateur Radio License (we’ll talk more on how to do that later), you are ready to get on the air! First thing you should do is listen to how other hams do their communication so you can pick up on a few things. Different bands have different approaches to communication, so it really helps to hear a couple of exchanges before you make your first contact. Most people start with a Technician license with either a handi-talkie (hand-held transceiver) or a portable radio by going through something called a local “repeater”. Let me explain: The most popular way to communicate for a newly licensed ham to talk with other hams is through a local repeater. It’s a two-way radio system that receives communication on one frequency and then re-transmits what it hears on another frequency at exactly the same time. It’s simply a machine that relays your message since your transceiver has a limited range. It’s limited because of the size of the antenna and how the earth curves. A repeater can get your signal to reach a much further listener this way. There are repeaters all over the country. To make a contact on the 2 meter band through a repeater, I press the mike button and say:
And that’s it! It’s really that simple. And it exciting and fun to keep track of all the different folks you get to talk with all over the country and world.
“CQ” means “calling any station”. Some licenses permit you to operate on different bands, like SSB on 10 meters. Here’s what you’d do in this case: You always start by finding a clear frequency. Let’s say you’ve chosen to operate on 28.460. You want to speak clearly and ask “Is this frequency in use? This is KJ6ZFH.” If you don’t get a response, ask a second time just to be sure. If there’s still no response, you can continue. However, note that if the frequency is in use, just move to another frequency and try again.
Now you get to call: “CQ CQ CQ. This is Kilo Juliet Six Zulu Foxtrot Hotel calling CQ CQ CQ. This is Kilo Juliet Six Zulu Foxtrot Hotel, KJ6ZFH calling CQ and waiting for a call.” Wait and listen for a return call. If you’re on an HF (high frequency) band like 10 meters, the signal you get back might be very strong to very weak or anything in between, so use your ears here.
You may hear “Kilo Juliet Six Zulu Foxtrot Hotel this is (their call sign) calling.” You respond by saying “(Their call sign, using phonetics) this is KJ6ZFH. Thanks for the call your signal is 59. My name is Aurora and my QTH is San Luis Obispo. So how do you copy? (Their call sign) this is KJ6ZFH over.”
You made HF (high frequency) contact! You can make the contact as you wish depending on the band conditions and what you find to discuss with your new friend in a new country!
Q signals are used primarily in CW. They provide an abbreviated way of asking a question or making a statement. A Q signal followed by a question mark (?) asks a question. A Q signal without the “?” answers the question or makes the statement.
The following are Q signals commonly used by CW operators world wide:
You can find a complete list of Q signals here.
If you’re ready to build your own amateur radio station, here’s a video to get you started:
This is a video on selecting your first radio. Some folks feel that a HT (handi-talkie, or hand-held transceivers) does not make good first radios, however for kids it’s a great first step into the hobby, and it’s not a huge investment… and it comes with the antenna and everything you need, all in one package. You can get a Baofang UV-5R if you’d like an inexpensive handi-talkie for about $60.
If you’d like a larger radio, get yourself a portable radio 30-60W in the 2 meter / 70cm bands – this will keep you busy for a long time. My first radio was the Yaseu 7900.
Sometimes, you’ll hear reference to the word “oscilloscope” or “o-scope”. If you’re wondering what it is, it an instrument used in the electronics/electrical fields (which includes radio) to help hams keep their equipment working properly. Most folks get their first exposure to one of these in a college level lab, but here’s sneak peek so you don’t have to wait. Here’s how it works:
The first thing you’ll want to do is set up your radio to the appropriate frequency, offset, CTCSS tone (if needed) so you’ll be ready to make your contact – all of this is covered in your instruction manual that comes with your radio.
Silly as this sounds, I spent to much time getting my equipment dialed in right that when it came time to speak, I clean forgot my call sign! I had to stick it (KJ6ZFH) on a post-it note right in front of me so I wouldn’t forget.
After watching these videos and learning about radio communication, are you ready to get your license? If you’re excited about the idea, then NOW is a great time to jump on it. Would it surprise you to know that when I got my license, I woke up the morning of the test without even knowing that I was about to take the test? Not only that, I had not even cracked open an book on the subject? Sure, there are only 35 questions to answer, and they take them from a published pool of 350 questions, but honestly, it was a surprise date from my husband.
He drove me to a testing center where we studied for 5 hours, then took the test… all in a single day! No long weeks of studying theory, no late nights or giving up other activities… just a day of studying, take the test, and boom! I got my license. It cost me $20. So I totally encourage you to do it now while you’re excited and have momentum in this direction… that’s the moment you make the decision that takes you in a direction you really want to go. You can look up information on testing at the ARRL.
Enough said – here’s a quick video on getting your license you might find helpful:
Many wonders are visible when flying over the Earth at night, especially if you are an astronaut on the International Space Station (ISS)! Passing below are white clouds, orange city lights, lightning flashes in thunderstorms, and dark blue seas. On the horizon is the golden haze of Earth’s thin atmosphere, frequently decorated by dancing auroras as the video progresses. The green parts of auroras typically remain below the space station, but the station flies right through the red and purple auroral peaks. You’ll also see solar panels of the ISS around the frame edges. The wave of approaching brightness at the end of each sequence is just the dawn of the sunlit half of Earth, a dawn that occurs every 90 minutes, as the ISS travels at 5 miles per second to keep from crashing into the earth.
Video Credit: Gateway to Astronaut Photography, NASA
This is the stuff of dreams, imagination, creativity and innovation.This is especially cool for parents to have their children witness something “out of this world” live as it happens. This is American science education at its absolute finest.
NASA’s Jet Propulsion Laboratory (JPL) has done it again, BIG TIME!
In normal fashion for JPL in Pasadena, this was no normal, everyday kind of landing, as Curiosity will blast into the Martian atmosphere at 13,000 miles per hour and in a death-defying “Seven Minutes of Terror” come to a soft landing on Mars. Fingers and toes were crossed. And, due to its heavy weight, it will not land like Spirit and Opportunity did about 8 years ago landing in cushioned, inflated air bags that looks like giant raspberries. Curiosity was lowered to the surface under a rocket-powered sky-crane, never before attempted by any spacecraft. Mars Science Laboratory Curiosity is the most sophisticated and complex robotic spacecraft ever built.
Even now that this event has happened, you can witness this history-making event through these special NASA TV video along with millions of people around the world.
Curiosity was launched on an Atlas V rocket from Cape Canaveral on November 26, 2011:
Some folks may have heard that there was a problem anticipated with the transmission of the landing telemetry (radio signal), possibly taking hours before we would know what happened during the landing. That problem was with America’s Mars Odyssey spacecraft orbiting Mars (along with America’s Mars Reconnaissance Orbiter and Europe’s Mars Express Orbiter). A “reaction wheel” that helps control Mars Odyssey’s orbital path location had problems, that could have impacted its ability to receive and relay the telemetry as it happens. The week before landing, JPL engineers successfully corrected the issue, putting Mars Odyssey back on course to directly receive the landing telemetry and beam it back to Earth as it is happening.
Newsflash! Curiosity has successfully landed on the surface of Mars!
Bear in mind that the transmission time from Mars to Earth will be about 14 minutes at the speed of light, so Curiosity will have experienced the Seven Minutes of Terror and landed before we get the signals from Mars. Hold your breath and wish Curiosity the best as you watch these videos!
Here are some of the first images:
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More images are being posted by NASA here: Mars Science Laboratory Image Gallery
What is math? It can be compared to a very useful tool, or maybe a collection of tools. Sometimes textbooks concentrate a lot on teaching about the small details of each and every type of tool. But it’s also really important to focus on how and when to use the different tools. This is my practical approach to teaching the subject. And it’s also important to note that math is much more than just numbers! If you’re really good with shapes and how they relate, you might enjoy geometry. And if you are good at solving puzzles, chances are that logic will be a great match for your skills.
NOTE: Be sure to pause the video when the timer reaches 6:30 to work on the Earn, Break Even, or Lose problem.
Do you think you'll need to know how to multiply by 12 or 11 more? Think of it this way: how often do you need to figure out how many dozen you need of something? It comes up a lot more than needing to know how many batches of 11, doesn't it? That's because of the way we've decided to group things mathematically as a society.
Here's why: We picked 12 based on how we used to count on our fingers using the "finger segment" system. If you look at your hands, you'll notice that your index finger has three segments to it. So does your middle finger, ring finger, and pinkie. Since you have four fingers, you actually have 12 sections for counting with (we're not including your thumb, which is the pointer... your thumb rests on the section you're currently on). When your thumb touches the tip of your index finger, that means "1". When your thumb touches the middle segment, that's "2", and the base segment is "3". The tip of your middle finger is "4", and so on. That's how we came to use the 12-in-a-batch system.
If you're wondering why we didn't use the 24-in-a-batch system (because you have two hands), that's because one hand was for 1-12 and the second hand indicated the number of batches of 12. So if your left hand has your thumb on the ring finger's base segment (9) and your right hand has the thumb touching the index finger's middle segment (2 complete batches of 12, or 2 x 12), the number you counted to is: 24 + 9 = 33.
Fortunately we now have calculators and a base-ten system, so this whole thing worked out well. But still the number 12 persists! So I thought you'd like this video, which expands on the idea of quickly multiplying two-digit numbers and three-digit numbers by eleven. This is very similar to the shortcut used when multiplying by eleven, but it also involves some doubling. Are you ready?
Can you look at a number and tell right away if it’s divisible by another number? Well, it’s pretty easy for 2 – if it’s an even number, it’s definitely divisible by two. Testing whether a number is divisible by five is easy as well. How can you tell?
In this video, I’ll show you some tricks to determine if a number is divisible by 3, 4, 6 and 7 before you start to divide. Some are simple and fast and some are a bit more complex. These can be very useful tricks for working with larger numbers (or just really fun to play with for a bit).
This is not only a neat trick but a very practical skill - you can figure out the day of the week of anyone's birthday.
If you were born in the 20th Century, (1900-1999), we can use math to find out which day of the week you were born. If you’re a little too young for this, try it with a parent or grandparent’s birthday. Watch the video and I'll teach you exactly how it works.
This is a really fun riddle! It’s a math logic puzzle involving the calendar that will really blow your mind. Pay close attention to the clues I give in the video and see if you can work out how it works. Pause the video at about the 1:30 mark if you would like to try and work out the answer before I show you how it works!
This is a neat logic trick which allows you to flip over a stack of cards numbered 1-10. When you flip the back upright, they are in numerical order. There is a special way to make it work, so pay close attention to the video. I’ll show you exactly how it works.
Magic squares have been traced through history as known to Chinese mathematicians, Arab mathematicians, India and Egypt cultures. The first magic squares Magic squares have fascinated people for centuries, and historians have found them engraved in stone or metal and worn as necklaces. Early cultures believed that by wearing magic squares, it would ensure they had long life and kept them from getting sick.
Benjamin Franklin was well-known for creating and enjoying magic squares, and it was all the rage during his time. Here's the deal: we're going to arrange numbers in a way so that all the rows, columns, and even the diagonals add up to a single number (called a Magic Sum). In this video, I show you the first Magic Square published in Europe way back in 1514. Plus, I show you how to make your very own Magic Square. You can use it to test your friends.
If you’ve watched my “What Is Math?” video, you’ve seen a sample of the Bagels math logic game. This is one of my family’s favorites! It’s a guessing game, but you can use logic and strategy in order to guess the numbers very quickly. In this video, I’ll show you in more detail how it works. I’ll also show you how to use the game to guess numbers even larger than three digits. Once you’ve mastered the strategies in this game, you’ll never lose another game of Mastermind again.
If a friend had chose a three-letter word and asked you to guess it, how would you start? It seems like it might take a while to narrow it down, right? This is a neat word guessing game that uses some strategy to make the guessing both a little easier and more fun. When you try to guess your partner’s three-letter word, they can simply give you one of two clues that will make it a bit easier to narrow down the answer. Watch the video for an explanation.
The first folks to play this game lived in the Roman Empire, but it was called Terni Lapilli and instead of having any number of pieces (X or O), each player only had three, so they had to move them around to keep playing. Historians have found the hatch grid marks all over Rome. They have also found them in Egypt!
In 1864, the British called it “noughts and crosses”, and it was considered a “children’s game”, since they would play it on their slates. In recent times (1952), OXO was one of the first known video games, as the computer played games against a person.
Tic-Tac-Toe can be fun, but when you get a “cat’s game” (no winner), it can get a little boring pretty quickly, right? In this video, I’ll show you some cool ways to change the game to make it more interesting by changing one or two of the basic rules. It’s much more engaging and strategic that way! Currently there are over 100 variations of Tic-Tac-Toe, and I’m going to show you my favorite ones. In fact, last time I taught a live science workshop, all 120 kids played this at the same time with squeals of delight!
Cryptography is the writing and decoding of secret messages, called ciphers. Now for governments these secret ciphers are a matter of national security. They hire special cryptanalysts who work on these ciphers using cryptanalysis. The secret is, solving substitution ciphers can be pretty entertaining! Ciphers are published daily in newspapers everywhere. If you practice encoding and decoding ciphers, you too can become a really great cryptanalyst.
In this video, I’ll show you how to use the Rail Fence Cipher. Before you start, say this three times fast: cryptanalysts use cryptanalysis to crack ciphers!
In this video, I demonstrate a Twisted Path Cipher. It uses a matrix and a path in order to encode your message. The shape of the path you create within the matrix of a Twisted Path Cipher determines how difficult it will be to break the code. Watch the video to learn exactly how it works.
Shift ciphers were used by Julius Caesar in Roman times. The key is a number which tells you how many letters you’ll shift the alphabet. These are fairly simple to encode and decode. However, you have to be extra careful when encoding because mistakes can throw off the decoding process. Watch the video to see why it’s important to double check your work!
The Date Shift cipher is a much harder code to break than, for example, the more simple Shift cipher. This is because the shift number varies from letter to letter, and also because it’s polyalphabetic (this means that a single number can represent multiple letters). I’ll explain it all in the video.
The Pig Pen cipher is of the most historically popular ciphers. It was used by Freemasons a century ago and also by Confederate soldiers during the Civil War. Since it’s so popular, it’s not a very good choice for top secret messages. Lots of people know how to use this one! It starts with shapes: tic-tac-toe grids and X shapes. I really like it because coded messages look like they’re written an entirely different language! Watch the video to learn how it works.
Polybius was an ancient Greek who first figured out a way to substitute different two-digit numbers for each letter. In the Polybius cipher we’ll use a 5×5 square grid with the columns and rows numbered. Take a look at the video and I’ll show you how it works.
Cryptograms are solved by making good guesses and testing them to see if the results make sense. Through a process of trial and error, you can usually figure out the answer. Knowing some facts about the English language can help you to solve a simple substitution cipher. For example, did you know that an E is the most commonly-used letter in the English alphabet? It’s also the most commonly-used letter to end a word. Watch the video below to learn some more tips and tricks to get you on the right track to being an expert cryptogram solver!
Have you ever heard of a dollar word search? It’s a special kind of puzzle where the letters in a word add up to a coin value. For example, an A is worth a penny, the letter B is worth two cents, C is worth three cents, and so on. Are you completely confused? That's okay! Just watch the video and I’ll show you how it all works.
