Static Electricity Activity

You are familiar with electrical conduction through wires, but today you’ll experiment with electrical conduction in alternative ways. Static electricity is a buildup of electrical charge in an object. Static electricity is the same as electricity that is produced by batteries and magnets.

Most of the materials we interact with every day are neutrally charged, meaning they have the same number of protons and electrons. But some are naturally positively or negatively charged. Today, you will be experimenting with the triboelectric effect of static electricity to understand how electrons move between positively charged and negatively charged materials through physical contact.

Negatively charged materials have an atomic structure that provides an abundance of weakly bound electrons in the electrical field. These electrons are easily pulled away by contact with a positively charged material which has atoms that are lacking electrons in their electrical fields. Contact between these materials creates an exchange of electrons from the negatively charged materials to the positively charged material, thereby changing the charge to negative and creating a buildup of electrons and electrical charge. There are several ways static electricity is generated, but you will be most familiar with static charge from a door knob. As you walk on carpeting (primary material), static charge builds up on the soles of your shoes and your body (secondary material). The charge on your body is discharged when your body makes contact with a discharge path, like a metal doorknob.

Purpose

The purpose of this experiment is to actively transfer electrons, and thus electricity, from one material to another in order to model basic electrical impulses.

Experiment

Imagine you are an early scientist studying the largely unexplained force of electricity. You’ve experienced static shock and are experimenting ways to control the charge. In these experiments you will be using a comb or a party balloon to create a static charge and transfer that charge to a light bulb, which acts as a discharge path. Continue reading

Reverse Engineering Activity

Taking apart objects to see how they are constructed is an essential part of understanding engineered products. It is often the “science” or research that helps us to understand materials and eventually create better ones. For example, scientists take apart plant stalks down to the microscopic structure. This structure is made up of a naturally strong material called cellulose. By understanding the structure of cellulose, we can learn how to mimic nature and create manufactured materials that are strong and flexible, just like plants stalks are.

Purpose

Reverse engineering is a process that allows the explorer an opportunity to see how an engineered product was constructed, and to try to rebuild it. Why is the rebuilding process important? Because this activity helps our brains remember things better!

Activity

Professional engineers are very thorough in their work. Engineering requires the ability to plan things well, and execute them with a lot of attention. Often they take copious notes and are very organized. You can explore how an engineer works by conducting the following “reverse engineering” activity. This activity will require you to be organized and take notes! It will be interesting to see if you can take something apart and it put it back together properly. How good will your notes be?

Materials

  • A household object that can be disassembled and reassembled
  • A workspace
  • Any work tools that will be required (i.e. a screwdriver. This will depend upon the selected object).

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How is Your Brain Like Play-doh?

Brain plasticity is a term you may have heard of and not really understood but one great thing about it is that it evokes the impression of an old favorite childhood toy: Play-doh. Okay, bear with me, we are going to think outside the box here (or should I say outside the little yellow plastic canister) as I explain how Play-doh has properties much like our brain.

Play-doh is a highly flexible material in its ideal state whose structure and function is easily influenced by both mechanical stimuli (hands, plastic tools, sticks, rocks) and chemical stimuli (water, air, homemade slime, you name it). While we do not take our brains out and physically manipulate them (what an interesting visual that makes!), we certainly do influence our brains through chemical stimuli and through psychological stimuli such as thoughts and emotions (although some psychologists, called Behaviorists, believe that emotion and thought are strictly the result of chemical interactions in the brain – so to them, it’s all chemical).

Take a look at the chart below. I’ve listed a few of the things that influence brain plasticity. Scientifically, plasticity is the ability of an organ to change over a lifetime and compared them to things that influence Play-doh plasticity. Are my comparisons to Play-doh way off base? Okay. I’ll admit – these are based on my years of a long love affair with the smell and texture of Play-doh. Who doesn’t love the smell of Play-doh?

Table 1: Factors that Influence Brain Plasticity vs. Factors that Influence Play-doh Plasticity

So we have here things that happen to our brain that are beyond our control: genetics factors, brain injury, some diseases, and some experiences (note that many of these cause stress, some do not). And then there is stuff we actively put into our brains: dietary factors, experiences (believe it or not we choose a lot of these), stress (we can actually manage stress so that it impacts our brain and body less negatively), psychoactive drugs, and many diseases related to diet (again with the diet stuff!).

Scientists have found that people with brains that are more “plastic” or physically adaptable (i.e. their nervous systems can change structure and function throughout their lives) have better quality of life. They have better memory and learning ability, they recover more quickly from injury or diseases of the brain, and they are more adaptable to new experiences or circumstances. Continue reading

Origami, The Environment, and Sourcing Materials

Folding and paper engineering take us to an interesting intersection of materials and environmental science every time you set up for a new project. How? It’s your personal call about which material is selected and how you will source it; how much of your personal budget is available to spend; how you envision the final product; and whether you are willing to accept an unexpected result.

Before you buy a boxed kit or purchase expensive die cut origami papers at the art or crafts store, consider repurposing paper or otherwise potentially foldable materials. It’s fun, inexpensive, and makes you think about purpose and utility in design.

Everyone goes through lot and lots of papers. In fact, each time you try a new model, it takes refolding the same model several times until you get it exactly right. So why not practice on repurposed material? It’s free! Plus, you create something unique in the process. Fooling around with different weights and textures of recycled materials gives you a good idea of the range of outcomes a tweak in material selection can provide. The result may pleasantly surprise you! Continue reading

What Creates Magnetism?

Unless you are an expert, magnetism can be a confusing topic. We all know that magnets are attracted to or repel certain elementary materials. But what makes this phenomenon occur?

Magnetism is a force that occurs in the natural world, from the cosmic level to the subatomic level – and everything in between. It is one of the four fundamental forces (non-contact) in the Universe. Gravity is the best-know and, for the average person, the most easily understood force. The other two forces are the weak nuclear force and the strong nuclear force. The strong nuclear force is the force that actually “holds” protons and neutrons together (which make up the nucleus of an atom). The weak force is a little more complex. This force is responsible for radioactive decay (the process in some elementary materials of natural decay or death of a nucleus that results in an atom losing electrons or positrons). The weak force is caused by the exchange of specific bosons (certain sub-atomic particles) within an atom’s neutron.

Magnetic force is created when electrons spin around the nucleus of an atom (thus it is caused by electricity). The movement of the electron creates a flow. An atom with more electrons than protons has a negative charge, but when it has more protons than electrons, it has a positive charge. Oppositely charged materials naturally attract each other, while materials with the same charge repel each other. This is the magnetic force. Continue reading

Origami Engineering

While we all know that the ancient art form of origami creates amazingly beautiful art pieces, and some imaginatively intricate and interesting designs, it’s also now being used in science and technology applications. Yes, it’s true – origami, sometimes referred to as paper folding or even “paper engineering,” is helping to advance some high-end exciting technologies!

The FORTE (Fast On-orbit Recording of Transient Events) satellite in the image above detects, records, and analyses radio energy (electromagnetic radiation) at the Earth’s surface. It also collects data about the physics of lightning and the composition of the ionosphere (the electrically-conducting layer of the atmosphere that is 50-600 miles above Earth’s surface)!

Developed by Los Alamos National Laboratory and Sandia National Laboratory (both in New Mexico), the satellite’s radio frequency antenna is used to gather and store data and to ‘download’ that data back to Earth. It consists of a long ‘boom’ that unfolds to expose the antenna. The boom was designed by AstroAerospace engineers. When the FORTE satellite was launched, the amazingly long antenna structure, which is 35 feet long, was very carefully folded into a 1 foot long canister. WOW!

Making a satellite compact important because the larger the satellite is the more fuel is required to launch it into space. Carefully fitting all of the important scientific “payload” equipment (the devices and instruments that conduct the experiments) into small spaces also means that a satellite can be multi-functional and carry the necessary equipment for more than one experiment, as the FORTE does. Continue reading

What’s The Best Snow for Snowball Fights?

Have you ever pulled something out of the freezer, like a frozen waffle, that had ice crystals on it? Snowflakes are made up of many very small ice crystals that have formed into specific shapes; sometimes that shape is a flake. In many ways they are similar to the ice crystals on your waffle, but there are some distinct differences too.

Snowflakes form when temperature in the atmosphere drops below freezing. The atmosphere must also have enough humidity for water droplets to condense (i.e. in a cloud). You can have very cold temperatures or a lot of humidity, but if you don’t have both, snowflakes won’t form. As soon as these conditions are met, though, the water droplets in the air freeze condense onto microscopic dust particles that are floating around, creating an ice crystal. Depending upon the conditions, it can be a very quick process growing from one crystal to a full snowflake (with as many as hundreds of individual ice crystals), because crystals will continue to condense onto the original as it “falls” towards the ground. Sometimes, when temperatures fluctuate around the freezing point, ice crystals can form and melt repeatedly.

It is interesting is that all snowflakes have six sides. Why is this? As the two hydrogen and one oxygen (H²O) molecules in the water freeze and become ice, they automatically align into a lattice structure. The temperature, humidity, and amount of dust particles in the air determine exactly how the structure forms (i.g. the final shape), but the lattice structure is limited to a six sided structure. The crystals might be shaped like spikes, hollow columns, flat plates, or stars.

So which snow IS the best for snowball fights? Powdery snow has low moisture content and is full of air. The crystals are big and sparkly. It falls on days that are well below freezing temperatures. Powdery snow doesn’t pack well (but, you can always dig down and get the snow closest to the ground since this snow will have been warmed by the Earth and naturally packed by the weight of the snow on top of it). The very best snow for packing into snowballs is denser, moister snow that falls when it is near freezing. If you wake up to a blanket of white snow and it’s about 30° outside, you’ll most likely have optimal snowball fight conditions! Continue reading

Classes in Duct Tape 101? You betcha!

I am attending the Massachusetts Institute of Technology (MIT) ESP (Educational Studies Program) “Splash” event – an annual convergence of thousands of middle and high school students from across the country who come to participate in seminars ranging from Fermi Estimations to Hungarian History. There is also a lineup of lighthearted courses like chocolate tasting, duct tape 101, and making a gigantic rubber band sphere.

The seminars are varied – so varied in fact, that it was really hard to decide what seminars to sign up for (over 400 different classes this year!). Some of the classes are limited to an hour, and some last the whole day (like Designing a Building). But here’s what’s really cool about this event – – kids come from across the country to participate. I don’t just mean the Boston area, or even New England, or even the eastern half of the US. I heard about a family that came from California just for the event! WOW! – Walking the hallowed halls of MIT, I twice saw kids reuniting with friends made the previous year. (as I was peeking into the graduate student Materials Science Lab. Hmmmm – huge hydrogen tanks…. what DO they do in there???) Continue reading

Engineering an Egg-Protection Device

If you’re like me, you probably think eggs are fun to work with. The shell of an egg allows us to ponder deeper questions such as, “What makes the shell of an egg so strong?” or “Why do these silly things come in different colors?” (Have you ever seen a blue or green egg!?)

I have participated in egg drop contests and they are interesting to me because at the beginning every participant believes that his or her egg-protecting contraption will keep the egg from breaking. Out of the many dozens of contraptions I have seen used, I only saw three actually work. Not very good odds I’d say. But, there are a few egg-physics points to consider when you are creating an egg-protective device:

A falling egg has momentum, which, for the mathematically minded, is mass times velocity. Downward momentum increases the longer the egg is falling because of the pull of gravity on the egg. The potential energy that the egg has at the beginning of the drop is transformed into kinetic energy.

When a dropped egg reaches the ground, it has a lot of kinetic energy built up until its momentum is stopped very suddenly at the moment of impact and the kinetic energy is released into the ground and into the flying egg debris (the liquid yolk, white, and bits of shell). How might an egg impact look in slow motion?

If you consider dropping an egg into a pile of feather pillows, what do you think will happen to the egg? Because the pillows slow down the momentum of the egg over a longer period of time (not in one short impact as would happen when an egg hits the ground) as the kinetic energy is transferred from the egg into the pillows. In essence, they are disbursing the kinetic energy. Continue reading

Father and Son Team Send Balloon Into the Upper Atmosphere

Balloon

Most of you have seen or at least heard of weather, or high altitude, balloons. These balloons are generally used to lift scientific instruments high into the atmosphere for everything from studying weather to taking scientific pictures and video. While scientific launches of these balloons are not uncommon by groups such as NASA or the NOAA it is fairly uncommon for private, non commercial parties to have successful launches.

The balloon in question here is one launched from Brooklyn, New York. This balloon was a 19-inch helium-filled weather balloon with a small capsule attached to it containing some basic scientific instruments. What makes this balloon and experiment so unique is that it was thought up, tested, and executed by Luke Geissbühler and his 7-year-old son Max. That’s right, a man and his 7 year old son sent a balloon filled with helium into the stratosphere about 100,000 feet into the sky.

First, let’s look at what these two came up with to send to the edge of space. To start with, they needed a way to get everything into the sky. They achieved this with a 19-inch weather balloon filled with helium. Next, they needed a way to get the balloon to stop going up and start coming back down. This was actually one of the easiest parts, since as the balloon rises; air pressure becomes less, which allows the air inside the balloon to increase in volume. This means that the balloon that was 19-inches across when it was launched, grew to around 18 feet across before bursting! It is this bursting that allows the balloon to begin it’s descent back to Earth. A parachute slowed the scientific package, so that the electronics in the container could survive the return trip. Next, let’s look at what was in the scientific package. Continue reading