Science of Technology

Modern technology depends on energy resources and materials found on Earth.
Economic and environmental issues can influence the choice of resources.
Small Forces can be leveraged into large forces (Fd tradeoff).
Energy is a quantity that can be measured and transformed (Conservation).
Many natural resources are mixtures of molecules, and can be separated by physical means.
Some molecules release energy when they experience a chemical change.
Electricity can be measured on scales of voltage, current, and power, which are related but different concepts.
Ohm's Law describes the relationship between voltage, current, and resistance in an electrical circuit.
Many forms of technology rely on a complex web of inputs, processes, output, and feedback.
Complex information can be simplified into streams of binary digits.
There is a spectrum of electromagnetic wave energy, with varied frequencies and wavelengths.
The transmission and absorption of electromagnetic waves varies, and can be used for many purposes.
Newton's Laws of Motion can predict the location, velocity, and acceleration of objects.
Newton's Law of Universal Gravitation predicts interactions of objects throughout the cosmos.
Cosmology gives a sense of our place in the Universe.
Stars go through a predictable life cycle, governed by gravity and nuclear forces.
The Earth changes over time, both rapidly and gradually.
Mapping conditions of the Earth can help anticipate natural disasters.

What are things made of?
How do we turn natural resources into useful materials?
What happens to these materials when we are done with them?
How can we multiply our strength to move massive objects?
How can the same RPMs produce different speeds?
How do things burn?
What makes a good fuel?
What is in the exhaust?
How does the power company calculate your bill?
How can the same voltage produce different wattage?
How do sensors automatically control your devices?
How does visual information flow to TVs, monitors, and printers?
How do our cell phones work?
How are radio-waves related to x-rays?
How can we leave our home planet?
What would it be like to travel in outer space?
What kinds of stars are out there?
Will our Sun ever die, and if so, how?
How is our Earth dependent on ancient stars?
Can we predict weather? Earthquakes? Volcanos?
What was the Earth like in the past, and how will it change?

Metals are typically found as part of a chemical compound.
The periodic table of the elements displays 98 elements which can be found in nature, and the majority of them are classified as metals. Metals have many important properties, but here we will focus on their electrical conductivity and physical deformability. In nature, almost all metals are found chemically bonded to other elements. In most cases, in order for the metals to be useful, these chemical bonds must be broken. That process is called smelting. Once that process is finished, the metals can form new chemical bonds, which we call corrosion. In some cases, blending different elements makes the result more valuable than the pure element. These materials, called alloys, can be stronger, more flexible, or more resistant to corrosion than the metals that make up the alloy.
Carbon compounds can be combined into long-chain molecules called polymers.
Some molecules, like water, are made of just a few atoms linked together, but some macromolecules, made of many atoms linked together, are very common and important. Some macromolecules, like cotton, linen, wool, and silk, are the result of a natural process, and have been used for centuries. Some macromolecules, like plastic, have only been known for a few decades, and must be synthesized from natural materials. Plastics are also called polymers, because a single simple component (called a monomer) is linked together in long chains. These chains give polymers great strength and durability. Although there are many different forms of plastic, six are common enough to have a recycling code. Most polymers are based on a chain of carbon atoms, with different atoms branching off of this long chain. The polymer known as polyethylene is made when a molecule called ethylene has its double bond broken by a catalyst and links together into a long chain. The resulting material can be pressed into low-density or high-density form, and is the most common material used for plastic bags, milk jugs, and detergent containers. The recycling codes are #4 for Low-Density Polyethylene (LDPE) and #2 for High-Density Polyethylene (HDPE) and are commonly accepted for recycling. After processing, the material can be used for products like plastic lumber.
Some materials are naturally radioactive, and others can be made radioactive.
Different chemical elements are different because of the number of protons in the nucleus. If two elements have different names, they have a different number of protons. This number can be found easily on the periodic table of elements by looking for the atomic number. This number is always an integer, and increases sequentially as the number of protons increases by one. The nucleus also typically contains a number of neutrons, and this number can be variable. Some elements found in nature have the same number of neutrons, but other elements exist in several varieties, called isotopes. These isotopes must all have the same number of protons, but have different numbers of neutrons. We identify these isotopes by name and total mass (equal to protons plus neutrons. For example, helium normally has two protons and two neutrons and we call it He-4. If we find a helium atom with three neutrons, it would be called He-5. Carbon-12 is a very stable atom, and forms many common and useful molecules, like carbon dioxide, carbohydrates, and many pharmaceuticals. In nature, we also find a small percentage of Carbon-14, which is radioactive. This means that plants absorb some radioactive carbon dioxide, make some radioactive carbohydrates, and make humans very slightly radioactive. Other elements have radioactive isotopes in nature, and this natural radioactivity is a larger source of radiation for most people than anything resulting from technology. Some isotopes, however, have useful applications, using the radiation to kill dangerous organisms or tumors.
Maximizing the value of natural resources requires attention to “The Three Rs”.
Much of the waste we generate gets buried in landfills or burned in incinerators. The \“Three Rs\” (Reduce, Reuse, Recycle) offer alternative methods of dealing with this waste. \“Reduce. Reuse, Recycle\” describe these methods in order of desirability for saving materials and energy in order to minimize environmental impact and resource availability. Recycling takes discarded materials, separates them by type, and processes them to become raw materials for a new product. Some distinguish Recycling into \“Upcycling\”, which converts low-value material into a high-value product, and \“Downcycling\”, which converts high-value material into a low-value product. Reusing finds a way to get more use out of discarded products without the energy requirements involved in Recycling. When items are repaired, cleaned, given to others, or used for a new purpose, the items can be considered reused. Reducing involves finding a way to get the same value out of a smaller investment of resources. When unnecessary products, packaging, or components can be eliminated, resources are conserved for later use. When superior design accomplishes the task with less material, waste has been reduced.
Energy is a quantity that can be found, but never created.
The modern economy relies extensively on natural energy resources that can be transformed into the type of energy we need. Some of these energy resources are renewable, with energy continuously provided as long as the sun shines, winds blow, and rain falls. The Earth also has reserves of non-renewable energy sources, which can be mined or pumped out of the Earth, and are not regenerated on any reasonable time scale. Some of these resources are used to provide heat, and some used to produce electrical energy. In an electrical power plant, kinetic energy is converted to electrical energy in a generator. The moving air, water, or steam turns a set of blades or spins a turbine, and electrical energy is produced by an electrical generator. Some resources provide a steady supply of kinetic energy, while others can be stored and used on demand. The choice of energy resource can depend on many factors. Sometimes, price/availability is the main factor. In other cases, the ability to store the energy is critical (as in an automobile). Sometimes, harnessing a resource (like wind, solar, or hydroelectric) requires certain features of geography or climate. In many cases, the versatility of electrical energy makes it a desirable form of energy, worth the effort of transforming natural resources into electricity.

Large masses and small masses can balance.
Small forces can be leveraged into large forces.
Leverage can be achieved in many ways.
Some machines trade a large input force for a large output speed.
Friction takes away from mechanical advantage.

A small number of elements can combine in different ways to make different substances.
Nature provides a variety of hydrocarbon resources.
Some materials change in a way that form or break chemical bonds.
Some materials change in a way that preserves the original molecule.
Hydrocarbon combustion involves predictable chemical reactions.

Electrical energy can be produced in a variety of ways.
Energy is a quantity that can be wasted, but never destroyed.
Voltage and current are different.
Energy can be transformed at different rates; this rate is known as power.
Alternating current can be transformed to higher or lower voltages.

Electrical switches can be made to reflect logical conditions.
Images can be digitized by breaking the image into pixels.
The full range of colors can be reproduced by adding distinct frequency ranges.
Colors can be reproduced by subtracting frequency ranges from natural light.
Some materials allow current to flow under certain conditions.

Information can be carried through waves.
Electrical signals can be converted into analogue sound waves and vice versa.
All waves moves through a given medium with a fixed speed.
A moving change creates electromagnetic radiation.
Radio communications can be based on encoded carrier waves.

Inertia is a property of matter.
Net forces accelerate objects.
All forces involve an interaction between two objects.
Orbits follow predictable patterns.
The human body experiences acceleration in ways comparable to gravity.

There is a great diversity in the physical properties of stars.
Gravity ignites fusion in stars.
Stars evolve and die.
The universe is really big.
The universe is expanding.

Rocks on Earth cycle into and out of its molten core.
Carbon cycles in and out of the atmosphere.
Water cycles in and out of the atmosphere.
The Earth's climate fluctuates dramatically across geologic times scales.
Human activity introduces distinctive contaminants into Earth's ecosystem.

Refineries put ore through a chemical change, releasing the metal from the compound.
Different metals can be mixed in order to produce desired properties.
'Different monomers are used to make different polymers.
Polymers can be extremely strong and durable.
Radioactive materials can give off different kinds of radiation.
Different isotopes of the same element can be stable or radioactive.
\“Reduce\” requires careful analysis of the value added by each component, and pre- planning.
\“Reuse\” and \“Recycle\” are different; recycling breaks products into raw materials.
Mechanical energy can be harnessed from natural sources of motion (wind and water).
Natural resources of chemical energy can be converted into mechanical energy in power plants.

Mass and distance from a fulcrum are equally important in determining balance.
Center of mass can be used to predict rotational properties.
Small forces must be applied over large distances to move large objects a small distance.
The mechanical advantage of a lever can quantify the amount of leverage.
Lever-like machines have a clear input and output distance.
Wedge-like machines produce an output force in a different direction than the input force.
Gear ratios can predict the multiplication of speed.
Chains of simple machines can multiply each machine's mechanical advantage.
A certain amount of force is necessary to initiate movement in machines with friction.
The difference between expected and observed MA can be quantified as \“efficiency\”.');

Carbon, hydrogen, and oxygen make many molecules essential to life.');
Alkanes are a family of related hydrocarbon molecules.');
Hydrocarbons can be “cracked” into smaller molecules.');
Organic synthesis can produce useful materials from simple building blocks.');
Fossil fuels are carbon based remains of ancient living organisms.');
Biofuels are carbon- based fuels extracted from living organisms.');
Evaporation and condensation can separate crude oil into useful fractions.');
Aerosol cans often use flammable hydrocarbon propellants.');
The \“fire triangle\” summarizes the essential conditions for combustion.');
Pollution results from the by-products of combustion.');

An electrical generator converts mechanical energy into electrical energy. ');
Batteries move electrical energy from one material to another. ');
Mechanical energy produces some amount of friction, which converts useful energy into heat.');
Electrical currents produce heat, which may or may not be desired.');
The same voltage can produce different amounts of current, depending on the resistance. ');
Batteries can be connected in series or in parallel, producing different voltages. ');
High power devices transform energy quickly; low power devices transform energy slowly.');
Energy demands are calculated by multiplying average power and total time of use.');
Large currents increase fire risks. ');
Higher voltages increase electrocution risks. ');

Switches in parallel create OR conditions.');
Switches in series create AND conditions.');
Objects smaller than a pixel cannot be represented in detail.');
Sequences of images can create the illusion of moving pictures.');
The full range of visible light (ROY G BIV) can be approximated by mixtures of RGB.');
Mixed colors can be identified by the amount of RGB represented by a binary code.');
Some materials subtract out R, G, or B from natural light.');
Cyan, Magenta, and Yellow are the complementary colors to Red, Green, and Blue.');
Semiconductors allow the flow of current under conditions triggered by light or charge.');
Mechanical switches have moving parts with make and break electrical continuity.');

There are two distinct distance measurements of waves: amplitude and wavelength .');
There are two distinct rate measurements of waves: frequency and speed.');
An electrical current in a coil of wire will be pushed by a nearby permanent magnet.');
A moving diaphragm can generate a current in an attached coil in the vicinity of a magnet.');
The frequency of the moving charge determines its properties (RMIVUX-G).');
When a certain threshold frequency is crossed, EM radiation becomes ionizing.');
Wavelength is directly proportional to its speed and inversely proportional to its frequency.');
Unlike sound waves, radio waves are not mechanical, much faster, and extend to higher frequencies.');
FM signals modulate the frequency of the carrier wave–AM modulates its amplitude.');
A tuner isolates the vibrations of a particular frequency in order to tune out other signals.');

An object will persist in its state of uniform motion OR rest, in the absence of external forces.');
Objects in free fall observe Newton's First Law very clearly.');
An object's acceleration is directly proportional to net force and inversely proportional to mass.');
When more than one force acts on the object, only the net force will determine its acceleration.');
The mutual actions of two bodies on each other are equal and opposite.');
Gravity is a universal force of attraction between two massive objects.');
Gravity puts objects into an elliptical path around the center of mass of the system.');
An orbiting object speeds up as it approaches perigee and slows down as it approaches apogee.');
A lateral acceleration of 9.8 m/s/s feels indistinguishable from Earth\'s surface gravity.');
The acceleration (or deceleration) of a lift-off (or accident) can be harmful.');

Among main sequence stars, mass, temperature, and intensity are all mutually proportional.');
Reflecting and refracting telescopes focus light to allow more careful analysis.');
Gravitational attraction of mass collects matter into clusters, increasing speed and temperature.');
At a critical temperature, hydrogen fuses into helium and releases tremendous amounts of energy.');
As stars use up hydrogen, they expand and cool before collapsing and heating up again.');
A massive star's collapse can initiate a supernova, leading to a neutron star or black hole.');
Light from the most distant stars has been on its way to Earth for billions of years.');
Stars are clustered into galaxies, like the Milky Way.');
The more distant the galaxy, the more its light is red-shifted, the result of a Big Bang.');
There is a residual amount of microwave radiation from the Big Bang.');

Heat and pressure can create crystalline structures, like glass or jewels.');
The Earth's crust has distinct plates, whose boundaries give rise to earthquakes and volcanoes.');
Carbon dioxide levels decline as organisms grow, and increase as organisms decompose.');
Carbon dioxide is one of several atmospheric molecules that trap solar energy.');
Precipitation is a chaotic system, sensitively dependent on moisture and temperature.');
Water quality can be compromised by organic and inorganic contaminants.');
Ice ages have happened at irregular intervals in Earth's history, for reasons not fully understood.');
Temperature trends are increasing, with a scientific consensus that human activity is the primary cause.');
The effectiveness of a particular chemical should be weighed against any negative consequences.');
The EPA regulates six atmospheric pollutants which pose risks to human health.');

Science of Technology

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