Physics 

What is ‘Tensile Testing’?

The ‘tensile’ properties of a material describe its most basic mechanical behaviour – how much does a material stretch when it is pulled and how much of the stretching is permanent? ‘Tensile Testing’ is the process of measuring a material’s tensile properties. 

Why are tensile properties important?

Understanding of tensile properties is vital for any application that uses materials structurally, i.e. to withstand or apply force. The range of uses this covers is enormous. Strong and stiff structures are used in vehicles (cycles, cars, trains, aeroplanes, spacecraft), bridges and buildings, sports equipment and bio-implants (e.g. hip joint replacements). Flexible materials are also used in many of these applications. Thin but robust materials are used in touchscreens. Hard materials are used in machines and robots that process and shape other materials and as durable coatings that improve the performance and lifetime of aerospace and bio-implant components. Elastic materials can be stretched enormously before any permanent change is made and are used in springs and high performance fabrics. And it’s not just how a component is used – many manufacturing processes involve changing a component’s shape or response to applied forces, e.g. extrusion to make tubes, beams and bottles; drawing to make springs or wires; or forging and rolling to shape and harden metals.

Use this experiment to find out more!

​Download the file below for the quick guide for the Tensile Testing experiment (requires login) or follow these brief instructions:

To select a sample:

• Click the lower jaw to go to the sample view.
• Open the calliper jaws, drag a sample of choice between the jaw and fully close the jaws around it. (In this LITE version you can only select one of the samples).
• Use the Vernier scale to measure the sample width.
• Click the sample held in the callipers to use it in the tensile testing machine.
• Or open the callipers, return the sample to its original position and choose another sample. (Only available in the full version).

To set the strain increment:

• Click the Set button (display starts to flash).
• Use the keypad and the Del button to enter the desired Step value.
• Click the Set button again (display stops flashing).

To apply strain to samples:

• Set the strain increment value as described above.
• Click the up arrow to increase the applied strain by the Step increment value.
• Click the down arrow to decrease the applied strain by the Step increment value.
• Measure (and record) the applied load (force) using the needles on the Load dial.
• Turn off the strain control unit and click on the lower sample holder to select a new sample.

Download the file below for full instructions for the Tensile Testing experiment (requires login).

Structural materials are required to withstand a variety of applied loads in use. Understanding how these materials respond to the applied loads is vital for informed materials selection. Here we investigate how materials behave under tensile loading (loads applied along the length of a material to cause stretching).

The Tensile Test experiment allows a number of mechanical tests to be performed on materials, including:

• Determination of full stress-strain curve to fracture, using either ‘engineering’ or ‘true’ value
• Observation of elastic behaviour and calculation of Young’s modulus
• Observation of the onset of plastic behaviour and permanent deformation
• Calculation of moduli of resilience and toughness
• Calculation of strain energy in a system
• Calculation of work done in deforming a sample

Download the file below for activities for the Tensile Testing experiment (requires login). 

• QUICK ACTIVITIES: 9 quick activities to try
• ACTIVITY 1: Elastic deformation
• ACTIVITY 2: Plastic deformation
• ACTIVITY 3: Fracture

(Available as separate downloads or all activities)

*NEW* Now also available in editable Microsoft Word format

We have also provided a spreadsheet file to allow you to enter your SAMPLE WIDTH, STRAIN and APPLIED LOAD data and obtain stress-strain plots. (HINT: to investigate the general form of stress-strain curves with younger students, use a default sample width of, say, 7 mm)

Watch the video above and download the file below for the background science behind the Tensile Testing experiment (requires log in).

Ohm’s law

Voltage, current and resistance are the most fundamental quantities for describing the flow of electricity. Ohm’s law shows how these three quantities are related and so is a powerful way of understanding the basic nature of electricity.

This is relevant to vast areas of technology today, including national electricity grids, power generation, design of all electronic devices and all electronic circuits, heating, electrical safety and understanding of natural phenomena such as lightning. This experiment will allow you to explore Ohm’s law by making measurements of voltage, current and resistance.

Resistors

Resistors are the simplest and most commonly used electronic component and almost all electronic circuits contain them. They can be used to change the properties of any circuit they are part of, such as current flow, how voltage is distributed across components, the speed of a circuit, the amount of amplification from a circuit, the response of a sensor or the amount of electrical heating from a circuit.

The simplest resistors are made of a thin film or wound wire of carbon or metal. They usually have a series of coloured bands that represents both their target resistance value and how much the actual value might vary from this (the ‘tolerance’). This experiment lets you practise selecting the appropriate colour bands on a resistor to achieve a certain resistance value.

Digital Multimeters

Digital multimeters (DMMs) are versatile pieces of equipment commonly found in electronics, physics and engineering labs. In this experiment you’ll learn how to use a DMM to measure voltage, current and resistance. You’ll see this piece of equipment in many other FlashyScience experiments!

Use this experiment to find out more!

Download the file below for the quick guide for the Ohm's Law experiment (requires login) or follow these brief instructions:

To measure resistance:

• On the right-hand Digital Multimeter (DMM), rotate the switch to resistance measurement.
• Click and drag the clips on the wires attached to the right-hand DMM so that they snap to the wires either side of the resistor (make sure the power supply is turned off).
• Note the resistance value shown on the DMM screen.

To change the resistor:

• Click the resistor you wish to change to move to the Selection screen.
• Click on the colour band you wish to change.
• Click on the palette colour you wish to select.
• Click on the resistor wire to return to the main screen.

To use voltage and current:

• Turn on the power supply (right hand side of screen) and turn the dial to set the voltage.
• To measure current through the resistor – turn the left-hand DMM dial to DC current.
• To measure the voltage across the resistor – turn the right-hand DMM dial to DC voltage.
• NOTE: in this experiment the power supply voltage is also shown directly on its display.

​Download the file below for full instructions for the Ohm's Law experiment (requires log in).

Download the files below for activities for the Ohm's Law experiment (requires login).

• ACTIVITY 1: Investigate what the different coloured bands on resistors mean
• ACTIVITY 2: Learn how to use a DMM to measure electrical resistance
• ACTIVITY 3: Explore the effect of the tolerance band (band 4) on resistors
• ACTIVITY 4: Explore the statistics of resistance values from resistors with the same band colour coding
• ACTIVITY 5: Investigate Ohm’s law by measurement of voltage and current with a resistor
• ACTIVITY 6: Investigate Ohm’s law by measurement of current for different resistors with a fixed voltage
• ACTIVITY 7: Investigate Ohm’s law by measurement of voltage for different resistors with a constant current
• ACTIVITY 8: Investigate the power consumption due to electricity flowing in a single resistor
• ACTIVITY 9: Investigate the power consumption due to electricity flowing through different resistances

(Available as separate downloads or all activities)

*NEW* Now also available in editable Microsoft Word format

Download the file below for the background science behind the Ohm's Law experiment (requires log in).

It is safe to say that gravity is important to us! Without gravity there would be no life on Earth and, in fact, without gravity, the Earth would never have existed.

Gravity is responsible for stars forming in the first place, keeping the Sun from exploding from the heat it generates, and for the structure of galaxies. It also keeps the Earth in orbit around the Sun, keeps our atmosphere and oceans in place and means we don’t float off into space. Gravity even allows plants to detect which way is ‘up’ so they send their roots and shoots in the right directions. You can see more at this NASA web page.

So, why does it matter that we know how strong gravity is?

Well, for lots of reasons.

The strength of gravity is essential to know in Civil Engineering projects such as design of
buildings and bridges so we can calculate the stresses materials are under.

Aircraft and space rocket designers must know the strength of gravity that must be overcome and satellite technology is based upon a certain strength of gravity to maintain orbits at particular heights above the Earth.

Hydroelectric power generation also relies on gravitational potential energy, either through energy ‘storage’ in dams or from the water flow or tides in rivers or oceans.

Our quality of life would be very different too. Most sports rely on gravity (we’re not counting chess as a sport here!) and gravity even keeps food in a saucepan while it cooks!

Use this experiment to find out more!

​Download the file below for the quick guide for the Free-fall due to Gravity experiment (requires login) or follow these brief instructions:

• Choose between using a Pressure Pad sensor and Light Gate sensors using switch on side of timer.
• If using Pressure Pad sensor:
  • Click and drag the electromagnet 
  • Read the height of the ball on the electromagnet using the magnified view of the ruler
  • Press the Start/Reset button to release the ball from the electromagnet
  • Read the time (from the timer) for the ball to drop to the pressure pad
  • Press the Start/Reset button to return the ball to the electromagnet and reset the timer to zero
• If using the Light Gates:
  • Click and drag the electromagnet and both light gates to adjust their height on the ruler but ensure the separation of the electromagnet and first light gate is constant throughout your experiment
  • Measure the distance between light gates using the magnified view of the ruler
  • Press the Start/Reset button to release the ball from the electromagnet
  • Read the time for the ball to fall between the light gates
  • Press the Start/Reset button to return the ball to the electromagnet and reset the timer to zero

Measured Earth’s gravity? Click on the poster to explore gravity elsewhere in the Solar System too!

Download the file below for full instructions for the Free-fall due to Gravity experiment (requires log in).

Download the files below for activities for the Free-fall due to Gravity experiment (requires login).

• ACTIVITY 1: Measurement of g using pressure pad sensor
• ACTIVITY 2: Measurement of g using light gate sensors
• ACTIVITY 3: Travel the Solar System!
• ACTIVITY 4: Uncertainty in g based on uncertainty in individual measurement

(Available as separate downloads or all activities)

*NEW* Now also available in editable Microsoft Word format

Download the file below for the background science behind the Free-fall due to Gravity experiment (requires log in).

Radioactive elements (radionuclides or radioactive isotopes) produce high energy particles and are used in a huge range of applications. Most people know about nuclear power, which converts the energy of radiation from uranium-238 or plutonium-239 into heat and then electrical power, even in small-scale form for remote applications (e.g. spacecraft). There are far more widespread uses all around us though.

Radionuclides are used in many medicinal applications. They can be used as tracers to follow fluid flow inside the body by detecting the radionuclide emitted radiation (e.g. technetium-99, thallium-201, iodine-131 and sodium-24). Medical imaging can use radioactive elements that naturally collect in particular parts of the body and image the radioactive emission. For example, iodine-131 is used to image the thyroid and other isotopes can be used for other organs, such as bones, heart, liver and lungs. Larger doses of the radionuclides (e.g. cobalt-60) are used to create a targeted radiotherapy treatment of cancer in these organs. It is even possible to detect the presence of Heliobacter pylori (an unwanted bacterium that can be in stomachs) with a simple breath test that uses carbon-14.

You may have radioactive materials in your home, school or workplace. Smoke detectors use alpha radiation from americium-241 to ionise smoke particles for detection. Glow-in-the-dark inks on clocks, watches and emergency signs that convert radioactive particle energy from promethium-147 into light.

You may also have food that has been treated with radiation. Many foods (including tomatoes, mushrooms, berries, cereals, eggs, fish and some meat products) are irradiated with gamma rays from cobalt-60 to kill micro-organisms and improve the food’s shelf life (without making the food radioactive!). Similarly, gamma radiation from caesium-137 is used to sterilise medical products such as syringes, heart valves, surgical instruments and contact lens solutions.

Radioactive elements are used in industry too. For example, the absorption of different types of radiation mean it can be used to monitor the thickness of manufactured components and sheets. Radionuclides are also used for detecting leaks from pipes, the direction of underground pipes and waste dispersal in the environment. Radioactive sources are also used in industrial imaging, with the sample placed between the radiation source and a detector. Certain isotopes are used as chemicals in order to trace chemical reaction routes, e.g. carbon-14 in photosynthesis. Similar approaches are used in biology to test when proteins undergo important ‘phosphorylation’ reactions (using phosphorus-32) to learn when their function is activated by other proteins or small chemicals.

Radioactive elements can also be used for historical dating of objects, e.g. carbon-14 dating for estimating the age of organic matter and uranium-238 for rocks. Similarly, radioactive decay from vintage drinks such as wine can be used to prove their age, since radionuclides were released into the atmosphere by nuclear explosion tests after World War II and are present in all food and drink produced since then.

With so many uses, it’s no wonder that radioactive decay is an important aspect of science and engineering!

Use this experiment to find out more!

​Download the file below for the quick guide for the Radioactivity experiment (requires login) or follow these brief instructions:

Select the radiation source:

• Click on the Source holder.
• Click on one of the radiation sources in the tray and then in the holder.

Detecting radiation:

• Click the power switch on the Geiger-Müller counter.
• Read the needle position on the dial to measure level of radiation.

Changing the filter material and thickness:

• Click on the filter holder.
• Click on the material of choice to increase its thickness in the holder by 1 mm.
• Click on the material in the holder to reduce its thickness by 1 mm.
• Measure the filter thickness using the markings inside the holder.

Change the source-detector separation:

• Click and drag the holder mount to move it along the ruler.
• Measure the mount’s position using the magnified ruler view seen while clicked on the holder mount.

Time travel!

• Move time forward by one minute, hour, day, month or year by clicking on the appropriate value on the clock.

Download the file below for full instructions for the Radioactivity experiment (requires log in).

Download the file below for activities for the Radioactivity experiment (requires login).

• ACTIVITY 1: Radioactive half-life… and time travel! (used in GCSE Physics)
• ACTIVITY 2: Inverse square law (used in A-level Physics)
• ACTIVITY 3: Which materials absorb different types of radiation?
• ACTIVITY 4: Radiation absorption strength
• ACTIVITY 5: Alpha radiation (advanced experiment)
• ACTIVITY 6: Mixed radiation sources

(Available as separate downloads or all activities)

*NEW* Now also available in editable Microsoft Word format

Or see if you can do some of the following:

• Measure the half-life of different sources (GCSE)
• Measure how detected gamma radiation varies with source-detector separation
• Find out how alpha, beta and gamma radiation is absorbed by various materials
• Explore multi-decay type radioactive sources

Download the file below for the background science behind the Radioactivity experiment (requires log in).

Electronic materials are crucial to our life today, and electrical ‘resistivity’ tells us how good or poor a material is at conducting electricity.

We use materials with low electrical resistivity to transmit electrical power from generators, across grid distribution networks, and to homes and workplaces for use. Designers of electrical devices rely on knowing the resistivity of wire used in order to calculate the resistance of components.

These devices range in size from enormous machines such as wind turbines or industrial lifting equipment; motors or engines in electric vehicles and all-new electric aircraft; consumer products such as washing machines, hair dryers and ovens; and the nanoscale components within the computer chips found in smart devices, laptops, and mobile phones.  

In fact, modern computing is based on controlling the resistivity of semiconductor materials in a type of transistor (known as ‘field effect transistors’ using ‘CMOS’ technology).

Measuring electrical resistivity helps us to understand the properties of materials, to monitor manufacturing processes, and to select the best material for an application.

Use this experiment to find out more!

Download the file below for the quick guide for the Resistivity of a Wire experiment (requires login) or follow these brief instructions:

1. Click on the right hand wire post to move to the Select Wire screen.
2. Open the micrometer by dragging the thumbwheel down.
3. Choose a material and drag the unlabelled wire into the micrometer.
4. Close the micrometer and measure the wire's width.
5. Click on the wire while it's in the micrometer to return to the main screen.
6. Click on the switch to turn it on.
7. Measure voltage and current for a variety of contact positions on the wire.
8. Calculate resistance for each contact position. 
9. Plot resistance vs contact position and calculate the gradient of a line of best fit.
10. Multiply the line's gradient by the wire's cross-sectional area to obtain the wire's electrical resistivity.

Download the file below for full instructions for the Resistivity of a Wire experiment (requires log in).

Download the file below for activities for the Resitivity of a Wire experiment (requires login).

• QUICK ACTIVITIES: 5 quick activities to try
• ACTIVITY 1: Different wire lengths

(Available as separate downloads or all activities)

*NEW* Now also available in editable Microsoft Word format

Download the file below for the background science behind the Resitivity of a Wire experiment (requires log in).

Stretching – the truth!

You may wonder why we study springs and why questions about stretching springs appear on exams. Sure, springs are used in the world, but are they really so important? Why is it important to know how springs stretch when they are pulled?

Well, first, springs are incredibly useful. When made from elastic materials, such as most metals, springs stretch when pulled and return to their original size when released. They can also be compressed and, again, return to their original size when released. The stretching or compression stores energy that is then returned when the spring is released. This energy storage and return is the key reason springs are useful. Springs use this capability in all sorts of applications, including in high tech areas such as automotive, industrial tools and robotics, to more everyday items such as trampolines, mattresses, children’s play equipment, door handles and retractable pens. 

The second reason is that the way that springs respond to force being applied to them (i.e. being pulled or mass added to one end of them) is identical to how materials in general behave. If materials are pulled, then they stretch. The coiled shape of a spring, though, means that the ends tend to move large distances compared to a regular shape of the same material (e.g. a simple rod). This means that studying what happens to springs when they are pulled allows simple measurements to be performed that give us understanding of how all materials behave when they are pulled. Materials behave this way in any application where they have force applied to them, e.g. in construction, vehicles, heart valves, body implants, plants, rocks, furniture, tools, footwear – the list goes on and on. And don’t forget this includes your body too!

Use this experiment to find out more!

Download the file below for the quick guide for the Hooke's Law experiment (requires login) or follow these brief instructions:

1. Click on 50 g or 100 g masses to add them to the mass holder.
2. Click on the ruler to go to a zoomed view (centimetre scale).
3. Click on the masses on the holder to move them back to their boxes.
4. To change to a different spring:

• Remove all mass from the holder.
• Click on the spring.
• Select from Low, Medium, High or Unknown Stiffness.
• Click again on the spring to return to main screen. 

5. To change to a different part of the Solar System: 

• Remove all mass from the holder.
• Click on the poster to choose where to do the experiment.

6. Click the Information button to see the controls.

Use this experiment to:

• Test Hooke’s law.
• Measure spring constants.
• Test the ‘limit of proportionality’ for springs.
• Calculate the stored energy of a spring.
• See how different strengths of gravity affect the weight added to a spring.

Download the file below for full instructions for the Hooke's Law experiment (requires log in).

Download the files below for activities and associated worksheets for the Hooke's Law experiment (requires login).

• ACTIVITY 1: Testing Hooke’s law
• ACTIVITY 2: Measurement of the stiffness of a spring
• ACTIVITY 3: Energy stored in a spring
• ACTIVITY 4: Limit of proportionality of a spring
• ACTIVITY 5: Travel the Solar System!

(Available as separate downloads or all activities)

*NEW* Now also available in editable Microsoft Word format

Download the file below for the background science behind the Hooke's Law experiment (requires log in).

There are lots of ways that we use materials that see them change temperature. Some examples include heating systems in buildings (especially storage heaters), simple household appliances such as an iron or an oven, combustion engines in cars, jet engines in aircraft, high speed machines such as drills, and industrial furnaces; however, examples also include applications where the temperature is reduced, for example in refrigerators, freezers and heat sinks, which are used to help cool another component.

A change in a material’s temperature will also result in a change in its heat energy. Different materials, however, will have a different change in heat energy for a given change in temperature.

The material's property we use to show this difference is called specific heat capacity. This property is key to allowing us to understand how components will perform in thermal applications and help us to choose the most appropriate material. If you go to study Physics or Engineering at university you will probably also learn how specific heat capacity values depend on a material’s types of atom, atomic bonding and electrical properties.

Use this experiment to find out more!

Download the file below for the quick guide for the Specific Heat Capacity: Solids experiment (requires login).

Download the file below for full instructions for the Specific Heat Capacity: Solids experiment (requires log in).

Download the files below for activities and associated worksheets for the Specific Heat Capacity: Solids experiment (requires login).

• ACTIVITY 1: Measurement of specific heat capacity of a material
• ACTIVITY 2: Comparison of specific heat capacity for different materials
• ACTIVITY 3: Measurement of specific heat capacity using different heating powers
• ACTIVITY 4: Effect of insulation on measuring specific heat capacity

(Available as separate downloads or all activities/all worksheets)

*NEW* Now also available in editable Microsoft Word format

Download the file below for the background science behind the Specific Heat Capacity: Solids experiment (requires log in).

The FlashyScience Acceleration and Force experiment might use a toy car on a table top but the science you can learn from it helps us to understand the world around us, to design all sorts of new vehicles and machines, and even to understand our bodies better.

At the largest of scales, knowing the huge forces involved with galaxies, stars and planets show us how these huge objects move and even how they form. We use our knowledge of force and acceleration to launch objects into space using rockets and to put satellites into stable orbits. This knowledge also allows us to calculate the acceleration of high performance cars (e.g. F1 cars) and aircraft, to design and build machines with moving parts, and to understand the forces parts of our bodies experience through an area of science called biomechanics. Force and acceleration can even be used to measure the mass of atoms and molecules through scientific techniques called mass spectrometry, and help us to understand how atoms interact in gases.

You can see that knowledge of force and acceleration is essential to lots of areas of science, engineering and our lives in general.

Use this experiment to find out more!

Download the file below for the quick guide for the Acceleration and Force experiment (requires login).

Download the file below for full instructions for the Acceleration and Force experiment (requires log in).

Download the files below for activities and associated worksheets for the Acceleration and Force experiment (requires login).

• ACTIVITY 1: Investigating acceleration, F = ma (mass transfer between car and mass holder)
• ACTIVITY 2: Investigating acceleration, F = ma (constant holder mass, increasing car mass)
• ACTIVITY 3: Distance versus time graphs

(Available as separate downloads or all activities/all worksheets)

*NEW* Now also available in editable Microsoft Word format

Download the file below for the background science behind the Acceleration and Force experiment (requires log in).

The thermal conductivity of materials is hugely important for how we live today.

Thermally-insulating materials are found in lots of places around the home. This includes safety items such as oven gloves or fire blankets and inside ovens and refrigerators to stop them heating or cooling the rest of your kitchen! Your hot water pipes and water heating system will probably have thermal insulation around them to stop unwanted heat loss. Houses and other buildings usually have thermal insulation around them to reduce heat loss when it is cold outside and reduce heat entering when it is very hot outside. This is important as we try to reduce CO2 emissions from energy use as part of our fight against climate change. Insulating materials are also used around industrial furnaces, in refrigerated vehicles and packages (e.g. for transporting food or medical supplies) in aircraft to keep crew and passengers warm in the cold air, and in spacecraft to stop the insides reaching temperature extremes and protecting the spacecraft itself from burning up if it re-enters Earth’s atmosphere.

Thermally-conducting materials are also very important to heating and cooling systems, such as heating elements in kettles and furnaces, radiators, high speed industrial machines and heat-sinks found in electronic devices.  

Heat conduction is also really important in many renewable energy technologies, such as solar cells (photovoltaics), which work less efficiently if they heat up, and ‘thermoelectric generators’ (TEGs), which are most efficient if they conduct electricity well but conduct temperature weakly.

This huge range of applications means there is a lot of research and development of materials with new thermal conduction properties. How materials conduct heat is also related to their atomic-scale structure – this means that we can learn about the materials from how they conduct heat and change their structure in order to create new properties that are better suited for particular applications.

Use this experiment to find out more!

Download the file below for the quick guide for the Thermal Insulation experiment (requires login).

Download the file below for full instructions for the Thermal Insulation experiment (requires log in).

Download the files below for activities and associated worksheets for the Thermal Insulation experiment (requires login).

• ACTIVITY 1: Effect of a material as thermal insulation
• ACTIVITY 2: Comparison of different materials as thermal insulation
• ACTIVITY 3: Effect of material thickness on heat conduction
• ACTIVITY 4: Effect of temperature difference on its rate of change (Advanced experiment)

(Available as separate downloads or all activities/all worksheets)

*NEW* Now also available in editable Microsoft Word format

Download the file below for the background science behind the Thermal Insulation experiment (requires log in).

Any object emits electromagnetic radiation due to having a temperature above absolute zero (about -273.15°C), although different surfaces emit the radiation to different levels. This might seem like a curiosity created just for lab measurements but it has lots of real-world relevance.

The hotter an object is, the stronger this thermal emission is. Objects with different temperatures emit different parts of the electromagnetic spectrum too. Objects close to room temperature (like us!) only emit infrared radiation (‘IR radiation’), which we feel as warmth. Objects at hundreds of degrees Celsius start to emit visible radiation (wavelength from 400 – 700 nm), those at thousands of degrees Celsius emit ultra-violet (UV) radiation (wavelength from 100 – 400 nm), while the hottest objects in the galaxy (e.g. regions around black holes) emit X-ray radiation (wavelengths shorter than 100 nm).

The most important aspect of thermal emission is that life on our planet would not exist without it! Our nearest star, the Sun, is so hot its IR emission reaches across over 140 million kilometres (that’s over 90 million miles) of space to warm our planet. The Sun’s visible light also allows us to see. The Earth’s ozone layer plays an important role in absorbing most of the UV light from the Sun, which would otherwise reach us at harmful levels.

Astronomers also use the thermal emission from other stars and astronomical objects to learn about how they were formed, their lifecycle, and the processes that go on within them.

Climatologists and meteorologists (scientists who study the Earth’s climate and weather) use satellites to map the IR emission of the Earth’s atmosphere and land to help predict future weather events and trends. The surface of the Earth can also be imaged to locate underground heat sources, objects and water flows.

In smaller-scale applications, surface materials are often chosen to help either cool or insulate an object by either maximising or minimising IR emission, depending on what is needed. IR emission is used in some household or industrial heaters and to measure temperature in areas such as industrial manufacturing processes and medical applications, e.g. measuring the temperature of a patient.

‘Thermal imaging’ cameras create images from IR emission for a huge range of applications, including night vision (e.g. for security systems or non-invasive imaging of wild animals), analysing heat sources in electronic circuits, industrial monitoring (e.g. web servers, aircraft engines), and analysing the thermal efficiency of objects from miniature devices to houses.

Use this experiment to find out more!

Download the file below for the quick guide for the Leslie Cube (IR emission) experiment (requires login).

Download the file below for full instructions for the Leslie Cube (IR emission) experiment (requires log in).

Download the files below for activities and associated worksheets for the Leslie Cube (IR emission) experiment (requires login).

• ACTIVITY 1: Infrared emission from different surfaces (basic)
• ACTIVITY 2: Infrared emission at different surface temperatures (basic)
• ACTIVITY 3: Detected infrared emission versus distance from source (advanced)
• ACTIVITY 4: Measurement of emissivity of different surfaces (advanced)
• ACTIVITY 5: Temperature dependence of infrared emission (advanced)

(Available as separate downloads or all activities/all worksheets)

*NEW* Now also available in editable Microsoft Word format

Download the file below for the background science behind the Leslie Cube (IR emission)  experiment (requires log in).

We use light in all sorts of ways. You are probably using a screen that emits light to read these words now and might be in a room that is lit by artificial light from a lightbulb.

This experiment deals with how light interacts with transparent materials. The fact that you can read this is down to how transparent materials in your eyes interact with and redirect light to create images. If you wear glasses or contact lenses, you are relying on these effects even more!

In fact, there are lots of types of imaging systems that work by redirecting light. These include a wide variety of microscopes and telescopes for making the very small or very large parts of our world and universe visible to us. These work by refracting light through lenses or by reflecting light from mirrors, or a combination of both.

Light scanners use light refraction or reflection in all sorts of applications, from barcode readers to laser display systems to laser machining tools used to process materials. 

Vast amounts of information are sent worldwide every minute of every day using packets of light travelling down transparent fibre optic cables. This vital technology depends on how light interacts with interfaces between two types of material. The future might see super-fast all-optical computers that use light to process information.

The way light interacts with a material can also tell us a lot about the material. Lots of scientific techniques use light to probe the nature of all sorts of materials.

The FlashyScience Reflection & Refraction of Light experiment allows you to learn about the way light behaves at surfaces and through transparent materials – this is a great starting point to understanding many of the ways we use light in the world around us!

Download the file below for the quick guide for the Reflection & Refraction of Light experiment (requires login).

Download the file below for full instructions for the Reflection and Refraction of Light experiment (requires log in).

Download the files below for activities and associated worksheets for the Reflection and Refraction of Light experiment (requires login).

• ACTIVITY 1: Reflection from a surface
• ACTIVITY 2: Refraction in materials: air-to-glass
• ACTIVITY 3: Refraction in materials: glass-to-air
• ACTIVITY 4: Transmission of light

(Available as separate downloads or all activities/all worksheets)

*NEW* Now also available in editable Microsoft Word format

Download the file below for the background science behind the Reflection and Refraction of Light experiment (requires log in).

Most people are familiar with waves on the surface of water from looking at ripples created by, for example, dropping stones into the water. This might seem to have little to do with how we live but this couldn’t be further from the truth – waves are essential for our existence and there is a huge range of applications of them in our world.

Understanding waves on water Is essential for understanding important topics like coastal erosion and how to reduce it, using renewable electricity from wave poower, designing ships, and even calculating the speed of tsunami events.

We find all sorts of other waves, too, though. Light is a kind of electromagnetic wave, together with all parts of the electromagnetic spectrum, including radio waves, microwaves, infrared radiation, ultra-violet, X-rays, and even gamma rays. The range of applications from these is immense, and includes, among many other areas, optics (do you wear glasses or contact lenses?), communications, displays, sensors, telescopes and microscopes, imaging techniques, medical diagnostics and therapies, radar, cooking, heating, energy applications, and manufacturing techniques (e.g. laser-selective melting 3D printing), and all sorts of scientific methods of measurements or controlling matter, e.g. measuring the distance between atoms in a material, finding the structure of a protein molecule, or even laser-cooling and trapping of atoms.

The vibrations in materials are waves, too, and these allow us to make all sorts of musical instruments with different sounds. Sound then travels through the air and materials as a wave, and this allows us to design soundscapes and tones using acoustics. These effects also allow sonar to map below the surface of the sea, acoustic imaging to visualise underground structures, and ultrasound imaging to show us inside the human body, for example, to check the health and development of a growing foetus through to visualising damage to a bone joint.

At a larger scale, seismology uses how wave vibrations travel through the Earth to understand its structure and why events like earthquakes happen. Understanding waves then also helps us to design buildings that can withstand earthquakes. Seismology is now even being applied to other planets in the Solar System to understand their structures, too. Believe it or not, the Sun’s surface shows ripples due to pressure waves inside it, and scientists study these to learn more about what happens inside the Sun. And, within the last few years, scientists have detected gravitational waves that travel through the universe!

Zooming back to the smallest scales, atoms and subatomic particles such as electrons often behave like waves (if you continue to study science will learn more about this in the coming years). These properties have been incredibly important for us to understand fundamental physics and have given us new areas of science such as ‘quantum mechanics’. This helps to explain the nature of atoms, how they interact, and why different elements have such different properties – these were huge questions for humankind for centuries. Indeed, all chemistry comes from electrons having wave properties, while the electrical properties of metals, semiconductors, and insulators, as well as most magnetic properties of materials, come from the wave properties of electrons.  Today, we’re seeing new technologies based on quantum mechanics, such as unbreakable codes (cryptography) and super-powerful ‘quantum computing'. These same wave properties of electrons lie behind crucial biological processes such as photosynthesis, without which there would be no life on Earth.

What’s great news is that waves have many common properties, whatever type they and wherever they are found.

The FlashyScience Properties of Waves experiment will help you on the first steps of the journey to understand how waves travel and can be used!

Download the file below for the quick guide for the Properties of waves (Ripple tank) experiment (requires login).

Download the file below for full instructions for the Properties of waves (Ripple tank) experiment (requires log in).

Download the files below for activities and associated worksheets for the Properties of waves (Ripple tank) experiment (requires login).

• ACTIVITY 1: How wavelength changes with frequency
• ACTIVITY 2: Speed of waves on water
• ACTIVITY 3: Relationship between wavelength and frequency
• ACTIVITY 4: Effect of water depth on surface waves
• ACTIVITY 5: Waves on different liquids (advanced)
• ACTIVITY 6: Effect of gravity on surface waves on liquids (advanced)

(Available as separate downloads or all activities/all worksheets)

*NEW* Now also available in editable Microsoft Word format

Download the file below for the background science behind the Properties of waves (Ripple tank) experiment (requires log in).

We use light in all sorts of ways. You are probably using a screen that emits light to read these words now and might be in a room that is lit by artificial light from a lightbulb.

Use this experiment to find out more!

This experiment deals with how light interacts with transparent materials.  You can explore the nature of the refraction of light by taking measurements using four different materials and applying Snell's law. Refraction is an important optical effect. The fact that you can read this is down to how transparent materials in your eyes refract light to create images. If you wear glasses or contact lenses, you are relying on refraction even more!

In fact, there are lots of types of imaging systems that work by refracting light. These include a wide variety of microscopes and telescopes for making the very small or very large parts of our world and universe visible to us. These work by refracting light through lenses or by reflecting light from mirrors, or a combination of both.

Light scanners use light refraction or reflection in all sorts of applications, from barcode readers to laser display systems to laser machining tools used to process materials. 

This experiment also allows you to investigate total internal reflection with the various materials provided. Vast amounts of information are sent worldwide every minute of every day using packets of light travelling down transparent fibre optic cables. This vital technology depends on  total internal reflection of light at the interface of two types of material to direct the light with minimal loss of intensity. The future might see super-fast all-optical computers that use light to process information.

The way light interacts with a material can also tell us a lot about the material. Lots of scientific techniques use light to probe the nature of all sorts of materials.

The FlashyScience Reflection & Refraction of Light experiment allows you to learn about the way light behaves at surfaces and through transparent materials – this is a great starting point to understanding many of the ways we use light in the world around us!

Download the file below for the quick guide for the Reflection & Refraction of Light (Advanced) experiment (requires login).

Download the file below for full instructions for the Reflection & Refraction of Light (Advanced) experiment (requires login).

Download the files below for activities and associated worksheets for the Reflection & Refraction of Light (Advanced) experiment (requires login).

• ACTIVITY 1: Snell's law (calculating refraction)
• ACTIVITY 2: Total internal reflection

(Available as separate downloads or all activities/all worksheets)

*NEW* Now also available in editable Microsoft Word format

Download the file below for the background science behind the Reflection & Refraction of Light (Advanced) experiment (requires login).

Simple harmonic motion can be seen all around us in objects and applications that improve our lives. However, it is also seen in the fundamental behaviour of molecules and materials, although this usually occurs at frequencies and length scales that require scientific instruments for us to observe them.

A child on a park swing will just be enjoying the ride, probably unaware that the swing’s movement is an example of simple harmonic motion, or SHM.

The same child might go on a larger ride, such as a Pirate Ship, at an amusement park. The ride’s designers will have used simple harmonic motion principles to calculate the frequency of the Pirate Ship, its maximum speed, and the forces involved, and use this to specify the construction materials and the electric motor that should be used.

Musical instruments often use simple harmonic motion. For example, the strings of stringed instruments such as a guitar or violin vibrate back-and-forth in a way that obeys simple harmonic motion.

Our understanding and measurement of time has been affected by simple harmonic motion. Pendulum clocks use the regular, simple harmonic motion of a pendulum mass to determine how fast the clock hands move, while this is done in quartz clocks and watches using the simple harmonic vibrations of a quartz crystal.

Shock absorbers, including those in cars, use springs in an oil that move with ‘damped’ harmonic motion to reduce vibrations and give the vehicle passengers a smoother ride.

Simple harmonic motion is important for hearing too. The cochlea in our ears is lined with hairs called stereocilia just 0.01 – 0.05 mm in length. These hairs vibrate when particular frequencies of sound are transmitted through the cochlea and give us our sense of hearing.

The electronic bonds that hold atoms together in molecules and solids create forces that try to return atoms to equilibrium positions. This results in simple harmonic motion, even at this atomic scale.

Different molecules have atoms and groups of atoms with different masses bonded in different ways (e.g., single or double bonds) that can also vibrate in different ways (e.g. three atoms bonded along a single axis can all vibrate along the axis or laterally to it). This means that molecules have different sets of vibrational frequencies that absorb light of the same frequencies, usually infrared light. Forms of infrared spectroscopy are therefore used to find what molecules are in a measured sample.

These vibrations are one of the main ways molecules and solids absorb thermal energy, and increasing the temperature of molecules or solids will increase the amplitude of their simple harmonic vibrations.  

There are also some sophisticated scientific effects that show simple harmonic motion. One example is electrons at the surface of some metals. A sea of conduction electrons can form, which then acts as a single object. This sea of electrons, known as a surface plasmon, can be made to oscillate across the metal using light. The simple harmonic motion of surface plasmons is currently being developed in research labs to create high sensitivity detectors (e.g., of molecules, proteins, and bacteria), computer chips thousands of times faster than those we have today, and even improved makeup!

Download the file below for the quick guide for the Simple harmonic motion (Pendulum) experiment (requires login).

Download the file below for full instructions for the Simple harmonic motion (pendulum) experiment (requires log in).

Download the file below for the background science behind the Simple harmonic motion (pendulum) experiment (requires log in).