Tuesday 14 March 2023

Let there be Light


The human eye can be deceptive in judging light levels, as we can see in both dark and bright conditions. However, using the @Pascoscientific Light sensor revealed surprising actual figures to students. #LightSensor #ScienceEducation

Monday 13 March 2023

DNA Extraction

DNA Extraction from Strawberries is fun and can be done at home with just one special ingredient, extremely cold isopropyl alcohol. It's a great fun experiment to do.




Extracting DNA from strawberries is a fun and simple experiment that can be done at home using household items. Here's a step-by-step guide:

Materials:

  • Fresh strawberries
  • Ziploc bag
  • Table salt Sea salt is best
  • Dish soap or washing up liquid
  • Water
  • Meat tenderizer (optional)
  • Kitchen Roll for the filter
  • Rubbing alcohol (or its proper name Propan-2-ol or isopropyl alcohol)
  • Small glass or plastic cup
  • Wooden stick or skewer

Procedure:

  1. Start by placing a few strawberries in a Ziploc bag and mashing them with your hands or a rolling pin until they are completely squished.
  2. Put some isopropyl alcohol in the freezer. (Don't worry it will not freeze.)
  3. Mix 1/4 teaspoon of table salt, 1 tablespoon (20ml) of washing up, and 1/2 cup of water in a separate cup. Stir the solution gently to avoid creating too many bubbles.
  4. Pour the salt and soap solution into the Ziploc bag with the mashed strawberries and gently mix the contents together for about 5 minutes.
  5. Add a pinch of meat tenderizer to the bag and continue to mix gently for another 2-3 minutes. The meat tenderizer helps break down the cells' proteins and release the DNA.
  6. Place a coffee filter or kitchen roll over a clean cup and pour the bag's contents onto the filter. Let the mixture drain through the filter, and use a wooden stick or skewer to push the pulp through the filter to extract as much liquid as possible. This bit takes a long time.
  7. Carefully pour about 2-3cm or 1 inch of rubbing alcohol into the cup, and carefully pour the strawberry mixture onto the surface of the alcohol. Do not mix the alcohol and strawberry mixture; you should see a clear separation of the two liquids.
  8. Wait for a few minutes, and you should start to see white, stringy strands appear at the boundary between the alcohol and the strawberry mixture. These strands are the DNA! You can use a wooden stick or skewer to gently scoop out the DNA strands and examine them more closely.

Note: This experiment involves the use of rubbing alcohol, which can be dangerous if ingested or inhaled. Make sure to perform the experiment in a well-ventilated area, and avoid getting rubbing alcohol on your skin or in your eyes.



Sunday 12 March 2023

Flywheels and Gyros

Angular momentum is a property of an object in motion that depends on its mass, velocity, and distance from the axis of rotation. Students seem to find the concepts counterintuitive and almost magic.


 When an object rotates around an axis, it has angular momentum in the direction perpendicular to the plane of rotation.

In a gyro, a spinning rotor is mounted in a set of gimbals, which allow it to rotate freely in any direction. When the gyro is moved or rotated, the rotor resists the change in direction due to its angular momentum, causing the gimbals to move in a way that reflects the change in direction. This resistance to change in direction is known as gyroscopic stability.

Gyroscopes are commonly used in navigation systems, aircraft, and spacecraft to measure orientation and angular velocity. They are also used in stabilizing cameras, drones, and other equipment that needs to maintain a steady position in space.

Flywheels are often used as a form of energy storage because they can store energy in the form of rotational kinetic energy. This energy can be released quickly and efficiently when needed, making flywheels useful for various applications.

One of the most common applications of flywheels for energy storage is in electric or hybrid vehicles. When the vehicle is braking, the energy is used to spin up a flywheel, storing the energy as rotational kinetic energy. Later, when the vehicle needs to accelerate, the energy can be drawn from the flywheel, converting the kinetic energy back into electrical energy to power the vehicle's electric motor.

Flywheels can also be used to store energy in renewable energy systems, such as wind or solar power. The energy generated by wind turbines or solar panels can be used to spin up a flywheel, storing the energy until it is needed. This energy can be released quickly and efficiently, providing a reliable power source even when the wind is not blowing, or the sun is not shining.

Another application of flywheels for energy storage is grid stabilization. Fluctuations in power supply and demand can cause instability in the electrical grid, and flywheels can be used to smooth out these fluctuations by providing a buffer of stored energy that can be quickly released when needed.

Saturday 11 March 2023

Electrolysis Required Practical



Electrolysis Required Practical: When discussing electrolysis with a student who had not previously performed the experiment, observed a demonstration or watched a video on the topic, I instructed them to set up and conduct the practical on their own.

Friday 10 March 2023

Mendel and Genetics


 I find this one of the hardest topics to teach because of the lack of practical work. Sure we can do some genetics at GCSE but it takes so much time and theory is so much better when based on some practical work. #ScienceEducation

Thursday 9 March 2023

Integrating parametric Functions


Teaching students how to integrate parametric functions using Desmos and Casio CG50 to display graphs and help them visualize. #MathEducation #ParametricFunctions #Desmos #CasioCG50
A parametric function is a mathematical function where the variables x and y are expressed as separate functions of a third variable, usually denoted as t. In other words, a parametric function describes the relationship between two variables in terms of a third variable. The parameter t is often interpreted as time, and the values of x and y at a given t represent the coordinates of a point on a curve or surface. Parametric functions are commonly used to describe motion and change over time in physics, engineering, and other fields.





Wednesday 8 March 2023

From black powder to beautiful blue crystals



 Why I enjoy teaching Chemistry so much. Taking a black powder and making some beautiful blue crystals of Copper Sulfate

A level computing 12 Mark questions

Practice planning the 12-mark A-level computing questions. It is not just about getting the facts down but also about organizing them effect...