Biofuels

Biofuels are made from recently living organisms, while fossil fuels are made of long-dead organisms from millions of years ago. 

Biofuels usually come from plants or algae, since they can photosynthesise and store energy inside themselves, biofuels are also cheap to make and are renewable,
we classify biofuels as carbon neutral, and we can combine fossil fuels with biofuels.

One of the biggest issues is that we need lots of lands to grow these biofuels, which means we normally need to convert natural land by digging and clearing forests, transporting the fuels and harvesting and processeing the biofuels thus making more C02.

Geothermal Power

 Thermal energy is energy stored in the earth's crust, like in hot springs.

We can use it to heat things using geothermal energy, mainly by pumping water deep underground, waiting for it to heat up and then pumping it back to the surface. 

To heat our homes, but in order to generate electricity we must first pump it underground then we wait for it to heat up so much to the point it becomes steam and as the steam rises it turns turbines that turn the hot steam into electrical energy via generators, but these places to gather geothermal energy is rare, but the power gathered from these sources are extremely eco friendly as the initial startup of the geothermal power plant is slight, but it doesn't produce any pollutants at all while running.   

Wind & Solar

One way to gather energy is via wind power, which is used to power wind turbines. There is a difference between windmills and wind turbines, as windmills are commonly used in the Netherlands for grinding grains like wheat, hence the name. 

Wind turbines are placed in places with strong winds, often used in 'wind farms'. Generators turn the kinetic energy of the rotating blades into electrical energy. 

Solar is gathered by solar panels, which are sheets of metal with solar cells, the the technical term is a photovoltaic cell. 
Often used in watches and calculators since they don't need that much power.

These solar panels are placed in large plots of land, directly in sunlight to gather as much solar power as possible. But since we have lots of plots of land, solar power is becoming more popular, especially in cities with roofs as the roofs of houses or shade can be topped with solar panels to help make passive electricity. 

But solar and wind power have pros and cons, as wind power needs.. Strong winds, while the solar needs the sun, so if it is not a windy day at the wind farm,
it won't produce much power, same with the solar panels if the sky is cloudy the electricity gathered by the cells would be lacklustre compared to a day where the sun is blistering hot. 

A pro to this is that it doesn't make carbon dioxide to generate electricity, compared to fossil fuels or coal, but the upfront cost or the price of setting these alternative power sources is high, along with the fact that making these often makes solutions like carbon dioxide, they also take lots of space and you can't really increase the amount of power if the dammand gets higher.

Energy Resources

 Humans have relied on wood for energy, for burning for cooking and keeping us warm, but most developing countries use wood for burning. 

Most modern countries use lots of coal, oils and natural gasses, daily, in recent years there are now more ways to get large amounts of energy, although they are not as efficient as the un-renewable sort.  

There are hydroelectric, geothermal, solar, wind, and lots of other ways to generate electricity. In most countries, most of the energy resources collected are used for transport and domestic use, such as in homes.

During the Industrial Revolution, coal was used in trains. It was found that burning coal produced energy that could be used to power trains.
Now most trains are powered by electricity since there are many other ways to gather electricity than coal, along with biofuels, which are types of fuels made from plants which are 100% renewable when farmed correctly, and use of electric cars and now hydrogen cars.

Along with natural gasses, which are burnt on stovetops to boil water, we used unrenewable coals last time. 

One thing about electricity is that it isn't 'renewable' or 'non-renewable', as how it is gathered changes how  

Nuclear energy is actually more efficient and better for the planet than burning fossil fuels, even though it is a finite resource, nuclear energy is harder to use because of how rarer it is, along with the fact that it creates radioactive waste which stays radioactive for thousands of years and must be stored carefully.

It is also very expensive to run a nuclear power plant, and the danger of a nuclear meltdown, which can cause environmental damage by releasing harmful radioactive material into the atmosphere. 

 

Power & Work Done

First of all, Power is the rate of energy being transferred, the equation for this is P=E/T or (Power = Energy / Time).

Work donee works at what rate "Work" is done, so if you push a car down a ramp it is considered to be work done, the equation for this is P=W/T or (Power = Work Done / Time). 

But both these follow the same measurements, power is in watts, energy in joules, and time in seconds. 

So let's use both equations to figure out which lamp is better.
Lamp 1 transfers 1200 joules over 20 seconds.
Lamp 2 transfers 1500 joules over 30 seconds.

For this equation, we will use the first equation, or the P=E/T. Now, we plug in lamp 1's numbers, so 1200J / 20s = 60 watts.
For the 2nd lamp, we put 1500J / 30s = 50 watts.
So even though the second one has more power in the form of joules, because of its time in seconds, the amount of power (watts) is worse than the 1st. 

Let's figure out how much power an 1100-watt microwave need, so first let's turn it on for 3 minutes. First lets change out 3 minutes into 180 seconds by multiplying the 3 * 60(minutes), now we can do 1100 * 180 =  198,000 joules. But when we get a big number we can convert it to kilojoules or 198,000 / 1000 = 198KJ.
  

Physics pt. 12: Analog vs Digital signals

 Analog is trying to reproduce the signal of what is happening, think changing a piano piece, to a guitar tab, it's the same, but different.

A digital signal turns sound to ones and zeros to then does its best to reproduce the original sound, think chiptune music, and 8-bit audio.

The problem with analogue signals is interference, let's take a number, 24 in this case and let's make it analogue, if you were to take the 24th signal, if it were to be analogue, it would not be straight, as it would be a wavy line, and it may not look like a 24 because it would fluctuate.

But if you were to take a digital signal, that 24, will always be a 24, and never go higher or lower, and not fluctuate either. That's why when you listen to guitar it sounds more bouncy, while listening to more chiptune music it will sound more robotic and less genuine.

Talking is an analogue signal, and when you add words, you are "encoding" the signal with words,  

Physics pt. 11: Digital and analog information

 Something analogue can be any value within a given range, and something digital can have multiple discrete and different levels, an analogue clock has hands which move around the centre and since it's analogue you can make it so that it displays certain numbers (10:30, 11:31, 5,03) and so on and it has infinite values.
A digital clock can do 10:30 and 10:30:51, which is more precise, but they have a finite number of values.

Sound is not only a wave, but it is an analogue, the amplitude, the volume, and the frequency we hear as pitch are all infinite possible combinations.

The first recording of sound was imprinted on a material, like a vinyl record, cassette tape, or a music box, which sound is imprinted on a surface or material. 

But the thing about recording on such surfaces is that if you smudge a cassette tape, or scratch a vinyl record, that recording will deform the recorded sound waves and thus, cannot reproduce the sound that was recorded before the cassette, or vinyl damage.

Eventually, soundwaves were digitized, so how this was done the analog inputs were assigned numbers

2:28 14mins

Physics pt. 10: Absorption and Reflection

Light can interact with many things, Absorption and Reflection.
If you were to be in the mountains and take a look at a clear pond, you would be able to see the surrounding mountains which are reflected off the water causing it to reflect the light.

And the same with snow, if you were to look straight at the snow, it would hurt your eyes, because it is very reflective and can blind you. That's when people are in he snow for a long time, they have to wear spectacles so they don't get blinded. And why some ski masks have tinting to help.

Physics pt. 10: Waves

If you would take a rope and tie it to a pole jutting out of the ground.
Grab the other end and move it up and down, you will notice it waves up and down performing a waving motion, a wave is a disturbance, which can probate.

A mechanical wave is a type of wave that travels through a medium in this case it is the rope, and something to keep in mind is that waves transfer energy but not transfer matter.

Now what does that mean?.
It means that the moving of the rope is moving the rope as it is transferring energy. While it's not moving the ropes position as it is still attached to the pole. 
As the kinetic energy of your hand moves the rope causes it to move.

The period in a wave is measured in seconds and tells us how long each wave cycle takes to complete. 
Next is the wavelength, which as the name suggests the difference in distance between adjacent waves.

To calculate this, you would do an equation that looks like this: Frequency = Cycles/s = hz. 
Or the frequency is wave cycles divided by seconds. To get speed you would calculate distance * time. 

Different types of waves move at different speeds. For example, lightning is a form of wave that has two "Waves", the 1st wave uses the bright flash of lightning, and the second wave is the thunder that accompanies the lightning. Both are waves.
The reason why you see the bright light faster is because it is an electromagnetic wave, which is light, which travels faster than sound.
Electromagnetic waves are special as they don't need a medium to travel fast, that's why you see lightning before thunder. As different waves move at different speeds. 

When you speak, you use soundwaves to push the particles in the air around your "soundwave" and people around you can hear you.

When you look at a wave, you will see, well a wave.
But there are names to the parts of one, the tips or the elevated areas are named "Crests", while the drooping parts are named "Troughs", and the distance between the resting line of a wave is named "Amplitudes", and the distance between waves are named "Wave-lengths".

A wave's "Frequency" can be measured by how many crests appear at a certain time, say 25 crests in 5 seconds, meaning that every second there are 5 crests every 1 second.

Light can be perceived as a wave. Light can be seen as different colours and the frequency can be how bright the light is, and visible light is called electromagnetic waves.
Like Ultraviolet light, X-ray, or Gamma rays. Or Infrared, or radio waves. And these are different frequencies of what we classify as electromagnetic waves. 

Transmission means when a wave transfers materials.
Let's take the sun for an example, imagine how many materials the sun's rays have to pass through to hit the green grass.

First, it has to travel 93 million miles from the deep vacuum of space and that's interesting as light doesn't need a medium to travel through, unlike sound and, electromagnetic waves.
And has to travel through kilometres of the Earth's atmosphere. 

Sound waves are just travelling pressure waves through the air, if you are in a room, and you close the door, you can still faintly hear outside as if someone is speaking to you from outside the sound waves have to travel through the air and then while the air is vibrating with the sound wave, go to the direction of the closed door, and vibrate the air around the outside, though the door and in the room you are in, some frequencies are better at travelling through certain materials.

If you were to put a pencil in a cup of water, it looks like the pencil is bent, and it is refraction, as it is light refraction.
But light refraction is not the only wave that can be refracted, 

Physics pt. 9: Energy

 Kinetic energy is a type of energy that relies on mass and speed, to exist.

So let's say you roll on the ground a lightweight ball and a heavy ball, with the same force, the heavier one will roll faster since it has more mass. 

But if you roll the lighter ball with more force than the heavier one, the lighter one will move faster. 

The equation that we use is Ke = M* V^2
Ke means kinetic energy or kinetic energy is equal to Mass times Velocity squared.

Potential energy is energy that is stored in an object. And it has the potential to output that energy to say, Kinetic energy.

First is Gravitational Potential energy.
Let's take the earth for an example, lets put a yellow ball 50 feet in the sky, and another red ball 100 feet into the sky.
Which ball do you think will fall the fastest, well its the red ball because the red ball is further away and has more GPE or Gravitational Potential Energy 

The second is Elastic  Potential energy.
Let's use a rubber band as an example, if we pull on it, and when we let go, it will spring back to its normal position, but wait, why did it snap quickly and not slowly go back into shape, well Elastic Potential Energy. Another good example is a spring as when you compress a spring, it will try to "spring" back and cause the Elastic Potential energy, to happen.

Third is Electric Potential energy.
Which is an object that is electrically charged due to another charged object, which means that a positive charge and a negative charge is next to each other they attract. While two positive or two negative charges repel.

Forth and last one is Magnetic potential energy.
Magnetic potential energy is a type of energy that comes from the magnetic force of magnets, not only the position of the magnets matter (how near and how far they are). But also the orientation of the magnets affects the potential energy.

All these are potential energy. Potential energy, in summary, is an object's orientation, position, and the material it is made of. It is compared mainly using mass, size and shape.

Energy cannot just "disappear" as part of The Law of Conservation of Mass, "Matter is not created nor destroyed", so if one object loses its energy, another object but inherit that lost energy.

Energy can change forms, for example, if you were to use a blow dryer, it turns electrical energy into heat or thermal energy.
Or when a car speeds up too fast, the kinetic energy while driving is turned into thermal energy.
And when you hit the breaks on a bike, the breaks cause the wheels to stop and cause the tyres to produce heat because of kinetic energy and friction.

Physics pt. 8: Electromagnets

One type of magnet is an Electromagnet, which is a magnet that only becomes magnetic when it is charged with electricity. They usee

Electromagnets are magnetic materials that become magnetic when an electrical current flows through them.

electrically charged particles in motion actually have small electrical currents in them. So if we run an electrical current through a wire, a magnetic field will created around the wire.

Now the strength of the magnetic field can be affected by multiple factors, can one, send more electricity through that wire, you can increase the density of the electrical particles, and you can do this by looping the wire into a coil, 
if you were to take the electrical wire and reverse the direction, the electromagnet would also change in direction.

The drastic difference between an electromagnet and a permanent magnet is that an electromagnetic is usually made out of an electrical wire and a coil.

Another difference is that you can change the North and South poles of a magnet, pick up a pile of metal scraps with the North side of the magnet, and then flip the electrical current to put the magnet on the South side and drop the scraps into a bin.

Another difference is that not only the poles can change to help attract and repel, but they can also change in strength, as you need much more magnetic pull to lift a metal crate, but much less to pick up a truck.

Most electromagnetics work with copper, cobalt or other minerals in a coil, and the more wires that coil has, the more powerful it is, so it increases charge density.

Physics pt. 7: Fields

 Let's say you drop a ball, and it falls through the ground, why did that happen.
Nothing was pulling it down right, nothing touching it, well it is because of gravity which is a non-contact force that is causing it to be pulled down, but these forces act over a sort of region, so since that ball is on earth it causes the ball the fall due to the ball being in the region known as earth because the ball is in the gravitational "field' of the earth, it falls down and hits the ground.

New field forces include Electrical, Magnetic and gravitational forces, and since these are non-contact they can exert a force without touching an object.

So to understand why things are this way, scientists came up with the idea of: "Fields", which under the definition says: "Objects that extend through space".

Gravitational forces affect objects with mass, think of a ball, a cat, or paper, every object with a Gravitational force has a force that pulls objects near it to its centre the further you move away from the object the weaker the force is.

An Electric field surrounds any object with a net charge, and what is in those fields relies on what direction that charge is going along say, a wire or cable.

Magnetic Fields are for magnets and other materials with magnetic properties.

Every field has two things about it, Magnitude (how strong it is), and Direction (where it's going).

Let's take an example, let's put a planet down, and since a planet has a lot of mass, it will have a strong gravitational pull to its centre, and if we move further away from the planet, the field gets weaker, that's why if you jump on earth you fall back down quickly, but in low orbit space, you float, because the Earth cannot pull you down from that distance.
Now let's put an astroid going parallel from the planet, and its pretty close to the planet. The asteroid will be attracted to the planet as the planet has a strong Gravitational pull, so when it flies by, it might get pulled closer, and closer, until it might crash into the planet due to the astroids proximity to the planet plus the gravitational pull of the planet

Physics pt. 6: Magnetic Forces

 Ah, magnets are a vital piece of physics used from the humble fridge magnet, to large computers, these forces are, well, a force. 
Magnetic forces are a force that pulls similar to the gravitational force of the earth, magnetic forces pull on each other to pull objects closer.

The orientation of a magnet is important as the different poles cause the magnet to do different things. Now you are probably wondering, "Poles what is that?", there are two poles on a magnet, and each pole is different as one pole is positive and the other is negative, now if you were to put two magnets one facing the positive side and the other on the negative side, they will attract and pull each other closer.
Now if you were to do that with say, two negatives or two positives, they will repel as they are pushing away from each other.
The strength of the magnetic force decreases with range. Further the magnets are from each other, the weaker the magnetic force.

If two magnets have a strong force at 5 centimetres, increasing that distance to 10cm makes the forces weaker.

For example, MagLev trains use super strong magnets to push the train above the tracks to make the train have no friction due to wheel spin, and due to friction can travel at speeds of 500km or 310 miles per hour.

Physics pt. 5: Electric forces

 Electric forces are pretty interesting, for example, if you take your clothes out from the clothes dryer you might see that your clothes are sticking together and that's due to static electricity.

All matter has an "Electric charge", some have more charge than others, and thus there are mainly three types of charge. Positive, Neutral, And Negative charges each with their own perks. 

Back to the electrically charged clothes, since they were spinning in the dryer they were rubbing against each other, and that caused the negative electric charges to start to become positive because of friction, and then when you try to remove the clothing items apart you may notice that they stick since of the positive charge they both possess. 

As the name implies it is an "Electric force" and forces push and pull like a gushing river or a spinning typhoon, the electric force pulls or pushes depending on its electrical charge.

Now how does the attraction or repelling work, well the saying is "opposites attract", which means a positive charge will be attracted to a negative charge and vice versa, meaning in the dried clothes one of them is negatively charged while the other is positively charged.
But if both are the same (negative or positive charged), they will be repelled and try to avoid each other.

Now the strength of the electric force depends on the amount of electric charge in the object, so a strong electric charge causes it to be a strong pull or push, and how this pull and or push gets weaker is distance, as the further the object charged object is to the other object causes the strength to differ.

Physics pt. 4: Gravity

Gravity is pretty cool, as it helps pull objects together, it attracts things to the floor, so if there's a ball flying through the air, the gravitational force is pulling it down so it doesn't go into space.

It is an attractive force, as it exists for everything that has mass, first of all, what is mass, well mass is how much stuff an object is made of.'

Gravity will be different for things that are made of different mass, and distance, as the heavier or more mass something is the faster it falls, or the stronger the gravitational force.

The Earth itself is nearly six septillion kilograms, that's a six with 24 zeros after or (6,000,0000,0000,0000,0000,0000,0), for scale a cat usually weighs about 4 kilograms.

That is just one reason that affects the gravitational force, the other is the distance, the closer an object is to the gravitational force, the weaker it is, so us being on the ground you barely feel the forces pulling you down, the only way to not feel the gravitational force of the Earth is to go REALLY far away, or Outer Space.
Take a look at the moon, it is nearly 400,000 kilometres away from Earth, and it is still affected by Earth's gravity, but since the moon is really far away, and it is also big, you can also feel the gravitational pull it, and that's why ocean Tides exists as the moon is pulling the water which causes high and low tides.

But how can we walk around and not feel any sort of strain and not face planted dragging ourselves around, well it's because we only notice the strength of it when it is a really big planet or star, and the gravitational pull on you dragging you down is much weaker compared to the forces you use every day, let's say you pick up a ball or a glass of water, since the gravitational force pulling the water down, if you pick up the glass of water you are overpowering the gravitational pull of the Earth to pickup that water and move it to your mouth.

Physics pt.3 Action and reaction forces

 For every force, there is an equal or opposite reaction force - Newton's 3rd law:

Let's take an aeroplane as an example, the jets from the aeroplane are pushing the air molecules away but in turn, causing the reaction force of the air molecules going away to push the jet forward, the equal force is the air molecules being pushed back, while the opposite force is the plane is being forced forward.  

How about rockets and rocket fuel, rockets will ignite the rocket fuel and the force will push the air molecules downward, but then the rocket will go up because of the opposite force pushing it upwards,
note that the reaction force is not on the same object, it is on a different object.

Physics pt.2: Force, mass and eccelaration

 Applying a force to an object when pushing or pulling can change its acceleration, and the mass of said object can affect how much acceleration that object can take.

For example, if you push 20km into a huge rock, that rock is accelerating at 20km, but due to the mass of said object let's say 35kg, it could accelerate at 10km.

Now let's take into space and say there are two rockets both pushing an asteroid (100kg) with a combined speed of 200km (low number but bear with me) the asteroid would move with ease, but remove that one rocket and it becomes a much slower process since there's not much accelerating happening due to the single rocket pushing the asteroid at 100km, and if you increase the mass from 100kg to 200kg, it becomes an even slower process.
And if you have two rockets both going at 100km, pushing the same asteroid but going in opposite directions, the net force of the asteroid would be zero since they are applying the same force from both sides.

Physics pt.1: Reperesenting Motion

Units 

Let's start with units, units are a type of measurement usually for position (meters), mass (Kilograms) and motion (Meters per second), let's say you have a cat that's 25 units tall, and a swimming pool that's 45 units wide. Well, that doesn't make sense, how can a cat be bigger than a pool, that's where units of measurement come into play, the main two systems the world uses are the metric and imperial systems, both very valid forms of measurement (although 95% of the world uses metric).

When comparing data (weight, height, length), try to stick to one system for measuring to make the comparisons easier to understand. 
For example, for the cat analogy, we can say the cat is 25 centimetres tall, as that is a unit of measurement we are familiar with, and for the pool, we can say that it is 45 meters long and we are easily able to understand what that means. 

Since there are two forms of measurement things can get confusing, there was once a rocket ship (the Mars Climate Orbiter around 125million USD) that due to a measuring mistake, exploded when landing on Mars.

Frames of reference:

These are so that people are on the same page when talking about subjects in physics, for example: Let's say a blue car is travelling right at 45 kilometres per hour, and you standing still on the ground, it will look like the car is whizzing by you at 45 km.
Now that that same scenario but instead of being on the ground stationary, I put you in a yellow van that's going 40km, it will feel like the blue car isn't going very fast, which makes sense as the person standing on the ground and the person in the Yellow van is watching from a different Frame of reference.
We would write this as "The blue car is going, to the view of the Yellow car at 5km"