Around made of school series 22

 Atoms — What Everything Around Us Is Made Of

We learnt that everything is made of atoms. It was easy to remember and difficult to imagine.

Look around us: a table, a tree, a glass of water, the air we breathe, our own bodies. All are made from atoms.

An atom is incredibly small. At its centre is a nucleus, containing protons and neutrons. Around the nucleus are electrons.

The number of protons determines which element the atom is.

For example:

1 proton → Hydrogen

6 protons → Carbon

8 protons → Oxygen

13 protons → Aluminium

28 protons → Nickel

The Periodic Table we began this School Series with is essentially a wonderfully organised map of these different kinds of atoms.

Atoms can join together to form molecules and compounds. Two hydrogen atoms and one oxygen atom, for instance, make a molecule of water — H₂O.

And here is the astonishing part: although atoms are unimaginably small, they are the building blocks of everything we can see, touch and even breathe.

The chair we sit on, the food we eat, the stars we see in the sky and we ourselves are all arrangements of atoms.

We began this series with the Periodic Table and travelled through electricity, water, light, the human body, DNA, evolution, the Solar System, friction and pressure.

Now we come back to the smallest level.

The world around us looks solid and continuous. But beneath it is an astonishing universe of tiny particles, constantly interacting and rearranging themselves.

And perhaps that is the perfect place to pause our first journey through The School Series:

Everything begins with atoms.

Invisible push school series 21

 Pressure — The Invisible Push

We learnt in school that pressure is force acting over an area. It sounded like another formula to remember:

Pressure = Force ÷ Area

But pressure is everywhere around us.

Why does a sharp knife cut more easily than a blunt one? The sharp edge concentrates the same force over a much smaller area, producing greater pressure.

Why can a needle pierce cloth so easily? Its tiny tip concentrates force into an extremely small area.

The opposite principle is equally useful. Snowshoes have a broad surface so that a person's weight is spread over a larger area, reducing pressure on the snow and preventing the person from sinking deeply.

We also live under pressure every moment.

The atmosphere around us exerts air pressure, even though we don't normally feel it. Our bodies have adapted to this constant pressure.

And pressure is not restricted to solids. Water pressure increases as we go deeper, which is why divers experience greater pressure beneath the surface.

So pressure is not simply about how hard we push.

The same force can have very different effects depending on the area over which it acts.

That simple school formula explains everything from a sharp knife to a snowshoe, from a needle to deep-sea diving.

Sometimes it isn't the strength of the push that matters—it is how concentrated the push is.

Force school series 20

 Friction — The Force We Usually Try to Avoid

We learnt in school that friction is a force that opposes motion. It sounded like something inconvenient—something that makes machines wear out and objects harder to move.

But without friction, life as we know it would be impossible.

Try taking a step on a perfectly frictionless surface. Your foot would simply slide backwards. It is friction between your shoes and the ground that allows you to push against the Earth and move forward.

Friction lets us:

Walk and run

Hold objects

Write with a pencil

Stop a bicycle or car with brakes

Light a match

Grip a steering wheel

At the same time, friction can be troublesome. It produces heat, wears down moving parts and wastes some energy in machines. Engineers therefore try to reduce it with lubricants, bearings and smooth surfaces.

So friction is neither simply good nor bad.

We need enough friction when we want grip and as little as possible when we want things to move smoothly.

That little force we were taught to avoid in physics class is actually one of the reasons we can stand, walk, write and live normally.

Sometimes the force that resists us is precisely the force that allows us to move forward.

Suprising scale school series 19

 The Solar System — Our Small Corner of Space

We learnt the names of the planets in school—Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus and Neptune. Many of us even memorised them in order.

But the Solar System is far more extraordinary than a list of eight names.

At its centre is the Sun, an enormous star whose gravity holds the planets and countless smaller objects in orbit. The Sun contains almost all of the mass of the Solar System.

The four inner planets—Mercury, Venus, Earth and Mars—are relatively small and rocky.

Beyond them lie the giant planets. Jupiter and Saturn are gas giants, while Uranus and Neptune are ice giants.

And then there are the countless smaller members: moons, asteroids, comets and dwarf planets.

Earth is just one planet among eight, yet it has something we know of nowhere else so far: life.

Our Moon orbits Earth. Earth orbits the Sun. And the entire Solar System is itself moving through the Milky Way galaxy.

Perhaps the most surprising part is scale.

The distances between planets are so enormous that if we tried to represent the Solar System accurately on a classroom chart, the planets would have to be very far apart.

So that little diagram we drew in school, with all the planets neatly lined up, was not really to scale.

It was simply our first introduction to an immense cosmic neighbourhood.

We live on one small planet, orbiting one ordinary star, in one galaxy among perhaps hundreds of billions of galaxies.

And yet, from this tiny corner of space, we have learnt to look outward and understand something of the universe around us.

Life change school series 18

 Evolution — How Life Changes

We learnt about evolution in school, often accompanied by the familiar picture showing an ape gradually becoming a modern human.

That picture, however, can give the wrong impression.

Evolution does not mean that apes turned into humans. Humans and modern apes share ancient common ancestors and have followed different evolutionary paths over millions of years.

At its simplest, evolution is the gradual change in populations of living organisms across generations.

Individuals within a species naturally have differences. Some of those differences can help an organism survive and reproduce in a particular environment. Over many generations, such characteristics can become more common.

This is the principle of natural selection, famously associated with Charles Darwin.

And evolution is still happening.

Bacteria can evolve resistance to antibiotics. Animals adapt to changing environments. Plants develop characteristics that help them survive particular conditions.

The extraordinary thing is the timescale.

A small change in one generation may seem insignificant. But over thousands or millions of generations, countless small changes can produce enormous differences.

So evolution is not a ladder with one creature climbing towards perfection.

It is more like a vast branching tree of life, with different branches adapting and changing in different directions.

And perhaps the most humbling lesson is this:

We are not separate from the story of life. We are one relatively recent branch on an immensely old tree whose story is still being written.

Natures kitchen school series 17

 Photosynthesis — How Plants Make Food

We learnt a simple equation in school:

Sunlight + Carbon dioxide + Water → Food + Oxygen

We called it photosynthesis and moved on.

But think about what is actually happening.

A plant cannot go to the kitchen and prepare its food. It cannot eat a meal. Instead, its leaves contain a green pigment called chlorophyll, which captures energy from sunlight.

The plant takes water from the soil through its roots and carbon dioxide from the air through tiny openings in its leaves. Using sunlight, it converts these ingredients into glucose, a form of chemical energy that the plant can use and store.

And there is a wonderful gift in return.

Oxygen is released into the atmosphere.

Every green leaf is therefore, in a sense, a tiny solar-powered food factory.

The food produced by plants doesn't remain only with the plant. It becomes the foundation of almost every food chain on Earth. Animals eat plants; other animals eat those animals—and ultimately, the energy comes from sunlight captured by plants.

So that little diagram we memorised in school was actually describing one of the most important processes on Earth.

Plants take sunlight, air and water—and turn them into food, while giving us the oxygen we breathe.

Perhaps photosynthesis deserves to be remembered not as a chapter in biology, but as the process that helps make life on Earth possible.

Rocks school series 16

 Rocks — The Three Great Families of the Earth

We learnt in school that rocks are divided into three types: igneous, sedimentary and metamorphic.

It sounded like something to memorise for an examination. But these three families tell the story of how the Earth itself is constantly changing.

1. Igneous — Born from Fire

When molten rock—magma beneath the Earth or lava at the surface—cools and solidifies, it forms igneous rock.

Granite and basalt are familiar examples.

They are, quite literally, rocks born from Earth's heat.

2. Sedimentary — Built Layer by Layer

Rocks are gradually weathered into tiny particles. These sediments are carried by wind, water or ice and deposited in layers. Over enormous periods, pressure and minerals bind them together.

Sandstone and limestone are examples.

Sedimentary rocks can sometimes preserve fossils, giving us clues about ancient life.

3. Metamorphic — Changed by Heat and Pressure

Existing rocks can be transformed deep inside the Earth by intense heat and pressure, without completely melting.

Limestone can become marble.

Shale can become slate.

The rock changes, but its material remains part of the Earth's continuing story.

And the fascinating part is that these families are not permanent categories. Through the rock cycle, one type of rock can eventually become another.

A rock may be melted, cooled, broken down, buried, compressed and transformed—over and over again.

So the rocks beneath our feet are not lifeless objects frozen in time.

They are part of a slow geological journey that has been continuing for billions of years.

We learnt three names in school.

What we were really learning was the story of a restless Earth.