PushQuantum x Deutsches Museum
Science Communication Lab
Every object has a spin that can be thought of as an arrow
Spins of different objects can be added if they point in the same direction
This way big objects made from smaller ones can have huge spin
A spin can be pulled on by a magnetic field but also creates its own field
This is what happens in magnets
A normal magnet consisting of many tiny particles has a big field
This field can pull on the spins in other objects
The spins in these objects align
The complete object is pulled by the magnet
This way big objects made from smaller ones can have huge spin
A spin can be pulled on by a magnetic field but also creates its own field
This is what happens in magnets
A normal magnet consisting of many tiny particles has a big field
This field can pull on the spins in other objects
The spins in these objects align
The complete object is pulled by the magnet
Solution
A compass has a magnetic needle
It is pulled on by the magnetic field of the Earth
This field always points North
In a hardrive an electromagnet induces pulls on a spot on a metal disk
The part of the disk becomes magnetic
The strength of the magnetic field can be read as data
In an MRI machine very strong magnetic field pull on hydrogen atoms
These are an integral part of your body
Different surrounding make the atoms react different
These differences allow us distinguish different materials in the body
Quantum Tunnelling
Explanation
Objects are made from atoms.
Atoms contain electrons that are on distinct energy levels.
Electrons can jump to higher energy levels by gaining energy.
Light is made up of photons, i.e. packages of energy.
If a photon hits an electron it vanishes and its energy is in the electron.
The electron jumps to a higher energy level.
We also say the atom is at a higher energy level.
For combinations of atoms the different levels can occur differently.
Examples are by physically changing positions.
Or by not having levels but different smeared out bands.
Solution
In an eye there are different molecules.
If a photon hits the molecules they jump to a different energy level.
This sends a signal to the brain.
Different colours of light cause different jumps.
This allows the brain to distuingish colour.
In a leave the substance chlorophyll can absorb photons.
Molecules in the substance jump to a higher energy level.
These energetic molecules are then used to build fuel called sugar.
Solar panels consist of many atoms that create energy bands.
Sun light hits the panel and lets electrons jump.
The electrons jump far enough to escape the atom into a wire.
From the wire the electrons energy can be extracted as electricity.
Explanation
Objects are made from atoms.
Atoms contain electrons that are on distinct energy levels.
Electrons can jump can fall to lower energy levels.
For this they have to lose energy.
Light is made up of photons, i.e. packets of energy.
Different colours have different energies.
To fall to a lower energy level the electron throws away a photon.
For this to happen, the lower levels have to be free.
If we have many atoms the levels are smeared out bands.
Solution
In a laser there are atoms of one specific element.
Their electrons are made to repeatedly make the same jump.
Thus they always emitt the exact same photon.
This makes all photons the same colour.
LED light-bulbs have electrons pushed to high energy bands.
These fall back down to lower bands emitting a photon.
The jump is only approximately the same.
It is still close enough for humans to seem the same colour.
In a flame the electrons are excited by the thermal energy.
Different temperatures lead to different inital levels.
The different jumps are then seen as different colours.