The fear of strong solar storms and cyber attack has renewed interest in protecting our sensitive electronics.
And fortunately there are plenty of opportunities for that, thanks to an invention made by the English physicist Michael Faraday in 1836 – the Faraday cage.
The principle is at play in Faraday bags, Faraday curtains and even Faraday wallpapers that claim to stop cell phone and Wi-Fi radiation and protect devices from electronic eavesdropping.
Even the hallmark of the "die hard" conspiracy theorists - the silver foil hat - is based on Faraday's principles.
There are plenty of possibilities. But smaller can also do it.
In this article you will be guided to build your own Faraday cage, and then you will get the story of the genius Faraday and the physics behind the spectacular solar storms and Chinese EMP weapons.
What is a Faraday cage?
In 1836, the English physicist Michael Faraday built a 3.5 square meter box in his laboratory.
The box consisted of four glass windows mounted on a wooden frame. The outside was covered with a thin layer of metal foil.
Faraday energized the box from the outside and stepped into it. Here he stayed for two days to measure the amount of electromagnetic radiation that penetrated the box.
Inside the "cage" Faraday detected no electricity; only the metal foil surrounding the room conducted electricity.
The discovery was ground-breaking: It proved that electricity is a force and not a material fluid that flows through wires like, for example, water through a pipe, which was otherwise the common view at the time.
In other words, Faraday's cage acts as a shield that blocks electromagnetic radiation from the entire electromagnetic spectrum, such as radio waves and microwaves.
If you apply current to a cage that is covered in a fine-mesh mesh of steel wire, the "shield" redistributes the electrons and thus neutralizes the field inside the cage - as shown here:
A good example of a Faraday cage in everyday life is a microwave oven, which keeps the microwaves trapped in the machine so that they heat the food and do not escape into the kitchen.
On a larger scale, Faraday cages are also used in hospitals to prevent radio waves from entering MRI scanners and interfering with the equipment.
How sturdy should my Faraday cage be?
The smaller the electromagnetic waves that you want to keep out, the denser the electrically conductive material must be.
Let's take an example: An FM radio tuned to a station at 100 MHz emits radio waves at three meters.
In order to block the electromagnetic waves in the radio spectrum, the holes in the net around the cage must not be more than three meters in diameter.
A 5G signal from your phone has a much smaller wave. These have frequencies around 30 GHz, which gives a wavelength of around one cm.
As long as the holes in your mesh wire Faraday cage are no larger than one cm. in diameter, they will therefore be able to block telephone signals.
How to build a Faraday cage for your smartphone
- Aluminum foil or copper foil.
- Plastic wrap or plastic bags.
- Electrician's tape or glue.
- Wrap your smartphone in a plastic bag or plastic wrap. The layer acts as a non-conductive barrier between the phone and the aluminum foil.
- Next, cover the unit with aluminum foil. Make sure that there are no holes or cracks in the foil, otherwise the radiation will penetrate. Use electrical tape or glue to ensure the layers stay in place.
- For additional protection, you can repeat the process with additional layers of plastic wrap and aluminum foil, alternating between layers. Three coats of each should be enough.
- Try calling your phone or sending a message. If the box acts as a Faraday cage, the signals will not reach your phone
What does the Faraday cage protect against?
The magnetic field around the Earth acts as the planet's very own Faraday cage.
The field is formed by magnetic rays, which flow out from the Earth's outer core, surround the planet and act as a shield that shields us from radioactive particles, the Sun and other cosmic radiation.
But during so-called solar flares, so-called solar storms occur, where gigantic showers of energy-rich particles are hurled from the Sun's surface.
Just one tenth of all solar storms collide with the Earth's magnetic field. And when a solar storm on a rare occasion rushes towards the Earth, it is primarily expressed in the form of beautiful northern or southern lights – thanks to the Earth's magnetic field.
If the solar storms are powerful enough, they can break through the magnetic field and bombard the Earth with electromagnetic radiation that can damage satellites and electrical networks.
It happened i.a. in 1859, when a violent shower of electrically charged particles hurtled toward Earth with the same energy as 10 billion detonated atomic bombs.
Huge hailstones rained down from the sky, and meter-high waves crashed onto the shores. In the USA and Europe, the telegraphs short-circuited and caught fire due to the magnetic disturbances.
Nuclear explosions:
