The Biggest Magnet in the World

The history of magnets goes back a long way. In fact, the Greeks were aware of magnets from around 600 BC. Philosopher Thales of Miletus wrote about minerals – known today as lodestone – being attracted to iron. Descriptions of magnets also came from Anatolia – modern-day Turkey – as well as India and China around the same time.

Yet it wasn’t until the eleventh century that the Chinese invented the magnetised compass for navigation. Within two centuries, compasses were in common use through the Far East, Europe and the Arabian Peninsula.

In 1600 in his book De Magnete, physician WIlliam Gilbert discovered the Earth is a magnet and then in the 1820s, electromagnets were developed. In 1831, American scientist Joseph Henry built the world’s largest magnet to that point, capable of lifting a weight of 340 kg.

When it comes to the largest magnets on the planet today, strictly speaking the world’s biggest magnet is actually the Earth itself. In the outer core of our planet, molten metals are being churned at over 5,000 degrees centigrade. This creates electric currents that create a magnetic field.

This article is therefore about man-made magnets, and when it comes to the biggest magnet on Earth, one of them is so powerful, you won’t believe what it can do. Clue: it involves an aircraft carrier… Here then are the contenders for the biggest magnet in the world.

Weighing six tonnes, Project 11 is not the world’s biggest magnet by physical size but it is the world’s most powerful resistive magnet. It reached a magnetic field strength of 41.4 tesla at the National High Magnetic Field Laboratory in Tallahassee, Florida in 2017. The $3.5 million magnet is made of copper and a copper-silver alloy and it’s hoped it will go some way to further our understanding of quantum mechanics.

The Hybrid Super-Magnet is one of the twenty-first century’s most complex scientific projects and is the world’s most powerful hybrid magnet. Made of a mix of superconducting and resistive magnets, it has the combined magnetic force of 45 tesla. It’s not the biggest magnet in the world but it is one of the most powerful.

Like Project 11, the $14.4 million, 31.7 tonne magnet is housed at the National High Magnetic Field Laboratory in Tallahassee, Florida. It’s kept at an operating temperature of -271 degrees centigrade and if it ever gets up to room temperature, it can take six weeks to cool it back down. It uses 6,400 metres of copper wire, enough for around 80 houses!

A contender for the title of largest magnet in the world is the Barrel Toloid. The world’s largest superconducting magnet consists of an array of eight magnetic coils measuring twenty-five metres long and five metres wide. The 100-tonne magnet is part of the ATLAS Detector, the largest detector ever built, itself part of the Large Hadron Collider at CERN in Geneva. It uses a four tesla magnetic field to bend the paths of particles produced in the LHC.

The world’s biggest magnet, known as the Central Solenoid, is one of the most complex feats of engineering ever attempted. It’s installed in the core of the International Thermonuclear Experimental Reactor in France and it’s hoped it will eventually produce net-positive nuclear fusion, that is, fusion that produces more energy than it uses. In other words, it will try to replicate the process of energy production seen in the centre of the sun.

As the largest magnet in the world, the Central Solenoid is a result of over five years of research and development at General Atomics in California and the statistics are mind-blowing.

The massive magnet is eighteen metres tall, over four metres wide and weighs about a thousand tonnes. Its magnetic field is 13 tesla, or 280,000 times stronger than the Earth’s, and because it’s so strong, a structure has been built to house it which needs to be able to withstand forces twice that of a space shuttle taking off.

To understand just how powerful the biggest magnet on Earth really is, it has the ability to generate enough magnetic force to lift the world’s biggest aircraft carrier, the 101,600 tonne USS Gerald R Ford, six feet into the air.

A research team at the Chinese Academy of Sciences’ High Magnetic Field Laboratory in the city of Hefei have made one of the world’s most powerful magnets, but if you think massive power means massive size, you’re wrong. This magnet is miles away from being the world’s largest magnet, in fact its bore is no bigger than a £2 coin – a diameter of just 33 mm – but it generates 45.22 tesla, over a million times stronger than the Earth’s magnetic field.

These are the world’s largest and most powerful man-made magnets. Incredible feats of science and technology for sure, but we have to look to outer space for the most powerful magnet known to humankind.

We can’t really call it the biggest magnet in the world since it’s not technically in our world but it gives you some sort of sense of the vast scale of our universe. Discovered in 1979, SGR 1806-20 is a magnetic neutron star known as a magnetar. It’s located 42,000 light years from Earth in the constellation Sagittarius. It’s the most powerful magnetic force in the known universe, with a magnetic field strength of 100 billion tesla.