How helium enables MRI machines to look inside organisms

How helium turns the Large Hadron Collider into the world's largest cryogenic system

Across three stages, five "cryogenic islands," and weeks of cooling, 36,000 metric tons of magnets are successively brought down to temperatures colder than outer space using a closed liquid helium system. Helium continues to circulate during the collider's operation to maintain the magnets' temperature and the transmission of electrical current with zero resistance.

Why trying to freeze helium creates a fluid that can travel through solids and climb walls

Once cooled to temperatures just above 2 Kelvin, helium-4 atoms begin to exhibit superfluidity, a quantum property in which all atoms collectively inhabit the same low-energy state and behave in perfect unison. This coordination removes the internal friction that causes liquids to cling to surfaces, allowing them to slide through microscopic pores and scale container walls.

The industrial methods for recovering helium, including filters and cryogenic separation

Membranes with microscopic pores of varying sizes can be used to selectively filter out components of natural gas, including helium, which can then be concentrated. Because helium requires the lowest temperature of all elements to condense into a liquid, extracted natural gas can also be cooled until only helium remains as a gas.

How helium greatly improves the efficiency of barcode-scanning lasers

Rather than directly energizing neon atoms, electrical discharge at lower, more practical power levels can excite helium atoms to energy levels nearly equal to those in neon atoms. Within a helium-neon laser, these gases are present in a 10-to-1 ratio, enabling helium to efficiently transfer energy to neon, which is then discharged as red light.

Why helium mixtures are used in respiratory medicine

Unlike the air near Earth's surface, which is primarily composed of oxygen and nitrogen, heliox is composed entirely of oxygen and helium. Because helium is lighter than nitrogen, the lungs do not have to work as hard to push air, easing the uptake of oxygen via a ventilator, mask, or nasal tube.

Temperatures colder than Pluto can allow electricity to flow resistance-free

Since its discovery in 1911, applications of superconductivity have made MRI machines and maglev trains possible due to quantum effects at extreme temperatures. These effects are modeled as electrons cooperating in pairs and flowing more efficiently.

Ultrasound machines emit and collect high-frequency sound waves to construct images

Before its use in medical imaging, the technology was employed in World War I for submarine detection, the same way bats use sound for echolocation of obstacles. Differences in the penetrating power of different frequencies allow medical professionals to detect different structures in the body.

How do brain scans work?

There’s only one thing in our solar system sophisticated enough to study itself: the human brain. But this self-investigation is challenging because a living brain is shielded by skull, swaddled in tissue, and made up of billions of tiny cells. How do we study living brains without harming their owners? Two experts explain how the various techniques like EEGs, fMRIs, and PETs work in this TedEd talk.

Medical imaging allows 3D printers to create patient-matched devices

With imaging data on a person's anatomy, external prostheses and implants, such as cranial plates or hip joints, can be custom-printed to better match a patient's body. Fabrication of porous structures can promote bone growth, leading to longer-lasting implants.

Lasers, semiconductors, medical imaging, and atomic clocks rely on quantum mechanics

Semiconductors, crucial in electronics, operate based on quantum superposition. Lasers use stimulated emission, a quantum process, and MRI machines leverage the quantum spin of hydrogen atoms for imaging. Atomic clocks measure time with unprecedented precision using quantum transitions.

How radioactive isotopes are created and used for medical diagnostics

In particle accelerators, protons can be accelerated into other atoms to create radioactive isotopes, which can be attached to specific molecules to create radiotracers that are taken up by specific cells. Radiotracers can emit particles that produce light once they collide with an electron, and this light can be captured by a PET scanner to diagnose specific ailments.

Radio waves are used in broadcasting, weather radar, telecommunications, and GPS

Its ability to bend around obstacles and reflect off the ionosphere—an electrified layer of Earth's upper atmosphere—allows this type of light to travel long distances without damaging living things due to its low energy. MRI scanners, WiFi, and Bluetooth technologies are also applications of this form of light.

Magnetism comes from quantum properties of electrons aligning in specific structures

Permanent magnets exist because electrons have an intrinsic magnetic moment, which can align in certain atoms. When many such atoms line up their magnetic fields within regions called domains, the result is a visible, macroscopic magnetic effect.

Hacking the body for a future that didn't happen

Journalist Adi Robertson experimented with one of the most accessible biohacks: magnets. Having a tiny magnet in their right ring finger meant they could sense magnetic fields, attract small metal objects, and more. But magnets weaken over time, eroding this new sense. Such implants do more than offer a new way of interacting with the world, they also pose new complications, such as the inability to get an MRI.

Metal detectors identify induced magnetic fields in conductive objects

A changing magnetic field in a transmitter coil causes an electric current to be produced in materials that conduct electricity. This current generates its own magnetic field, which can be detected by a receiver coil and transmitted to a control box, which identifies the presence and depth of an object.

Webb's sunshield enables extreme cooling for precision space observation

To avoid interference from its own heat, the telescope uses a five-layer shield to stay ultra-cold and stable, allowing its instruments to function at cryogenic temperatures. One instrument, MIRI, gets so cold it needs a helium-powered cooler to reach just 7 Kelvin, or -447°F.

Deep sea fish rely on a molecular strengthener to prevent being crushed

Trimethylamine N-oxide (TMAO) stabilizes hydrogen bonds and prevents water and proteins within organisms from being misshapen under immense pressure. Compounds called piezolytes protect cellular membranes from being crushed in regions like the Mariana Trench, where pressures are 1,100 times greater than surface atmospheric pressure.

The trajectory of particles in bubble chambers reveals their properties

The presence of magnetic fields produces spiraling paths in charged particles as they move across the field, with faster and more massive particles moving in wider turns. Gaps in the trails indicate the presence of short-lived particles that are undetectable until they decay.

Scientists have tested atmospheric models by firing rockets into the aurora borealis

Functioning like components of a CT scan, the missiles transmit signals that can be used to identify charged particles and electromagnetic currents in slices. The slices are then combined to construct a computer-based model of Earth's atmospheric structure, which is used to compare the accuracy of physics-based models.

Using deep learning to analyze tumors

The explosive growth of life sciences data is driving artificial intelligence methods to gain traction in biology and medicine — including cancer research.

NASA captures image of ghostly cosmic hand

NASA's X-ray space telescopes, Chandra and the Imaging X-ray Polarimetry Explorer, have joined forces to study a hand-shaped structure in space, revealing the magnetic field "bones" of a pulsar wind nebula. Pulsars are rotating neutron stars with strong magnetic fields, creating extreme physics conditions. The combined data from these telescopes provide insight into how pulsars inject particles into space and shape their environment, with the magnetic field playing a crucial role.

Microwave ovens heat food by agitating certain molecules with non-ionizing light

Molecules with resonant frequencies within the microwave range vibrate, producing heat between adjacent matter, just as hands warm when rubbed together. The mesh in front of an oven's door confines the microwaves to the container, while the rotating plate allows different parts of food to travel through regions of maximum vibration.

How spoiled meat helped uncover a bacterium that can survive the vacuum of space

When a can of ground beef and pork spoiled despite attempts to sterilize it with gamma radiation, researcher Arthur Anderson isolated the bacteria in the food and discovered Deinococcus radiodurans. The polyextremophile has since been found on the walls of nuclear reactors and overcomes radiation damage through highly optimized DNA repair mechanisms.

Explore a 3D model of the experimental setup Rosalind Franklin used to take Photo 51

To capture the X-ray diffraction image of DNA from the thymus of a calf, Franklin built a humidity-controlling camera to isolate the B form of DNA. The exposure lasted 60 hours and produced a cross pattern, indicating a helical structure.

NASA designed the Golden Record using hydrogen to ensure it's universally readable

The Golden Record holds what is essentially a human "time capsule," featuring music, nature sounds, and greetings from around the world. NASA used the radiation period of hydrogen's simplest transition as a baseline to convey timing and structure. The first coded image is included on the cover as a test so aliens can check if they decoded it correctly.

Objects can be 3D printed with light by projecting 2D computerized tomography (CT) scans onto rotating cylinders of resin, which solidify upon exposure.

The history of many kitchen appliances involves unexpected discoveries and applications, including wartime radar turned hamster defroster and replacing an 'ice king' with heat-stealing boxes.

Planeterrellas create artificial auroras that mimic the atmospheric displays of light by setting up an electric field between two metal balls in a jar filled with a small amount of air.

While atoms are normally made of protons, neutrons, and electrons, exotic ones have been built with antimatter—alternate versions of normal matter that live for fractions of a second and are about a billion times as rare.

Radioactive elements can introduce software errors because the ionizing radiation they produce can detach electrons from atoms, and computer code relies on the distribution of electrons.

Against his wishes, Albert Einstein's brain was removed before his cremation, and the pathologist responsible stored it for decades in mason jars within a beer cooler.

Visualize how CRISPR-Cas9—a type of immune system used by single-celled organisms to attack invasive viruses—targets and makes precise changes to a gene's DNA.

Scientists can determine Earth's past climate conditions by analyzing air trapped in microscopic bubbles within ice cores—columns of compressed snow layers that build up over hundreds of thousands of years.

Alzheimer's can lead to brain shrinkage, with an average of around 2% of volume reduction per year

Sony set the standard for cylinder-shaped batteries when it repurposed manufacturing equipment used to make rolls of magnetic recording tape.

The first image of a black hole was captured by creating an Earth-sized virtual observatory from a network of eight radio telescopes.

Explore the animals that populate the depths of the ocean, from fish and coral in the first few hundred feet, all the way down to the bottom of the Mariana Trench.

Power lines are dotted with large, brightly colored balls to improve the visibility of these thin wires to helicopters and small planes and help prevent potential crashes.

As of 2025, the most cited papers in science include a review of graphene, methods to improve image recognition, streamlining electron density calculations, and optimizing protein studies.

Bone marrow (soft tissue found inside certain bones) generates roughly 500 billion new blood cells each day

Larger animals like giraffes, elephants, and blue whales have developed a unique defense against cancer, a phenomenon known as Peto's Paradox

Experimental hantavirus vaccines and therapies, still under development, have long been funded by the US military.

Hurricanes, which rely on air consistently spinning in the same direction, cannot cross the equator because air curves in opposite directions north and south of it.

After 25 people used virtual reality headsets to practice flying with virtual wings—flapping their arms—their visual cortex responded to the wings almost as if they were real arms, treating them as body parts.

Pure water does not conduct electricity because this flow of energy requires the movement of charged particles, and water is a neutral molecule.

See images of medical cases of firework injuries shared on this 'Instagram for doctors.' (Warning: Graphic content)

Double world record holder Hunter Ewen helped conquer his fear of balloons, called globophobia, by training to win Guinness World Record titles for balloon inflation.

Take a 3D tour of the Hajj, Islam's annual pilgrimage to Mecca, undertaken by more than 1.5 million Muslims each year.

The Mona Lisa's celebrity status and repeated restorations have obscured what made the painting so revolutionary for its time

In 2026, Finland was named the world's happiest country for the ninth consecutive year based on its wealth, social safety network, and high life expectancy, among other factors.