Understanding Our World

Glacier ice often contains bubbles of ancient air, captured at the time the water froze. These form a record of the atmosphere going back thousands of years. Scientists cut cores from the ice and sample the air in the bubbles to build up a picture of the past climate.

Photomicrograph of a marine diatom of the genus Thalassiosira. Diatoms are a type of tiny algae that use photosynthesis to make their own food. This process also produces oxygen. Diatoms are the second most important oxygen producer in the world after the rainforests. This image is about 0.2mm wide.

The Veil Nebula, NGC6960, is an expanding cloud of gas and dust from a huge star that exploded about 8,000 years ago. The gas has been ionised by losing electrons or negative particles. This lets us see the different gases as different colours. Red shows hydrogen while blue shows oxygen.

A Secchi Disk enables citizen scientists across the world to study phytoplankton. Phytoplankton are microalgae that live in the sea and are a vital part of the food web. Sailors lower the disk into open water and note when it disappears. The shallower the depth, the more phytoplankton there is.

Scientists carefully remove rock from a fossilised dinosaur spine discovered in the Lo Hueco area of Spain. In 2007 construction workers found a huge concentration of fossils from the Upper Cretaceous period (100-66 million years ago). The 10,000 fossils unearthed illuminate life at the end of the age of dinosaurs.

A simple spherical lens placed inside a patterned tube bends the light passing through it. The light bends more at the edge than the centre of the sphere. This makes the grid lines of the patterned tube look more curved the closer they are to the edge of the sphere.

This series of images shows a soap film in front of a loudspeaker while the song ‘My Way’ is being played. The different frequencies of sound create different patterns of thickness in the soap film which show up here as different colours.

Tension and relief in an operating theatre as Professor Robert MacLaren performs pioneering surgery. The surgeon used a new scanner to guide the procedure to treat an incurable form of blindness. They injected a virus containing a working copy of a faulty gene into the patient’s eye.

Magnifying the wings of an emerald swallowtail butterfly by 50 times shows these shimmering scales. The iridescent green colour is created by the shape of the cells in the scales. They reflect blue and yellow light to make the green we see.

This image shows how the sun moved across the sky over St Peters Cathedral, Adelaide, Australia. It was taken using a homemade pinhole camera with an exposure of four months. Broken or darker sections of the bright lines show when the sky was cloudy.

This aerial view of a salt lake makes it look like a jade green leaf. The green colour comes from types of algae that can live in the extremely salty water. Photographed at Da Qaidam in the Qinghai province of China.

A glowing drop of tonic water captured with a short duration ultraviolet flash. The quinine in tonic water gives it its characteristic taste and fluoresces in ultraviolet light. Although the human eye can’t see ultraviolet light, the quinine absorbs it then immediately releases the energy as a visible blue light.

Colour schlieren image of heat rising from four candles. Schlieren imaging allows differences in air density to be seen. Each candle generates a column of heated air visible well above the flames at the bottom.

Close-up view of drops of water refracting or bending the light from the screen of an iPad tablet computer. The droplets magnify our view of the red, green and blue dots that combine to make colour pictures.

In the summer of 2020 Comet NEOWISE came close enough to Earth to be seen with the naked eye. Here it passes through the sky above Hadrian’s Wall in northern England. Discovered in March 2020 by a space telescope, the comet won’t come this close again for 6,800 years.

Using a flash duration of just 10 microseconds, the photographer has captured a perfectly timed image. Two water drops collide as they fall into a glass of water beneath an unbroken soap bubble.

Cygnus spacecraft take 2,000kg of supplies to the International Space Station. A crew of six people can live and work on the space station for up to a year. They need regular cargo flights to keep them fed. Cygnus spacecraft are unmanned and aren’t reused.

A complex halo of light seen around the moon above a lake in Belarus. The halo pattern results from tiny ice crystals high in the atmosphere bending the moonlight as it passes through them.

The scientist used a scanning electron microscope to photograph a human tongue. They digitally coloured the image to show the location of taste buds in red. The microscope scans a beam of tiny particles called electrons across the surface of the object. It creates a picture from the signals the object sends back.

Freezing soap bubble. A soap bubble consists of a layer of water trapped between two filmy layers of soap. As it freezes, the water forms these beautiful large crystals.

A long exposure at night reveals star trails circling around Polaris, the North Star. This apparent circling is a result of the Earth's rotation. Objects in space appear to move across the sky as the Earth turns.

Animal, vegetable or mineral? The photographer grew this thin film of crystals on a glass microscope slide. The crystals grew in different directions and thicknesses, causing the many colours. These colours are only visible using polarised light. The light wave is filtered to vibrate in one direction rather than many.

Two researchers examining a microfluidic device used to artificially grow nerve cells for study. Growing cells outside the body allows us to study them more easily. The researchers work at the Johns Hopkins University School of Medicine, USA.

An X-ray image of a black tulip. The structure of the flower head is clearly seen near the top. X-rays use a type of very short wavelength electromagnetic radiation to produce images of the inside of objects, people and animals.

Close-up photograph of a single eye drop spreading out over the eye of a patient. Eye drops are used for a variety of reasons, from giving medicine to stopping the eye drying out.

Tiny pieces of powdered iron form spikes as they follow the magnetic field lines of a powerful magnet. Using a strongly magnetic material like iron lets us see the invisible force of magnetism.

Tiny flowers appear trapped in four drops of water. The shape of the water drops changes the direction of light as it passes through. It focuses the light like a lens to create a sharp image of the flower behind.

The Milky Way, our home galaxy, seen in the skies above Cetina, Croatia. Our galaxy is a disc-shaped spiral of 100-400 billion stars. The Milky Way looks like a band of stars to us because Earth is inside the disc. Crossing the galaxy would take at least 170,000 light years.

Skull of a small mammal seen in stereo. The stereo effect is created by taking images from slightly different viewpoints. This imitates the slightly different view seen by our two eyes. When looked at using a special viewer or defocusing your eyes, the images combine to look 3D.

This fossil coral was found in Indonesia. It lived about 20 million years ago. Over thousands of years a mineral called agate replaced the soft parts of the coral. Later the skeletons of the coral dissolved. Minerals called silicates filled the gap. This image shows just 7mm of fossil coral.

Single human tear drop seen under a microscope using darkfield illumination. The tear drop is easier to see because the technique makes everything around it look dark. Tears are made of different things depending on why someone is crying. Tears of sadness would look different to tears from chopping onions.

Fossilised bones are made when a skeleton is buried in layers of sediment which compact and harden to become rock. The bones dissolve and minerals replace them. This polished slice through a dinosaur bone shows many different colours and shapes. These come from the different minerals that made the fossil.

This photo was taken in complete darkness. The corn was lit by invisible wavelengths of light, including ultraviolet. The corn absorbed the energy and re-emitted it as invisible infrared light. The camera is set up to capture infrared. The parts of the corn containing chlorophyll, like the leaves, glow brightest.

North arm of the Advanced VIRGO+ Gravitational Wave Observatory. VIRGO+ is made of two 3km-long arms at right angles to each other. It detects gravitational waves, which are ripples in spacetime. The waves are caused by big events in space, like two black holes orbiting each other and merging.

Tiny spicules or spines from the skeletons of sea sponges are revealed through a microscope. These spicules are made of silica. Silica is the main component of glass. Spicules are thought to be used for defence from predators.

Hypnotic patterns formed by a Belousov-Zhabotinsky (BZ) reaction in a petri dish. Scientists add drops of one chemical to another in the dish. The drops seem to radiate concentric rings and spirals as waves of chemical concentrations move through the petri gel. Alan Turing described the mathematics behind these patterns.