The world around us is full of things that remain invisible to the human eye, yet play a vital role in our lives and nature. Modern technology allows us to peer beyond the limits of normal vision and see what was previously only accessible to the imagination. Microscopes, thermal imagers, infrared and ultraviolet cameras reveal the secrets of the world of microbes, tissue structures, thermal fields, and even light invisible to us. In this article, we've collected 10 amazing photographs of invisible objects that exist around us but remain beyond our field of vision. Each image will offer a new perspective on what's hidden from view and reveal the beauty and complexity of the unseen world.
10. Shock wave from the explosion
The Canadian Defence Research and Development Agency owns a vast tract of prairie land, far from civilization, and conducts various tests there. For example, in 2015, the agency conducted an explosives test. Someone on site took a photo of the fireball and unexpectedly captured the shock wave generated by the explosion.
The latter occurs when something moves (or expands) faster than the speed of sound, causing a sudden change in pressure. Shock waves are usually only visible in water, but a 2015 image captured a shock wave in air. What makes the photograph even more exceptional is its clarity. The shape of the shock wave is clearly visible, surrounding the explosion with a bubble-like patch.
9. Dark matter
This hypothetical form of matter cannot be detected by direct observation, as it does not emit anything detectable by modern instruments. Dark matter is believed to fill 85 percent of the universe.
How do scientists know about the existence of dark matter? Through its gravity, which pushes other matter and light. There's also a theory that dark matter forms halos around galaxies.
Scientists from the Harvard-Smithsonian Center for Astrophysics have created a simulation based on the popular theory that dark matter is made up of so-called weakly interacting massive particles.
To see if these particles behaved the same way regardless of the size of their universe, scientists modeled dark matter at 30 different scales. Sure enough, dark matter swirled around galaxies in halos. But even more encouragingly, it formed halos at all scales—even those too small to be seen. Halos are now recognized as features of dark matter.
8. Bird tracks in the sky
One question had long haunted Spanish photographer Xavi Bou. What do bird tracks look like? He imagined serpentine ripples following each bird. Several years ago, he discovered a way to photograph them.
Bowe used a video camera to film various species of birds in flight. He then combined the footage into a single image. The photograph, which made the invisible visible, shows the progress of each bird frame by frame, creating mesmerizing "trails.".
7. The Shine of Flowers
There are many unusual flowers in the world. But it turns out that even they, even the most ordinary sunflower, can literally glow under cold ultraviolet rays. This was discovered by American photographer Craig Burrows, who uses the UVIVF (ultraviolet-induced fluorescence) method to photograph flowers.
Simply put, he uses a lamp with powerful ultraviolet rays to illuminate the plants during photography. The resulting photo looks like an expensive piece of jewelry.
Researchers still can't solve the mystery of the role ultraviolet fluorescence plays in nature. However, photographs of flowers have shown that the brightest part of the plant is the pollen. This adds credence to the long-standing theory that flowers use fluorescence to attract pollinators.
6. Blood vessels in the zebrafish brain
This photograph of blood vessels in the developing zebrafish brain is stunning in its beauty. Using the magic of fluorescent labeling and a confocal microscope, the photographer captured an image reminiscent of a baroque biological neon sign.
5. Diffractive sun
The Top 5 Invisible Things Captured in Photographs reveals a wondrous phenomenon called the "Diffraction Sun.".
A researcher from the University of Cambridge's Faculty of Engineering directed a laser beam at a small liquid crystal spatial light modulator, causing the light to interfere (resulting in different colors from a monochrome laser) and diffract (spread in different directions). His image, resembling a psychedelic image of the sun, is the result of this diffraction.
The research behind this image could potentially help create a microscope that would allow people to see very fast and very small objects, such as a virus infecting a cell.
4. Magnetic field of the galaxy NGC 4217
The spiral galaxy NGC 4217 has a boring name. But in 2020, it was included in the Guinness Book of World Records thanks to an image of its magnetic field.
Virtually nothing is known about how galaxies generate their own fields. But their proportions can be determined. To remove the veil of invisibility around a galactic magnetic field, scientists simply measure the speed and behavior of cosmic rays in this region. And the magnetic field of NGC 4217 turned out to be colossal, reaching 22,500 light-years into space. Furthermore, it is X-shaped.
There are other spiral galaxies with X-shaped fields that extend for thousands of light-years. However, when the image was developed, it revealed mysterious phenomena within NGC 4217's field that had never been observed before.
- First, there were giant gas bubbles bouncing around, and they were also magnetic.
- Secondly, there was another magnetic field, twisting upward.
- And the strangest discovery was the loops that were thrown out.
3. The speed of light in slow motion
Since no one can travel at 300,000 km/s, the speed of light remained a mystery. Until 2019, when researchers created something that could capture their ultra-fast prey—the world's fastest camera.
A device called T-Cup was able to capture a laser beam passing through a bottle of milk. Why was this particular liquid chosen? Milk molecules scatter light particles, making them more visible.
The T-Cup operated at an astonishing 100 billion frames per second, yet the speed of light could only be observed in slow motion (the laser penetrated the bottle at a dizzying 2 billionths of a second).
2. Heart-shaped boron nitride molecule
Who else but scientists could give their beloved a heart made of a binary compound of boron and nitrogen? And one that's invisible to the naked eye, no less?
This boron nitride molecule, a near-perfect image of a heart, grows on iron foil. It was photographed by researchers from the University of Cambridge's Faculty of Engineering as part of the annual Zeiss Engineering Photos Competition.
1. Captured atom
Atoms are too small to be seen with the naked eye. But physicist David Nadlinger of Oxford University wanted to capture an atom in a regular photograph. And in 2018, he succeeded.
The photograph he took won the top prize in the Engineering and Physical Sciences Research Council's photography competition in the UK.
Nadlinger trapped an atom between electric fields before stabilizing it inside a vacuum chamber. A blue-violet laser colored the atom blue, making it visible to the naked eye.
Someday, this feat may help create quantum computers or something equally advanced. But right now, it offers a remarkable opportunity to look at something previously invisible—the building blocks of matter.