Physics is not just equations and data plots – physicists can sometimes create fantastic images. Here are some of our favourites from 2019.

Above is a scanning electron microscope image of the world’s smallest house, according to its creator Travis Casagrande of the Canadian Centre for Electron Microscopy at McMaster University in Hamilton, Ontario. It was assembled from pieces of silicon and the decorations were carved using a beam of gallium ions. To give you an idea of how small it is, the chimney opening is about 1 micron across. The house sits on the head of a tiny silicon snowman and the sculpture was made using a focused ion beam microscope that Casagrande normally uses to prepare even smaller samples for use in the centre’s powerful transmission electron microscopes.

“I think projects like this create science curiosity,” Casagrande says. “Looking into how this was made leads to more interest in science, and that builds more science literacy, which allows everyone to make better decisions.” Watch this video to learn more about how the house was made.

Sometimes all that is needed for a memorable image is an abstract shape and a nice colour scheme. The above photograph shows a guidewire being manoeuvred by magnets through a life-sized model of arteries in the brain. Developed by team of researchers at the Massachusetts Institute of Technology, the new surgical tool can wind its way through some of the narrowest twisting networks of blood vessels to help treat stroke and aneurysm. Using hydrogels and magnetic materials, they have created a magnetically steerable guidewire that can slide easily through blood vessels to reach blood clots in the brain.

Seeing is believing, which is why I have included the above atomic force microscope images of a ring of 18 carbon atoms and its precursors. This image of the  hotly debated carbon ring allotrope was taken by researchers at IBM Zurich in Switzerland.

In August, engineers successfully connected the two halves of NASA’s $8.8bn James Webb Space Telescope (above) for the first time. Engineers at Northrop Grumman’s facilities in California used a crane to lift the mirror and science instruments onto the sunshield and spacecraft. Now that the observatory has been mechanically connected, the next steps will involve electrically connecting the halves, followed by testing those connections. Engineers will then fully deploy the intricate five-layer sunshield, which is designed to keep the telescopes’s mirrors and scientific instruments cold by blocking infrared light from the Earth, Moon and Sun.

NASA’s New Horizons mission reached a small lump of rock and ice some 6.5 billion km away in the Kuiper belt at the beginning of the year. The above images, which were taken on 1 January when the craft was around 27 000 km from the object, reveal that 2014 MU69, or Ultima Thule, is a “contact binary”, consisting of two connected spheres around 31 km long. The large sphere (Ultima) is 19 km across and the other (Thule) is 14 km long. “This fly-by is a historic achievement,” says New Horizons principal investigator Alan Stern from the Southwest Research Institute in Boulder, Colorado. “Never before has any spacecraft team tracked down such a small body at such high speed so far away in the abyss of space.”

The skyrmion is one of our favourite quasiparticles here at Physics World, so we were chuffed to discover earlier this year that the magnetic excitations can sometimes behave like a school of fish. Hayley Sohn and colleagues at the University of Colorado, Boulder, first spotted the behaviour by accident, but quickly realized that they had discovered an intriguing new form of active matter. Their work could lead to the development of new types displays with the potential to transform the ways in which humans and computers interact.

Another obsession we have is with the tennis ball towers made by Andria Rogava, who is a physicist at Ilia State University in Georgia. The towers are held together by friction between the balls, and Rogova keeps coming-up with new designs to see how far he can push the concept, as he explains in “Physicist creates remarkable tennis-ball towers, including one made from 46 balls“.