In June 1938, writer Jerry Siegel and illustrator Joe Shuster introduced Superman to readers. Since then, the Superman has become a cultural symbol, appearing in films, novels, TV series and more.

On April 4, 2024, a copy of that original 1938 Superman comic (漫画) book — called Action Comics No. 1 — sold for $6 million during a Heritage Auctions sale. It’s now the most valuable comic book in the world.

“Thursday was a historic day for a historic comic book, and we expected no less,” says Barry Sandoval, vice president at Heritage Auctions.

The comic has been given a “very fine” grade of 8.5 out of 10 by CGC, a third-party grading service for pop culture collectibles. It’s one of just 78 copies CGC has graded, though the company thinks around 100 still exist. Just 200,000 copies of Action Comics No. I were published in 1938. The price beats out the previous record-holder, a 1939 issue of Superman No. I that sold privately for $5.3 million in 2022. Until then, the record had belonged to a copy of Amazing Fantasy No. 15 — which introduced readers to Spider-Man in 1962 — that sold for $3.6 million in 2021.

Action Comics No. 1 tells the story of a baby boy who was born on a dying faraway planet. His father places him in a space capsule (太空舱) and sends him away just before his home planet gets destroyed. Finally, the capsule lands on Earth, where a passing driver discovers the sleeping baby and saves him. The child — Clark Kent — grows up and realizes he has superhuman strengths and abilities.

Superman’s popularity skyrocketed in the following decades, and Action Comics continues to this day. “Without Superman and Action Comics No. 1, who knows whether there ever would have been a Golden Age of comics — or if the medium would have become what it is today?” says Sandoval.

Compared to metal, ceramics (陶瓷) can better resist high temperatures and certain severe environments, but they are fragile. This potentially causes problems for innovators trying to create lightweight versions of these materials, explaining why ceramic materials are not typically used as structural components.

Facing the challenging task of developing lightweight, high-strength ceramic materials, Mechanical Engineering Assistant Professor Ling Li has turned to the knobby sea star from the tropical Indo-Pacific for design inspiration.

Sea star skeletons (骨骼) are made of an easily broken material. However, the body of the sea star demonstrates high strength and flexibility. Uncovering the principles of this structure may help solve the challenges of making stronger ceramics.

What the team found was unexpected. The skeleton of the knobby star consists of many millimeter-sized skeletal elements. Li and his team discovered that each is constructed of a microlattice (微晶) structure so uniform that it can be described mathematically. Even more interesting, the team found the uniform structure of the microlattice is essentially a single crystal structure at atomic level.

Based on the finding, Li and his collaborators used 3D printing to model and generate large-scale versions of these complex lattice structures, a useful approach in understanding the complexity of these unique geometries. While the 3D-printed models created by Li's team were indeed visually inspiring, the technology needed to bring new, stronger ceramic micro-architectures to market still lay in the future. Currently, 3D printers produce structures at the micrometer level, but printing ceramics still requires firing the final product, which possibly introduces many uncontrolled tiny holes and cracks. These make the structures extremely fragile.

Li hopes that continued advances in the field of 3D printing and further understanding of the formation mechanisms of biological structures like sea star skeletons eventually offer a solution.

Petra may be the treasure of an ancient world, hidden behind a tall mountain. Its beautiful scenery makes it one of the greatest ancient sites still standing today. Common sense says “perhaps there’s nothing on the planet that looks like it”. Without doubt, there’s nothing in the world that resembles it. The rock-carved rose-red town of Petra is filled with a mysterious charm that had been “designed to strike wonder into all who entered it”.

Petra is the legacy from the Nabataeans, a hard-working group of Arab people who settled in southern Jordan more than 2,000 years ago. Admired then because of their culture, architecture and complex dams and water channels, Petra has become a UNESCO (United Nations Educational, Scientific and Cultural Organization) world heritage site and listed in the New Seven Wonders of the World.

Petra is the most well-known site in Jordan located about 262 km south of Amman and 133 km north of Aqaba. The Dead Sea is 80 kilometres north of it. The steeply rising sides of a long, cool, dark and narrow gorge basically keep the sunlight out. Suddenly the gorge opens right into a natural square covered with Petra’s most well-known monuments, which glows in the bright sun. The ancient city shows the visitors its beautiful look. The town is large and the quality of the architecture is surprising. It leads someone to think about the creativity from the Nabataeans who made Petra their capital.

Petra was the top architectural site for more than 400 years until it was occupied by the Romans in 106 AD. It was seen first when discovered in 1812 after being lost through the 16th century for nearly 300 years! Petra has 800 monuments, including buildings, tombs, baths, halls, temples, and streets, which were mostly carved in the pretty sandstone. Petra sights are in their finest in the early morning and the late afternoon. Once the sun warms the colorful stones, you will see the majesty of Petra.