Popular Mechanics September/October 2025

IF YOU LIKE BUILD THIS WIENER DOG BOOT SCRAPER / P.54 CHECK OUT BUILD A DIY ROUTER SLED TO FLATTEN WOOD SLABS DID YOU KNOW? POP MECH MEMBERS GET ACCESS TO A LIBRARY OF EXCLUSIVE DIGITAL ISSUES. DOWNLOAD THEM NOW. IF YOU LIKE THE IDENTITY OF A FAMOUS CRIMINAL / P.20 CHECK OUT 7 PEOPLE HAVE CONFESSED TO BEING D.B. COOPER. A TWIST IN THE CASE SAYS ONE TOLD THE TRUTH. IF YOU LIKE OUR GLOBAL POPULATION / P.11 CHECK OUT A.I. WILL DOUBLE THE HUMAN LIFESPAN BY 2030, TECH CEO CLAIMS. IS THIS THE DAWN OF IMMORTALITY? IF YOU LIKE DON’T TOUCH THAT DIAL! /P.22 CHECK OUT WIFI IS ILLEGAL IN THIS AMERICAN TOWN. (AND YES, PEOPLE ACTUALLY LIVE THERE.)…

AS CLIMATE CHANGE CONTINUES TO impact countries and communities around the world, humanity is hungry for alternative sources of green energy. Turbines harvest wind energy, solar panels collect the sun’s light, generators capture the power in a wave’s motion, and even geothermal heat transforms into usable electrons. Now, some scientists are considering a completely new renewable energy source: Earth’s rotation. Okay, maybe not completely new. Back in 2016, Christopher Chyba of Princeton University published a paper exploring the possibility of generating electricity by rotating through Earth’s magnetic field. This drew some criticism, as most experts figured that any net voltage would be canceled by the rearrangement of electrons during said generation process, according to Phys.org. To prove that the idea had merit, Chyba decided to construct a foot-long cylindrical device made…

SKELETONS UNDER DEPARTMENT STORE Recently 317 medieval and post-medieval skeletons were discovered at the site of a department store being remodeled into a university. This was oddly unsurprising, as other skeletons from the Roman and medieval periods have surfaced since renovation efforts began in 2023. Nonskeleton artifacts will be put on display once the new campus opens. —Elizabeth Rayne ROMAN GRAVE UNDER SOCCER FIELD Renovations on a soccer field outside of Vienna, Austria, uncovered a Roman-era mass grave that held the remains of roughly 150 males. Experts believe the site was likely a battlefield where a “catastrophic event” took place near the end of the first century, an idea potentially corroborated by the hasty covering and disorderly nature of the burial. —Tim Newcomb…

THE STATE KNOWN AS LUCID DREAMING IS an unquestionably surreal one, and it just got even more so. A team of researchers at Radboud University Medical Center in the Netherlands has discovered that lucid dreaming is a state of consciousness separate from both wakefulness and REM sleep (the state usually associated with dreams). In fact, it is associated with its own type of brain activity. To identify what sets lucid dreaming apart from the rest of sleep, the team pulled previous studies together into what is now the most extensive dataset in this field of sleep research. The researchers then compared brain activity patterns for wakefulness, REM sleep, and lucid dreaming to find that the eerie self-awareness experienced in lucid dreams is connected to certain types of brain waves. Perception and…

BETWEEN 14,800 AND 5,500 YEARS AGO, the Sahara—known for being one of the driest places on Earth—actually had enough water to support a way of life. Back then, it was a savanna that early human populations settled to take advantage of the favorable farming conditions. Among them was a mysterious people who lived in what is now southwestern Libya and should have been genetically sub-Saharan—except, upon a modern analysis, their genes didn’t reflect that. A team of researchers analyzed the genes of two 7,000-year-old naturally preserved mummies from the Takarkori rock shelter. Though genetic material does not preserve well in arid climates, there was enough fragmented DNA to give insights into their past. “The majority of Takarkori individuals’ ancestry stems from a previously unknown North African genetic lineage that diverged from…

HOMO SAPIENS IS THE MOST SUC-cessful mammalian species in Earth’s history, and it’s not even close. However, a new study suggests that the impressive nature of humanity’s proliferation may have been vastly underreported. Most estimates place Earth’s human population at around 8.2 billion, but Josias Láng-Ritter—a postdoctoral researcher at Aalto University in Finland—claims that these estimates could be underrepresenting rural areas by a significant margin. “We were surprised to find that the actual population living in rural areas is much higher than the global population data indicates—depending on the dataset, rural populations have been underestimated by between 53 percent to 84 percent over the period studied,” Láng-Ritter said in a press statement. With a background in water resource management, Láng-Ritter looked at a different kind of population data gathered from rural…