Exercise slows cancer growth, interstellar 3I Atlas chemistry, and Bohr-Einstein quantum test

Summary

This week’s New Scientist episode features three science stories. First, exercise in mice appears to slow breast cancer growth by creating a glucose competition where muscles outpace tumours for glucose. Second, the interstellar comet 3I Atlas displays unusual chemistry including high carbon dioxide and surprisingly high methanol, hinting at prebiotic molecules in other star systems. Third, a cutting-edge quantum experiment using a single atom as a movable slit resolves aspects of the Bohr-Einstein debate on wave-particle duality, reinforcing the quantum view of nature. The show also touches on life’s origins and related science controversies.

Section 1: Exercise and Cancer in Mice

Researchers at Yale conducted a mouse study to investigate how exercise affects tumor growth. They injected breast cancer cells into 18 mice, of which 12 were obese, and allowed half the mice to run freely on an exercise wheel for four weeks. Tumors in the exercising obese mice were 60% smaller than those in sedentary obese mice and smaller than their non-obese sedentary counterparts. By 30 minutes of exercise, glucose uptake in skeletal and cardiac muscle rose while uptake by tumours declined, supporting a model in which exercising muscles outcompete cancer cells for glucose. Gene analysis showed more than 400 metabolic pathway genes changed, including downregulation of MTOR, a key cell growth regulator, suggesting multiple mechanisms behind the cancer-suppressing effect. Although a small mouse study, researchers argue that these metabolic shifts are conserved across mammals and may occur in humans under appropriate medical supervision.

Section 2: Interstellar 3I Atlas and Prebiotic Molecules

3I Atlas, an interstellar object visiting our solar system, has been studied with JWST, Hubble, and ground-based telescopes. It shows a coma with unusually high carbon dioxide and detectable complex carbon-bearing species such as hydrogen cyanide and methanol. These findings imply that some star systems may host more methanol than our own, raising possibilities for prebiotic chemistry elsewhere. The presence of metals and methanol hints at processes inside the comet that could release organic compounds when warmed by the Sun, informing our understanding of how life’s building blocks might arise in other systems and possibly be delivered to planets like Earth.

Section 3: Origin of Life and Genetic Organization

The episode revisits discussions about how life began, including comparisons to amino acids and ribosugar detected on asteroids such as Bennu. The conversation emphasizes that while organic molecules are widespread, several additional ingredients and energy sources are needed to organize them into living systems. A cover feature proposes a provocative idea that prions could have played a role in organization and the emergence of metabolism or information pathways, illustrating the ongoing debate about how genetics, information, and metabolism first coupled in the origin of life.

Section 4: Bohr-Einstein Quantum Experiment

In a century-old debate about whether light is a particle or a wave, scientists have now built a version of the original thought experiment using a single atom cooled by lasers as a movable slit on springs. By tuning momentum, the team shows that measuring momentum can destroy interference, aligning with Bohr’s notion of complementarity, yet they also observe a regime where partial information and partial interference coexist. The result strengthens the idea that photons exhibit both wave and particle properties, a cornerstone of quantum mechanics, and demonstrates the precision of modern quantum experiments.

Closing Notes

Alongside these studies, the show reflects on how such findings empower patients and the public while acknowledging that not all cancer stories end in triumph, and that the quest to understand life’s origins remains complex and open-ended.