Wissenschaft

For decades, astronomers wondered why most nearby galaxies are speeding away from the Milky Way instead of being pulled in by its gravity. New simulations reveal the answer: our galaxy sits in a gigantic, flat sheet of matter surrounded by huge empty voids. This hidden structure—dominated by dark matter—balances gravitational forces and lets neighboring galaxies drift outward. The discovery finally explains the puzzling motions of galaxies just beyond our Local Group.

Electrons in solar materials can be launched across molecules almost as fast as nature allows, thanks to tiny atomic vibrations acting like a “molecular catapult.” In experiments lasting just 18 femtoseconds, researchers at the University of Cambridge observed electrons blasting across a boundary in a single burst, far faster than long-standing theories predicted. Instead of slow, random movement, the electron rides the natural vibrations of the molecule itself, challenging decades of design rules for solar materials.

Researchers created an AI-driven liquid biopsy that scans patterns in fragments of DNA circulating in the blood. The system detected early liver fibrosis and cirrhosis—conditions that often go unnoticed until serious damage occurs. By analyzing genome-wide DNA fragmentation patterns rather than specific mutations, the approach captures hidden signals about a person’s overall health. Early detection could help doctors treat liver disease sooner and potentially prevent cancer.

Scientists have uncovered new genetic rules that determine whether the immune system’s “killer” T cells remain powerful long-term defenders or become worn out and ineffective. By building a detailed genetic atlas of CD8 T cell states, researchers identified key molecular switches that push these cells toward either resilience or exhaustion. Remarkably, disabling just two previously unknown genes restored the tumor-killing power of exhausted T cells while preserving their ability to provide lasting immune protection.

A new study shows that as humpback whale populations recover from past whaling, older males are gaining a major advantage in reproduction. Early in the recovery, breeding groups were dominated by younger whales. But as more mature males returned, they increasingly fathered more calves than their younger rivals. Scientists say experience in singing and competing may help older males win the breeding battle.