A mysterious force driving the expansion of the Universe may have undergone a dramatic reversal billions of years ago. Scientists exploring an overlooked branch of an alternative gravity theory discovered that dark energy could have switched from negative to positive roughly 9.5 billion years ago, potentially changing how we understand cosmic history.
Dark energy may have flipped from negative to positive 9.5 billion years ago
Original reporting
Science Daily: read the full reportRelated stories

How Sen. Chris Van Hollen plans to flex Democratic power on the foreign aid front
The Maryland Democrat, who's the ranking member of the Senate Foreign Relations Subcommittee, just announced he's going to run for Majority Leader. He spoke to NPR about his foreign aid vision.

Climate action discussed at youth COP meeting
School children gather to discuss climate issues to coincide with the COP31 conference in Turkey.
Scientists discover a hidden danger of viral infections that vaccines may prevent
A new study reveals that viral infections may leave behind hidden damage to the immune system long after symptoms disappear. Researchers found that mice recovering from an acute infection experienced lasting changes to their spleens and weakened immune responses, potentially leaving them more vulnerable to future threats. Surprisingly, prior vaccination completely prevented these harmful changes in the mouse model.

Happy World Kindness Day! Check out our kind photos of kindness to humans -- and cats
Friday, November 13 is World Kindness Day. Your mission: Do something kind. Small acts of kindness definitely count!

Summer heatwave put bin crews lives at risk, says council worker
Crews faced a "perfect storm" of challenges during the UK's record-breaking weather, it's claimed.
Superheated magma could fuel towering lava fountains
Why do some volcanoes erupt with spectacular lava fountains while others release lava more quietly? Scientists have discovered that a hidden effect of extreme heat inside magma may help explain the difference. Experiments revealed that superheated magma can delay crystal formation for more than eight hours, compared with just 20 minutes in magma that has not been superheated.