We can tie knots in three dimensions because one-dimensional ropes “catch on each other”. This is why a long rope wound around itself, if done right, won’t come apart. We trust knots with our lives ...

A subtle gravitational-wave “hum” from merging black holes may help settle the cosmic fight over how fast the universe is ...

Lower-income adults with an aging parent, spouse or partner are more likely to be caregivers than those in higher income tiers. Fresh data delivered Saturday mornings Thank you for subscribing! In the ...