The world’s largest river, the Amazon, has fallen to its lowest level on record in the past few weeks, a development that has shocked experts around the world. Rising temperatures, fueled by global warming, seem to be the driving force behind the powerful drought. They’re parching the largest freshwater reservoir …

On Tuesday, the scientists John J. Hopfield and Geoffrey E. Hinton received the Nobel Prize in Physics for discoveries that helped drive the development of artificial neural networks — a technology that is now essential to the operation of search engines like Google and online chatbots like ChatGPT from OpenAI. …

Look up, stargazers: A comet discovered last year is getting brighter as it makes its closest pass by Earth later this week, and this could be humanity’s last chance to see the comet before it disappears into the cosmic depths. The celestial visitor is Comet Tsuchinshan-ATLAS, or C/2023 A3 to …

John J. Hopfield and Geoffrey E. Hinton received the Nobel Prize in Physics on Tuesday for discoveries that helped computers learn more in the way the human brain does, providing the building blocks for developments in artificial intelligence. The award is an acknowledgment of A.I.’s growing significance in the way …

J. Robert Oppenheimer teemed with contradictions. He was shy and bold, naïve and brilliant, a loyal husband who cheated, a gentle man whose bomb could kill millions. That he loved quantum physics may be no accident. The field holds that some basic phenomena of the material world have opposing features …

Thirteen states and the District of Columbia sued TikTok on Tuesday, accusing the company of creating an intentionally addictive app that harmed children and teenagers while making false claims to the public about its commitment to safety. In separate lawsuits, a bipartisan group of attorneys general cited internal company documents …

Vice President Kamala Harris outlined a new proposal for home health care on “The View” on Tuesday, describing a Medicare expansion plan that she said would help what is called the “sandwich generation” to take care of aging parents. That constituency includes many adults who find themselves straddling the responsibility …

About 3.3 percent of high school students identify as transgender and another 2.2 percent are questioning their gender identity, according to the first nationally representative survey on these groups, published by the Centers for Disease Control and Prevention on Tuesday. Transgender and gender-questioning teenagers reported alarmingly higher rates of bullying …

Insulin for $35 a month. A limit of $2,000 a year in out-of-pocket drug costs for older Americans. Billions of dollars in savings for Medicare resulting from drug negotiations. Whether these policies expand or, in the case of the negotiations, survive at all may be determined by the election in …

Q: I can never figure out how best to time my meals with my workouts. Should I be eating before I exercise or after? We’ve all been there: It’s 6 p.m. and you just got home from work. You want to go for a run, but you’re hungry. Should you …