The Ukrainian military fired U.S.-supplied longer-range missiles into Russia for the first time on Tuesday. Ukraine said it hit a Russian arms depot with the Army Tactical Missiles System missile (ATACMS). President Joe Biden allowed Ukraine to use the missiles against military targets in Russia after Ukrainian President Volodymyr Zelensky pushed for and received authorization to use ATACMS missiles to target select locations inside Russia. Russian President Vladimir Putin warned that the act would mean that NATO was "at war" with his nation.

SEE HOW PUTIN IS RESPONDING TO UKRAINE'S BOMBINGS

A growing belief in Silicon Valley could have immense implications: the breakthroughs from large AI models -- the ones expected to bring human-level intelligence in the near future -- may be slowing down. Since the launch of ChatGPT in 2022, AI fans have maintained that improvements in generative AI would accelerate exponentially as tech giants kept investing. Progress was advancing at such a rapid pace that leading industry figures, including Elon Musk, called for a moratorium on AI research. Yet the major tech companies, including Musk's own, pressed forward, spending tens of billions of dollars.

SEE WHY AI MAY HAVE MORE LIMITATIONS THAN ANTICIPATED

Americans are expected to set a travel record this Thanksgiving, with nearly 80 million people forecast to journey 50 miles or more from home -- an increase in 1.7 million over last year and 2 million more than in 2019, according to travel group AAA. The projected figures this year include, for the first time, the Tuesday before and the Monday after Thanksgiving, providing a more comprehensive view of the travel period as more people travel to celebrate the holiday season.

SEE HOW TRAVEL PRICES COMPARE TO PREVIOUS HOLIDAYS

When did the number of air travelers surpass train travelers in the US?

Monday's answer: The oldest fast food restaurant chain still in operation is White Castle, which was founded in 1921 in Wichita, Kansas.