US to hit debt ceiling Tuesday, starting Congress’ countdown clock
The nation will hit its roughly $36 trillion debt limit on Tuesday, when the Treasury Department will start taking extraordinary measures to allow the government to pay its bills, outgoing Treasury ...
Redefining the second: Optical atomic clock achieves record accuracy in comparison measurement
The next generation of atomic clocks "ticks" with the frequency of a laser. This is about 100,000 times faster than the ...