BBC5 个月
The 12 and 24 hour clock
For any time before 10 o'clock in the morning, a zero is placed at the beginning. The first two digits show the hour and the last two digits show the minutes. We don't use AM or PM here ...
Doomsday clock set at 89 seconds to midnight, closest ever to "global catastrophe"
The clock was initially set at seven minutes to midnight and has moved 25 times since then. It can move backwards and forwards, with movement away from midnight showing that people can make positive ...
BBC6 年
Doomsday Clock frozen at two minutes to apocalypse
When it debuted the clock's hand stood at seven minutes to midnight and it has been reset 23 times since. According to the Bulletin, its design was conceived by artist Martyl Langsdorf.