This is evidence of something very severe that has occurred: THE SPEED OF THE EARTH'S ROTATION, THE LENGTH OF OUR DAY AND OUR NIGHT, HAS BEEN SHORTENED.
(something very severe; has occurred; ) (THE LENGTH OF OUR DAY AND OUR NIGHT; HAS; BEEN SHORTENED) Context(THE LENGTH OF OUR DAY AND OUR NIGHT HAS,List([96, 136))):(This; is; evidence of something very severe)
THE LENGTH OF OUR DAY AND OUR NIGHT HAS,List([96, 136))
something very severe THE LENGTH OF OUR DAY AND OUR NIGHT This
has occurred HAS is
BEEN SHORTENED
evidence of something very severe