Recent molecular phylogenetic studies suggest that most placental orders diverged about 100 to 85 million years ago and that modern families appeared in the period from the late Eocene through the Miocene. But paleontologists object that no placental fossils have been found from before the end of the Cretaceous. The earliest undisputed fossils of placentals come from the early Paleocene, after the extinction of the dinosaurs. In particular, scientists have recently identified an early Paleocene animal named Protungulatum donnae as one of the first placental mammals. The earliest known ancestor of primates is Archicebus achilles from around 55 million years ago. This tiny primate weighed 2030 grams (0.71.1 ounce) and could fit within a human palm.
When is the earliest know primate thought to had exist?
55 million years ago

After many other more or less successful attempts with relatively weak rotating and reciprocating apparatus the Prussian Moritz von Jacobi created the first real rotating electric motor in May 1834 that actually developed a remarkable mechanical output power. His motor set a world record which was improved only four years later in September 1838 by Jacobi himself. His second motor was powerful enough to drive a boat with 14 people across a wide river. It was not until 1839/40 that other developers worldwide managed to build motors of similar and later also of higher performance.
What was Jacobi's improved motor used to propel?
boat

Reporters in Chengdu said they saw cracks on walls of some residential buildings in the downtown areas, but no buildings collapsed. Many Beijing office towers were evacuated, including the building housing the media offices for the organizers of the 2008 Summer Olympics. None of the Olympic venues were damaged. Meanwhile, a cargo train carrying 13 petrol tanks derailed in Hui County, Gansu, and caught on fire after the rail was distorted.
Where were office towers evacuated?
Beijing