Tension on the Russia-Ukraine border is high as Russia has sent thousands of its soldiers on the frontier. German Chancellor Angela Merkel has demanded that Russia stops the build-up of troops. Ukraine President is visiting the eastern part of the country. Meanwhile, a scientific discovery about sub-atomic particles called muons is being touted to be capable of leading to groundbreaking advances in the field of Physics. Read this and more in our top 10 news of day.Vladimir Putin wearing a suit and tieRussia-Ukraine border crisis:MY VIDEO ON THIS