Cai Mingjie (蔡明杰, born 1952) is a Singaporean taxicab driver and former biology researcher, known for his blog, "A Singapore Taxi Driver's Diary". He is described variously as "Singapore's most educated taxi driver" and "the only taxi driver with a Ph.D.". Using only the above description and what you know about the world, "Cai Mingjie is 70 years old today" is definitely correct, incorrect, or inconclusive? 