Chinese scientists want to use lasers to power ultrafast, stealthy submarines. A laser expert says there's a major flaw in their plan.

Reuters

• The US and China are in a race to develop the most advanced submarines.  
• Chinese researchers say they have made a breakthrough in laser propulsion technology that could one day be used on submarines and missiles.
• A laser propulsion expert at McGill University told Business Insider they see flaws in the claims. 

Submarines...