Congress President Rahul Gandhi on Wednesday mourned the death of British physicist Professor Stephen Hawking, terming him a "celebrity face of modern physics"."His physical challenges notwithstanding, Professor Stephen Hawking was the celebrity face of modern physics," Gandhi tweeted."A torchbearer for logic, reason and scientific temper, the professor left an indelible mark on our society."Like millions of his fans around the world, I mourn his passing," he added.Hawking, who shaped modern cosmology and inspired millions despite suffering from a life-threatening condition, died on Wednesday -- leaving millions in mourning globally. He was 76.