Professors don't have time to follow up trails that seem cold. But sometimes these produce the most outstanding breakthroughs, says Chang. "This is a major problem."
老師沒多餘時間花在冷門的領域，「但最冷門的領域，往往能產生最突出的成果」，張福國認為「這是個大問題」，他自己手上的研究計畫，就都是和目前最實用的航空科技有關。