(1) You can go into physics and possibly do something good for mankind, but get pair at a normal level of the United States, which is about $48,000 a year.
(2) You can go into political science and to absolutely nothing good for mankind, but at least potentially make many more dollars.
So, when you die, do you want to know that you made the world better, or do you want to know that you made more money than people who made the world better?