@Knowsstuff This is a direct quote from MITChris.
http://talk.collegeconfidential.com/massachusetts-institute-technology/1900611-does-mit-care-about-the-act-science.html
“It’s not strongly weighted in our process because it’s not as predictive as e,g. the math section.”
Don’t worry too much about the science score. Did you know that many of the questions on that section can be answered correctly without actually reading the texts, just by going straight to the questions? You can save a lot of time on that section by doing that which can help your score. But only retake if you have nothing better to do on test day that can help your application more.
And don’t worry about you physics test score since you plan on retaking it anyway. If you got a 660 without even studying, you’ll do a lot better with some effort.
Your physics score will not stick out at MIT admissions because you want to major in physics. They might ask on your application what you want to major in, but only because they want to learn about you and your interests. You do not actually apply to a specific major, and you have time to decide once you finish you Freshman year. The only reason this score might be worrisome is because there are 2 required physics courses at MIT in order to graduate, no matter what you choose to major in, and admissions wants to be confident that all their admits will succeed.