Back to the Future: Does physics of Marty's time travel add up?

Today is 21 October 2015 – the date Marty McFly and Doc Brown travel to in Back to the Future Part II. Can we reconcile the films with reality?

100+ Best Time Travel Movies – Creepy Catalog

Forward to the Future: Visions of 2045

TIL that Carl Sagan considered Back to the Future 2 the greatest time travel movie ever made, due to the movie's accuracy in handling the multiple timelines. : r/todayilearned

Scientists explain how time travel could be possible – but only in one direction - Daily Star

Back To The Future's Time Travel Explained: How It Works & Is It Accurate?

What's the real-life science behind time travel?

Where are we with time travel?

Back to the Future with MARTY!

Time Travel Is Possible but Changing the Past Isn't, Study Says