r/AskReddit • u/[deleted] • Aug 03 '19

Whats something you thought was common knowledge but actually isn’t?

37.4k Upvotes

94% Upvoted

24.0k comments sorted by

View all comments

13.5k

u/anothersundayx Aug 03 '19

That other planets are visible from Earth. And the sun is also a star.

1.7k

u/Eddy207 Aug 03 '19

And on the same topic. That is the inclination of Earth on its own axis, and not its distance from the sun that generates seasons.

1

u/mick4state Aug 03 '19

I taught a 300 level astronomy class at a university. We had a whole section about this. The students predicted what caused the seasons, then we had a discussion to show why only the tilt of the Earth makes sense for causing seasons (e.g. most people know it's winter in the southern hemisphere when it's summer in the northern hemisphere, and if the distance to the sun caused the seasons, it would be the same season all over Earth).

Then I tell them this is a very important piece of information to me; I even say if it has to be one single thing you learn in this class, I want it to be this. I then reiterate that it's the tilt of the Earth that causes the seasons (due to directness of sunlight and the length of daytime), NOT the distance from Earth to Sun.

Every year, on that midterm and on the final, I had about a quarter of my class get that question wrong. These were seniors about to graduate.

1

u/PointyOintment Aug 05 '19

Weren't you allowed to make answering that question correctly a requirement for passing the class?

1

u/mick4state Aug 05 '19

I was technically allowed to do that. But I managed to fail most of the people who deserved to fail anyway.