I remember my first science based thought was based on a survival scenario. If you are a small boat going over a waterfall then you need to crawl to the back, grab hold of the boat and just before you hit the water you jump from the boat. Thus saving yourself from a 100ft fall by making a three foot jump. Ta da.
I used to believe that if you dropped a coin on a table and gulped in the air as it fell, that you would be swallowing 'energy' and that this would make you energetic. This is because I had seen a children's science programme on television which said something about energy being 'released' if you dropped a coin.
I first saw Star Wars when I was seven. When the characters spoke about making the "jump to light speed" I instead heard them say "jungle light speed" and I assumed that light moved at a faster speed in jungles.
As a child, I believed in the law of balance. I don't even know where I got the idea. I believed if there were two options or two ideas, one had to be one way, and the other had to be the opposite.
Like winding an old clock, you had to let it wind down or you'd break the spring if you kept winding it. We had a bathroom with two light switches, one of them not connected to anything. So when I flipped the switch for the light up, the unused switch had to go down, and vice-versa.
Or if I had to turn around to the right to do something, I'd then have to turn back around to the left, as if there was some invisible string attached to me that would get wound around me oddly and somehow make my life more difficult if I didn't unwind it the other way.
I also believed that if I was walking with someone closely, like a friend or parent, there was some sort of invisible connection between us, and if I let something pass between us, like me walking on one side of a pole and the friend walking on the other, we'd break the connection and our relationship might start to fall apart. So I always scooted to be sure we walked on the same side of things together, eve if we had to go single-file.
That's pretty much the oddest thing I believed.
My parents used to have plastic plug-socket protectors (i.e. the plug prongs attached to a shield bit) to prevent inquisitive toddlers from electrocuting themselves.
Apparently I was of the belief that they were actually there to prevent the electricity from flowing out!
Pretty sensible, I thought! :)
When I was five I believed that I could restore the elasticity in my sagging crew socks by turning them inside out and then stretching them. I assumed the outward stretching force would be directed inward once I turned them right side out again, thus pulling the socks toward my legs.
That if two spiders could levitate in the air if they walked on each other's feet in perfect symmetry (similar to how they climb up walls, but using each other's feet for support)
I used to think that if I put small piles of rocks in the road, I could make cars jump through the air like on "The Dukes of Hazzard." Then I tried it and the unsuspecting driver threatened to call the police.
My dad used to get annoyed with me opening the car windows on the motorway, he told me that if we were driving fast and the window was open, the air pressure would make the car lift up of the road and we would flip over. I still have a thing about opening windows in cars.
I was told that diamonds were made out of coal, crushed under the earth. So I put a piece of coal under a brick in the garden, and checked it regularly. I knew I didn't have enough pressure for diamond, but I figured I'd get something good - possibly chocolate.
At the age of ten, I had a fantastic idea for walking on water. I put inflatable arm-bands around my ankles and stepped 'onto' the swimming pool. Luckily my dad was there to rescue me as I dangled upside-down under water :)
As children, my best friend (who will remain anon because he is now a respected Engineer) tried to convince me that raising the seats on our bicycles actually made them heavier, because there is more metal showing.
When I was a kid, I used to believe that the sky was the surface of a solid sphere and that we were inside this sphere.
I think the fact that the sky is usually blue and satellite pictures showed the Earth as being blue led me to belive this.
I was never able to figure out the knotty problem of how rockets managed to pierce through this solid wall of sky to make their way into space though.
Somehow I got this strange idea that if you held a piece of paper so that it's edge was facing a piece of glass, and pushed it fast enough it would actually travel through the glass without the glass breaking. I thought it was a phonomenon associated with time travel but later as I discovered that all material thigs were made up of atoms I figured that the paper was actually squeezing through the spaces in between the molecules. Actually none of my experiments to make the paper pass through the glass ever worked but I figured that it was because I couldn't move the paper fast enough.
I used to believe that if I dug up my garden enough I would discover a completely new colour that no-one else had ever seen before. I tried to imagine what this colour would be, and it was always orange.
As a seven-year old, I believed that every noise ever made or that will be made goes directly to a cave in some vast mountain, and that they will remain there until the destruction of the earth when they will all be released simultaneously.
When, as a kid, I first found out about atoms and how they had some particles in the nucleus and others flying around the nucleus, I thought it was like a miniature solar system, and there were tiny people living on each subatomic particle. I'm still not entirely convinced it's not true.
I used to think that if a near-sighted person held a mirror and viewed the reflection of a distant object, they should have no trouble seeing the object in perfect focus. After all, they're looking at the mirror, and it's only a foot or so away.
I used to think you could yell into a bag or jar and trap your voice...but it would only work if closed it fast enough.
I asked my teacher what protons were made of and when he said "quarks" I thought he said "cork" and for a long time after that I thought that cork was the fundemental substance of the universe and that the cork on wine bottles were made of "pure" matter.