Materials and mechanics
If you add a small amount of sugar to concrete, its curing will be delayed. If you add much more, the concrete will never cure. Once concrete cures, it can still be eaten away by sugar.
Try to chop a rebar or tor steel bar with an axe, and you will end up with a bent or broken edge, but if you fix the axe on the ground blade up, place the bar on the axe and hammer it from above, the rod will slice cleanly with little damage to the axes edge.
Sugar does not dissolve in gasoline, so the popular idea - "Adding sugar to a vehicles gas tank will gum up its engine and ruin it!" is untrue. Even if you were to add powdered sugar directly into the carburetor of the said vehicle, it will just burn into carbon without any adverse effects.
Water saturated with flourine becomes a very good electrical insulator. It is possible to immerse a CRT monitor into a tank of such water and it continues to function perfectly.
Ruby and Sapphire are the same mineral - Corundum.
When steel and aluminum come in contact, the steel corrodes very rapidly.
Concrete continues to cure for many years after it is cast. If cracks form, they get "healed" eventually.
To steer a two wheeled vehicle in one direction, the handlebars are pulled in the opposite direction. This causes the vehicle to lean into the turn and travel on a circular path. This is known as counter steering.
Most metals turn soft when heated. In contrast, aluminum turns hard and brittle. In fact this is how aluminum powder is manufactured - It is heated and then pulverized.
So called "shock absorbers" don't actually absorb shocks. Their function is to dampen oscillations. The things that absorb shocks in a vehicle are the springs.
Your blind spot is several times larger than the size of the moon ( angular size ).
There exists a plant in Africa whose berries, when ingested, make you taste sour stuff as sweet.
Until a few centuries ago, tomatoes were considered poisonous.
The General Sherman tree ( the biggest in the world ), transports a volume of more than 10000 cubic meters of water every month. Even assuming the all the water does not reach the top of the tree ( at 85 meters ) but only halfway up, the power required to do that is at least 2 horsepower, and the tree has been doing that for most of its lifetime ( ~2700 years ).
Honey is the only food that never goes bad. Honey found in Egyptian tombs was still as fresh as it was 1000s of years ago.
Sodium vapor lamps used in street lights are the most efficient form of electric lighting known to man.
There is no such thing as pink light. Pink and similar colors ( e.g. Magenta ) do not exist in the visible light spectrum.
There are a number of cross-sections (other than circles) that can roll smoothly. The simplest example is a Reuleaux triangle. If you roll a slab on a flat surface with rollers shaped like this, the slab will move smoothly with no vertical movement.
The GPS navigator in your car relies on Quantum mechanical principles for its electronic components to function, but the GPS satellite data has to be adjusted according to Einstein's General Relativity theory, to get accurate positioning ( because the time on a satellite flows slower than on Earth ). However, these theories are mutually contradictory and cannot both be true.
When a pin is dropped, the sound reaching the human ear causes the eardrum to move by a distance less than the diameter of a hydrogen atom.
A photon which is generated near the center of the sun takes several thousand years to reach the surface and escape into space.
If you keep two grains of sand 30 meters apart, and completely shift the electrons from one to the other, the resulting electrical attraction will cause a force of 30,000,000 tons!