Two flat prongs you see on standard plugs used in North and Central America make sense.
But how about those holes near the tips? They're not always there.
But there's a good reason manufacturers put them on plugs. Thanks to these holes,
the outlet grips the plug more firmly. This way, it doesn't fall out. There are small,
lined-up bumpers inside most outlets. They fit perfectly inside the holes on plugs.
It's a win-win situation: the prongs are safe inside the outlet. But with enough force, you
can still remove the plug. The second thing about the holes is that they allow you to wire electric
power directly to the prongs. In this case, you don’t even have to use an electrical outlet.
Also, you can put a locking mechanism or bar through the prongs. This way, no one will be
able to plug the device into an outlet. Some pens have caps with holes in their tops. Those are put
there as a safety measure. If someone accidentally swallows a cap while chewing on it, they'll still
have some space to breathe! Airplane windows have little holes which might make you nervous
when you see them. But they’re actually extremely important, and a plane needs them to fly safely.
These holes protect you from the difference in pressure outside and inside the cabin. When
you order a soda to go, it usually comes with a plastic lid. This lid is useful when you're in the
car or walking and want to prevent your soda from spilling. But it can also be a great coaster! Just
flip the lid upside down and place it under your cup. Most doorknobs are made of brass and other
copper alloys, and it's not accidental. These materials are known to be self-disinfecting.
And thanks to these antimicrobial properties, bacteria don't spread as much as they could.
Different numbers are often put on the sides of many cosmetic products.
These numbers aren't picked randomly. They tell you how long your product will actually last.
This way, you won't put it on your skin after it expires. Those escalator brushes can clean shoes
pretty well, huh? But they're actually made for safety reasons. When people are on an escalator,
brushes keep them away from the sides. And this prevents bags and clothes from getting stuck.
Most spaghetti spoons have a hole in the middle. Such a hole can be quite useful when you scoop
some pasta and need to drain it. But it's also a great measuring tool! The hole fits exactly one
serving of pasta. Some ovens have a little drawer at the bottom. At first sight, it's perfect for
storing pots, pans, and trays. A couple of extra points for creativity if you use it this way!
But it's not the drawer's main purpose. It's designed to keep the food you've just cooked warm
while you're waiting for lunch. When you take a box of aluminum foil, pay attention to the tabs on
the sides. You can press them in, and they'll keep the foil straight and prevent it from rolling.
Aaah, nothing better than a cold soda drink on a hot day. Soda cans come with a small
tab that helps you easily open the beverage. But the hole in the tab also has its purpose.
That's where you can put your straw to stop it from floating up to the surface.
Soda bottles also have small secrets of their own. Their long necks are made this way to keep
your drink cool for a longer time. And if you only touch the neck of the bottle instead of its body,
you won't have enough time to warm your drink up. Most plastic bottle caps have a soft little disc
inside. Pull it out, and you'll still be able to close your bottle. But if you don't have that soft
part and turn your bottle upside down, the liquid may leak out. Another purpose of this soft pad
is to keep your soda carbonated for a longer time. Hungry? It might be a good time for some Chinese
food! But keep in mind the takeout container isn’t only a good way to carry your food.
Unfold it – and you'll have a nice paper plate to properly enjoy your meal. The hole you might have
noticed in the elevator door comes in handy when an elevator gets stuck. In this case, a mechanic
needs to operate it manually. They have a special key that gets inserted in that very hole, which
releases the doors. Lots of people keep forgetting which side of their car the gas tank is on.
Luckily, on the dashboard, there's a small gas pump next to the fuel gauge. It has an arrow
pointing left or right. This arrow lets you know which side you're supposed to pull up to the gas
pump. And you don't even need to go out of the car to check it. Let's say, you got distracted
and climbed into your car while the gas nozzle was still in the tank. No worries, even if you
accidentally drive off like that, nothing terrible will happen. The nozzle has a special break-away
device. This device makes the nozzle and hose detach if you pull on them with enough force. Now,
embarrassment? Well I can’t help you with that one… Just a little bit of ketchup left? No need
to hit the bottom of the bottle for the product to come out. Instead, try tapping the middle of the
bottle. But not just any spot. There's a specific place with the number on most ketchup bottles.
That's where you should tap if you want to make the rest of the ketchup appear. If you prefer to
buy milk in plastic containers, you've probably seen big circles on their sides. These circles
absorb the shock if you drop the milk jug on the floor. They also create some extra room for
the jug to expand if needed. That's how you can see if the milk's turned bad without tasting it.
In most cases, wooden hangers are more expensive than plastic ones. Then why use them? They do look
more elegant and fancy. But more importantly, they are made out of cedar. And that's a special type
of wood that's known to repel bugs. A nice way to keep your clothes safe. If you're an iPhone user,
you must have noticed a small black dot between the flash and the lens on the back of your phone.
The dot is there to provide you with better sound quality. It also cancels out background noise,
especially when you're in some crowded place, like a concert hall. Lots of erasers have two parts.
Most people believe that the rougher end can be used to get rid of ink, but that's not quite true.
The darker side, usually gray or blue, is there to erase pencil markings from grainy paper, like the
one used by artists. And the pink side is supposed to erase stuff from more delicate paper. Women's
blouses mostly have their buttons on the left. But the majority of people are right-handed. So it'd
definitely make more sense to put buttons on the same side! But a hundred or even more years ago,
only rich women had blouses with buttons. And they had maids who dressed them. The buttons on
the left were actually on the right for the maids who faced the women they were dressing. Let's say,
you want to eat some applesauce. But you don't have a spoon with you. Just take the lid, twist
one of its ends to turn it into a handle, and make a scoop. Ta-da, your little spoon is ready!
Bon Appetite! Once all the tissues are out of the tissue box, don't throw it away immediately.
You can use it to store plastic bags and pull them out whenever you need them. A good way to
keep your kitchen more organized. Binder clips are also a great way to apply your creativity.
Grab one, hang your key on it, and then, use it to bind your money and cards. A practical way
to not carry too many things while going out. It can be rather irritating to see you can’t finish
your stick deodorant. There's a little bit more left, but it's hard to reach it. Okay, the trick
is easy: unscrew the bottom, take a pencil, and force it underneath the moving platform.
This way, you'll push what's left of the deodorant out. A few more weeks of using the same stick,
not bad! The thermos bottle was invented by James Dewar, a Scottish scientist. The man wanted to
keep his chemicals at a stable temperature. He took two bottles and put the smaller bottle inside
the bigger one. Then he pulled out the air that remained between them. Later, it turned out that
this system worked for food and drinks too. When they were first invented, golf balls had a smooth
and perfectly round surface. But this design didn't work that well. Golfers soon realized
that balls flew through the air much better and farther when they had dimples. Those cause the
air to cling to the surface, which increases the speed and spin rate. So now you know.