7 Simple Inventions I Absolutely LOVE

by Vlad Dolezal on August 23, 2008

Every day, as I look at all our awesome inventions, I say to myself “Neat.” But every now and then, “neat” just isn’t enough. It’s more like “Holy flying cow that’s frickin’ awesome! And the principles behind it are soooooo simple!”

Which is what this article is about. 7 inventions that are based on amazingly simple principles, and yet are incredibly effective. In fact, this article was inspired by #1 on the list (don’t skip ahead to see what that is. Build some anticipation :)). When I first found out how it works, I was just blown away by how simple the science behind it was. Enjoy!

(Update: It used to be 10 inventions. It’s only 7 inventions now! When I first wrote the article, I got a bit overexcited, and included some inventions that were just awesome, not TOTALLY awesome. So here you go. 7 Simple Inventions I Really Absolutely LOVE :D)

7. Bottle caps

Once you open a bottle, you can screw the cap back on really easily, and take it off again, and repeat as many times as you want. It takes almost no effort. And yet it can hold all the liquid if you turn the bottle upside down, and shake it, and put it on the ground and step on it with all your weight. And not a single drop spills out!

I can remember a time when all bottles were glass. And there was this really annoying contraption you could use to re-seal them after they were opened. But it wasn’t easy to use, and it required quite a bit of strength. PET bottle caps ftw!

6. Soap

Ever tried washing grease off your hands with just water? It doesn’t work too well. (doesn’t work at all, really). It’s because oil/grease/fat doesn’t mix with water.

At the risk of oversimplifying things, there are basically two ways that molecules in a liquid hold together. Polar and non-polar. Polar liquids can mix with other polar liquids, and non-polar with other non-polar. But polar liquids (like water) don’t mix with non-polar (like oil). That’s why, if you put oil and water in a bottle and shake thoroughly, they will eventually separate and form two distinct layers. They just don’t mix.

Which is where soap comes in! Every soap molecule has a polar “head” and a non-polar “tail”. So half dissolves in water and half in grease/oil/fat. Then you can wash your hands with water, and the attached oil washes off as well. Awesome!

5. Stairs

Have you ever driven a car in the mountains? The road doesn’t lead straight up, because that would be too steep for most cars. Instead, the road leads along the mountain, only rising slightly, then back in the other direction, again only rising slightly. That way you travel longer distance, but… well… you TRAVEL. As opposed to not traveling at all if the road was too steep. It trades distance for difficulty.

And stairs rock because they do exactly the same. Except they have another twist that makes them even MORE awesome. All the surfaces are HORIZONTAL. You don’t slip!

Oh, and if you don’t get why stairs are so awesome, try carrying a heavy load (like an old TV) up the stairs. Good. Next try carrying it up a ladder. You’ll get my point 🙂

4. Wet t-shirts

Yeah, I consider wet t-shirts a great scientific invention. Wait, don’t call the men in white coats just yet! First read my reasoning.

When I was a kid, we used to play sports at my school. During half-time, I would be really hot and sweaty. One day, I went to the washroom, and put a little water on my t-shirt and in my hair. And, surprisingly, it worked really well to cool me down. Next time, I completely wet my whole t-shirt, and within a minute I went from dying from heat to FRICKIN’ FREEZING.

I asked my physics teacher wtf was going on (I phrased the question slightly differently), and she explained. When you have something wet, it’s going to dry as long as the surrounding air has fairly low humidity. Now, each water molecule that evaporates needs to gain enough energy to be turned from liquid to gas. That’s quite a lot of energy. And the energy comes from its surroundings, which is you and the t-shirt. So the molecules with the most energy leave, leaving behind molecules with less energy, i.e. colder. As the water evaporates, the wet t-shirt keeps getting colder. And, unless you’re the abominable burning man, you will soon be ice cold under the shirt. Nice!

(by the way, you can use this same principle on a really hot summer night, if the heat is preventing you from falling asleep. Just wet a blanket slightly, and wrap it around yourself. Don’t wet it too much though, because you would freeze.)

(another by the way – blowing on your soup to cool it down works along the same principle. But here, when soup evaporates, a lot of the hot moist air hovers right above the plate. When you blow at it, you replace the hot moist air with cool dry air. The soup then evaporates faster, and hence cools down faster.)

3. Clothing

Here’s a simple quiz. What would warm you up more, three thin sweaters, or one sweater, but three times as thick?

Answer before reading on.

Hopefully you answered it’s about the same. Because then I can tell you you’re WRONG and feel better about myself :). Three thin sweaters will warm you up a LOT more than one thrice-as-thick sweater. And you know why? Because the clothing doesn’t warm you up. The air between layers of clothing is what warms you up.

The layers of air act as insulation. Just like in a window with two window panes. The whole point there is to have an extra layer of air between the cold outside air and the hot inside air.

Also, along the same principle, some smart designers built houses from hollow bricks. One might think that hollow bricks would provide less insulation, because… well… there’s LESS BRICK between you and the outside. But the extra air layer provides MORE insulation. Great example of putting a new twist on an old idea!

2. Wheel

Of course a list like this wouldn’t be complete without the wheel.

The wheel is great because you lift the surface off the ground at the back of the wheel, and lay it on the ground at the front of the wheel, instead of just sliding it along. For comparison, try walking. Then try standing with your feet together, and move by sliding both feet simultaneously forward. Feel the difference? 🙂

The first version of the wheel were simply round bits of wood under a heavy load. You would just push the load along, remove the bits of wood behind it and place them back in front.

|________________________| ->

Despite being so simple, the wheel is one of the most efficient machines, and it’s been reinvented hundreds of times. Just recently, I read a website (pics included) about that – apparently some scientists came up with a great way to transport water in poor countries… reinventing the wheel yet again!

So simple, yet so damn effective. I love wheels 😀

1. Toilet

When I was a kid, I used to wonder how the toilet works. Specifically the part where your waste goes. I thought there were some complicated sensors to make sure the water level is always maintained as it is, and I used to worry they would somehow break and our house would be flooded with filth.

It turns out I had nothing to worry about. Because there aren’t any high-tech parts that could fail. In fact, it’s all built on beautifully simple principles.

The water level is simply maintained because of the principle of “connected vessels”.

When you flush, the filthy water flows away into the sewers. It’s replaced by clean water, and the water plug prevents bad smells from entering your house. (That’s a HUGE effect. Go smell a field that’s been recently fertilized with cow dung. Now imagine your house would smell like that. Thank the water plug for preventing it :))

So there’s my list of simple scientific inventions. Every time I see them, I get this warm feeling. Like “Yeah, I’m proud to be part of the western world.”

If your favorite didn’t make the list… that happens. There were only 10 spots, and I picked MY 10 favorites (Update: Only 7 favorites now) . Feel free to suggest your favorites in the comments.

Hopefully I managed to get across my love for simple and elegant inventions, and maybe I made you realize how much your life rocks. Cheers!

{ 17 comments… read them below or add one }

JKJ August 23, 2008 at 19:37

Nice list, but at least five of these could make the “things that will be the premature end of mankind” list 🙂


Matt August 24, 2008 at 15:20


I think the precursor to frisbees were coffee can lids being thrown by college students. Some guy saw that, and said “I can make something better than that”


moxnix August 24, 2008 at 20:41

These are the types of revelations kids have in their first science class, (hopefully) giving them a lifelong interest in the how the physical world around them works.

Don’t forget the edge of the modern frisbee has an aerodynamic edge that provides lift, like a circular airplane wing. It’s more fun to throw them when they stay up longer.

The simple sleep mask has also been improved on: the Dreamhelmet sleep mask has a sound muffling pillow attached, limiting input to three senses (sight, hearing, touch. Invented, patented 1998-2000).


Anonymous August 24, 2008 at 22:13

Yay! Physics for the win!


Kevin August 25, 2008 at 18:20

How about the book? Where would we be without books?


Arun August 26, 2008 at 13:49

Internet – information, just one click away.

Its changing the world !!!!!


rachel September 4, 2008 at 15:15

hello =)


jona September 23, 2008 at 10:53


keep up da gud work—

God bless yah–



KeLvHonG January 12, 2009 at 14:58

What were the 3 other ‘awesome’ inventions??
i’m interested=)


L@ May 5, 2009 at 23:45

I´ve been living on a campus for some time now and with all the equipment we (don´t) have here, I discovered some other great inventions you may not notice otherwise. They aren´t as simple as yours, but still:
a) a washing machine (have you ever tried to wash sweaters or jeans in hand? you´ll see what I mean)
b) a PDF – editor (surprisingly many documents in this format just waste space and your paper; automatic 2-sided print comes in handy too)
c) your own bathroom, ideally situated in your own apartment, but at least next to your room and not across the whole hall (alright, that´s not an “invention” in terms of the previous ones, but still: hurrying in pyjamas – assuming you´re really wearing it – to that room and meeting 10 people on the way isn´t very comfortable)


Anonymous October 21, 2009 at 21:16



Dj285k December 18, 2009 at 11:05

ureally inspire me dawg. 4 tad i feel like huggin u dude.but listen.im participatin inna compt.cos spore gov is damn [censored],12 year olds like me hav 2 go invent stuff.any ideas.if yeah,email me @ daneshp2a@hotmail.com.thanks vlad.


ricky December 28, 2010 at 06:48

I.Like to do a little brianstorming.I like to learn how simple thing work any ideals?


inventions for kids March 15, 2011 at 22:34

It is not complete and where are the other ideas?


micko August 18, 2011 at 12:41

but this is very hard.
so bad 🙁


Anonymous January 29, 2012 at 01:24

thats so stupid i mean really a wet t shirt i can get mine wet when i get in to the pool


SwEeT_FuCk_TaE March 13, 2012 at 12:02



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