A Fan With No Blades

By Anupum Pant

Fans have always had blades which chop up the air and send a turbulent gush towards you. Also, “you can’t put your head or hand through the traditional fan”. Although these things aren’t big problems that the device says it’d solve, I still like how different and innovative this thing is. Certainly worthy of sharing in my engineering section…

This one, one of the many amazing things invented by sir James Dyson, is a blade-less fan. Or as the man likes to call his invention – an air multiplier. As the name suggests, the device has no blades and yet it is capable of shooting out a steady stream of air on your face.

It’s amazing how it works. Watch Sir James Dyson himself explain it to you.

Stone Age Technology Still Makes the Best Blades

By Anupum Pant

Normally, the electric shaver gets the work done. So, I almost never  have to use a fixed blade razor for shaving my facial hair, but after seeing this, I think I should start using a fixed blade. Here is a highly magnified image (using a scanning electron microscope) of two strands of hair. The left one was cut using a fixed blade and the right one was cut using an electric razor. See the difference for yourself.

magnified image of Hair cut using a fixed blade and electric shaver


So, even if the major thing that causes a messed up strand is due to the fast moving blade of an electric razor, but one other important factor is the sharpness of the blade. The point is, electric shaver blades aren’t too sharp, while fixed blade steel razors are pretty sharp. Thus, the steel blades can give you a clean cut.

Still, when it comes to fine tools, steel blades stand nowhere. Look at what a Gillette blade looks like when its put under an electron microscope (at not even a very high magnification – 150x).


Yes, even those seemingly perfect Gillette blades can be that jagged under high magnification. Thank goodness, blades can get much finer.

Obsidian Blades

Obsidian is a naturally occurring black volcanic glass. A glassy rock, you could say. It is very hard and of course, like most hard things are, it is brittle too. So, if it isn’t handled with good care, it breaks pretty easily. Yes, that kind of a rock.

When it breaks, it forms very sharp edges. These edges can sometimes get much much sharper than your normal steel blades. Also, even if they are brittle, they are pretty durable in a sense that they can hold their edge for much longer times. These were the reason, our ancient palaeolithic ancestors used to chip these rocks and made them as the tips of their spears and arrows.

Blade edges made out of obsidian are so sharp that they don’t seem jagged even when seen under an electron microscope. Their edges, if made carefully using processes like pressure flaking process, can get up to 3 nm thick. Good quality blades can make cuts down to single molecules! That is about 500 times sharper than the sharpest steel blade.

Left: Obsidian tip under and electron microscope. Right: Steel point under an electron microscope.
Left: Obsidian tip under and electron microscope. Right: Steel point under an electron microscope.

While blade edges made out of obsidian are not approved by the FDA, surgeon scalpels are still made using them. Studies say that cuts made using these blades get healed much faster than the ones made by steel blades because obsidian blades can make extremely narrow cuts between the cells, and not tear the cells apart.

Lee A. Green, associate professor of family practice at the Medical Center, uses obsidian knives for removing moles and repairing torn earlobes. – Source

Of course synthetic diamond blades have been made. But obsidian blades are still better in terms of durability.

Stone age technology is still the best.

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