# When will we bump into a transistor everywhere?

A while ago I made a comparison between Ostrogothia (Östergötland) and a silicon wafer. I wanted to put things into a graspable scale. If a transistor compares to an everyday object – how present will they be?

Maple-Martin, while digesting some Guinness at an Irish conference, suggested to take a look at the total number of available transistors on earth. According to Intel there were some 1.2e21 transistors worldwide last year(-ish).

Let’s take some other dimensions into the picture:

• On earth, there are 7 000 000 000 human beings (give or take some 100 millions), 7e9
• The earth’s equator is 40 000 km (4e7 m)
• The earth’s total area is 510 million square kilometres, ie. 5.1e14 sqm
• The channel length of an average transistor is assumed to be 100 nm
• The channel width of an average transistor is assumed to be 100 nm
• Each human consists of some 37e12 cells  [according to http://informahealthcare.com/doi/abs/10.3109/03014460.2013.807878 ]

Now, with these numbers at hand: Let us assume that we have too much time and we have somehow magically collect all the chips on earth and scrape off all transistors (that’s a big bag of chips). Then we decide to take a walk around the globe and put down some transistors here and there (perhaps to find our way back by picking them up on the way back?)

So if we neatly put them next to each other (think a long cascoded current source) in a long a row, we would have to walk

• 1 200 000 000 000 000 000 000 pcs * 0.000 000 1 m/pcs = 120 000 000 000 000 m = 3 000 000 laps (!!!) around the globe.

Let’s assume we find that boring to just walk along the equator. If the transistors are 0.1 * 0.1 sq um big. They would then occupy 1e-14 = 1.2e21 * 1e-14 = 12e6 sq metres ~ 4000 * 3000 sq metres, or in non-American English: 4×3 sq km. Not that much (?)

If the transistors would be 600×600 sq um we would be able to cover the earth. 2010 – anyone?

We have 1.2e21 / 7e9 ~ 2e11 transistors per human being. That’s quite a potent processor! In an “ordinary” desktop computer there are some 5 billion transistors, i.e, 5e9 transistors. Which means that each human being is equipped, or has access to some 40 processors. (A phone, a computer, …)

Let’s bring the comparison further: Each human consists of some 37e12 cells which multiplies into a biomass of 37e12 * 7e9 = 270e21 human cells. Compare with 1.2e21 transistors – we are soon there! Soon we can assign one transistor to each human cell. 1984 – anyone?