All the talk around Apple’s new MacBook – the lack of anything other than a USB-C port and a headphone port, the new “Force Touch” trackpad (which really is amazing, and I’ll write about another time) and how light it is got me thinking.

Particularly, how light it is. That thing really doesn’t weigh at all: you pick it up, and it barely seems to be there. It’s a helluva contrast with the Apple laptops of yore; I recall people toting around PowerBook G3s. Hell, I remember when the first portables came in from Compaq: they were gigantic things which could have been used as pricey weight training add-ons.

The discussion about the ports and lightness of course centred around two sides of a really quite polarised debate. One side said: “Apple is being stupid with this ‘thin and light’ stuff. We need ports.” The other said: “People want their portable devices to be ever more thin and light, and Apple is just giving them what they want.”

Well, how far can this go? Doesn’t there come a point when there’s nothing more to be shaved off?

I thought it would be fun to dig back and see how Apple has driven the “thin and light” idea, going right back to the original Apple Portable from 1989. Look, here it is. Isn’t it adorable?

Introduced September 1989, weighed 7.2kg, measuring 10.3cm (closed) by 38.7cm by 37.7cm for a total volume of 15,027 cubic centimetres, and density of 479 kg/m^3 – a little more dense than barley (which is 400kg/m^3).

And then you compare this year’s model, 26 years later:

 

(All the data about the Apple products, by the way, comes from the invaluable resource of Mactracker, which tells you everything about pretty much every Apple product going back to the beginning of time, which for these purposes is 1975. And before you ask why I’m not comparing it with other PC makers’ laptops, it’s because there isn’t a simple or sensible comparison to be made, nor any easily available data as there is with Mactrack, which has a neat desktop and mobile app. So there.)

So when you start adding in the data about various laptop launches, trying to focus on the ones which are 12in or 13in (so that the screen size, and hence weight, is comparable), you find a definite trend.

He, He, He

It’s this: if we were relying on straight-line trends, we’d have weightless MacBooks by 2017. Yes. Perhaps they’d be airtight and filled with helium? Why not?

Before you snigger and yawn, just bear in mind that hard drive makers are now making them airtight – and filling them with helium. Not laughing so hard now, are you?

However if you take the more reasonable logarithmic trend, then it looks like we’re some way off weightlessness – although we might expect a half-kilo laptop in five years or so.

(The log curve is a better fit than the polynomial one, which I’ll use below for other graphs.)

Note too that the PowerBook 180, released in 1992, seems to have been a real outlier: much lower weight than you’d expect.

Turning the volume down

But what about volume? If Apple’s making these things thinner, while keeping the screen roughly the same size, then the volume’s going down. What’s happening there?

I’ve done two graphs, so you can see what it looks like if you exclude the original Portable. Notice how the latest machines lie below the trend line (which seems to work best as a power, rather than logarithmic, fit). There has to be a limit on how low volume can go, of course – you need a screen, you need some sort of keyboard – but Apple has really pushed the latter down in the new MacBook: the keys have less travel and the trackpad doesn’t move. That reduces the empty space needed to fit everything in, but I’d expect we won’t see much change in the next few years.

Gravity. I mean, density

Finally, if the weight is going down, and the volume’s going down, what’s happening to the density (which, let’s remind ourselves, is weight divided by volume)?

Turns out it’s increasing – quite quickly. From that barley-equalling density, it has moved quite quickly past the density of water (with the 2003 PowerBook G4 12in) and then solid magnesium (with the 2010 MacBook Air).

There’s however quite some way to go before it goes past solid aluminium (2700 kg/cubic metre). There’s a lovely list of densities of common materials – butter, 865kg/cu m, who’d have guessed? – which might allow one to play “guess the material the Macbook model matches”.

But what does it mean?

All those graphs. But what’s the conclusion? Quite obvious really – given enough time, Apple will produce a weightless laptop of infinite density, which will suck its buyers into its gravitational well, from which they won’t be able to emerge. It’s one way to hold on to your users.

Then again, given the gravitational pull that its designs exert on a significant chunk of the internet, you could argue that it’s doing that pretty well already.