square versus cube - you can't win!

[Ags]

As aperture increases the light grasp and resolution increase as the square of the aperture... Goody!

But the size and weight of the scope increase as the cube of the aperture... Rats!

[Peter Drew]

I think you'll find that resolution is linear, double the aperture equals twice the resolution. .

[FraserClarke]

and traditionally the cost increases as the fifth power of the dome diameter...

[Ags]

Depends how you calculate resolution. Using a pixel analogy, doubling the aperture halves the pixel diameter which means you are packing in 4 times more pixels.