Try our new info resource - "Aladdin's Cave" (Main menu)Just added a separate link to Ash's Dropbox thread (shortcut)
Rather than trying to visualise it. Try this exercise.Take a steel cube 100mm x 100mm x 100mm and work out the surface are and volume.Now slice the cube in half to give two pieces 100mm x 100mm x 50mm and now work out the total volume and surface area of the two pieces.You will find that whilst the volume remains the same, the surface area will have increased by over 30%. So the displacement method for determining surface area isn’t remotely accurate even for non complex shapes.I’ll let you do the actual maths which will clearly demonstrate the point