Growing
Faster than
the
Speed of Light
Using
Pythagoras’ Theorem to Find Difference between Actual Growth & Apparent
Growth
Part
1
Pythagoras’ Theorem states:
![]()
We’ll also use:
![]()
Image A
We have a right-angled triangle with
sides of 3, 4 and ‘?’.
We can find the side length ‘?’ by doing:

(in light-months and to 2 decimal places)
This is the length of the red line, the
left hand edge of the triangle. This is
the ‘apparent growth’.
To find the difference between this and
the ‘actual growth’ (the blue line, which is 1 light-month), we subtract the
‘actual growth’:
![]()
So the difference in apparent growth and
actual growth after 3 months is 1.65 light-months.
How do you think this difference will
change in subsequent images as time continues?
Will it increase, by more and more or
less and less, or will it decrease, by more and more or less and less?