We show how students can be led to an understanding of the connection between special relativity and general relativity by considering the time dilation effect of clocks placed on the surface of the Earth. This paper is written as a Socratic dialog between a lecturer and a student.

1.
Meno by Plato translated with an introduction by Benjamin Jowett, <etext.library.adelaide.edu.au/p/p71mo/>.
2.
The Bureau International des Poids et Mesures, <www.bipm.fr/>.
3.
Alex
Harvey
and
Engelbert
Schucking
, “
A small puzzle from 1905
,”
Phys. Today
58
(
3
),
34
36
(
2005
).
4.
Dan
Bruton
, “
The shape of rotating stars
,” <observe.phy.sfasu.edu/downloads/StarLight/Word/StarSpin.pdf>;
William K.
Rose
,
Astrophysics
(
Holt, Rinehart and Winston
, New York,
1973
).
5.
Subrahmanyan
Chandrasekhar
,
Ellipsoidal Figures of Equilibrium
, 2nd ed. (
Dover
, New York,
1987
).
6.

Colatitude is π2 minus latitude. It is the coordinate of choice for most references on planetary gravitational potentials.

7.
Claude
Audoin
and
Bernard
Guinot
,
The Measurement of Time
(
Cambridge University Press
, Cambridge,
2001
).
8.

This is the total mass of the Earth including the atmosphere. Because we are calculating the gravitational potential at sea level, we should subtract the mass of the atmosphere, but we do not need to do this subtraction as the mass of the atmosphere is roughly one millionth of the total mass of the Earth.

9.
Guy
Bomford
,
Geodesy
, 5th ed. (
Oxford University Press
, Oxford,
1986
).
10.
This value of a is defined to fit the ellipsoidal Earth model WGS84. See <earth-info.nga.mil/GandG/wgsegm/> for more details.
11.
David
Lide
,
CRC Handbook of Chemistry and Physics
(
CRC Press
, New York,
1997
).
12.
Bernard F.
Schutz
,
A First Course in General Relativity
(
Cambridge University Press
, Cambridge,
1985
).
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