10 February 2017

Dr Christian

Jarrett (CJ)

Christian edits The British

Psychological Society’s Research

Digest blog. His latest book is

Great Myths Of The Brain.

Alastair Gunn

Alastair is a radio astronomer

at Jodrell Bank Centre for

Astrophysics at the University

of Manchester, UK.

Robert Matthews

Robert is a writer and researcher.

He is a Visiting Reader in Science

at Aston University, the UK.

Dr Peter J Bentley

Peter is a computer scientist and

author who is based at University

College London, the UK.

Luis Villazon

Luis has a BSc in computing and

an MSc in zoology from Oxford,

the UK. His works include How

Cows Reach The Ground.

Alexandra Cheung

Alexandra has a degree in

environmental science, and

has worked for CERN and

Imperial College London, the UK.

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EXPERT PANEL

GETTY X2, REX

OA

&

Are left-handers smarter? • Why do knots weaken a rope? • Does

chicken soup really help a cold? • Do we all see the same colours?

• If you fell into a black hole, would time really feel slow?


• Why do phones explode?

Fundamentally, and ignoring the complications

of Einstein’s Special Relativity, it’s the same time

as it is here on Earth. But this is a bit of a cheat,

of course, because we haven’t defined how we

are measuring time.

There are many ways to define the ‘time’

at a particular location. Here, on Earth our usual

system (‘solar time’) is defined by the motion

of the Sun in the sky (although we usually keep

track of time with an atomic clock). This means

that the local time depends on where you are on

Earth and we get around this complication by

having many different time zones. Now, we could

also define a similar time system based

on the motion of the Sun as seen from the Moon.

Such a system exists (Lunar Standard Time) but

it is not much more than an interesting exercise

in physics. What is more useful, however, is

a definition of time that doesn’t vary with

location. This is called Universal Time (UT)

and is a modern form of Greenwich Mean Time.

It is the same everywhere in the Universe.

So, the UT time on the Moon is the same as

the UT time on Earth. AG

What time is it

on the Moon?