Posts Tagged ‘Christmas’

Theories and Facts about Santa Claus

December 21, 2014

My friend Alom Shaha recently scripted the video above to try to explain the concept of ‘a scientific theory’.

I like the video, but I feel one point gets lost. And that is that  ‘theories’ are like ‘plot lines’ in a TV detective programme – they link together ‘the facts’ to tell ‘a story’.

Example#1: Café Mimmo

  • I am observed at 10:15 a.m. leaving my house on Church Road
  • I am observed at 10:21 a.m. at the junction of Church Road and Walpole St.
  • I am observed at 10:27 a.m. near to Café Mimmo on Broad Street.
  • I am observed at 10:28 a.m. in Café Mimmo on Broad Street.
  • I am observed at 10:58 a.m. walking North on Church Road.

These are ‘the facts’. But what is really going on? Is there a ‘story’ that links all these facts together? Let me propose a theory:

  • Theory: Michael goes for coffee every day at Café Mimmo

This theory links all these facts i.e. it explains how they relate to each other.

If this is a good theory, it ought to be able to predict new facts – and these predictions could then be checked.

Notice that the theory doesn’t specify the route I take to the Café. So even though the theory explains why I was seen on Church Road, it doesn’t predict that I always will be.

But the theory does predict that I will go to Café Mimmo every day. This could be easily tested. And if I didn’t visit every day, the theory could either be invalidated, or it might need to be revised to state Michael goes for coffee most days at Café Mimmo

I am sure you get the idea. But notice how the theory is simpler and more meaningful than a large number of facts. Facts tells us ‘what happened’, but theories tell us ‘what’s going on’.

Example#2: Santa Claus

  • On Christmas Day (usually, but sometimes on Christmas Eve) children all around the world receive presents.
  • On Christmas Eve parents leave out gifts – typically whisky (please) and a carrot – and these gifts are at least partly consumed by the morning.

These are ‘the facts’. But is there a theory that links these facts together? In fact there are two theories.

The traditional theory is that a mysterious being known as ‘Santa Claus’ delivers the presents on a sleigh pulled by flying reindeer and filled with an improbably large bag of toys.

Alternatively, some people contend that there is a vast conspiracy in operation in which otherwise honest and rational parents consistently lie to their children, year after year. According to this theory, it is in fact parents that buy all the presents, and fabricate forensic evidence of a visit by the fictional being ‘Santa Claus’.

The traditional theory has been heavily criticised, largely due to the unknown identity and quasi-magical abilities of the ‘Santa Claus’ figure.

However, I have never been a fan of conspiracy theories – they always seem rather unlikely to me. In particular I am sceptical that millions upon millions of parents would systematically lie to their children. I would never do such a thing.

So I will leave it up to you to imagine experiments that you could perform that would help to decide which theory is in fact correct.

One obvious experiment is to stay up late on Christmas Eve and watch for the arrival of ‘Santa Claus’.

But can I please ask you to be careful: Santa Claus is known never to bring gifts to boys and girls that don’t go to sleep at night. So use a webcam.

But whatever you believe: I hope you have a Happy Christmas 🙂

Candles at Christmas

December 13, 2013

My colleagues at NPL have just finished making a video of my talk about candles so I thought I would share it with you while it was fresh.

Thanks to Lloyd for the video and thanks to everyone who helped with the talk. Personally I hate watching myself, but I hope you enjoy it.

You can follow up on the topics in the talk with the links below:

Harppy Crhistmas

December 20, 2012
Harppy Crhistmas 2012

Harppy Crhistmas 2012

I am a bit behind with Christmas cards this year. I have printed the first few – but in case you haven’t recieved yours yet, please enjoy the design above.

I would improve it now. At the time I couldn’t think how to get the ‘d‘ in ‘wonderful’ and used Dy, Dysprosium, but now I realise I could have used Nd, Neodymium followed by Er, Erbium (Picture at the end). But I haven’t found a better way to do the e in ‘Year’ other than using an electron 😦

In case you feel like spelling out the the names of things with elemental symbols, I present an alphabetical list of elemental symbols which include a particular letter as either the first or second letter.

H Ar P P Y  C Rh I S Tm As


Ac Ag Am Ar At Au Ba Ca Ga La Na Pa Ra Ta

B Ba Be Bi Bk Br Nb Pb Rb Sb Tb Yb

C Ca Cd Ce Cf Cm Co Cr Cs Cu Ac Sc Tc

Dy Cd Gd Md Nd Pd

Er Es Eu Be Ce Fe Ge He Ne Re Se Te Xe

F Fe Fm Fr Cf Hf

Ga Gd Ge Ag Hg Mg

H He Hf Hg Ho Rh Th

I In Ir Bi Li Ni Ti

K Kr Bk

La Li Lr Lu Tl

Md Mg Mn Mo Am Cm Fm Pm Sm Tm

N Na Nb Nd Ne Ni No Np In Mn Rn Sn Zn

O Os Co Ho Mo No Po

P Pa Pb Pd Pm Po Pr Pt Pu Np

Ra Rb Re Rh Rn Ru Ar Br Cr Er Fr Ir Kr Lr Pr Zr

S Sb Sc Se Sm Sn Cs Es Os

Ta Tb Tc Te Th Ti Tl Tm At Pt

U Au Cu Eu Lu Pu Ru



Y Yb Dy

Zn Zr

Harppy Crhistmas 2012

Harppy Christmas 2012

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