Welcome to Christ Church Cathedral !

Directly above where you are sitting is the cathedral Ringing Chamber. Contained within is a record breaking number of (19!) used for scientific (more about this later) - this is the largest number of bells used for this sort of ringing anywhere in the world.

What does a look like?

Your tour guide will now demonstrate Mathematics and Bell-ringing

Christ Church Cathedral ringers practice a form of ringing called change ringing. The bells here are not used to play tunes (called ringing) - change ringing is where the bells are rung in different combinations. The biggest challenge in change ringing is called a ‘’ where a sequence of 5000 or more changes without a repeat in the order the bells are rung - this usually takes around three hours or more!

When describing the number of possible combinations in the order of a group of things, mathematicians use the word Permutation. For example, the group of letters abc can be arranged a number of ways: acb, bac etc.

Mathematicians have also worked out how many combinations or permutations such a group of things can produce. This is done by multiplying all the numbers up to the number of things in the group. For example with our group of letters abc, containing 3 letters, the number of combinations would be 1 x 2 x 3 = 6. See if you can work out all 6 combinations of the letters abc:

The total number of combinations can also be described as the number factorial. Mathematicians have come up with a shorthand way of writing this. In our abc example the number of combinations is 1 x 2 x 3 or ‘3 factorial’ written as 3 with an exclamation mark or 3! which is equal to 6. So, 4 factorial would be written as 4! and is equal to 24 (1 x 2 x 3 x 4) Let’s try calculating 5!

The longest peal ever on tower bells was rung in England in 1963, consisting of all 40,320 changes possible on eight bells, taking just under 18 hours!

Imagine how many possible permutations there are for Christ Church’s 19 bells! Science and Bell-ringing

Much of ringing a ‘change ringing’ bell is about energy and the controlling of forces and can be looked at in terms of mechanics, which is the study of the motion of objects resulting from the forces acting on them.

There are two kinds of energy: potential and kinetic.

Potential energy is waiting to do work - a coiled spring, petrol in a fuel tank are both examples of potential energy. A weight hanging in a tree also has potential energy, which will increase the heavier the object is and the higher it is. Kinetic energy is energy of motion. Objects that are moving have kinetic energy. If a car crashes into a wall at 1kph it shouldn’t do too much damage. But if the care hits the wall at 60kph the car will be severely damaged because of the kinetic energy it possesses.

One of the basic laws of mechanics says that energy cannot be created or destroyed, but can be changed or transformed from one energy into another. Forms of energy include mechanical, electrical, chemical, heat, light and sound.

When a bell is rung ‘full circle’ it begins in the ‘up’ position. In this position it has the most potential energy. The ringer carefully applies a force to the bell by pulling the rope to being the bell past its balance point and the bell begins its spin or rotation. Potential energy is converted to kinetic energy and the bell swings quickly through its rotation.

The ringer controls this rotation as the rope wraps around the bell wheel and as it reaches this upright position again it slows increasing its potential energy. The ringer then applies a force by pulling down again on the rope to rotate the bell in the opposite direction. As the bell approaches the upright position, the clapper strikes the bell and makes the ring sound.

So the bell moves, the clapper strikes the bell and some of the kinetic energy is transformed into sound. Sound is a form of energy produced by vibrations that travel through a medium, such as air, and we are able to hear. When the clapper strikes, the bell begins to move quickly back and forth or vibrate and push the molecules in air back and forth of form sound waves, which are then picked up by your ears.

Think about how Christ Church is designed - how have the designers made sure that the bells can be heard by as many people as possible?

Unfortunately you probably don’t have the skills or experience needed to ring full circle - however, watch as your guide demonstrates how to ‘’ a bell and maybe have a go yourself!

Find out more:

There is lots of interesting information online about bell-ringing or ‘’. Have a look at the bell-ringing section in the ‘About us’ section of the cathedral website: www.christchurchdublin.ie for some more information and videos about bell-ringing.

Please feel free to ask your guide any questions you like or if you want some more information after the tour he can be contacted at [email protected]