Royal Institution Christmas Lectures 2010

Why mountains are so small

In 2009 the world's tallest building the Burj Khalifa was opened in Dubai; at almost half a mile high it is an engineering marvel. But will future generations think it puny and laugh at us? Could we build a tower to reach the moon?

We ask whether this engineering challenge is remotely possible and show that one of the major hurdles is the force that keeps space together – gravity. The curious way that gravity affects large things is nothing to the effect that time has on them. Not just a few years, or even decades but eons of time.

Could this explain why Earth's mountains are small fry compared to other mountains in the universe? How big to is too big for a glacier, a mountain or a planet?

Lesson 9: Can we build a tower into space?

Suitable for: 11–16

Curriculum and learning links: Forces and gravity, strength of materials

Learning objectives:

• Recognise design features of strong building structures.
• Explain why gravity is one of the most significant restricting factors when designing and constructing very tall buildings due to the increasing weight of the building crushing the material at its base.

Lesson 10: Concrete and other composite materials

Suitable for: 11–16

Curriculum and learning links: Construction materials, composite materials, properties of materials

Learning objectives:

• State that a composite is a mixture of two or more materials that has different properties from its constituent materials.
• Give examples to explain why composites are useful, using ideas about their properties.

Lesson 11: Making mountains

Suitable for: 11–16

Curriculum and learning links: Geological processes, plate tectonics, igneous rocks

Learning objectives:

• Describe how tectonic plates can interact to form mountains, volcanoes and earthquakes.
• Explain how convection currents in the mantle cause the tectonic plates to move.