Question 97
In this investigation, you will look at evidence that supports or contradicts hypotheses.
Work in groups of two or three.
Method
1 Read these facts.
• Tunguska is in northern Russia, far from any towns or cities. There is forest there, with many trees.
• In the morning of 30 June 1908 there was a very large explosion at Tunguska, between 5 km and 10 km above the ground.
• People living over 800 km away could see and hear the explosion.
• Vibrations from the explosion were recorded almost 5000 km away.
• The explosion flattened trees over an area of 2000 km².
2 Read these five hypotheses of what caused the explosion.
1 A comet impacting the Earth.
2 A type of volcano erupting.
3 Testing of a new type of bomb.
4 An alien spacecraft crashing.
5 An asteroid impacting the Earth.
3 Consider the evidence.
• All the trees that fell are pointing outwards from a central position.
• People discovered how to make very powerful bombs in 1945.
• No bomb this powerful has ever been made.
• Tunguska is very far from tectonic plate boundaries.
• Most comets break up higher than 10 km in the atmosphere.
• A small part of a comet is made from rock.
• Small rocky fragments have been found that show the signs of falling through the atmosphere at very high speed.
• No metal parts have been found at Tunguska.
Use the evidence to decide whether each of the five hypotheses can be supported or contradicted.
You can also use facts given in this topic as evidence.
Write about each hypothesis in turn.
Work in groups of two or three.
Method
1 Read these facts.
• Tunguska is in northern Russia, far from any towns or cities. There is forest there, with many trees.
• In the morning of 30 June 1908 there was a very large explosion at Tunguska, between 5 km and 10 km above the ground.
• People living over 800 km away could see and hear the explosion.
• Vibrations from the explosion were recorded almost 5000 km away.
• The explosion flattened trees over an area of 2000 km².
2 Read these five hypotheses of what caused the explosion.
1 A comet impacting the Earth.
2 A type of volcano erupting.
3 Testing of a new type of bomb.
4 An alien spacecraft crashing.
5 An asteroid impacting the Earth.
3 Consider the evidence.
• All the trees that fell are pointing outwards from a central position.
• People discovered how to make very powerful bombs in 1945.
• No bomb this powerful has ever been made.
• Tunguska is very far from tectonic plate boundaries.
• Most comets break up higher than 10 km in the atmosphere.
• A small part of a comet is made from rock.
• Small rocky fragments have been found that show the signs of falling through the atmosphere at very high speed.
• No metal parts have been found at Tunguska.
Use the evidence to decide whether each of the five hypotheses can be supported or contradicted.
You can also use facts given in this topic as evidence.
Write about each hypothesis in turn.
