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A long time ago scientists thought that the Universe never changed - Edexcel - GCSE Physics - Question 6 - 2014 - Paper 1
Question 6
A long time ago scientists thought that the Universe never changed. Now there is evidence to show that stars progress through various stages and that the Universe i... show full transcript
Worked Solution & Example Answer:A long time ago scientists thought that the Universe never changed - Edexcel - GCSE Physics - Question 6 - 2014 - Paper 1
Step 1
Step 2
Describe how the Sun reached its main sequence stage.
Answer
The Sun reached its main sequence stage through a series of steps:
- Formation in a Nebula: The Sun formed from a nebula consisting of gas and dust.
- Gravitational Attraction: Particles within the nebula were attracted to each other by gravitational forces.
- Temperature and Pressure Increase: As these particles came together, potential energy was converted to kinetic energy, causing the temperature to rise.
- Nuclear Fusion Initiation: Once the core temperature was sufficiently high, hydrogen atoms began fusing into helium, marking the transition to the main sequence stage.
Step 3
Suggest why knowing the age of the oldest star is not enough to tell scientists the age of the Universe.
Answer
Knowing the age of the oldest star provides a lower limit for the age of the Universe since stars can exist for billions of years. However, the Universe itself could be older due to the existence of other cosmic events or objects that formed before the oldest star, such as earlier stars that have since gone supernova or other processes like galaxy formation.