What would happen to the people on Earth if it suddenly stopped :
- a) to rotate on itself
- b) to revolve around the sun
If the Earth suddenly stopped rotating or orbiting the sun, human life as we know it could end. Depending on what caused the planet to stop spinning, certain areas of the world may be completely covered in darkness, while others may experience extreme heat and cold due to the absence of sunlight.

Additionally, many organisms that live underground or underwater would also be affected by the change in environment. Without an atmosphere or light source, these species would face significant challenges in adapting to their new environments.

However, some humans might survive the effects of stopping the earth's rotation because they are adaptable and have developed various survival skills over thousands of years. For example, those who live near water sources would still have access to drinking water, and individuals who can farm or hunt would continue to provide food for themselves and others.

Overall, the impact of halting Earth's rotation and orbiting the sun would be unpredictable and challenging, but many lives would likely be lost unless precautions were taken to ensure a smooth transition.