Humans cannot survive on Earth without the Sun's light and heat. The Sun is the primary source of energy for our planet and is crucial for sustaining life as we know it. Its light provides energy for photosynthesis in plants, which forms the basis of most food chains on Earth. The Sun's heat helps regulate our planet's temperature and weather patterns, making the environment habitable for various life forms.
If the Sun's light and heat were suddenly to disappear, the consequences would be catastrophic. The average surface temperature on Earth would plummet, leading to an extreme cold spell. The lack of sunlight would also halt photosynthesis, causing plant life to die off rapidly. With the depletion of plants, the entire food chain would collapse, affecting animals, including humans, that depend on them for sustenance. Additionally, the Earth's ecosystems, weather patterns, and atmospheric conditions would be drastically altered.
Under such conditions, it is highly improbable that humans would survive for an extended period. The exact time frame for human survival without the Sun's light and heat would be difficult to predict accurately, as it depends on numerous factors like existing food supplies, geographical location, and the ability to adapt to extreme conditions. However, it is safe to say that life on Earth, including human life, would not be sustainable in the absence of the Sun's vital energy.