How long would humans survive without the sun?

 In the absence of the sun, Earth would experience a rapid and drastic drop in temperature. The sun's heat is crucial for maintaining a suitable climate for life as we know it. Without this heat source, temperatures would plummet, making the planet extremely cold. This would have immediate and dire consequences for all living organisms, as they are adapted to the current temperature ranges sustained by the sun.

Furthermore, the sun plays a pivotal role in sustaining life through photosynthesis. Plants, which form the base of the food chain, rely on sunlight to convert carbon dioxide and water into glucose, providing energy for themselves and, subsequently, for other organisms. Without sunlight, photosynthesis would cease, leading to a collapse of ecosystems and a chain reaction that would impact all life forms dependent on these ecosystems.

The sun's gravitational influence also maintains the stability of Earth's orbit. Without it, the planet would no longer be held in its current orbit, resulting in a chaotic and unpredictable path through space. This gravitational disruption would have catastrophic effects on Earth's climate, seasons, and overall habitability.

In summary, human survival without the sun would be impossible in the long term. The absence of sunlight would lead to extreme cold, the collapse of ecosystems, and disruptions in Earth's orbit, rendering the planet inhospitable for life as we know it.