If the Sun were to suddenly get cold—a scenario that's physically impossible under normal cosmic laws—it would have catastrophic consequences for Earth and the solar system. Here's what would happen in stages:

1. Loss of Light and Heat:

   • Within about 8 minutes, Earth would go completely dark (because that's how long sunlight takes to reach us).

   • Temperatures would begin to plummet rapidly. Within a week, the surface temperature could drop below -70°C (-94°F).

2. Climate Collapse:

   • Photosynthesis would stop, leading to the collapse of the food chain.

   • Plants would die, oxygen levels would slowly decrease.

   • Most animals, including humans, would not survive the cold without artificial heating.

3. Atmosphere and Oceans Freeze:

   • In a year, Earth's average temperature could reach -240°C (-400°F), close to absolute zero.

   • The oceans would freeze solid, and the atmosphere would condense and fall as snow or frost.

4. Orbital Effects:

   • If the Sun became cold by turning into a dense, inert object (like a black dwarf), gravitational effects might remain the same, so Earth would keep orbiting.

   • But if it lost mass (like in a supernova), Earth might drift off into space.

In short: life on Earth would cease, and our planet would become a frozen, dark rock drifting through space. The Sun’s heat and light are absolutely essential for sustaining life.