...the sun suddenly disappeared

What would happen if our sun suddenly disappeared?

At first, we wouldn’t be able to tell, because the light of the sun takes eight minutes and twenty seconds to reach us. Also, the gravitational influence of the sun takes that long until it reaches us. After that, darkness and therefore coldness arrives and the earth starts flying in a straight line instead of circling around the sun.

Actually, the first few weeks we could get by without major problems. Since we still have a lot of resources available that we can use to produce heat and light, we can account for the missing sun at first. Due to no sunlight arriving anymore, every plant will stop performing photosynthesis and die. Therefore, no more oxygen will be produced, which in this aspect wouldn’t be a problem for the next 1000 years since we have so much oxygen available in our atmosphere. After that though, we won’t be able to breathe anymore.

Also, it will get cold. Really cold. After only the first week, the global temperature will have dropped to zero degrees Celsius. One year later it will be -73 degrees Celsius. One to three years after our sun disappeared, the oceans will have frozen all over and since ice is a good heat insulator, the very thick layer of ice will protect the deep sea from freezing for a few years. Also, geothermal spots will be places us humans could go to in order not to freeze to death, since the core of the earth will remain hot for many years to come and this heat can be harvested from geysers and other geothermal spots.

Ten to twenty years later, the temperature will be so low, that the air starts to solidify and people would have to get out of their super-insulated houses in special suits and shovel the “air-snow” into a container and then bring it inside to warm it up for it to make it transform into a gas again and make it breathable.

So all in all, if our sun suddenly disappeared, the biggest immediate problem would be the panic that would break out, rather than the missing light and therefore heat. Quickly after though, that changes and the global temperature would drop so low that we could only survive in special places near geothermal heat sources and even then, us humans would have a very hard time surviving.