What would happen if the sun was blocked out for a few days

What would happen if the sun was blocked out for 3 or for days??

If a shadow was cast over the entire earth. We would die. How fast?
Well if the shadow was cast by something being directly in front of the sun at its surface (that's a pretty darn big "something") then it would probably take about 1 hour for everyone to die. 8 minutes for us to see the sun get blocked out and for the light to stop hitting the earth. Another 52 minutes for the entire atmosphere to cool... well freeze... then everyone would die. The temperatures would plummet fast enough to freeze a layer of ice over all the oceans in a few hours. People could survive this if they had warning, although there would be no habitable world to come back to.

You need to understand that, without any sunlight, the earth would plummet to at least about -171º C. that's -279º F. What keeps us warm is the fact that one side of the planet ALWAYS has sunlight. + we have oceans and atmosphere to distribute heat. But if both sides of the earths atmosphere had to be subjected to those temperatures, it would simply freeze the more and more of the atmosphere until it got to the level that you breath O2 at. The oceans would cool much too fast to sustain any heat distribution and the ice caps would grow faster and faster and faster until the earth is frozen over.

My estimate is about 1 hour for ground level temperatures to hit a critical life threatening level.

a FEW days less than a month or so, no problem. ever been in a winter storm?

gradual cooling until the oceans froze over. than slow cooling unders insulating blanket of ice and snow until the internal earth heat energy flow rate stabalized

then hundreds of millions of years of stable temperature as the earth core cooled

there is some indication that the earth was once a total ice over ocean ball but life survived in the oceans not certain abouut that.