PLEASE ANSWER SOON WILL MARK BRAINEST! How did Ibn al-Haytham contribute to the development of the modern camera?

He defined how the camera obscura worked.
He was the first person to think of the camera obscura.
He created a camera based on the camera obscura.
He made the camera obscura popular by trading it on the Silk Road.

the space race was a battle to make advanced technology to get to the moon and to get a better understanding of space.

for hobos it was a very hard time most hid on the sides of the railroad tracks causing people to get bulls and get them off sometimes causing in fatal death they couldnt get people to give them money because the   people were also in need of money