Can people in Heaven see what is going on in the world or on Earth?
Certainly God is aware of what is happening on earth. Since Jesus has all authority over the world (1 Corinthians 15:24-25) it makes sense that he must be aware of what is going on in it. Since the angels rejoice when a sinner is saved (Luke 15:10), it can be assumed that they know what is going on in this world. Whether there is anyone else in heaven now is uncertain. (Please see What Does the Bible Say About..What Happens After Death for my previous answer about whether people go to heaven immediately after death.) If there is anyone else in heaven the Bible doesn’t say whether they are aware of what happens on earth or not.