Discover Questions

As per the photon concept of light ,does a ray of light have an end in space and do different rays have different ends? What is the highest unclimbed mountain that is not in Bhutan? If 2x^2+6>7x,prove that |4x-7|>1? Please help quick? Why is the curl of a vector field F not orthogonal to F? When x=0 does it have a y-intercept when it goes through both the x-axis and y-axis?