gr8shandini - you and me both. I've attached a photo below to show a visible shock, you will notice no condensation, its purely because of the change in refractive index of the air brought about by changes in the pressure field. Notice too, from the disturbed water that this must be the first area on a F-18 to produce a strong shock. As an aside, 747 crews tell of hearing a "rumble" just behind the top of the cockpit when the air flow over the hump reaches its Mcrit and a shock forms. Further, the design speed of a super sonic aircraft can be ball parked some times by measuring the angle made by a line drawn from the nose to the wing tip and using the sin formula mentioned earlier to calculate the Mach. Thats because you dont want the wing operating ahead of the shock cone formed by the nose.
