On the other hand when it comes to outgoing waves, the wave that goes most away from the observe bar or the straggle, so these two are the incoming waves and these two are the outgoing waves. So, now rest on this will depend what is a scattering and then what is a radiation? In case of radiation in case of radiation what you do that this obstacle it only radiates I energy. Basically radiates the wave that means only from here initially there was it is to like a car motor. What is this obstacle? It generates the wave and it oscillates or vibrates. So, when the process because of this it generates the wave and only g g radiated in both the direction, then we call this as the in call this as the outgoing there only outgoing waves exist. Here would have only outgoing waves, so that is happened in case of wave problem radiation.