1. Do we have observational proof for hawking radiation? Or is it verified only theoritically? 2. why is that only negative energy photon goes into blackhole and positive energy photon is going out from blackhole? what if the reverse happens? do we have an observatinal proof for this? 3. can someone tell me about quantum fluctuations in simple terms? 4. why the quantum fluctuations happening only near event horizon? do we have any proof for this?