AEDT is 16 hours ahead of UTC (Coordinated Universal Time). Beijing, on the other hand, is 8 hours ahead of UTC.
Given that it is 12 noon in Melbourne, we can convert this to UTC by subtracting 16 hours.
12:00 PM (Melbourne) - 16 hours (AEDT offset) = 04:00 PM (UTC)
Now, to calculate the time in Beijing, we add the CST offset of 8 hours to the UTC time.
04:00 PM (UTC) + 8 hours (CST offset) = 12:00 AM (Beijing)
Therefore, when it is 12 noon in Melbourne, it is 12:00 AM (midnight) in Beijing.