That's basic stargate safety protocol. You stand at least 40 feet away from the event horizon so that the unstable vortex doesn't annihilate you. It does not scale down, so follow the same rule on this miniature stargate made by YouTube user TheEnchantedBeer. S/he is working on this project with a colleague 9400 kilometers away. They hope to transport something between their stargates:
This is an international collaboration of friends located about 9400km apart, so a device for transporting across vast distances seems perfect. Unfortunately, I cannot yet generate wormholes at will, so we will have to settle for transporting information via the internet.
The project consists of a small(19cm diameter), SG-1 variety stargate with dialing computer. It will move and light up just like the version in SG-1. When a proper address is dialed, a connection will be opened up via the internet to a corresponding device or computer. Exactly what will be transmitted has not yet been decided. The hardware/internet interface will be via arduino.
*In reality, 20 feet is fine. But, you know--lawyers. So our rule is 40 feet.