You throw a shoe through the portal to see what happens

Being a cautious scientist, you decide that it would be inappropriate to simply leap into the portal. No, that wouldn't do. Not at all. Instead, you carefully remove your left shoe, attempt to calculate the force and angle necessary to deliver it directly through the center of the portal, and, failing that, hurl the shoe as hard as you can in the general direction of the portal.

1. You completely miss the portal and knock over a lamp
2. You make a direct hit on the exact center of the portal
3. The shoe bounces off the portal
4. The shoe is incinerated by the portal
5. You hear angry buzzing from deep inside the portal
6. You hear a loud thump outside your window as soon as the shoe has disappeared