Can these be intersected?

I asked a question about how to make the cube from meta from mesh earlier. I made it by using a sphere and selecting half of it and extruding it. and slecting the half of the half and extruding that. Now i want to intersect that mesh i made and a cube. You’ll see what i mean in the attachment. What i wanna know is if it’s possible to intersect the cube onto the mesh i made because i tried it and it and blender crashes.

Attachments

Mesh&Rctangle.blend (1.19 MB)

You’ve got way too many vertices on your object if you are trying to use the boolean function. Blender doesn’t like it.

I recall seeing a blendernation article on an app, the other day at the main blender site, the function of which was specifically mesh joining, and it looked pretty good too. you might review recent blendernation articles to see if you can find it.
(edit) I can’t find the link to the aforementioned app, but another way you might try, other than booleans, is retopo. The retopo tool is tricky to learn for some, but you’ll need it again and again.

How do i make less vertices but still have that shape the way it is?

again, retopo tool is the way to go for that purpose. you could also use a decimate modifier, but it might not be very pretty.
(edit) found the blendernation article on the app called " meshmixer" http://www.blendernation.com/2011/05/18/meshmixer05/