http://www.hitachi.com/rd/portal/highlight/quantum/index.html#anc04 http://www.hitachi.com/rd/portal/highlight/quantum/index.htm... It works when you send elec

http://www.hitachi.com/rd/portal/highlight/quantum/index.html#anc04 http://www.hitachi.com/rd/portal/highlight/quantum/index.htm... It works when you send electrons one at a time, suggesting they are somehow interfering with themselves. In other words, the electrons are in both slits at once until we check. That might not literally be true, but it's not possible to explain the interference by saying we just don't know which slit they're going through.