To merit their attention, professionals say, an outsider would have to show that he’s done his homework. Serious contenders have to understand the language of physics and get their math right. Most importantly, any new theory must agree with past experiments.
[…]
Frustrated amateurs can be aggressive, clamoring to have their ideas heard. Not surprisingly, physicists are more receptive to polite questions than to lengthy treatises accompanied by angry rants, and if the science is solid, they may listen.
To this I would add, you have to make sure it’s science to begin with.