I need some help in appreciating this consensus. We are told the following things: - that we have anti-electrons, anti-protons but no anti-photons. - that photons - or more specifically emr - have an electrical component and a magnetic component. - the the magnetic component of emr runs 90 degrees to the electrical component. So more specifically if you have an emr traveling towards you then if the electrical component is upwards at some point then the magnetic component will be 90 degrees to this. Now, technically 90 degrees can be either in a clockwise direction or an anti-clockwise direction. If it were 180 degrees - ie magnetic aspect 180 degrees to electric aspect - then there would be no question on my part. But it is 90 degrees - which implies in a clockwise or anticlockwise direction. That's fine. So say we have one emr with its electro moment up and its magnetic aspect 90 degrees clockwise then its magnetic effect will also be clockwise to the electric orientation. And if we have another emr with its electro moment up and its magnetic aspect instead 90 degrees anti-clockwise then its magnetic effect will be anti-clockwise to the electric orientation. So my query is that if you can have a clockwise emr effect and an anti-clockwise emr effect then why is not the clockwise emr considered to be the anti-particle of the anti-clockwise emr? Why are these two particles, which behave oppositely, considered to be the same particle?