Hi, i'm just after a definitive answer on how Hydrogen fuses into Helium in the Sun? Some places say the Sun is so hot that they overcome their same charge repulsivness and fuse together while other places say that our sun is not hot enough for that to happen and that they just get close enough to allow them to fuse from Quantum Tunnelling. It's been the same with the science guys they get on radio stations i've heard some say that our Sun is so hot that they just smash into each other and fuse while other stations they say the Sun simply isn't hot enough and it is Quantum Tunnelling that enables the fussion. So which is it.... is our Sun hot enough for Hydrogen to physically fuse into Helium or is it Quantum Tunnelling that enables the fussion? Obviously the Sun still has to be hot enough to get the Hydrogen close enough for Quantum Tunnelling to happen but is it Quantum Tunnelling thats causing the fussion or is the Sun hot enough that Fussion is happening without any Quantum Tunnelling?