ll never stick together).
             In order to get a proton to strike another proton (or a nucleus that contains several protons) they must be traveling at high relative speeds; if their "closing velocity" is not great enough, they will never get close enough to stick together, because they strongly repel each other. But, just as you can make two of the same magnetic poles touch each other by providing sufficient force, so too can protons "touch" when they have sufficient relative speed. This can take place in the center of the sun, where the temperature is extremely high. Temperature is related to atomic motion: the hotter something is, the faster its atoms are moving [] see demo "food coloring in water"[].
             Table 1 shows the nuclear reactions that are taking place in our sun, as well as nuclear reactions that take place in stars that are either older than our sun, or hotter than our sun. The reactions in columns 2 and 3 occur after a star has entered the "red giant phase". How fast a star evolves to this point depends on its mass: stars heavier than the sun can reach this phase in less than 5 billion years (the age of the sun) whereas stars with about our sun's mass take about 10 billion years to get there. The particles you may be unfamiliar with are: n the neutrino, g a gamma ray (high energy light wave), and b+ the positron (the antimatter version of the electron).
             TABLE 1. NUCLEAR REACTIONS IN STARS
             OUR SUN NOW OLDER, OR HOTTER STARS
             p + p ® 2H + b+ + n 4He + 4He ‘ 8Be + g 12C + p ® 13N + g
             2H + p ® 3He + g 8Be + 4He ® 12C + g 13N ® 13C + b+ + n
             3He + 3He ® 4He + p + p 12C + 4He ® 16O + g T1/2 = 10 min
             16O + 4He ® 20Ne + g 13C + p ® 14N + g
             3He + 4He ® 7Be + g 20Ne + 4He ® 24Mg + g 14N + p ® 15O + g
             7Be + p ® 8B + g 15O ® 15N + b+ + n
             8B ® 8Be + b+ + n T1/2 = 120 ms
             8Be ® 4He + 4He 15N + p ® 12C + 4He
             In our su...