The Weight of a Proton

So they weighed the proton and found it missing in mass. The difference between the expected weight and the measured weight was a full three standard deviations, which means that the proton was substantially lighter than expected.

At first glance, this may seem like little more than a curiosity. However, it does not require a whole lot of thinking to realize the significance of this measurement.

If protons are a lot lighter than expected, then exothermic fusion may in fact be the myth that I have suspected it to be, and the reason for this is simple.

The whole idea behind exothermic fusion is that mass in the proton is converted to energy when fused with another proton. This requires single protons to be heavier than protons that stick together with other protons and neutrons. With single protons being a lot less heavy than thought, there is a lot less energy to be had from fusing them together.

Stars that are supposedly fueled through hydrogen fusion in a super dense and super hot core, are now suddenly lacking a whole lot of energy. It may even be the case that the energy isn't actually there, in which case stars cannot possibly be fueled through fusion.

This is also a big blow to anyone invested in the promise of virtually limitless energy through controlled fusion on Earth. The energy that can be harvested is much less than has been expected.

The only reason exothermic hydrogen fusion is possible at all may be due to the fact that it isn't regular hydrogen that is used. The exothermic fusion that takes place in so called hydrogen bombs is not due to the fusion of regular hydrogen, but through the fusion of deuterium, a hydrogen isotope in which a neutron has already been fused to the proton.

The energy released in the fusion of two deuterium nuclei to produce a helium nucleus may be entirely due to the freeing of some of the energy that was consumed when the neutron was attached to the proton. The overall process of fusing two neutrons and two protons together to make a helium atom may very well be endothermic. If so, the fusion model of stars can be declared dead and void.

The fact that single protons are much lighter than thought is a very big deal. It puts the standard model of stars into doubt, and it makes controlled hydrogen fusion a lot less likely to ever deliver on its promise of limitless free energy.

When the dust settles around this latest discovery, I suspect that the conclusion will be that only heavy isotopes can produce exothermic fusion, and that fusion in general is endothermic.

Atomic nuclei of hydrogen, deuterium, helium, lithium and beryllium