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NEWSCIENCENEWSCIENCEN proven that some “uranium rays” were Helium nuclei (c-particles) for at least a decade, until Lord Rutherford started his experiments. The clairvoyants had given a "liquid drop" explanation of a- particle emission from radioactive nuclei, long before orthodox science. Bohr and Wheeler made the “liquid drop" model of atomic nuclei into sci- entific orthodoxy in the 1940's, half a century later. Even by the late 1920's orthodox sci- ence had no real understanding of the process. Gamow, Gurney and Condon realised that if an a-particle separated spontaneously from a parent nucleus would impart far too much motion energy to the escaping Helium nucleus. So it simply couldn't pop out of the nucleus and fly away. Instead, they argued, using the metaphysical imagery of Erwin Schriédinger's wave mechan- ics, it emerges from the nucleus but "blinks out of existence", then "tunnels" several nuclear diameters away from the parent nucleus, to a place where the electrical repulsion between the parent nucleus and the emerging a-particle is sufficiently reduced to impart the observed motion energy to the a-parti- cle, and at that point the a-particle somehow re-materialises back into existence then flies away. [See Fig. 2] The numbers all seemed to work out correctly, even if it was necessary to invoke the absurd hypothesis of "tun- nelling", so this was one of the pillars on which modern wave-mechanical the- ory has been based. The quantum mechanical theory of “tunnelling” was considered a great triumph even though it was counter-intuitive and philosophi- cally bizarre. Advocates of "tunnelling" theory fail to appreciate that an a-particle emerg- ing from a parent-nucleus is still half dissolved in nuclear fluid, and still attached to the parent nucleus, for some time as it initially draws away. This "sticky toffee" model of a-particle emission, though universally ignored, was put forward by clairvoyants in the Figure 2A If we imagine an o-particle emitted from a *"Polonium nucleus, leaving behind a ™Lead nucleus, then it turns out that the a-particle cannot have separated from the parent nucleus and been released at the nuclear surface (as above) because the mutual electrical repulsion between the two "spheres" would impart far too much motion energy to the escaping a-particle. This isn't what's happening. yx = 2.65 x, a - cork mysterious ty | "tunnelling" process Figure 2B Figure 2B To explain why the a-particle escapes with less energy than might be expected from electrical repulsion alone, Gamow, Gurney & Condon in 1928 proposed the notion of “tunnelling". The whole a-particle, having separated from the parent nucleus, simply blinks out of physical existence and tunnells several nuclear radii outwards. It eventually blinks back into physica! existence, emerging from the “tunnel”, at a place where the electrical repul- sion is sufficiently reduced to produce the correct motion energy for the outgoing a-particle. The length of this mysterious "tunnel" depends upon the observed motion energy of the a-particle, as measured a long way from the nucleus. This weird idea is one of the foundations upon which modern quantum theory has been constructed. the clairvoyant “classical-physics" interpretation of the process is that we can explain why nuclei emit a-particles in the first place. Quantum theory can- not explain why nucleons cluster into a-particles at the nuclear surface. We can! The earlier article on nuclear shells (NEXUS Vol.2, #5. pages 46-48) showed that nucleons (protons and neu- trons) inside a nucleus, arrange them- selves in concentric shells like the suc- cessive layers of an onion. The sim- plest shells are Platonic solids, with nucleons at each vertex. But in larger nuclei, the outer-shells are Buckey- Balls (named after Buckminster Fuller, inventor of the Geodesic Dome). 1890's. Gamow, Gurney and Condon made the fundamental mistake of assuming that an a-particle emerging from a nucleus “sees” the same electri- cal repulsion, and is free to respond in the same way as, an a-particle approaching the nucleus from outside! In fact one approaching from outside isn't attached to the "target" nucleus, whereas one emitted from a “parent” nucleus is. The viscous toffee-like strand attaching an emitted o-particle slows its escape, braking its outward acceleration, and preventing it from behaving like a totally free external a- particle. The quantum mechanical "tunnelling" process is just another way of viewing the stretching of a strand of nuclear fluid, out to some critical radius at which it snaps, prior to the release of the escaping a-particle. This is a much more intuitive, and sensible explanation than the “tun- nelling” idea introduced to quantum theory in 1928. Another really interesting thing about These Buckey Balls all have exactly 12 pentagonal faces, but any number of hexagonal faces depending upon how many vertices there are: ic: the number of vertices = 20 + 2 x (the number of hexagonal faces) NEXUS¢51 JUNE-JULY 1992 As with the Platonic shells occurring