A passive collapse is an induced change like observation.
When an observation particle enters a cloud, it collides with any grain of a particle to reflect in equal-probability, because the grains have common physical properties and the same chance in any location. Therefore, the collapse results are always in complete random, namely with matter-proportion expectation in the absolute universe. The matter-proportion expectation (MPE) can be expressed as:
MPE = 1/N· (L1last + L2last··· Lnlast),
where N represents there are N particles in the cloud; n represents there are n particles that compose the route of the reality in the cloud; numberlast means the link proportion of the number particle that last participates in the route.
Suppose there are two cloud systems A and B. The first particles from one to the other are all likely in the realities with least-time expectations. However, when the particles from the cloud A first arrive at B and induce a return to A; if the return is earlier than the first particles from the realities of B with least-time expectations to reach the target points, cloud B is passively collapsed while cloud A is actively collapsed. Then there is a reality between the two systems and the cloud A is the active system; the cloud B is the passive system. This phenomenon, as passive collapses, a reality is determined with matter-proportion expectation but without least-time expectation is named as passive-cloud effect.
Quantum Zeno effect10–12 may be a typical phenomenon of passive-cloud effect, since observation will reduce the matter proportion of a particle and the rest of grains is in a reality with matter-proportion expectation. Because the decay part of grains may be quite small, the reality is likely without an atomic decay. Furthermore, if observing particles like photons enter a changing system, only if all observations in an entire change progress are in the changing-part reality, the change can occur.
Because passive systems are almost not release energy, if there is a third system, it can only receive information from the active but can’t receive any information except a holistic effect like gravitation from the passive. What’s more, every time particles from the active arrive at the passive may make such an effect. This phenomenon is named as dark-cloud effect. In addition, the passive system is determined by too less information and can still be seen as a cloud with many superposition realities but without bright and most of orderly part from the view of the third system, so it could be named as a dark cloud.
If when a dark cloud formed, atomic structures have already been established, the matter in the dark cloud is the same with us.
Dark clouds in the universe the so-called dark matter may be mainly composed of low atomic weight materials, such as hydrogen and helium. And they may be cold and sparse in vast space or may be some celestial bodies we have never seen before. However, the properties of such a cloud are different from that of the matter in a certain reality.
I argue that, from the fundamental principle, there may be no difference between dark-cloud effect and quantum Zeno effect. If the dark cloud effect occurred before specific atomic structures were formed, the clouds maybe will have some special potential features when they collapse.