The vast Universe, which so intrigues man, has mysteries seemingly out of the reach of man. How big is it? Does it have boundaries? Does it go forever, or is it circular? Is it all an illusion? Is it homogeneous throughout? So many questions. Does the Universe have physical boundaries? We do not know, nor are we allowed to know in the density we are in, 4th Density. To us, with our instruments and in our travels, it appears to be boundless. We travel only so much, using home as a base, and limit our travels not because of distance but due to what is known about certain parts of the Universe, which would be poisonous to us. We too use probes, set to take their measures and return. This is the manner by which your Solar System was located, not by us, but by others. If the probe returns with data that indicates an environment that would be poisonous or quickly fatal, we do not, understandably, explore that part of the Universe. Travel in light form, during higher densities, does not carry those risks.
Different sections of the Universe have different compositions. By this we mean the elements are found in different proportions and the resultant chemical reactions that ensue therefore have different characteristics. Some worlds have silicon based life. Some suns emit radiation that is poisonous to us and would be to you also. Those environments contain severe dangers, as silicon based microbes are ones your immune system could not begin to muster a defense against. An analogy we could use is the soil across a terrain. One place is acidic and is covered with moss, another has soil that compacts into rock-like hardness, discouraging probing roots. The variables are many, and any horticulturist will tell you that a wildflower taken from one location could not be expected to grow in another. Just so is the Universe, we have discovered, and the mix of elements that compose the soil in this section of the Universe is our and your niche. Incarnated, we are not allowed, not able, to explore outside this niche.
Beyond some simple statements, we are not at liberty to explain the Universe to humans, as we are restrained by the Rule of Non-Interference and also by our ignorance. For you, it seems that the Universe is limitless, and boundless, and is not an illusion. So be it, as for you that is a reality and in particular the reality which you must live in. It is also the reality which we, the Zetas, must live in, and in truth we do not know that much more about the functioning of the Universe than you do. The Universe holds secrets that we are not allowed to know at this time, at our stage of spiritual growth. These questions must go unanswered, for the time being.