A television receives many channels simultaneously. When you select a channel, you do not create that programme—you select it from what is already being broadcast. The other channels do not vanish. They continue to exist. You simply are not tuned to them.

Key points: Multiple signals exist simultaneously. The receiver's configuration determines which signal becomes content. Changing the tuning changes the experienced channel, not the existence of the others.

NDR treats all of reality this way. Your access state is the tuner. The domain you experience is the channel you are currently receiving. The broadcast medium corresponds to an underlying reality that supports many possible domains of content.

The entire internet exists at once. When you type a URL, you are routed to a specific page. You did not create that page by typing the address. The address determined what you accessed.

When you visit google.com, it appears as if "Google" is the only world that exists—that is your current experienced reality. Not because it is the only site that exists, but because it is the URL you are currently routed to. Change the URL, and you are routed to a different part of the same underlying network.

In NDR terms, the URL is your access state, the page is the domain, and the routing protocol is the function R(s) → d. The full internet is the nested structure of reality. You can only visit one page at a time, but the rest does not cease to exist.

A microscope gives you access to the cellular domain. A telescope gives you access to the astronomical domain. Neither instrument creates what it reveals. Both are routing technologies—they change your access state so that a different domain becomes available to you.

Without the microscope, the cellular domain is still there. You simply lack the access conditions to experience it. The instrument modifies your access state, which changes your routing, which changes your projection.

A space suit does not create outer space. It provides the access conditions—temperature regulation, pressure, oxygen—that allow a human observer to survive in and interact with a domain they could not otherwise access.

Diving gear operates on the same principle for underwater domains. These are examples of access-and-survival technology: modifications to the observer's state that enable routing to a domain, and sustained presence within it.

Dreaming is a literal example of a world within a world. When you dream, your body remains in the same place. The external environment does not change. Sensory input is largely reduced. Yet you experience an entire, coherent world with its own spaces, events, and timelines.

This shows that radically different experienced worlds do not require transport, new environments, or the creation of separate universes. The only thing that changes is the internal state of the brain. From a scientific standpoint, this is powerful because it isolates the variable that matters.

Cross-domain influence: If a television is playing while someone sleeps, elements of that external world often appear inside the dream. Sounds, voices, or images from the room can be incorporated into the dream narrative. This demonstrates that the dream is a domain nested within a larger one—the routing conditions are set by brain state, but signals from the outer domain can still influence the inner one in limited, structured ways.

NDR does not claim dreams are "unreal." It treats the dream domain as a domain within the nested structure—accessed when the observer's state meets specific conditions (REM sleep, particular neurological states).

A user wearing a VR headset experiences a coherent world with its own objects, rules, and affordances. The user's physical body, however, remains in the same room, subject to the same physical constraints as before.

What has changed is the access state: sensory inputs are rerouted through displays and sensors, actions are interpreted through a simulation, and the experienced domain is now a virtual environment rather than the surrounding physical room.

In NDR terms, the access state s has been modified by the VR system, and the routing function R selects a different experienced domain. This does not imply that the physical world has ceased to exist—it shows how changing access and mediation can select a different coherent domain of experience within a broader reality.

Biology provides one of the most intuitive examples of domain nesting:

• Molecules exist within cells
• Cells exist within organs
• Organs exist within organisms
• Organisms exist within ecosystems
• Ecosystems exist within the biosphere
• The biosphere exists within the planet

Each level is a domain with its own structural conditions. Each is nested within the next. None is separate. All are part of one continuous structure. NDR generalises this observation and applies it to all of reality, not just biology.