What is the "radio bubble" created by signals sent from Earth into space so far?

Earth’s leaked radio transmissions are forming an expanding spherical “radio bubble” that is now spreading through nearby space.

In theory, some of these signals could reach other star systems, but their strength drops rapidly with distance under the inverse-square law.

The article highlights intentional messages like the Arecibo message and the proposed BitG concept as examples of purposeful interstellar communication.

It also ties the idea to SETI and the Fermi paradox, suggesting humanity’s faint radio footprint may help explain why we have not detected alien civilizations.