Tunnning

Tunnning, commonly written tunneling or tunnelling, refers to creating or using a tunnel—a passage through or under obstacles such as rock, soil, water, or buildings. The concept appears in civil engineering, physics, computer networking, and medicine.

In civil engineering, tunneling builds transportation and utility tunnels deep underground. Methods include tunnel boring machines that grind through rock or soil, shielded tunneling, cut-and-cover, and immersed tubes for underwater routes. Ground control, dewatering, and ventilation are key safety and operation concerns.

In physics, quantum tunneling describes particles crossing energy barriers that are classically insurmountable. This probabilistic process arises from wave-like matter properties and underpins phenomena such as nuclear decay, electron transport in semiconductors, and scanning tunneling microscopy, while not violating energy conservation.

In computing and networking, tunneling encapsulates one protocol within another to transfer data securely or across incompatible networks. Examples include VPN, SSH, IPsec, and SSL/TLS tunnels. Tunneling enables remote access and private communications, but can be used to bypass restrictions.

In medicine, tunnning can refer to a channel forming under tissue that connects a wound bed to the surface or to another cavity. Such tunnels complicate healing and require clinical management to reduce infection risk.