Editing Reflection (physics) (section)

==Other types of reflection==

===Neutron reflection===
Materials that reflect [[neutron]]s, for example [[beryllium]], are used in [[nuclear reactor]]s and [[nuclear weapon]]s. In the physical and biological sciences, the [[Neutron Reflectometry|reflection of neutrons]] off atoms within a material is commonly used to determine the material's internal structure.

===Sound reflection===
[[File:Studio soundproofing panel.jpg|thumb|right|Sound diffusion panel for high frequencies]]
{{see also|Acoustic mirror}}

When a longitudinal [[sound wave]] strikes a flat surface, sound is reflected in a coherent manner provided that the dimension of the reflective surface is large compared to the wavelength of the sound. Note that audible sound has a very wide frequency range (from 20 to about 17000&nbsp;Hz), and thus a very wide range of wavelengths (from about 20&nbsp;mm to 17&nbsp;m). As a result, the overall nature of the reflection varies according to the texture and structure of the surface. For example, porous materials will absorb some energy, and rough materials (where rough is relative to the wavelength) tend to reflect in many directions—to scatter the energy, rather than to reflect it coherently. This leads into the field of [[architectural acoustics]], because the nature of these reflections is critical to the auditory feel of a space. 
In the theory of exterior [[noise mitigation]], reflective surface size mildly detracts from the concept of a [[noise barrier]] by reflecting some of the sound into the opposite direction. Sound reflection can affect the [[acoustic space]].

===Seismic reflection===
{{Further|reflection seismology}}
[[Seismic wave]]s produced by [[earthquake]]s or other sources (such as [[explosion]]s) may be reflected by layers within the [[Earth]].  Study of the deep reflections of waves generated by earthquakes has allowed [[seismologist]]s to determine the layered [[structure of the Earth]].  Shallower reflections are used in [[reflection seismology]] to study the Earth's [[crust (geology)|crust]] generally, and in particular to prospect for [[petroleum]] and [[natural gas]] deposits.

===Time reflections===
Scientists have speculated that there could be time reflections.  Scientists from the [[Advanced Science Research Center|Advanced Science Research Center at the CUNY Graduate Center]] report that they observed time reflections by sending broadband signals into a strip of [[metamaterial]] filled with electronic switches.<ref>{{cite web | last=Orf | first=Darren | title=Time Reflections Are Real: What Are They, and How Do They Work? | website=Popular Mechanics | date=2025-03-02 | url=https://www.popularmechanics.com/science/a63979764/time-reflections-real/ | access-date=2025-03-03}}</ref>  The "time reflections" in electromagnetic waves are discussed in a 2023 paper published in the journal ''[[Nature Physics]]''.<ref>{{cite journal | last=Moussa | first=Hady | last2=Xu | first2=Gengyu | last3=Yin | first3=Shixiong | last4=Galiffi | first4=Emanuele | last5=Ra’di | first5=Younes | last6=Alù | first6=Andrea | title=Observation of temporal reflection and broadband frequency translation at photonic time interfaces | journal=Nature Physics | publisher=Springer Science and Business Media LLC | volume=19 | issue=6 | date=2023-03-13 | issn=1745-2473 | doi=10.1038/s41567-023-01975-y | doi-access=free | pages=863–868 | url=https://arxiv.org/pdf/2208.07236 | access-date=2025-03-03| arxiv=2208.07236 }}</ref>