Editing Ultramicroscope

{{Short description|Type of high-resolution microscope}}
{{Use American English|date = April 2019}}
An '''ultramicroscope''' is a [[microscope]] with a system that lights the object in a way that allows viewing of tiny [[particle]]s via [[light scattering]], and not [[Reflection (physics)|light reflection]] or [[Absorption (electromagnetic radiation)|absorption]]. When the diameter of a particle is below or near the [[wavelength]] of [[visible light]] (around 500 [[nanometer]]s), the particle cannot be seen in a [[optical microscope|light microscope]] with the usual methods of illumination. The ''ultra-'' in ''ultramicroscope'' refers to the ability to see objects whose diameter is shorter than the wavelength of visible light, on the model of the ''ultra-'' in ''[[ultraviolet]]''.

==Synopsis==
In the system, the particles to be observed are dispersed in a liquid or gas [[colloid]] (or less often in a coarser [[suspension (chemistry)|suspension]]). The colloid is placed in a light-absorbing, dark enclosure, and illuminated with a convergent beam of intense light entering from one side. Light hitting the colloid particles will be scattered. In discussions about light scattering, the converging beam is called a "[[Tyndall cone]]". The scene is viewed through an ordinary microscope placed at right angles to the direction of the lightbeam. Under the microscope, the individual particles will appear as small fuzzy spots of light moving irregularly. The spots are inherently fuzzy because light scattering produces fuzzier images than light reflection. The particles are in [[Brownian motion]] in most kinds of liquid and gas colloids, which causes the movement of the spots. The ultramicroscope system can also be used to observe tiny nontransparent particles dispersed in a transparent solid or gel.

Ultramicroscopes have been used for general observation of [[aerosols]] and [[colloids]], in studying [[Brownian motion]], in observing [[ion]]ization tracks in [[cloud chamber]]s, and in studying biological [[ultrastructure]].

==History==
In 1902, the ultramicroscope was developed by [[Richard Adolf Zsigmondy]] (1865–1929) and [[Henry Siedentopf]] (1872–1940), working for [[Carl Zeiss AG]].<ref name=zmond>{{cite web| first1=Richard Adolf |last1=Zsigmondy |title=Properties of Colloids – Nobel Lecture |work=Nobel Lectures, Chemistry 1922-1941 |date=December 11, 1926 | url=http://nobelprize.org/nobel_prizes/chemistry/laureates/1925/zsigmondy-lecture.html | location=Amsterdam | publisher=Elsevier Publishing Company |url-status=live |archive-url= https://web.archive.org/web/20230530134944/https://www.nobelprize.org/prizes/chemistry/1925/zsigmondy/lecture/ |archive-date= May 30, 2023 }}</ref> Applying bright sunlight for illumination they were able to determine the size of 4 nm small [[nanoparticle]]s in [[cranberry glass]]. Zsigmondy further improved the ultramicroscope and presented the immersion ultramicroscope in 1912, allowing the observation of suspended nanoparticles in defined fluidic volumes.<ref name=mappes12>{{cite journal |doi=10.1002/anie.201204688|pmid=23065955|title=The Invention of Immersion Ultramicroscopy in 1912-The Birth of Nanotechnology?|year=2012|last1=Mappes|first1=Timo|last2=Jahr|first2=Norbert|last3=Csaki|first3=Andrea|last4=Vogler|first4=Nadine|last5=Popp|first5=Jürgen|last6=Fritzsche|first6=Wolfgang|journal=Angewandte Chemie International Edition|volume=51|issue=45|pages=11208–11212}}</ref><ref name="timmap">{{cite news |last1=Mappes |first1=Timo |title=IMMERSIONSULTRAMIKROSKOP nach R. Zsigmondy von Winkel-Zeiss, Göttingen |url=https://www.musoptin.com/item/immersionsultramikroskop-nach-r-zsigmondy-winkel-zeiss-32607-1930/ |publisher=Prof. Dr.-Ing. Timo Mappes |date=20 November 2017}}</ref> In 1925, he was awarded the Nobel Prize in Chemistry for his research on colloids and the ultramicroscope.

Later the development of [[electron microscope]]s provided additional ways to see objects too small for light microscopy.

==See also==
* [[Dark-field microscopy]], a different technique that leverages light scattering against a dark background
* [[Light sheet fluorescence microscopy]]

==References==
{{reflist}}

[[category:Microscopes]]
[[Category:Optical microscopy techniques]]
[[Category:Scattering, absorption and radiative transfer (optics)]]
[[Category:Hungarian inventions]]