Changes

|location=London

|location=London

|url=http://www.nationalgallery.org.uk/paintings/joseph-wright-of-derby-an-experiment-on-a-bird-in-the-air-pump

|url=http://www.nationalgallery.org.uk/paintings/joseph-wright-of-derby-an-experiment-on-a-bird-in-the-air-pump

|quote=A travelling scientist is shown demonstrating the formation of a vacuum by withdrawing air from a flask containing a white cockatoo, though common birds like sparrows would normally have been used. Air pumps were developed in the 17th century and were relatively familiar by Wright's day. The artist's subject is not scientific invention, but a human drama in a night-time setting.

|quote=A travelling scientist is shown demonstrating the formation of a vacuum by withdrawing air from a flask containing a white cockatoo, though common birds like sparrows would normally have been used. Air pumps were developed in the 17th century and were relatively familiar by Wright's day. The artist's subject is not scientific invention, but a human drama in a night-time setting. The bird will die if the demonstrator continues to deprive it of oxygen, and Wright leaves us in doubt as to whether or not the cockatoo will be reprieved. The painting reveals a wide range of individual reactions, from the frightened children, through the reflective philosopher, the excited interest of the youth on the left, to the indifferent young lovers concerned only with each other.  

The bird will die if the demonstrator continues to deprive it of oxygen, and Wright leaves us in doubt as to whether or not the cockatoo will be reprieved. The painting reveals a wide range of individual reactions, from the frightened children, through the reflective philosopher, the excited interest of the youth on the left, to the indifferent young lovers concerned only with each other.  

|acessdate=2012-10-7}}</ref> Later the air pumps were used to demonstrate that sound does not travel in an airless space. The first ''molecular pump'' to be used for creating a vacuum in experimental chambers based on Knudsen's investigation on flow of gases through long and narrow tubes was introduced by Gaede in 1912 at the meeting of ''German Physical Society''.<ref name="Handbook on vacuum">{{cite book

|acessdate=2012-10-7}}</ref> Later the air pumps were used to demonstrate that sound does not travel in an airless space. The first ''molecular pump'' to be used for creating a vacuum in experimental chambers based on Knudsen's investigation on flow of gases through long and narrow tubes was introduced by Gaede in 1912 at the meeting of ''German Physical Society''.<ref name="Handbook on vacuum">{{cite book

|title=Handbook of Vacuum Technology

|title=Handbook of Vacuum Technology

* [[MRE]]

* [[MRE]]

== Source ==  

== Sources ==

The New American Desk Encyclopedia, Penguin Group, 1989

The New American Desk Encyclopedia, Penguin Group, 1989

{{reflist|2}}

{{reflist|2}}

[[Category : Science]]

[[Category:Science]]

[[Category : Physics]]

[[Category:Physics]]

[[Category : Food Storage]]

[[Category:Food Storage]]