![](https://pinterest.com/pin/create/button/?url=http://www.dartofscience.com/video/vanishing-glass/&media=http://www.dartofscience.com/wp-content/uploads/2016/07/Vanishing-Glass.jpg&description=<a href="http://www.dartofscience.com/wp-content/uploads/2016/07/vlcsnap-2016-05-20-16h35m08s268.png"><img class="alignleft size-medium wp-image-750" src="http://www.dartofscience.com/wp-content/uploads/2016/07/vlcsnap-2016-05-20-16h35m08s268-300x169.png" alt="vlcsnap-2016-05-20-16h35m08s268" width="300" height="169" /></a>We all know that glass is transparent. Then how is it that we can see it in the first place? When the light beam is incident at an angle to the glass, some of the light is reflected, while the rest of it goes through, but it slows down and changes its direction as it travels from the air to the glass. This is known as refraction. To make something invisible, we have to make it so that the behaviour of light does not change when it encounters the object. This means that we need to eliminate both reflection and refraction if we want to make the glass disappear. So, we use a glass that has a refractive index approximately equal to that of oil. Now, when a glass test tube is submerged in a beaker full of oil, the light ray encounters the beaker, then the oil, then the test tube and finally the air again. If we fill the test tube with oil, then the light rays don't deviate from their path discernibly, since the refractive indices of all the media obstructing it are nearly the same. The only 'object' that we can see is the beaker full of oil, because light has to travel from air to the beaker, changing its direction.){kind=spacer}
![](https://www.linkedin.com/shareArticle?mini=true&url=http://www.dartofscience.com/video/vanishing-glass/&title=VANISHING GLASS&summary=<a href="http://www.dartofscience.com/wp-content/uploads/2016/07/vlcsnap-2016-05-20-16h35m08s268.png"><img class="alignleft size-medium wp-image-750" src="http://www.dartofscience.com/wp-content/uploads/2016/07/vlcsnap-2016-05-20-16h35m08s268-300x169.png" alt="vlcsnap-2016-05-20-16h35m08s268" width="300" height="169" /></a>We all know that glass is transparent. Then how is it that we can see it in the first place? When the light beam is incident at an angle to the glass, some of the light is reflected, while the rest of it goes through, but it slows down and changes its direction as it travels from the air to the glass. This is known as refraction. To make something invisible, we have to make it so that the behaviour of light does not change when it encounters the object. This means that we need to eliminate both reflection and refraction if we want to make the glass disappear. So, we use a glass that has a refractive index approximately equal to that of oil. Now, when a glass test tube is submerged in a beaker full of oil, the light ray encounters the beaker, then the oil, then the test tube and finally the air again. If we fill the test tube with oil, then the light rays don't deviate from their path discernibly, since the refractive indices of all the media obstructing it are nearly the same. The only 'object' that we can see is the beaker full of oil, because light has to travel from air to the beaker, changing its direction.&source=http://www.dartofscience.com)
NOTICE BOARD
d’Art of Science partners with DFC 2017
Starting this year, d’Art of Science partners with DFC for promoting Hands-on/DIY Culture in Schools by starting a sub-award in the annual DFC Challenge. One school selected under the Best Prototype Award will get a chance to travel to Goa and develop their solution prototype in Goa with us. Over… READ MORE…
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