Science - Light

This half term our science focus has been all about light. We have been using 'Star Words' such as light source, reflection, refraction, opaque, transparent and translucent. In one lesson, we looked at the parts of the human eye and how studying this may support us in a career in Optometry! 

Mirror Mazes

We  used mirrors to reflect light, creating a mirror maze to light up the image of an eye. We know that light travels in straight lines. We are able to see because light travels from the light source, hits the object, causing light to reflect off of it into our eyes. Usually light emits from all directions from a light source, reflecting off of objects around it; this is why we are able to see many things all around us. 

We know that darkness is the absence of light. 

Periscopes

Using our knowledge of reflection, we made periscopes which meant we were able to see above us or around corners. Periscopes use two mirrors at 45^o angles. Light enters the top of a periscope, reflects off of the first mirror down the periscope, hits the second mirror and reflects into a persons eye.

Periscopes were used in trench warfare and are still used today on submarines!

Shadows

Shadows occur when an opaque object blocks light. Light travels in straight lines so cannot 'bend' around the object. This is why shadows are the same/similar shape to the object blocking the light. Translucent objects let some light through and transparent objects let all light through. 

We used card to block the light and then our hands - it was like a shadow puppet show! We even watched a clip from BGT of the group 'Attraction' whose act was formed using shadows. 

Refraction

Refraction happens when light changes direction, or bends, when it moves from one material to another - usually from air to water. This can distort the image we see. For example, light traveling through the air refracts when it hits water. This can make a straw in a glass of water look bent at the surface of the water. 

We completed an experiment using water in a glass. We noticed how the arrow appeared bigger when placed behind the glass of water. When we placed a penny under the glass of water and looked through the side, it appeared as if the penny had disappeared! Finally, we created a 'lens' from the curved piece of plastic on a bottle and placed water in it. When we read text through it, the text appeared larger and 'wavy' - it was like a magnifying glass!

We also used prisms to separate white light into the colours of the spectrum: red, orange, yellow, green, blue, indigo and violet.