1 / 7

RAINBOWS

RAINBOWS. ?. ?. WHAT IS A RAINBOW?. Wikipedia suggests that ‘ a rainbow is an optical and meteorological phenomenon that causes a spectrum of light to appear in the sky when the Sun shines onto droplets of moisture in the Earth's atmosphere.’

lukas
Download Presentation

RAINBOWS

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. RAINBOWS

  2. ? ? WHAT IS A RAINBOW? Wikipedia suggests that ‘arainbow is an optical and meteorological phenomenon that causes a spectrum of light to appear in the sky when the Sun shines onto droplets of moisture in the Earth's atmosphere.’ shines on condensation or moisture in the air which This basically means that the sun causes the eyes to see a band of colours. These light rays cause a multicoloured arch to form, with red on the outside and violet on the inside. Rainbows can be caused by other forms of moisture, including mist, spray and dew. A rainbow’s arch is made of a continuous spectrum of colour bands. These so-called "bands" are a result of human colour vision. ? ?

  3. VISIBILITY OF A RAINBOW. Rainbows can be seen when there are water drops combined with sunlight that is coming from behind a person when they are on the ground. Rainbows can often be seen near waterfalls or mountains.

  4. SCIENTIFIC SIDE. When the light first enters the raindrop, it is refracted, then reflected off the other side of the raindrop, and again refracted as it exits the drop. The conclusive effect is that the light entering the drop is reflected back over a wide range of angles. The most intense light is at an angle of 40°–42°. The angle varies slightly depending on the size of the raindrop, and its refractive index.

  5. As the refractive index of seawater is higher than that of fresh water, the radius of a seawater rainbow is smaller than that of a true rainbow.How much light is refracted also depends on its wavelength, and its colour. Blue light has a shorter wavelength than red light, so it is refracted at a much larger angle. Although, because of the light that is reflected out from the back of the droplet, the blue light exits the droplet at a smaller angle to the red light.

  6. There is also such thing as a moonbow, a lunar or night time rainbow. A Moonbow can be seen on strongly moonlit nights, but as human colour perception is weakened in low light, moonbows often appear to be white.

  7. Museum Victoria leads us to conclude that a secondary rainbow is found higher up in the sky and are caused when light is reflected twice within a raindrop rather than only once like a normal rainbow. The colours in a secondary rainbow are in reverse, with red on the inside and violet on the outside. In the distance between a primary and secondary rainbow, the sky is very dark. SECONDARY RAINBOWS.

More Related