• Question: Could you explain to me in depth about electromagnetic radiation?

    Asked by 284bdta27 to Rob on 14 Nov 2014.
    • Photo: Rob Appleyard

      Rob Appleyard answered on 14 Nov 2014:

      That’s a very big question!

      Electromagnetic radiation is the scientific name for what most people call light. It’s carried by things called ‘photons’ which travel at the speed of light (surprise!), which is about 300,000,000 metres/second.

      How it behaves depends on how much energy it has. If it has very low energy, it’s a radio wave, if it has very high energy it’s an x-ray or even a gamma ray. Each of those behaves in different ways when they strike an object. Microwaves (less energy than light, more than radio) interact with water and heat it up, which is how a microwave oven works. X-rays will pass through soft tissue but are stopped by bones, which is how you get x-rays in the hospital.

      Anything specific you’d like to know?

Comments

  • Photo: 284bdta27

    284bdta27 commented on :

    Oh, so the x- rays go through the soft tissue but are blocked by bones which then show up clearer so you can identify the bone. So, basically, x-rays showing bones are like light rays showing shadows because both objects block the rays and show up clearer. Microwaves interact with water and heat it up, which is how a microwave works like you said but it also heats up food. Does it interact very differently with food than water or is there no significant difference?