Categorized | Experiments

Try this: Reversing perspective

You will need

  • printed copy of this file on separate pages
  • Coloured pencils
  • Scissors
  • Glue

What to do

  1. Colour in the house picture.
  2. Cut out the picture along the thick black lines.
  3. Fold along the dotted lines so the picture sticks up in the middle like a flat-topped pyramid.
  4. Put glue on the tabs marked ‘a’, and stick them down to keep the pyramid shape.
  5. Put glue on the ‘b’ tabs, and stick the pyramid onto the rectangle on the other sheet of paper.

To view the illusion

  1. Put your house picture up on the wall in a big room.
  2.  Go to the other side of the room and close one eye.
  3. Look at your house picture – does it look like it goes in instead of sticking out?
  4. Move around a bit and keep looking at the picture – does it move strangely?

What’s happening?

Your body has several different ways of seeing in 3D. You have two eyes for a good reason – they see the world from two slightly different angles. By comparing these two images, your brain can work out how close objects are. This type of 3D vision works best with objects that are close to you. When you are looking at objects far away, the images from your eyes are too similar and your brain can’t work out the distance. If you have one eye closed, then your brain doesn’t have a comparison at all – everything looks flat!

Your brain can also pick up clues from experience. You’re quite used to seeing rooms, so if you see something that looks like one, then your brain will try to match what you see with what you know. Rooms are hollow, so you imagine the house picture in this activity is also hollow, instead of sticking out as it does. As you move around looking at the picture, it doesn’t change the way you’d expect, leading to a very strange effect.


To create the illusion, this picture uses perspective drawing. This technique was originally developed hundreds of years ago to draw accurate pictures of objects in the real world. In perspective drawing, parallel lines such as straight train tracks are drawn so they would meet at a ‘vanishing point’. It also gives mathematical rules for drawing far away objects smaller.

A picture that follows these rules closely will look realistic and 3D. The house picture you made uses these rules to trick you – the walls get smaller as they move towards the centre, making them look further away, and the lines along the edges of the rug, pictures, skirting and cornices appear to meet at a ‘vanishing point’ in the centre of the image.

instruction 1

Colour in the printout of the house.

instruction 2

Cut out the house along the thick black lines.

instruction 3

When you're viewing the illusion,try to get rid of big shadows by lighting from the front instead of from above.

Comments are closed.

Children like to be challenged

If you want to find educational toys that your youngsters will take pleasure in enjoying with, the most effective factor to do is have them check it out.

Recent Posts

Monitoring Software

The Internet can be tricky for parents to deal with because kids often need to use the Internet for school, but parents parents are often worried about the various activities that their children might be engaged in. Peer-to-peer file sharing can lead to lawsuits and even a criminal prosecution. Some teens might engage in activities online that are embarrassing to the family or may lead to viruses or hackers accessing the computer. Fortunately, there are various forms of monitoring software that can offer parental control.

Monitoring software can also be very helpful when parents are trying to learn what their children are up to, such as whether they are attending class or doing their homework.

Many teens use the computer purchased specifically for schoolwork to play computer games or chat with friends. Monitoring software can not only record activities on the computer, but smartphone software such as Mobile Spy can silently record the teen's GPS information, text messages and phone call information.

Monitoring software sits silently on a computer or mobile device and monitors all of the activities carried out on the device, encouraging the teen to consistently use the device for communication. Activity is usually uploaded to an online account so that the parent can monitor activity from anywhere without having to get close to the phone. This is crucial since parents will usually not have physical access to the phone without arousing suspicion.

Many monitoring programs also come with keystroke loggers, which log keys recorded on the computer, a contextual blocker, and features that allow parents to block certain websites. All of these features allow parents to have a peace of mind when allowing their teens to use the Internet.