How do we interact with the Universe?
Lifeforms are a collection of senses, in order to detect the world around them robots must also have sensors.
Types of Sensors
See – Most Human beings can see visible light (Wavelengths from 450 (Violet) – 700 (Red) nm. this helps us to differentiate between different things, such as colour of different leaves, based on the energy of light they absorb or reflect. This can be effected by different factors, such as temperature or the chemical reactions taking place. Such as those that give leaves their green colour (Chlorophyll that carry out photosynthesis mostly reflect the green waveband of light).
How many different colours of leaves can you see, can you tell if a leaf is dead or unwell based on its colour? Imagine a robot with the job of looking for sick plants based on their leaf colour.
Touch: Humans need to feel for a number of reasons, they feel so that they can handle delicate equipment carefully pick up and move. They can use the same hands to crush or break things. They may also want to detect how hard, wet or hot things are. For humans touch is also defensive, to warn our brains when we are in danger.
Imagine picking up a snail, you would be able to feel the hardness of the shell, or the sliminess of its body, you know that if you apply too much force with your fingers you will break the shell. How would a robot do the job of collecting live snails?
Smell / Taste: Humans have an extra but limited way of telling what something is, if you are blindfolded you may still be able to tell what something is using Chemosensory mechanism such as smell. For example humans can smell flowers or baking bread, their Olfactory cells detect chemicals in the air and can be tricked, however this can be useful for trained chemists as it can help them determine the difference between different clear liquid chemicals WARNING do not sniff chemicals without supervisions, some gases are poisonous or corrosive and there are serious health risks associated with inhaling them. Robots do not have cells, so how would they be able to determine chemicals that look identical?
Taste is another example of a Chemosensory mechanism, our tongs have Gustatory cells that react to food or drink mixed with saliva and send nerve signals to the brain, this again allows us to all be able to taste what chemicals we are eating and two blindfolded people should be able to determine what they are eating. However this is limited and the brain can be fooled. However robots do not have cells and so do not have chemosensory perception…. however there are other ways to add these senses which will be discussed below.
Hear: Human ears can detect pressure vibrations in the air, between about 0 and 160 dB but past 85 dB the sound will do permanent and possible fatal damage to your ear drum, this is because the Ear feels the pressure applied by a sound wave, the louder it is the more force is applied to the eardrum, too little and the ear will not notice it and too much and it will break the drum. The frequency of how often a sound is made can also be measured by the ear and humans can hear from around 20 to 20,000 Hz (Hetzs) or beats per second. any faster or slower and the ear will not notice the sound wave. Here we can hear a sound and see how a robot would recognise a sound, make sure the volume isnt too high, WARNING it may cause some discomfort to listen to. See what your hearing range is.
Understanding our own senses helps us recognise our limitations as well as helping us make robots that can work in unsafe and distant environments. Perfect for looking for life on your planet.
“Sixth” sense: Some animals, such as birds, can use the Earth magnetic field to navigate, yet humans only discovered magnetic fields around 2000 years ago. Chinese scientists discovered that some metals are magnetic and these can be used to make compasses, without which we would find it difficult to find which way is North. There are other things that we can only feel the effects of such as the amount of charge our bodies have, if you have ever had a static shock when your body quickly charges or discharges. We know which way is down and can feel if our bodies are out of balance thanks to the bodies vestibular system, a utricle and set of three semi-circular canals which together with touch and sight let us balance and keep track of our orientation. There are many things that we cannot sense without machines that we can measure in Space and on other worlds.
Next: Learn about different sensors for your spacecraft.