How Far Can We See and Why?
The human eye is capable of seeing far into the distance. However, it takes time for this ability to develop. The visual system does not fully mature until around age 20 or so. At that point, most people are able to see objects up to several miles away (and even farther).
But how far can we actually see? And why do some people have better vision than others?
For centuries, humans believed that they could see objects as far away as the moon and stars. Later, telescopes were developed which allowed us to observe further into space. Today, with modern technology such as binoculars and telescopes, we can view objects much closer to home. For example, we can now look through a telescope at the Moon and see its surface details including craters and mountains. Even though we cannot see all of the lunar surface, we can still make out many features on the Moon’s surface.
In fact, if you hold one end of a pair of binoculars parallel to each other and then move them apart, you will be able to see the Moon’s shadow cast across the sky. Once the two ends of the binoculars are parallel, you will be looking straight at the Moon. This is an easy way to find the Moon in the sky.
So how far can we see?
In theory, we were able to see the moon and beyond. But with objects on Earth, there is a limit to how far away we can see them depending on different factors such as lighting conditions and weather. Over long distances, we see objects in the sky such as birds and we can see stars at night. Light only travels so far.
The Earth’s atmosphere has quite an effect on how far we can see. On Earth, light is reflected off of objects such as buildings and gets in our eyes. However, when you are in space without air, you can see much further into the distance. This is because there are no lights to reflect light and confuse our eyes.
Most objects you see every day are much shorter distances away and that’s how far you can see them. The atmosphere also blurs distant objects giving them a blurry appearance. This is why we can’t always see far away things with complete clarity. In the future, if we develop technology to view even more distances objects will appear less blurry but for now, objects in the distance still appear blurred.
Light and Brightness
Seeing objects that are distant is not always about how far away they are but also how bright those objects are. Some objects such as the Moon, stars and planets are much brighter than others. The reason for this is because they are either reflecting light much more towards you or emitting their own light.
Other objects such as birds and insects only reflect a small amount of light making them appear blurry when you try to look at them.
Sources & references used in this article:
How far can we push chemical self-assembly? by F Robert – Science, 2005 – certh.gr
How far can we go beyond linear cryptanalysis? by T Baigneres, P Junod, S Vaudenay – … on the Theory and Application of …, 2004 – Springer
Equilibrium modeling of alpine plant distribution: how far can we go? by A Guisan, JP Theurillat – Phytocoenologia, 2000 – researchgate.net
High χ–Low N Block Polymers: How Far Can We Go? by C Sinturel, FS Bates, MA Hillmyer – 2015 – ACS Publications
The Role of Public International Law in the WTO: How far can we go? by J Pauwelyn – American Journal of International Law, 2001 – JSTOR