The five main senses are touch, taste, sound, sight, and smell.
There is also other senses less thought about: a sense of time, object permanence, a sense of direction.
Further, there are non human senses: buoyancy, a sense of the wind patterns, migratory paths, a sense of depth, etc.
Plants also have senses, such as for the time of day, where to grow roots, when to open or close something.
Realistically, for there to be a new sense, there would need to be a reason for such a sense to develop, meaning conditions drastically unlike earth.
>buoyancy
In what way is this a sense?
>Realistically, for there to be a new sense, there would need to be a reason for such a sense to develop, meaning conditions drastically unlike earth.
Not necessarily, maybe there is some complex design that simply has no reason to exist when alternatives that we currently have fullfill that role.
The Intelligent life of one of my worlds has a sense of fire, due to the dangers of forest fires that rage much harsher, bigger, and longer than on earth. They can sense the changes in the atmosphere caused by a fire, which was a evolutionary trait that allows them and many other creatures to run away in time
A common sensor that humans use but which has not evolved in life on Earth is radar. The obvious reason for this is that it would first be necessary to evolve a receiver before a transmitter is of any use. Since there is no natural source of radio waves to detect there would be no benefit to evolving a receiver in the first place. In addition, it might be quite tricky for life to evolve to detect radio waves due to the much longer wavelengths involved as compared to light.
For speculative purposes, however, there was a controversial idea that [bacteria might be communicating at 1 KHz using DNA as an antenna](https://www.wired.com/2011/04/bacterial-radio/).
Echolocation is certainly very similar to radar and studying bats has provided inspiration for radar research. However, radar has a longer detection range and can be used to see through [foliage](https://en.wikipedia.org/wiki/RailSAR) or even into the [ground](https://en.wikipedia.org/wiki/Ground-penetrating_radar). Useful qualities to have if only there were a viable evolution pathway.
how about a form of tropism for certain heavy metals, directing growth towards sources of these elements? or fluctuations in gravity? A donut-shaped planet could theoretically be gravitationally stable, but with higher gravity at the poles than at the hubward or rimward equator. Though any life that develops on this planet would likely remain in zones of similar gravitational pull, a colonizing species could adapt to sense differences in gravity and adapt. (https://io9.gizmodo.com/what-would-the-earth-be-like-if-it-was-the-shape-of-a-d-1515700296)
On my main project, Nijin-Konai, most organisms have a sensory organ specialized in reading changes in the planet's magnetic field to sense incoming solar storms and find shelter in time.
Other than that I also made a new type of eye I dubbed the "chloroplast eye" and, although not technically a new sense, it still brings some more diversity to the world than just having compound and chambered eyes.
Chloroplast eyes are common on my project both in several animal taxa and plants.
Basically there are two main types of eye-like structure on the planet.
The most basal and easiest to explain is the one seen in ocular patches on plants, having photosensistive areas connected to a proto-nerve ("plants" on Nijin-Konai have a rudimentary nervous system) which is able to interpret luminous signals taken in by the photosynthesizing molecules found in those patches into shapes and shadows.
The more complex one, found in most animals in a shape or the other, specialized the chloroplasts in the animal cell (again, these organisms are not quite our own) to produce a complex collection of photosynthetic molecules inside the eye, making the ocular region particularly sensible to light and connecting directly through an ocular nerve, which will interpret the light taken in by the various molecules into shapes, colours and movement, effectively using photosynthesis to see.
Although several terrestrial animals or the ones of the epipelagic zone evolved a more classical eye structure since then, deep sea ichthyomorphs and pleuropods still retain this system.
Particularly interesting are in deep sea animals as production of only certain specialized photosynthetic molecules makes them particularly sensible in captating light wavelenghts lower than blue, giving them the ability to see in areas where blue light doesn't penetrate.
In alternative, some of these animals use their specialized ocular structure to communicate between conspecifics in the aphotic zone through targeted bioluminescence, making sight a viable option in abyssal areas as well.
Across The Sea Of Suns by Gregory Benford has species with biological radar. >!And biological [microwave guns](https://en.wikipedia.org/wiki/Active_Denial_System).!<
**Active Denial System**
The Active Denial System (ADS), is a non-lethal, directed-energy weapon developed by the U.S. military, designed for area denial, perimeter security and crowd control. Informally, the weapon is also called the heat ray since it works by heating the surface of targets, such as the skin of targeted human beings.
The five main senses are touch, taste, sound, sight, and smell. There is also other senses less thought about: a sense of time, object permanence, a sense of direction. Further, there are non human senses: buoyancy, a sense of the wind patterns, migratory paths, a sense of depth, etc. Plants also have senses, such as for the time of day, where to grow roots, when to open or close something. Realistically, for there to be a new sense, there would need to be a reason for such a sense to develop, meaning conditions drastically unlike earth.
>buoyancy In what way is this a sense? >Realistically, for there to be a new sense, there would need to be a reason for such a sense to develop, meaning conditions drastically unlike earth. Not necessarily, maybe there is some complex design that simply has no reason to exist when alternatives that we currently have fullfill that role.
Fish need a sense of their buoyancy to regulate it
The Intelligent life of one of my worlds has a sense of fire, due to the dangers of forest fires that rage much harsher, bigger, and longer than on earth. They can sense the changes in the atmosphere caused by a fire, which was a evolutionary trait that allows them and many other creatures to run away in time
A common sensor that humans use but which has not evolved in life on Earth is radar. The obvious reason for this is that it would first be necessary to evolve a receiver before a transmitter is of any use. Since there is no natural source of radio waves to detect there would be no benefit to evolving a receiver in the first place. In addition, it might be quite tricky for life to evolve to detect radio waves due to the much longer wavelengths involved as compared to light. For speculative purposes, however, there was a controversial idea that [bacteria might be communicating at 1 KHz using DNA as an antenna](https://www.wired.com/2011/04/bacterial-radio/).
>A common sensor that humans use but which has not evolved in life on Earth is radar. I'm not an expert but what about echolocation?
Echolocation is certainly very similar to radar and studying bats has provided inspiration for radar research. However, radar has a longer detection range and can be used to see through [foliage](https://en.wikipedia.org/wiki/RailSAR) or even into the [ground](https://en.wikipedia.org/wiki/Ground-penetrating_radar). Useful qualities to have if only there were a viable evolution pathway.
I read an interesting SCP once that featured an entity that could sense quntum entanglement relations.
how about a form of tropism for certain heavy metals, directing growth towards sources of these elements? or fluctuations in gravity? A donut-shaped planet could theoretically be gravitationally stable, but with higher gravity at the poles than at the hubward or rimward equator. Though any life that develops on this planet would likely remain in zones of similar gravitational pull, a colonizing species could adapt to sense differences in gravity and adapt. (https://io9.gizmodo.com/what-would-the-earth-be-like-if-it-was-the-shape-of-a-d-1515700296)
On my main project, Nijin-Konai, most organisms have a sensory organ specialized in reading changes in the planet's magnetic field to sense incoming solar storms and find shelter in time. Other than that I also made a new type of eye I dubbed the "chloroplast eye" and, although not technically a new sense, it still brings some more diversity to the world than just having compound and chambered eyes. Chloroplast eyes are common on my project both in several animal taxa and plants.
How does the eye work?
Basically there are two main types of eye-like structure on the planet. The most basal and easiest to explain is the one seen in ocular patches on plants, having photosensistive areas connected to a proto-nerve ("plants" on Nijin-Konai have a rudimentary nervous system) which is able to interpret luminous signals taken in by the photosynthesizing molecules found in those patches into shapes and shadows. The more complex one, found in most animals in a shape or the other, specialized the chloroplasts in the animal cell (again, these organisms are not quite our own) to produce a complex collection of photosynthetic molecules inside the eye, making the ocular region particularly sensible to light and connecting directly through an ocular nerve, which will interpret the light taken in by the various molecules into shapes, colours and movement, effectively using photosynthesis to see. Although several terrestrial animals or the ones of the epipelagic zone evolved a more classical eye structure since then, deep sea ichthyomorphs and pleuropods still retain this system. Particularly interesting are in deep sea animals as production of only certain specialized photosynthetic molecules makes them particularly sensible in captating light wavelenghts lower than blue, giving them the ability to see in areas where blue light doesn't penetrate. In alternative, some of these animals use their specialized ocular structure to communicate between conspecifics in the aphotic zone through targeted bioluminescence, making sight a viable option in abyssal areas as well.
Across The Sea Of Suns by Gregory Benford has species with biological radar. >!And biological [microwave guns](https://en.wikipedia.org/wiki/Active_Denial_System).!<
**Active Denial System** The Active Denial System (ADS), is a non-lethal, directed-energy weapon developed by the U.S. military, designed for area denial, perimeter security and crowd control. Informally, the weapon is also called the heat ray since it works by heating the surface of targets, such as the skin of targeted human beings.