Ultralight universe

[S.A.M.]

How do organisms with vision beyond the range of normal light see the universe? Do they also have vision in the normal range? If yes/no, how does that affect perception of matter?

 

[Oli]

Good question.
Since (I assume) their brains are matched to take the input they how can we know exactly how they perceive things?
I know bees see further into the ultra violet (which we can "translate" to get a snapshot of what they see), but being able to constantly see in those frequencies would (probably) give a different take on things.

 

[draqon]

Ultraviolet Mars

Infrared Mars

The way we see Mars

 

[S.A.M.]

Just wondering, when we "see" objects, its basically a function of light and how its reflection/refraction/bending is interpreted by the brain. Is that also true of space and time? Do we "perceive" space and time based on our acuity of perception? Space is a function of dimensions and measurement, and should be affected by light. Time is a concept of dimension and sequence, also dependent on linearity of events, which in turn are decided by us. ie we either classify events in relation to each other or in relation to a specific focus (past, present and future vs before and after).

Which means that for all practical purposes, either by concrete or abstract foci, we determine space and time as a function of vision.

So is space and time "fundamental" to those with a different kind of vision, the way they are to us?

 

[Oli]

Do we "perceive" space and time based on our acuity of perception?

How could it be otherwise?

Space is a function of dimensions and measurement, and should be affected by light.

How so?
Light exists within space, do distances alter when it's dark?

Which means that for all practical purposes, either by concrete or abstract foci, we determine space and time as a function of vision.

So blind people have a different conception of time and space?

So is space and time "fundamental" to those with a different kind of vision, the way they are to us?

Perceptional abilities vary along with size of creature (i.e. I don't know of any human-sized creatures that see at different frequencies, but the smaller ones do).
So their perception of time and space would depend more on the relative sizes of them and the "real world" and their lifespans, more than by what/ how they see, neh?
For example something that sees in the infra-red would notice things warming up over time and cooling down (at different rates - land heats up quicker than water, and cools quicker), but the heating still comes from the Sun, which follows the same timing for them and us, since it's the same Sun.

(Forgive the seemingly facetious answers Saiyyadati, but I'm not sure where you're heading...)

 

[S.A.M.]

I'm rambling

e.g. the "space"between two objects is defined by the notion of the dimensions of that object; so I guess what I am asking is, is the ability to perceive that dimension constant.


e.g.2. time is the process of change, but again it requires the ability to "recognise" the point A from point B to know that there has been change.

Actually I was reading on the "timeless" gene, and I got to wondering what the notion of time is for those who may lack the ability to perceive two independent points that define change.

 

[Oli]

I'm rambling

That's a relief - I thought I was being lured into nefarious logic trap

e.g. the "space"between two objects is defined by the notion of the dimensions of that object; so I guess what I am asking is, is the ability to perceive that dimension constant.

Nope.
There was a thread about why does an airliner look smaller at 5000 ft altitude than it does at 5000 ft away on the ground.
You need some comparison...
IIRC there was tale about a tribe of jungle-bred natives who only ever saw things inside the forest.
One of their guys was taken on a trip and, upon spotting his first-ever elephant on the horizon, asked "what sort of insect is that?".
Because all his life anything that looked small WAS small, because the distance was never more than 10 feet or so...

e.g.2. time is the process of change, but again it requires the ability to "recognise" the point A from point B to know that there has been change.

That's deeper.
I was about to say that it doesn't, since you could see a change in an object and "know" that time has passed.
But, since I just showed above that perceptions depend upon experience...
Umm, maybe our wiring makes us think that time passes, changing things.
Ook, is about the best i can do without considerably more thought... :bugeye:

Actually I was reading on the "timeless" gene, and I got to wondering what the notion of time is for those who may lack the ability to perceive two independent points that define change.

Doesn't that say the 24 hour circadian rhythm is built in?
I mean, once I'd waded through things like "suprachiasmatic nucleus" it read to me like all creatures have the same time sense.
(and I thought that our "natural" rhythm was ~27 hours - or is that a false memory from somewhere?).

 

[S.A.M.]

So if its built in, in some, what about those who don't have all those marvelous genes to "keep" time? Do they perceive time the same way?

e.g.

Free running organisms still have a consolidated sleep-wake cycle when in an environment shielded from external cues, but the rhythm is not engrained and may become out of phase with other circadian, or ultradian rhythms such as temperature and digestion. This research has influenced the design of spacecraft environments, as systems that mimic the light/dark cycle have been found to be highly beneficial to astronauts.

And:

It appears that the SCN ("suprachiasmatic nucleus" )takes the information on day length from the retina, interprets it, and passes it on to the pineal gland (a pea-like structure found on the epithalamus), which then secretes the hormone melatonin in response. Secretion of melatonin peaks at night and ebbs during the day.

So could difference in perception of light, affect perception of time?

Also:

The ability of light to reset the biological clock depends on the phase response curve (to light). Depending on the phase of sleep, the light can advance or delay the circadian rhythm. The required illuminance varies from species to species, much lower light levels being required to reset the clocks in nocturnal rodents than in humans.

In addition to light intensity, wavelength (or color) of light is an important factor in the degree to which the clock is reset. Melanopsin is most efficiently excited by blue light (420-440 nm).[6]

You see what I mean?

 

[Oli]

Umm, I must have missed all that - probably fell asleep trying to pronounce superacharismaticexpialinukular.

Easy (until I came across the bit about wavelength - damn).
The illumination still comes from the sun - same rate for everyone.

But on the wavelength thing - are there any species that can't see into blue?
Does the varying wavelength vary with species?
I.e. are those that see other "colours" also the ones that have the "other" wavelength requirements to give the time sense?

What about:

In non-mammalian vertebrates, however, such as birds, fish and amphibians, melanopsin is found in certain other retinal cells, and also outside the retina in structures known or presumed to be directly photosensitive, such as the iris muscle of the eye, deep brain regions, the pineal gland, and the skin.

(Wiki).
If skin can "tell the time" for us how necessary is that eyes work on that wavelength?

 

[S.A.M.]

Did you also miss the part about "presumed to be directly photosensitive"

 

[Oli]

I saw it.
Is the skin not photosensitive?
Oh, you mean that skin may only take in the wavelengths that eyes do?
Does it?
*thinks*
Nope.
Eyes don't register UV (blue) - skin does.

 

[S.A.M.]

I saw it.
Is the skin not photosensitive?
Oh, you mean that skin may only take in the wavelengths that eyes do?
Does it?
*thinks*
Nope.
Eyes don't register UV (blue) - skin does.

uh-uh, its the chemicals that react to the wavelengths. e.g. you need a certain wavelength of light to produce vitamin D in your skin. But they can be blocked by certain other chemicals produced by the skin (like melanin, which is why darker sinned people need more exposure to produce same amount of vitamin D as light skinned people).

So relating it to the topic, does photosensitivity to light affect perception of time and space; do all species "see" the same universe?

 

[GhostofMaxwell.]

uh-uh, its the chemicals that react to the wavelengths. e.g. you need a certain wavelength of light to produce vitamin D in your skin. But they can be blocked by certain other chemicals produced by the skin (like melanin, which is why darker sinned people need more exposure to produce same amount of vitamin D as light skinned people).

Sidenote: Would preventing any exposure to sunlight cause a deficiency in vitD that can not be made up in any other way? Would zero skin exposure to the suns rays be detrimental to health in any other way?

 

[Oli]

uh-uh, its the chemicals that react to the wavelengths.

The uh-uh is "no skin is not photosensitive"?

e.g. you need a certain wavelength of light to produce vitamin D in your skin. But they can be blocked by certain other chemicals produced by the skin (like melanin, which is why darker sinned people need more exposure to produce same amount of vitamin D as light skinned people).

Relevance? (Keep the "icky bits down, Aashan Khaatir, - I dropped biology at 12 (good grief! forty years ago, now I feel old )).

So, okay, it's not the skin.
But does the retinohypothalamic tract only transmit wavelengths that the eye/ brain combination "sees"?
I.e. is it conducting the required blue light to the SCN even though that wavelength may not be registered as "visible" by the processing part?

You added some!

So relating it to the topic, does photosensitivity to light affect perception of time and space; do all species "see" the same universe?

Okay... what light that comes in (gets in) all comes from the sun (more or less), and the whatever frequencies are required are available (natural selection would, presumably do something nasty to something required red light to know the time and couldn't receive it in any way).
And the sun has the same rhythm for everything - i.e. mice, good ol' drosophila, men, elephants still get all their cues from the sun as it moves.
So how can they have a different time sense?
Yeah, different frequencies appear at different times of day (e.g. at noon there's less atmosphere filtering wavelengths out than there is in the morning or evening), but they still come in on the same cycle.
What am I missing?

 

[S.A.M.]

Sidenote: Would preventing any exposure to sunlight cause a deficiency in vitD that can not be made up in any other way? Would zero skin exposure to the suns rays be detrimental to health in any other way?

You could take it orally, though the metabolic consequences are not fully understood (prevents rickets though). Plus this is one of the chemicals we know is altered by photochemical reaction. Melatonin is another; there may be other chemicals that are unknown or not understood.

 

[S.A.M.]

Okay... what light that comes in (gets in) all comes from the sun (more or less), and the whatever frequencies are required are available (natural selection would, presumably do something nasty to something required red light to know the time and couldn't receive it in any way).
And the sun has the same rhythm for everything - i.e. mice, good ol' drosophila, men, elephants still get all their cues from the sun as it moves.
So how can they have a different time sense?
Yeah, different frequencies appear at different times of day (e.g. at noon there's less atmosphere filtering wavelengths out than there is in the morning or evening), but they still come in on the same cycle.
What am I missing?

Malish ya Ali, ana lissa mat khallas tafkeer.
(I arabised your name!!)

So everything is maintained in rhythm by the spectrum of light, and regardless of the perceptual acuity, it is used to maintain the circadian or seasonal rhythm. BUT, (and this is where you are losing me), is the perception of the environment the same? Is the perception of time and space the same?

 

[Oli]

Malish ya Ali, ana lissa mat khallas tafkeer.
(I arabised your name!!)

Saiyyadati min al-Yasmin Ibtasaamaat ilai, Jazakallah Khairan.
*Tabassum*
Now all I need is a translation - I'll work on it and PM you for one if I fail...

So everything is maintained in rhythm by the spectrum of light, and regardless of the perceptual acuity, it is used to maintain the circadian or seasonal rhythm. BUT, (and this is where you are losing me), is the perception of the environment the same? Is the perception of time and space the same?

The perception of time (if given solely by light - of whatever frequency) should be the same - because that light always varies on a 24-hour cycle, neh?
I tend to think that perception of time would vary more with animal size - heart rate, lifetime, (reflexes?) etc.
Space?
Is a metre any less (or more) than a metre if seen in IR or UV?
Environment:
Perception of texture would obviously vary (since reflections will vary with wavelength and small discontinuities not visible to us would be glaringly obvious in other frequencies).
Colour - again, not the same.
Some creatures/ plants have warning/ come-hither signs in frequencies humans can't see (plants especially have UV-visible patterns "for" bees).

Umm, bats/ owls supposedly (wildlife-documentary level understanding here) build up sonar pictures and use those - sound will reflect differently from different materials so colour is irrelevant, but a wood-echo is different from a grass one - do bats/ owls designate them brown and green?
And (for sound at least) the sizes (at certain frequencies) will "glossover" some objects, not enough discrimination at those frequencies to distinguish.
But light has a sufficiently small wavelength to pick up very small objects/ gaps that longer frequencies would miss.

Maybe if there was something that "saw" in, say, the 10-metre-wavelength radio frequencies then we'd be talking.
Dogs/ cats etc wouldn't be noticeable, humans neither, since to discriminate you need a minimum size of half a wavelength, IIRC.

But I don't see how space and time would/ could vary due to frequency of light.

 

[S.A.M.]

Hmm need to chew on the basics some more. Back to the drawing board. Thanks.

(PS you may get stuck at mat, if so try ma)

 

[Oli]

Hmm need to chew on the basics some more. Back to the drawing board. Thanks.

Anytime.

(PS you may get stuck at mat, if so try ma)

Bah, now you tell me!

 

[GhostofMaxwell.]

You could take it orally, though the metabolic consequences are not fully understood (prevents rickets though)..

So if one only lived in a windowless cell with no yard time, for instance. One would inevitably get rickets without supplementing dietry vitD with pill form vitD?