Questions tagged [perception]
The perception tag has no usage guidance.
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Why does pouring water have a slightly different color when viewed from above?
I have noticed when I view a hose pouring water the color of water slightly changes when looking from above compared to when looking from the front.
Also, the same thing applies when you pour water ...
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How do our eyes perceive a parallel beam?
So if our eye is considered a lens, a parallel beam (sort of like collimated light from a flash light) should converge to a single point, the focal point. So does that mean our eye will see a finite ...
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Is it possible to design a wheel without the wagon-wheel effect?
Wagon-wheel effect is a well-known optical illusion due to the persistence of vision. It happens when the spoke of a wheel rotates to a certain position after the duration of persistent vision. ...
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Does intense, cyclically-pulsed light appear brighter than its average?
Background
The Wikipedia article on the Talbot-Plateau law mentions:
If a light flickers so rapidly that it appears as continuous, then its perceived brightness will be determined by the relative ...
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Do vibrational frequencies produced from sound pass through your entire body? from one side to another? [closed]
when there is a noise by me, i feel the vibration on my skin from the direction it’s coming, it moves into my body. a wall of what sound would feel like passing through me. i perceive it as container ...
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Fermi calculation to show that all crowds sound the same?
I live in an arabic speaking country, and while I was sitting in a food court today, I noticed that the sound of the crowd was the same as the one I see in the stereotypical sound of the crowd. I have ...
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Is this statement accurate: We are 4D beings (l,w,d,t) with the ability to visualize in 3D (using our brain) and see in 2D (using our retinas)? [closed]
I've read conflicting information on us being 4D beings (length, width, depth, time) and in what dimension we are able to see. Interested to hear your thoughts, especially if you provide sources.
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Finding the solid angle of a beach ball
Suppose I have a beach ball whose radius is 0.5m, and the distance between myself and the center of the beach ball is 10m. How do I go about setting up a diagram for finding the solid angle of the ...
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Is color perception linear? [duplicate]
I'm learning about the trichromatic theory of color perception. Say a receptor detects a wavelength $\lambda\in\mathbb{R}$ and responds with $f(\lambda) = (r,g,b) \in \mathbb{R}^3$. This system is ...
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Choice and Energy [closed]
Does the action of making a choice expend energy?
If any conscious choice is predetermined, it must always be taken towards a greater entropy state, which means it must somehow "know" ahead ...
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Is there any proof we all see same? [closed]
Today me and my friend was sitting. He was wearing sunglasses (different from the normal specs). Then a think came in my mind that after wearing the sunglasses we see different colour for a same thing....
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How does the human eye form an image of a certain size at a certain distance?
In looking at how geometric optics works and how an eye rebuilds an image of a certain size at a certain distance, some questions came to me:
Let's take a look at the first picture for example; the ...
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Are human eyes interferometers?
It seems like 2 eyes is enough “wetware” to do interferometry inside brain. Can you definitely see some reason why this could not be happening, or some way to test if it does happen?
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Is timbre a physical noumenon or a perceptual phenomenon? [closed]
I have a question relating the "timbre" of a sound, namely what is exactly and exhaustively defined by this word? Most definitions that I come across seem somewhat loose as "the color ...
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Does the perceived curvature of the earth's horizon subjectively underestimate the vastness of earth's actual curvature? [closed]
When one is standing on a beach and looks out onto the horizon, including peripherally and/or turning one's head from side to side, the horizon certainly appears curved to me. And yet the sheer size ...
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Can humans feel artificial light? [closed]
I know humans can feel sunlight - even blindfolded, it's easy to tell if one is in the noon sun or indoors. However, I don't know about artificial light. Can humans feel sufficiently harsh artificial ...
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Are radiance and luminance really independent of distance to observer?
Recently, I learned that apparently both radiance and luminance are independent of the distance between the light emitting object and the observer.
The reasoning was that although the radiant/...
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How does curvature of our eye affect our perception of the world? [closed]
The front part of the eye which can allow light to enter is a bit curved, so shouldn't this cause us to see a curved distorted version of reality when it is really not there? Is there any way to ...
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Can we tell on which side of a lens an image appears?
Suppose I look through a single, thin, converging lens at an object on the opposite side. Depending on where the object is placed, the lens will either produce a real image on the side of the lens ...
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Theory for the relative scale of objects?
I've been pondering what Prof. Brian Cox said in an interview (still searching for it) where he said something along the lines of: we (human beings) are very small relative to the earth, universe. I'...
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Why can we hear instruments but not voices?
I've seen this graph:
But I don't get something. Consider the 2kHz line (highlighted in red).
This graph implies we can hear an orchestral instrument at 2kHz before we can hear a human at the same ...
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Blinking LED and the human eye/perception
When an LED is flashing at 2 times a second, the human eye can perceive the ON and OFF state. We can clearly see when the ON state is and when the OFF state is.
When it is flashing 10,000 times per ...
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Does sound travel through FINGERS?
as we know that sound's speed is fastest in solid (and slowest in air).
QUESTION - what is the reason when we close our ears and don't really hear loud noises though sound travels faster in solids?
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Black body radiation: why can it glow yellow?
With black body radiation, light of different wavelengths are emitted in various proportions depending on the temperature of the emitter.
Graphs of spectral radiance vs wavelength for different colour ...
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Are we misunderstanding time? [closed]
I think time is a constantly and uniformly flowing thing made by us to compare and relate different events with each other by it. It help us to predict things at different points in this flow. It ...
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Why objects dont appear closer and smaller to a myopic person and far and larger to hypermetropic person after wearing spects?
I am a myopic person, and wear a concave lens. It is taught to us that lens I wear help to form image on my far point and thus help me to see far object.
1.But we have also learn that concave lens ...
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Can Consciousness be Understood as an Emergent Phenomenon of the Evolution of the Human Brain? [closed]
Straight question - is explaining (or at least understanding) consciousness in the realm of physics?
Detailed question:
We know that consciousness exists. Or rather, I know that I have it. The rest of ...
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Are there an infinite or finite number of colors (can we see infinity?) [closed]
Take any blue or red, mix in equal parts and you have purple. Now mix 50 units of red and add 25 units of blue for another purple, then 50 units of red and 12.5 units of blue for yet another purple ...
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Quantum Brain Dynamics (QBD)
I found an article that broach this matter, I wanted to know if this Quantum Brain Dynamics (QBD) is treated in the scientific environment with such seriousness or is it some kind of unfounded ...
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Is there a relationship between quantum physics and chaos theory on a classical scale?
Im a complete physics lay person and I read somewhere that chaotic systems are subject to tiny differences in initial conditions and that the brain is a chaotic system.
Does that mean our thoughts are ...
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Why do I keep forgetting the physics I've learned? [closed]
I've taken quite a few physics classes over the years and I read about physics when I can. However, I always forget what I've learned. When someone talks about a concept, until I go review briefly ...
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Does brain activity generate anything outside our bodies? [closed]
I have been reading recently about the Law of Attraction and while I don't believe in its 'scientifical' basis it did make me think about whether our brain produces any kind of activity strictly ...
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Perception of simultaneous events
I have a two-fold question about the light-cone structure of spacetime, specifically about space-like separated events.
As far as I understand it, any two events that happen at the same time in a ...
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Spacetime distances and perception
My question is about how things appear in human perception vs how things are in spacetime.
Take as an example my perception of the laptop screen while I am writing this.
As far as I understand it, ...
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Why does an audio signal sound differently if we randomly flip gradients between each adjacent pair of samples?
Let's assume the samples of our audio signal are always in the interval [-1,+1]. When flipping all the samples (multiplying them by -1), listening to the sound ...
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Resources on understanding the Orchestrated objective reduction
I was trying to understand the mathematics behind the theory of Orchestrated objective reduction, and clearly, first I read the original paper of Penrose & Hameroff. Then I tried some other ...
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How can we discern so many different simultaneous sounds, when we can only hear one frequency at a time?
As I understand it, the eardrum works like any other kind of speaker in that it has a diaphragm which vibrates to encode incoming motion into something the inner ear translate to sound. It's just a ...
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Why doesn't ice in a glacier feel as cold when I touch it as the ice I get from my freezer?
When I was in Iceland, I went to a tour in a glacier and I remember the ice that was there. It looked and felt like a huge amorphous block of glass: hard, smooth, not wet, and not that cold.
Not as ...
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Why don't we perceive high pressure and low pressure areas as distinct in a sound wave?
I was watching this video when I came upon this question: wether it be high frequency or low frequency, sound waves are made of high pressure and low pressure areas (they are waves, after all).
I mean:...
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Is the Big Bang occurring or did it already occur (a question about time) [duplicate]
I understand how time (space/time) is perceived according to the theories of relativity, but I still don’t understand:
Did the Big Bang occur 13.8 billion years ago or is it occurring relative to us ...
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Why can't the human eye focus to make blurry photos/video clear?
The human eye focuses by flexing the lens, changing its focal length. When we switch from looking at a near object to a far object, our lens flexes, moving the focal length such that the near object ...
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Why does the brain interpret light from a mirror the way it does? [closed]
When we place an object above mirror and viewed from side, we see the image to be below the object, as if the reflected light is coming from inside the mirror.
From the image above, the light from top ...
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Is the ear really phase insensitive?
If the ear is phase insensitive (Ohm’s Law of acoustics), and you listen on headphones, how can the brain hear a phase inversion on one channel of a stereo signal?
I play bass guitar and practice on ...
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How we feel (perceive) exact size of object through our eyes?
Light after getting reflected from objects gets focused on retina by our lens. The images formed on retina is small, which is then sensed by our brain and depending on distance we feel size of that ...
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Would a navigator announcing ship velocity whle approaching lightspeed make linear announcements?
Given my admittedly limited understanding of relativity, I believe that as a hypothetical space ship approaches the speed of light at a constant acceleration, what the crew would "see" on ...
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About parallel and intersecting timelike worldlines
Suppose that two straight timelike worldlines are (not) parallel with respect to some frame $S$. Will these worldlines remain (not) parallel with respect to any other system $S^{\prime}$ related to $S$...
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Does the vanishing point of linear perspective occur when there's a 1-to-1 matching between the lights in the source, and the sensors of the observer?
Imagine we have a panel of lasers in a truly dark vacuum, together with a panel of sensors, facing each other, some distance apart.
Further, imagine that the number of lasers within the light-panel is ...
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Why we only see black colour when there is no light? [closed]
pls help me on it. I do not know if it is right but why do we only see black colour while there is no light.
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Third Eye and how the brain would see the world [closed]
Let's suppose that through engineering, a third bionic eye would be attached to a human and interfaced directly with the brain. Let's assume this third eye is positioned in the middle of the forehead.
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How can we see objects with the help of light if we cannot see atoms?
We know that the objects are made up of atoms. We also know that we cannot see atoms with the help of light as the wavelength of light is too big in comparison to atom. So, my question is then: how ...
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