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Questions tagged [perception]

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Perception of time [duplicate]

A video I came across in youtube recently had mentioned how Einstein perceived time. It said he thought of all moments, the present, past and future to exist together and how it is not like one ...
3
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3answers
761 views

Why do we perceive time?

Since everything (at least what we observe) is travelling through the time in the same direction and speed why do we even perceive the time? Of course, there is the time dilatation, but it is ...
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0answers
171 views

Building the Penrose Unilluminable Room [closed]

As an architect with an interest in the natural sciences I was intrigued when I first learned of the illumination problem and its proposed solutions, specifically the one proposed by Roger Penrose in ...
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0answers
22 views

Visualizing higher dimension [duplicate]

Why can't we visualize Higher dimensions greater than 3? Is it just because the dimensions doesn't exist (Certainly I know that space-time is four dimensional) or any other physical reasons.
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3answers
106 views

What had Feynman meant when he told nobody understands Quantum mechanics? What do we mean by understanding Quantum mechanics?

What had Feynman meant when he told nobody understands Quantum mechanics? What do we mean by understanding Quantum mechanics?
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2answers
58 views

Why do we see things upside-down when we’re upside-down but not a camera?

If I do a handstand, everything looks upside down (which is originally what we see if we’re upright but the brain switches this). I assume this is because the change in how light rays enter our eye. ...
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3answers
67 views

Virtual images - Work of a brain or work of a lens?

I am just a high school student trying to self study, so please excuse me if this question sounds silly to you. Many people tell me that virtual images are formed when two rays that are diverging ...
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2answers
171 views

Human perception of temperature

I had the following thought experiment recently: Suppose we have a vibrating plate for which we can tune the amplitude and frequency of vibration, and imagine we hold a finger against the plate. For ...
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0answers
26 views

The rise of BCI

If EEG and MEG are measuring different aspects of neural oscillations, why can't we measure the combined signals as a whole, when we are doing the same for higher frequencies? Why did the us navy ...
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1answer
99 views

Why hot soup is tastier than cold soup? [closed]

My physics teacher recently asked me this question. Can anyone answer the question?
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1answer
92 views

What is this optical illusion in which airplane propellers appear to rotate backwards? How is it explained? [duplicate]

This airplane's propellers are both rotating anti-clockwise. But as you see, they are seem like rotating clockwise seen from front (nose) side. This phenomenon is known as optical illusion. My ...
0
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1answer
62 views

Does intuition really matter in the beginning of any new physics course? [closed]

Encountering some new courses like quantum mechanics, theoretical solid state physics and some other courses made me feel dumber than I ever felt.  Basically, I'm that kind of students who hate to ...
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1answer
21 views

Feeling sound; frequency and volume

How loud and "low" must a sound be in order for one to feel some physical sensation in response? I've read that below certain frequencies humans can be expected to "feel" sounds in their chests, and I ...
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1answer
33 views

How do we hear harmonics and how does it affect audio fidelity?

First and foremost, do we hear a sound wave as a sum of all the individual harmonics, at the fundamental frequency, or do we hear all the associated harmonics above the fundamental frequency and ...
0
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1answer
235 views

Why don't we see inverted image while wearing spectacles? [closed]

We know that the lens in our eyes forms an inverted image on retina and brain reverses it to give the correct image. But when one wears specs the image would get reversed twice so we should see things ...
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5answers
7k views

Why can we distinguish different pitches in a chord but not different hues of light?

In music, when two or more pitches are played together at the same time, they form a chord. If each pitch has a corresponding wave frequency (a pure, or fundamental, tone), the pitches played together ...
2
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1answer
141 views

How does the Many-Worlds Interpretation of Quantum Physics relate to Consciousness? [closed]

According to the Many-Worlds Interpretation of Quantum Mechanics, each quantum event causes the world to "branch" into a superposition of outcomes. How come "my" consciousness only chooses one of ...
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2answers
140 views

Why does physics “make sense”? [closed]

I was wondering if anybody had an explanation for why physics makes so much sense to us humans. In physics, many concepts just seem to make sense to me, but I cannot explain why. You may say that this ...
1
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2answers
175 views

How many eyes are needed to see a four-dimensional world? [closed]

If a four-dimensional world were to exist, how many eyes would a creature minimally need to see it (in three dimensions)? Three? Four? (Bonus question: how should these eyes be spatially configured?)...
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1answer
40 views

EM spectrum and sense of sight

If we cant see all the spectrum does this mean that maybe exist objects we cant perceive? or it just the colors we cant perceive?
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2answers
51 views

Perception of curvature of human eye [closed]

How are human eyes able to detect the different curvatures of surface ? Basically how are the human eyes able to differentiate between a plane surface and a convex or a concave surface?
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6answers
9k views

How does light combine to make new colours?

In computer science, we reference colours using the RGB system and TVs have pixels which consist of groups of red, green and blue lines which turn on and off to create colours. But how does this work?...
3
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2answers
288 views

Why might Roger Penrose argue that Godel's incompleteness theorem(s) suggest that consciousness is non-algorithmic?

This past March, when I called Penrose in Oxford, he explained that his interest in consciousness goes back to his discovery of Gödel’s incompleteness theorem while he was a graduate student at ...
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1answer
63 views

Why can't our cognitive sense or five senses sense or fathom hyper-dimensional spaces? [duplicate]

Why can't our cognitive sense or five senses sense hyper-dimensional spaces? Is it because of the way our human body is built?
2
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1answer
127 views

Why do I see discrete images when moving an object in front of a screen? [closed]

I observed this while doing my homework. I have a habit of shaking my pen between my fingers vigorously while thinking something. My PC's screen is right in front of me (on my study table itself). ...
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2answers
82 views

Tiny blue and red paint close to each other result in black or magenta? [closed]

Now, if I draw two tiny spots with red and blue paint on paper and they are so close (but they do not cover each other) to each other that human eyes cannot identify there are two spots. To the color ...
1
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1answer
133 views

How is the subjective loudness of sound computed?

The intensity of a sound is a measure of the energy that the sound waves carries through space per unit time per unit area (since energy is conserved along the wave unless work is done on/by it and ...
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1answer
79 views

Why are the active noise cancellation headphones subjectively better in reducing “periodic” noise?

According to experience of mine and of my friends using active noise cancellation headphones, the technology is much more efficient in reducing "periodic" noise, such as humming of jet engine, fridge ...
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1answer
63 views

Why we see a static picture of the sea when we are traveling by plane?

This question may look stupid but it's something that came to my mind months ago when I was on a plane. When one looks through the window on a plane, there are light and dark parts of the ocean (it's ...
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0answers
32 views

How can we determine time flows in one direction? [duplicate]

Suppose that time could flow in either direction, forward or reverse, similar to a movie. How could our brain possibly record that time had moved backwards? Would there be any way to tell if time had ...
3
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1answer
510 views

Do we hear anything special when the beat frequency is in audible range, but the sounds producing the beats are not? [duplicate]

When the beat frequency is very low, we hear periodic maxima and minima. Our ear cannot perceive a on-off like sound when its frequency is more than 10 Hz. So, beat frequency in audible range will not ...
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0answers
53 views

What causes observed color differences in white LED's for near and far fields?

While running towards traffic early morning before sunrise I recently noticed that the new automobile LED (white) lights when viewed at a distance appear blueish, but when the light is viewed much ...
5
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1answer
212 views

Why do we experience a slice of time, but not a slice of space? [closed]

I (and every one I guess) perceive space as an extended region where things happen. In contrast, time is perceived as a lucky of slice. Also in space I can choose in which direction I want to move, ...
2
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1answer
82 views

Why doesn't the brain flip retinal image horizontally as well?

I was reading about the Camera Obscura and the physics of apertures, and I read that "The camera obscura produces a flipped (horizontally) image as well as an inverted (vertically) one." I understand ...
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3answers
97 views

What is Fourth Dimension?

Before people get pissed at me for asking a question that has likely been asked more than a few times, I just want to know a simple answer, if first dimension is that an object exists, (collision) ...
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2answers
76 views

Defocusing the eye and computer monitors

Im not sure whether this is the right site to post this on, but here goes : We are often told to relax our eyes when using computer/tv screens for extended periods of time. I often find that I forget ...
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2answers
131 views

How to define white color scientifically? [duplicate]

I'm sorry some of you may mark this question as duplicate, but even though I searched over about this I couldn't get satisfacory answer. Also I think this question is more related to biology, but I ...
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2answers
442 views

Why does the moon appear fairly flat to a naked eye?

When I look at the regular ball picture the "edges" appear somewhat darker. Here's a random image I just found on image search :) Image source and that's how I can tell it's "round". Or so I assume. ...
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1answer
107 views

Is visible light really visible? [closed]

As we know, colors only exist in the brain. How can we see light if it has no color? Our eyes detect light, but seeing occurs in the visual cortex. Is visible light really visible?
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1answer
70 views

What limits the electromagnetic radiation we can see? wavelength or frequency?

Can we only see electromagnetic radiation that has certain range of frequencies and a certain range of wavelengths?
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3answers
116 views

Travelling at a speed faster than light [closed]

Imagine yourself to be bat. You cant see anything. You don't have eyes. All you can do is echolocate, using ultrasound. Now imagine something is moving away from you faster than the speed of sound. ...
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3answers
302 views

How does the human ear guess the source of the sound?

Suppose a sound is produced behind you. You can easily tell that the sound came from behind. Our ear lobes face towards the front and hence traps the sound waves which come from the front. Yet, we ...
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2answers
50 views

If someone were to put really small objects 10x spaced on a background, would they see the objects or the background?

If someone were to put a sheet full of 1 micron x 1 micron black squares as a grid on a white piece of paper, and spaced them 10 microns apart (up-down, left-right, obviously diagonal doesn't count), ...
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3answers
4k views

Why does the Sun appear larger during the sunrise and sunset?

Why does the Sun appear larger during sunrise and sunset compared to its size during midday even though its distance from the Earth remains fixed all the day? It is only during the Winter when the Sun ...
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1answer
568 views

Is a human thought merely energy that is changed from one form to another? [closed]

Einstein: "Energy cannot be created or destroyed, it can only be changed from one form to another." Is a human thought merely energy that is changed from one form to another?
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1answer
169 views

Why do objects that are further away seem closer? [closed]

I am outside and am walking to my house from my car that is across the street. I get in my house and look out the window and my car seems like its right in front of my window. Why is that?
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1answer
137 views

If our eye lens and cornea were flat would we still receive the world upside down?

Usually the effect of a pinhole (or camera obscura) and the lens of our eyes are creating the world upside down on our retina. Now imagine the lens and cornea would be flat is the pinhole effect ...
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3answers
98 views

Can light be stopped after being perceived?

Please note the following sentence before you answer the question: you may assume the light itself is not affected by the observer perceiving the light. Imagine the following schematic: A = Source B ...
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4answers
13k views

Why does a yellow object turn white under a yellow light? Shouldn't it turn yellow instead?

Recently I was eating a yellow rice for lunch in a restaurant with only yellow lights. But the rice looked white! I was intrigued by this because I always thought it should look yellow since the ...
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0answers
26 views

Inverting Horizon?

everyone knows that looking at the horizon at something going far away, the last thing you see from it is its top, but what if you had a ground going up very very very slightly and something moves ...