Which pairing of name and property of light is correct

It serves as a barrier between the inner eye and the outside world, and it is involved in focusing light waves that enter the eye. The pupil is the small opening in the eye through which light passes, and the size of the pupil can change as a function of light levels as well as emotional arousal.

When light levels are low, the pupil will become dilated, or expanded, to allow more light to enter the eye. When light levels are high, the pupil will constrict, or become smaller, to reduce the amount of light that enters the eye. Figure 2. The anatomy of the eye is illustrated in this diagram. After passing through the pupil, light crosses the lens , a curved, transparent structure that serves to provide additional focus.

The lens is attached to muscles that can change its shape to aid in focusing light that is reflected from near or far objects. In a normal-sighted individual, the lens will focus images perfectly on a small indentation in the back of the eye known as the fovea , which is part of the retina , the light-sensitive lining of the eye. The fovea contains densely packed specialized photoreceptor cells.

These photoreceptor cells, known as cones , are light-detecting cells. The cones are specialized types of photoreceptors that work best in bright light conditions. Cones are very sensitive to acute detail and provide tremendous spatial resolution. They also are directly involved in our ability to perceive color. While cones are concentrated in the fovea, where images tend to be focused, rods, another type of photoreceptor, are located throughout the remainder of the retina.

Rods are specialized photoreceptors that work well in low light conditions, and while they lack the spatial resolution and color function of the cones, they are involved in our vision in dimly lit environments as well as in our perception of movement on the periphery of our visual field. Figure 3. The two types of photoreceptors are shown in this image.

Rods are colored green and cones are blue. We have all experienced the different sensitivities of rods and cones when making the transition from a brightly lit environment to a dimly lit environment. Imagine going to see a blockbuster movie on a clear summer day. As you walk from the brightly lit lobby into the dark theater, you notice that you immediately have difficulty seeing much of anything.

After a few minutes, you begin to adjust to the darkness and can see the interior of the theater. In the bright environment, your vision was dominated primarily by cone activity. As you move to the dark environment, rod activity dominates, but there is a delay in transitioning between the phases. If your rods do not transform light into nerve impulses as easily and efficiently as they should, you will have difficulty seeing in dim light, a condition known as night blindness.

Rods and cones are connected via several interneurons to retinal ganglion cells. Axons from the retinal ganglion cells converge and exit through the back of the eye to form the optic nerve. The optic nerve carries visual information from the retina to the brain. There is a point in the visual field called the blind spot : Even when light from a small object is focused on the blind spot, we do not see it. We are not consciously aware of our blind spots for two reasons: First, each eye gets a slightly different view of the visual field; therefore, the blind spots do not overlap.

Second, our visual system fills in the blind spot so that although we cannot respond to visual information that occurs in that portion of the visual field, we are also not aware that information is missing. The optic nerve from each eye merges just below the brain at a point called the optic chiasm. As Figure 3 shows, the optic chiasm is an X-shaped structure that sits just below the cerebral cortex at the front of the brain.

At the point of the optic chiasm, information from the right visual field which comes from both eyes is sent to the left side of the brain, and information from the left visual field is sent to the right side of the brain. This illustration shows the optic chiasm at the front of the brain and the pathways to the occipital lobe at the back of the brain, where visual sensations are processed into meaningful perceptions.

Once inside the brain, visual information is sent via a number of structures to the occipital lobe at the back of the brain for processing. As mentioned above, light enters your eyes as a wave. It is important to understand some basic properties of waves to see how they impact what we see.

Two physical characteristics of a wave are amplitude and wavelength Figure 5. The entire range of possible types of light, from the longest wavelengths radio waves to the shortest wavelengths gamma rays is called the electromagnetic spectrum. You may have learned in another course that light is peculiar in that it can be described as we just did as being a wave, but in some experiments it behaves, and can be described more accurately, as a particle.

When we describe light as a particle, we'll refer to an individual "packet" of light as a photon. You can still refer to the wavelength and the frequency of that photon, even though you are considering it to be a particle rather than a wave. If you go back to the very first discussion at the beginning of this page, we talked about how waves transport energy. So, each photon of light does carry energy, and the amount of energy depends on the wavelength or frequency of that photon.

The equation is:. Before we discuss the entire electromagnetic spectrum in detail, we will next discuss how astronomers represent the range of light emitted by a source in a diagram or image called a spectrum. Skip to main content.

Figure 3. Study 2 shows that this is the case, as only one of the specificity pairings replicated. These results show how restraining the choice of colors to one color vs. We used the same analyses as in study 1 for consistency. We did not bootstrap our data in this study since the primary purposes was to show that effects which do emerge within the context of an experiment are typically experiment-specific, and not likely to replicate in another. Figure 3.

Frequency of selection of colors for emotion: study 2. Table 3. Raw mean intensity followed by SD of the top colors selected for study 2. Neither of these emotions were included in study 1. Of the four emotions for which we found consistent pairings in study 1 anger, envy, fear, happy , none of these replicated, although the top-indicated color e. To address the concerns that participants perceived the colors differently since they could use their own device despite our efforts to limit the survey to users of the iPhone and instruct participants to adjust their screen brightness , we compared the top-indicated color for each emotion from study 2 to the lab control.

For 13 of the 20 emotions, participants indicated the same top color for both studies. For the remaining seven emotions, what was the top color for study 2 was either second or third or vice versa in the lab control.

We interpret this to mean that participants did not perceive the colors on their devices differently despite their ability to complete the survey in any lightning conditions. The amount of small variability we found was still qualitatively less than between the main results of studies 1 and 2. We used the same analyses as in study 1 for specificity. Again, we did not bootstrap the data. As in study 1, we analyzed each color separately.

Nonetheless, agreement among raters in all conditions was low to moderate. Finally, to test our hypothesis Hypothesis 2 that the individual facets of color HSL would better predict the color-emotion pairings than the perceived color referred to by the color name , we ran a series of nominal categorical regressions. First, we ran a categorical regression using HSL combined as predictors with emotion as the target. Then we ran the same regression with color referred to by color name as the predictor.

Finally, we looked at how the model changed with HSL added in individually. This allowed us to get a sense of which facet predicted the most agreement. From this we could compare with previous studies that suggested lightness and saturation are mainly responsible for emotion-color pairings.

Although the model was significant, only hue was a significant predictor. These findings confirm our second hypothesis that individual facets of color, namely hue and saturation, predicted agreement of emotion assignment better than the perceived color. Unlike other previous studies e. An evolutionary approach to emotion is consistent with the idea that there should be specificity and consistency for color-emotion pairings.

Consistency suggests that an emotion is reliably paired with a color s. Specificity suggests that a color s is specific to an emotion. We performed two studies, in which English-speaking participants completed a similar online survey assessing their color-emotion pairing by selecting up to three colors for each emotion and indicating an intensity.

In study 2, we added more emotions and colors. We also conducted a laboratory control study in which new participants completed the survey under controlled lighting conditions and the color on the computer monitor was calibrated for each participant. In study 1, we found that only four emotions showed any evidence of color consistency, and only nine colors showed any evidence of emotion specificity.

When we resampled our data, however, there was no evidence that any of these effects would be retained. Bootstrapping revealed no evidence that this would replicate with statistical certainty, consistent with our hypothesis that individual color-emotion pairings are due to the experimental context and not universal or stable across participants and formats. To this end, the standard error from resampling is a much better estimate of the standard deviation. The results are comparable to performing the experiment hundreds of thousands of times on the same participants.

In study 2, we found only two emotions that showed any evidence of color consistency, and only three colors that showed any evidence of emotion specificity. We also confirmed that participants' judgments are not influenced by perceiving the colors differently based on the device on which they take the survey, since the top-indicated color was the same across the majority of emotions between the laboratory control study and the results reported herein.

One reason is that previous investigations often severely limit the range of answer choices which imposes consistency and erroneously is used as an indication of the existence of a diagnostic signal for more on this, see Barrett, a , b. Said another way, the context created by the study can inflate agreement. Another reason is that our folk psychology—that which comes from our culture and is reinforced by our culture i. Metaphors not only communicate abstract concepts, but they might also be necessary for grounding them as well Gibbs, ; Lakoff and Johnson, ; Lakens et al.

This is true of emotion, too e. According to The Theory of Constructed Emotion Barrett, , as a child learns more emotion words, s he becomes better at perceiving emotion and shows more granular categories. In this view, emotion is no different from other abstract categories which are learned during development. Emotion words help to create discrete emotion categories because they help to activate situated conceptualizations which might increase the processing of sensory information that is consistent with such conceptualizations Barrett, a , b ; Wilson-Mendenhall et al.

We believe this to be similar for color language. For example, when people are asked to think about color-emotion pairings, they reference language. For instance, a person might reference linguistic phrases and metaphors that help clarify what color anger should be e.

Admittedly, the purpose of this paper was not to test the reasons behind any potential pairings, as much as it was to see whether such pairings exist and whether colors are specific to emotions. Future research should indeed further explore the reasons behind beliefs in color-emotion associations as well as explore differences in color-emotion agreement cross-culturally.

Although study 2 addressed several limitations of study 1, there remain several possible influences on color-emotion pairings which we could not or did not control.

For example, even though we included more colors and more emotions in study 2, there are over 1, notations listed in the Munsell book of colors. While there are some shortcomings to this research, we believe that the strengths lie in deriving our hypotheses with respect to emotion theory which we statistically test. In addition, we present our colors as swatches rather than color words paying attention to HSL , and allow participants to indicate a strength of agreement for up to three colors for each emotion.

JF was involved in all aspects of the research. CF helped disseminate the survey, reviewed the literature, prepared data for analysis, analyzed data, and aided in figure preparation. She was also responsible for most aspects of study 2.

Both authors approved the final revised manuscript for submission. The authors declare no conflicts of interest. Portions of this data were presented at the Psychonomics conference in and at the American Psychological Association conference in The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.

We would like to thank A. Scott McCauley, who helped develop the survey. We would also like to thank, Tuan Le Mau, who performed the bootstrapping analyses in Python.

Hanada, , p. He proposed that there are eight primary emotions consisting of four pairs of opposite emotions joy—sadness, trust—disgust, fear—anger, surprise—anticipate like complementary colors.

Other emotions are mixtures of primary emotions, like other colors are mixtures of primary colors. Although he implied similarities between the color and emotion circle, he did not seem to argue that his emotion circle matched the color circle cf. Interestingly, although commonly referred to in the media and popular psychology, there is little to no evidence that his color-emotion pairings were ever empirically tested or supported.

Accordingly, color-related terms, including basic colors within a language, are likely to play a role on how we both perceive and link color with emotion. For example, English has many color-emotion phrases which might influence color-emotion pairings e. A pantone huey MEU monitor calibration device colorimeter was used to calibrate the computer screen prior to each participant. All participants completed the survey in a dark room. The fraction of the difference pairs greater than zero is the desired probability.

In this case, probabilities smaller than 0. Adams, F. A cross-cultural study of the affective meanings of color. Cross Cult. Bargh, J. Goal and intent: Goal-directed thought and behavior are often unintentional. Barrett, L. Are emotions natural kinds? Solving the emotion paradox: categorization and the experience of emotion. Was Darwin wrong about emotional expressions?

Emotions are real. Emotion 12, — The theory of constructed emotion: An active inference account of interoception and categorization. Language as context for the perception of emotion. Trends Cogn.

Boyatzis, C. Children's emotional associations with colors. Brosch, T. The perception and categorisation of emotional stimuli: a review. Emotion 24, — Byrne, A. Color realism and color science. Brain Sci. Centore, P. An open-source inversion algorithm for the Munsell notation. Color Res.

Once in motion, the electric and magnetic fields created by a charged particle are self-perpetuating—time-dependent changes in one field electric or magnetic produce the other. This means that an electric field that oscillates as a function of time will produce a magnetic field, and a magnetic field that changes as a function of time will produce an electric field.

Both electric and magnetic fields in an electromagnetic wave will fluctuate in time, one causing the other to change. Electromagnetic waves are ubiquitous in nature i. These and many more such devices use electromagnetic waves to transmit data and signals. All the above sources of electromagnetic waves use the simple principle of moving charge, which can be easily modeled. Placing a coin in contact with both terminals of a 9-volt battery produces electromagnetic waves that can be detected by bringing the antenna of a radio tuned to a static-producing station within a few inches of the point of contact.

Electromagnetic waves have energy and momentum that are both associated with their wavelength and frequency. Electromagnetic radiation can essentially be described as photon streams. These photons are strictly defined as massless, but have both energy and surprisingly, given their lack of mass, momentum, which can be calculated from their wave properties. Waves were poorly understood until the s, when Max Planck and Albert Einstein developed modern corrections to classical theory.

In other words, there were only certain energies an electromagnetic wave could have. Momentum is classically defined as the product of mass and velocity and thus would intuitively seem irrelevant to a discussion of electromagnetic radiation, which is both massless and composed of waves. However, Einstein proved that light can act as particles in some circumstances, and that a wave-particle duality exists.

And indeed, Einstein proved that the momentum p of a photon is the ratio of its energy to the speed of light. The speed of light in a vacuum is one of the most fundamental constant in physics, playing a pivotal role in modern physics. The speed of light is generally a point of comparison to express that something is fast.

But what exactly is the speed of light? Light Going from Earth to the Moon : A beam of light is depicted travelling between the Earth and the Moon in the time it takes a light pulse to move between them: 1.

The relative sizes and separation of the Earth—Moon system are shown to scale. It is just that: the speed of a photon or light particle. The speed of light in a vacuum commonly written as c is ,, meters per second.

This is a universal physical constant used in many areas of physics. For example, you might be familiar with the equation:. This is known as the mass-energy equivalence, and it uses the speed of light to interrelate space and time. This not only explains the energy a body of mass contains, but also explains the hindrance mass has on speed.

There are many uses for the speed of light in a vacuum, such as in special relativity, which says that c is the natural speed limit and nothing can move faster than it. However, we know from our understanding of physics and previous atoms that the speed at which something travels also depends on the medium through which it is traveling.

The speed at which light propagates through transparent materials air, glass, etc. The refractive index of air is about 1.