# Tag Info

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When Did Humans First Observe a Lens in an Eye? People probably realized that the eye contained a lens (at least the eye of a fish) as soon as they began fishing for dinner. So, sadly the discovery of the hard lump that is a fish lens was probably prehistoric. Here is a picture of a fish lens from an Instructable on fish dissection. http://www....

9

As per your comment: Were there any other theories challenging them in the past? This topic was briefly discussed on Neil deGrasse Tyson's reincarnation of the TV show Cosmos. While I obviously can't insert the episode here (and can't recall which one it was, anyway), I can explain the basic premises of the early alternate theories, from other sources. ...

9

Young's original setup demonstrating interference of light was not double slit but sunbeam splitting with a single thin card. He presented a paper On the theory of Light and Color to the Royal Society in May 1801 published Proceedings of the Royal Society of London A 92 (1802) (see here and here), and in November 1803 gave a public talk Experimental ...

9

Probably the Swiss physician Felix Platter (1536 – 1614) that - according to Olivier Darrigol's A history of optics : From Greek antiquity to the nineteenth century, Oxford University Press (2012), page 23 - in his : anatomic treatise of 1583 made the retina the sensor of the visual species, and the crystalline humor a magnifying glass (perspicillum). [......

7

I’d say that F. Jentzsch (1925, p. 863) gives just the concise summary you want (emphasis added): Secondly, one had to understand and sufficiently clarify certain general properties of optical systems, such as the concepts of focal distance, focal points, principal points, magnification, etc. This was provided by Gauss. He was the first to bring his ...

7

There can be no doubt that he has seen them, for the simple reason that he determined their periods and configuration correctly, and published them. Therefore the other things (magnification of his telescope, light pollution etc.) are irrelevant for the answer. You can easily see them yourself using an 8x binocular.

7

It is more accurate to say that Hamilton anticipated some of the ideas of mathematics and heuristics of quantum mechanics, that would later inspire Schrödinger to produce his formulation of wave mechanics. The reason he was able to anticipate those ideas is that the quantum wave-particle duality had a classical predecessor, the optico-mechanical analogy. ...

7

Here's a very early bit of research. While it identifies the lens as critical to vision, it doesn't seem to recognize the lens as a focussing device From some classroom notes In the second century A. D., Galen had at least two different theories of the eye to choose from. He chose the extramission theory because it corresponded well with his image ...

6

There are no published papers where such interpretation is explicitly made. Born's Nobel lecture mention first appears in his celebrated Quantenmechanik der Stossvorgange (1926, Zeitschrift fur Physik 38, 803-827), also with no reference. According to Pais, well-known Einstein's biographer, the inspiration came from Einstein's never published remarks about ...

6

To the contrary, Young's point was to disprove the then dominant Newton's corpuscular theory of light by demonstrating light's wave properties, see How did Young perform his double slit experiment? The first "quantum" version of the experiment, with emission-absorption events creating a dotted pattern on the back screen, was performed by Taylor in 1909, ...

5

I'm finding information that attributes this to Sir Humphrey Lloyd, who looked into it at the beckoning of none other than Sir William Rowan Hamilton. From the Encyclopedia Britannica: In applying his methods in 1832 to the study of the propagation of light in anisotropic media, in which the speed of light is dependent on the direction and polarization ...

4

In 1825, Gauss introduced the coefficient of refraction k, which represents a way to quantify terrestrial refraction. He defined it as the ratio of the radius of the earth R and radius of curvature r of light ray (the line of sight). He found, on the basis of reciprocal vertical angle measurements near hannover, an average value of 0.13 for this coefficient....

4

Are you sure he did not try? Have you read Huygens? His contemporary Newton did try to explain it in his Optics. Anyway, if Huygens never addressed this question, it is hard to tell why. But it is easier to explain why it took 120 years before the correct explanation was given. The reason is that the wave theory was not popular until the end of 18th ...

4

I am sure that there are some good and fairly complete histories of the thinking over time of what light is, and specifically the colors. The following site is a simple and quick summary of the highlights: http://photonterrace.net/en/photon/history/ It goes from Aristotle (white and black combinations for the colors), to Newton identifying refraction and ...

4

Contribution of Newton to optics is enormous. He is considered a founding father of physical optics. I can only give some examples. His main discovery was that the sunlight can be dissolved into colors (spectrum). The discovery which lead to spectroscopy, and eventually to quantum mechanics. He also analysed what is called "Newton rings" (discovered by Hooke ...

3

There was no need to measure the intensity directly to determine that the photoeffect is independent of it. One could vary intensity by moving the metal plate closer to or further away from the source. How intensity falls with the distance is well-known. This is what Lenard did in his 1902 experiments that prompted Einstein's 1905 work. If there was a need ...

3

Because he did not think of wave fronts as "fronts of amplitudes" that can go both ways, and cancel each other when superimposed. Sometimes it is hard to imagine how simple ideas could be missed in retrospect, but perhaps they are "simple" to us only because we already know to pay attention. Huygens thought from what later came to be called the optico-...

3

My preliminary research starts with the dating of the first scientific studies of air pollution in general. I first cite some dates in a work by E.C. Halliday titled and sourced: A Historical Review of Atmospheric Pollution - Halliday (1961). In this paper, Halliday notes that, while pollution was known to be a social problem starting in the 14th century, ".....

2

The same Wikipedia article only mentions that he "attended school" for a short time. After that he became a bookkeeper's apprentice. So he probably learned some mathematics at school and as a bookkeeper's apprentice. Then we learn that he was appointed a land surveyor, which certainly requires more mathematics. This implies that he learned somehow the ...

2

"Optical illusion" is a phrase combining two separate words. Each was already a word in English, adapted (directly or indirectly) from respective Latin and Greek sources. Combining two English words to coin an English phrase is not at all controversial.

2

University of Michigan Physics Department -Nonlinear Optics 50th Anniversary Symposium was held on Octber 26, 2011. Peter Franken had focused a ruby laser on a quartz crystal in 1961. This was the first case of second harmonic generation in the optical regime, a material response to high intensity light. However, important nonlinear effects had been ...

2

It depends on what counts as "discovery". Interestingly, optical anisotropy was discovered before the elastic one, and the first anisotropic "material" modeled was... the luminiferous ether. Bartholinus discovered double refraction in calc-spar, a type of calcite, back in 1669, and Huygens showed in 1690 that two rays arising from refraction by calcite are ...

1

Consider one description of Newton's theories: (reference: Newton, I., Philosophical Transactions of the Royal Society 1672, 80, 3075–3087.) Newton introduced the term ‘colour spectrum’ and although the spectrum appears continuous, with no distinct boundaries between the colours, he chose to divide it into seven: red, orange, yellow, green, blue, ...

1

According to this lecture, Newton did measure $n_{air}$ compared with vacuum, tho' they give no details. Perhaps the original source, "Newton, Opticks, The Fourth edition, Ed. W. Innys, London, 1730," provides more details. It's available at Gutenberg.org . Peeking at Newton's book, I find The Refraction of the Air in this Table is determin'd by that ...

1

In geodesy, one usually looks horizontally, or almost horizontally, so the ray travels in the same layer of the atmosphere, where the temperature and pressure are almost constant, thus refraction is negligible. Sun only serves as the source of light in this case, so the refraction of the ray coming from the Sun to the devise does not matter. Refraction is ...

1

Here are some Roman Denari. Moon and stars. Looks like points on the stars.

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What Hamilton discovered is a mathematical "Hamiltonian formalism". It was applied to those parts of physics which were known at the time of Hamilton: classical mechanics and optics. There was no slightest reasons at the time of Hamilton to suspect that matter on small scale does not obey the laws of classical mechanics. That this is so, is a late 19s ...

1

We see objects because objects emit their own light. How? The electrons which orbit inside the atoms which comprise the object interact with ambient light radiation. This causes the electrons to switch to higher orbits. Then, inexplicably, the electrons return to their original orbit, and in that process emit photons which our eyes detect. Thus ...

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