John Naylor
@johncnaylor.bsky.social
Interested in the physics of sights and sounds in nature.
Author of “Out of the Blue, A 24-hour Skywatcher’s Guide”, “Now Hear This, A Book About Sound” & "The Riddle of the Rainbow"
Author of “Out of the Blue, A 24-hour Skywatcher’s Guide”, “Now Hear This, A Book About Sound” & "The Riddle of the Rainbow"
Pinned
John Naylor
@johncnaylor.bsky.social
· Feb 11
Rainbows have fascinated people since time immemorial. They have been the subject of myth, an inspiration to poets, a challenge to painters and the object of intense scientific interest. Read all about it! tinyurl.com/2wmwr5vb
This is the sort of rainbow that every aficionado of the phenomenon hopes to encounter, but seldom does! Note the dark band between arcs & brightness within the primary. The coloured arc is always centred on the observer's eyes, so the head's shadow marks the anti solar point & centre of the arc.
Good Morning! I took this photo in the Faroe Islands. It works for the #AlphabetChallenge #WeekSForShadows #EastCoastKin #Photography #Rainbow
With me in the center! Because...the rainbow's geometric center is precisely opposite the sun relative to my position, which is where the shadow falls.
With me in the center! Because...the rainbow's geometric center is precisely opposite the sun relative to my position, which is where the shadow falls.
November 10, 2025 at 4:24 PM
This is the sort of rainbow that every aficionado of the phenomenon hopes to encounter, but seldom does! Note the dark band between arcs & brightness within the primary. The coloured arc is always centred on the observer's eyes, so the head's shadow marks the anti solar point & centre of the arc.
A good illustration of the progression of sun's rosy hue during a sunset. Clouds in the upper right are uncoloured because they are now within the earth's show and so no longer directly illuminated by the sun. As the sun drops further below horizon, the rosy moves west (towards right of image)
September 29, 2025 at 2:29 PM
A good illustration of the progression of sun's rosy hue during a sunset. Clouds in the upper right are uncoloured because they are now within the earth's show and so no longer directly illuminated by the sun. As the sun drops further below horizon, the rosy moves west (towards right of image)
Fog bows are, as the name implies, formed in very small droplets of water such as those of which clouds and fog are composed. This one is a particularly good example of the phenomenon. For an explanation see www.atoptics.org.uk/droplets/fog...
September 28, 2025 at 1:25 PM
Fog bows are, as the name implies, formed in very small droplets of water such as those of which clouds and fog are composed. This one is a particularly good example of the phenomenon. For an explanation see www.atoptics.org.uk/droplets/fog...
High altitude clouds are the sine qua non of memorable sunsets. Without clouds to reflect the reddened sunlight coming from just below the horizon that light is only visible as a strip along the horizon.
#Lines of cloud over Chantry Island and its lighthouse shortly after sunset for the #AlphabetChallenge #WeekLforLines
#EastCoastKin #PhotoHour #StormHour #photography #landscape #clouds
#EastCoastKin #PhotoHour #StormHour #photography #landscape #clouds
September 21, 2025 at 2:37 PM
High altitude clouds are the sine qua non of memorable sunsets. Without clouds to reflect the reddened sunlight coming from just below the horizon that light is only visible as a strip along the horizon.
When the sun is just below the horizon, the distribution of colours in sunlight reaching the ground is skewed in favour of the red end of the spectrum due to Rayleigh scattering. Rain illuminated by this light results in a rainbow in which the red arc is very prominent.
September 21, 2025 at 2:28 PM
When the sun is just below the horizon, the distribution of colours in sunlight reaching the ground is skewed in favour of the red end of the spectrum due to Rayleigh scattering. Rain illuminated by this light results in a rainbow in which the red arc is very prominent.
This huge spraybow shows that these eye catching arcs are not confined to rain showers.
September 18, 2025 at 10:18 AM
This huge spraybow shows that these eye catching arcs are not confined to rain showers.
Sunshine & showers are the sine qua non of rainbows. But always bear in mind, a rainbow only exists if it is seen. This bright rainbow exhibiting many of the classic features was visible for several minutes from a street near my home a couple of days ago. An endlessly fascinating phenomenon!
September 15, 2025 at 11:06 AM
Sunshine & showers are the sine qua non of rainbows. But always bear in mind, a rainbow only exists if it is seen. This bright rainbow exhibiting many of the classic features was visible for several minutes from a street near my home a couple of days ago. An endlessly fascinating phenomenon!
Quite apart from the aesthetic aspects of reflections from the surface of gently undulating water, I enjoy the challenge of trying to identify the various sources that give rise to them by working out how the curvature of the surface brings about the distortions.
Reflections of a crane in the undulating waters of a harbour near Barcelona last week...with a few Miro-esque elements I thought!
#sharemondays2025 #fsprintmonday #stormhour #blueskymonday #thephotohour #eastcoastkin #photographersofbluesky #photography #artyear #smArtist #abstract #abstractart
#sharemondays2025 #fsprintmonday #stormhour #blueskymonday #thephotohour #eastcoastkin #photographersofbluesky #photography #artyear #smArtist #abstract #abstractart
September 9, 2025 at 2:04 PM
Quite apart from the aesthetic aspects of reflections from the surface of gently undulating water, I enjoy the challenge of trying to identify the various sources that give rise to them by working out how the curvature of the surface brings about the distortions.
This is a particularly striking example of a phenomenon that is often taken to be a rainbow by the uninitiated, ie by those for whom all coloured arcs are rainbows.
Best glory I’ve ever seen from a plane! It’s an optical phenomenon that occurs when light interacts in and around tiny droplets of water in the clouds, in the direction opposite the sun. More complex than a rainbow. Here’s a link to some more info: www.zmescience.com/science/phys... #optics #physics
September 7, 2025 at 2:57 PM
This is a particularly striking example of a phenomenon that is often taken to be a rainbow by the uninitiated, ie by those for whom all coloured arcs are rainbows.
Faraday was a natural philosopher in the fullest sense of that calling, perhaps one of the greatest there has ever been. It was he who first suggested (1846) that light is an electromagnetic phenomenon, an idea that was taken up & mathematised by J C Maxwell in his theory of electromagnetism.
Greatest experimental physicist of 19th Century: Michael Faraday discovered electromagnetic induction #OTD 1831 and transformed use of electricity. Ernest Rutherford noted “there is no honour too great to pay to his memory.”
Royal Institution Science | Royal Society
Royal Institution Science | Royal Society
August 30, 2025 at 2:22 PM
Faraday was a natural philosopher in the fullest sense of that calling, perhaps one of the greatest there has ever been. It was he who first suggested (1846) that light is an electromagnetic phenomenon, an idea that was taken up & mathematised by J C Maxwell in his theory of electromagnetism.
Reposted by John Naylor
Reposted by John Naylor
Back in February I took a series of 'star squiggles' photos, where I did 3.2sec exposure while wobbling the tripod to capture scintillation in the trails and the general star colour. I included Mars and Jupiter to show that planets do not scintillate. This was just a bit of creative fun
August 12, 2025 at 1:21 PM
Back in February I took a series of 'star squiggles' photos, where I did 3.2sec exposure while wobbling the tripod to capture scintillation in the trails and the general star colour. I included Mars and Jupiter to show that planets do not scintillate. This was just a bit of creative fun
This curious pattern is due to convection in fruit puree.
August 10, 2025 at 11:11 AM
This curious pattern is due to convection in fruit puree.
Great illustration of the relative angular dimensions of the moon & rainbow. Rainbow arc aprox 2° wide, Moon diameter aprox 0.5°.
Yesterday you made my day so special and you spoiled me so much with all the birthday wishes, I don't even know how to thank you 🥹
So here's a gorgeous picture of the moon and a rainbow (not mine) because it sums my feelings pretty well and I don't have the words...
I love you and thank you 🌈🌛
So here's a gorgeous picture of the moon and a rainbow (not mine) because it sums my feelings pretty well and I don't have the words...
I love you and thank you 🌈🌛
August 10, 2025 at 10:51 AM
Great illustration of the relative angular dimensions of the moon & rainbow. Rainbow arc aprox 2° wide, Moon diameter aprox 0.5°.
In a letter (1632) to J. Golius, Snel’s successor in the chair of Maths at Leiden, Descartes cheerfully admitted that he had never carried out a direct experimental test of the law. Golius found that Snel had already discovered the law of refraction, but never suggested that D. had plagiarised S.
The two thousand year search for the sine law of refraction #histsci #histtech
thonyc.wordpress.com/2025/07/30/f...
thonyc.wordpress.com/2025/07/30/f...
July 30, 2025 at 1:27 PM
In a letter (1632) to J. Golius, Snel’s successor in the chair of Maths at Leiden, Descartes cheerfully admitted that he had never carried out a direct experimental test of the law. Golius found that Snel had already discovered the law of refraction, but never suggested that D. had plagiarised S.
Runge & Goethe corresponded on the subject of coloured shadows, a phenomenon first described by da Vinci tinyurl.com/25b49db9 & correctly explained by G. Monge (1789). Descriptions on how to produce such shadows by Goethe tinyurl.com/476pbny6 & Rumford tinyurl.com/43w5vzj9. My flashlight version
July 24, 2025 at 10:56 AM
Runge & Goethe corresponded on the subject of coloured shadows, a phenomenon first described by da Vinci tinyurl.com/25b49db9 & correctly explained by G. Monge (1789). Descriptions on how to produce such shadows by Goethe tinyurl.com/476pbny6 & Rumford tinyurl.com/43w5vzj9. My flashlight version
As the author of "Now Hear This, A Book about Sound" I shall be listening on #WorldListeningDay to Radio Lento if I can't get out and about. ebook available at a generous discount here tinyurl.com/bdcud8mv
July 18, 2025 at 1:41 PM
As the author of "Now Hear This, A Book about Sound" I shall be listening on #WorldListeningDay to Radio Lento if I can't get out and about. ebook available at a generous discount here tinyurl.com/bdcud8mv
As an aficionado of sources of unusual sounds, I commend your wife’s ambition! My shop bought TT produces a large number of closely spaced harmonics, which one would not guess from its raucous sound. My T.T., 18cm long, is loudest at ~450Hz.
July 17, 2025 at 4:37 PM
As an aficionado of sources of unusual sounds, I commend your wife’s ambition! My shop bought TT produces a large number of closely spaced harmonics, which one would not guess from its raucous sound. My T.T., 18cm long, is loudest at ~450Hz.
A sunpillar is, in fact, a glitter path in the sky, an atmospheric twin to the glitter path that one sees when looking out at a large body of water when the sun is close to the horizon. In the latter case, light is reflected from the surface of waves that crisscross the water.
Bonne nuit les amis.
#ottawa #gatineau #photography #weather #stormhour #shareyourweather #skywatcher #photographie
#ottawa #gatineau #photography #weather #stormhour #shareyourweather #skywatcher #photographie
June 30, 2025 at 2:44 PM
A sunpillar is, in fact, a glitter path in the sky, an atmospheric twin to the glitter path that one sees when looking out at a large body of water when the sun is close to the horizon. In the latter case, light is reflected from the surface of waves that crisscross the water.
This is an excellent example of a late evening rainbow, when raindrops are illuminated by reddened light from a setting sun. Hence the inner "blue" band is almost invisible. Also note contrast in brightness between the sky enclosed by the rainbow and the so called 'dark band' beyond it
June 30, 2025 at 9:17 AM
This is an excellent example of a late evening rainbow, when raindrops are illuminated by reddened light from a setting sun. Hence the inner "blue" band is almost invisible. Also note contrast in brightness between the sky enclosed by the rainbow and the so called 'dark band' beyond it
Dave’s image gives the lie to the common claim that a sunpillar is due to sunlight reflected by a vertical column of ice crystals. Here clouds stretch almost to the horizon, and are closer to the eye than the sun, which would block the vertical column of crystals. This very evident in my photo.
June 29, 2025 at 2:53 PM
Dave’s image gives the lie to the common claim that a sunpillar is due to sunlight reflected by a vertical column of ice crystals. Here clouds stretch almost to the horizon, and are closer to the eye than the sun, which would block the vertical column of crystals. This very evident in my photo.
Parhelia are formed when sunlight passes through a cloud of hexagonal plate ice crystals. If the cloud is sufficiently extensive (say 60°) and centred on the sun, there may be parhelia ~25° either side of sun. Quite common though really bright ones are rare in my experience.
June 16, 2025 at 4:47 PM
Parhelia are formed when sunlight passes through a cloud of hexagonal plate ice crystals. If the cloud is sufficiently extensive (say 60°) and centred on the sun, there may be parhelia ~25° either side of sun. Quite common though really bright ones are rare in my experience.
Eye catching! Reflections in rippled water are amenable to the laws of reflection as you will learn from tinyurl.com/4zewy2j7 . As the diagram shows, the surface of rippled water provides several reflections of any given point on an object seen from the far side of a body of water.
June 16, 2025 at 4:13 PM
Eye catching! Reflections in rippled water are amenable to the laws of reflection as you will learn from tinyurl.com/4zewy2j7 . As the diagram shows, the surface of rippled water provides several reflections of any given point on an object seen from the far side of a body of water.
This is the optical equivalent of an anechoic chamber. Most instructive! Tempted to buy a small pot of Musou Black to experience the effect it has on obliterating surface features.
June 11, 2025 at 4:11 PM
This is the optical equivalent of an anechoic chamber. Most instructive! Tempted to buy a small pot of Musou Black to experience the effect it has on obliterating surface features.
The barometer was not made by Torricelli himself, but that he imagined what would happen and confided his thoughts to his great friend Viviani who had the apparatus made, procured the mercury, and was the first to make the experiment and to see the effect forecast by Torricelli.
Evangelista Torricelli (1608–1647), mathematician, physicist, inventor(?) of the barometer, the man who first showed that air has weight #histsci #histtech
thonyc.wordpress.com/2025/06/04/f...
thonyc.wordpress.com/2025/06/04/f...
From τὰ φυσικά (ta physika) to physics – XLV
Today we look at the life and work of the physicist and mathematician, Evangelista Torricelli (1608–1647), who is the second member of what I have termed the Galilei-Castelli school of mathema…
https://thonyc.wordpress.com/2025/06/04/from-τὰ-φυσικά-ta-physika-to-physics-xlv/
June 4, 2025 at 4:27 PM
The barometer was not made by Torricelli himself, but that he imagined what would happen and confided his thoughts to his great friend Viviani who had the apparatus made, procured the mercury, and was the first to make the experiment and to see the effect forecast by Torricelli.