Starlog 2019.04.30

Dear all (especially those enrolled in the SmithsonianX’s  online course “Star Trek: Inspiring Culture and Technology”, on edX.org),

This is my introduction post related to the course ..  😉

About 55 years 8 months, three weeks and five days ago a human being called Wilson Pardi Junior was born in a distant land called Brazil. Although a very long time has already passed he never forgot how he became fascinated with the possibility of finding, someday, the superior entity responsible for our creation!

Although a very big fan of “Lost In Space” TV series in his childhood, he had  some difficulties in understanding the classic episodes of “Star Trek: The Original Series”. However, this started to change when he went alone to a movie theater in 1979 to watch full screen what he still considers the best movie he had watched so far: “2001, A Space Odyssey”! Therefore, during his undergraduate days (he’s an electrical and electronics engineer) he watched all the episodes of “Star Trek: The Original Series” and also most episodes of “Star Trek: The Next Generation”..

The original Star Trek Enterprise Model

With the same passion and interest that he had when he enrolled in the “The Rise of Superheroes and Their Impact on Pop Culture”, “Rise of the Superheroes and the Heroes of the Future” and “Power and Responsibility: Doing Philosophy with Super-Heroes” courses from the Smithsonian Institute, he decide to enroll in the “Star Trek: Inspiring Culture and Technology” course because he thinks it’s a great opportunity to make friendship with science-fiction admirers from all over the world! He’s most excited in learning how Star Trek‘s episodes can influence or change people’s perceptions about their own lives. He also hopes to achieve a great satisfaction in acquiring knowledge about how current and newer technology can influence on the improvement and assimilation of different cultures through openness and diversity.

He’s also very happy in knowing that by completing the first unit of this course he was promoted to the rank of Chief Warrant Officer!  🙂

The insignia of Chief Warrant Officer

Advertisements

History of photography: the camera obscura (part 2)

Dear reader,

Last month I did a gentle introduction to the camera obscura, the precursor of the photographic camera. This month I continue writing about this simple, but very interesting device. Therefore, it follows bellow more examples using the principle of the camera obscura in the history of mankind:

  • 1450 to 1600 – earliest depiction, lenses, drawing aid and mirrors:

– the famous Leonardo da Vinci (1452–1519), familiar with the work of Alhazen and after an extensive study of optics and human vision, wrote the oldest known clear description of the camera obscura in mirror writing in a notebook in 1502, later published in the collection Codex Atlanticus (translated from Latin),

–  the oldest known published drawing of a camera obscura is found in Dutch physician, mathematician and instrument maker Gemma Frisius’ 1545 book De Radio Astronomica et Geometrica, in which he described and illustrated how he used the camera obscura to study the solar eclipse of January 24, 1544,

First published picture of camera obscura in Gemma Frisius’ 1545 book De Radio Astronomica et Geometrica

– Italian polymath Gerolamo Cardano described using a glass disc – probably a biconvex lens – in a camera obscura in his 1550 book De subtilitate, vol. I, Libri IV,

– Sicilian mathematician and astronomer Francesco Maurolico (1494-1575) answered Aristotle’s problem how sunlight that shines through rectangular holes can form round spots of light or crescent-shaped spots during an eclipse in his treatise Photismi de lumine et umbra (1521-1554),

– Italian polymath Giambattista della Porta described the camera obscura, which he called “obscurum cubiculum”, in the 1558 first edition of his book series Magia Naturalis  where he compared the human eye to the camera obscura, the popularity of Della Porta’s books helped spread knowledge of the camera obscura,

– in his 1567 work La Pratica della Perspettiva Venetian nobleman Daniele Barbaro (1513-1570) described using a camera obscura with a biconvex lens as a drawing aid and points out that the picture is more vivid if the lens is covered as much as to leave a circumference in the middle,

– in his influential and meticulously annotated Latin edition of the works of Al-Haytam and Witelo Opticae thesauru (1572) German mathematician Friedrich Risner proposed a portable camera obscura drawing aid; a lightweight wooden hut with lenses in each of its four walls that would project images of the surroundings on a paper cube in the middle (a very similar setup was illustrated in 1645 in Athanasius Kircher’s influential book Ars Magna Lucis Et Umbrae),

– around 1575 Italian Dominican priest, mathematician, astronomer, and cosmographer Ignazio Danti designed a camera obscura gnomon and a meridian line for the Basilica of Santa Maria Novella, Florence and he later had a massive gnomon built in the San Petronio Basilica in Bologna,

– in his 1585 book Diversarum Speculationum Mathematicarum Venetian mathematician Giambattista Benedetti proposed to use a mirror in a 45 degree angle to project the image upright where this leaves the image reversed, but would become common practice in later camera obscura boxes.

  • 1600 to 1650 – name coined, camera obscura telescopy, portable drawing aid in tents and boxes:

– The earliest use of the term “camera obscura” is found in the 1604 book Ad Vitellionem Paralipomena by  German mathematician, astronomer, and astrologer Johannes Kepler where he discovered the working of  the camera obscura by recreating its principle with a book replacing a shining body and sending threads from its edges through a many-cornered aperture in a table onto the floor where the threads recreated the shape of the book,

The first use of the term “camera obscura” was by Johannes Kepler, in his first treatise about optics, Ad Vitellionem paralipomena quibus astronomiae pars optica traditur (1604)

– In 1611 Frisian/German astronomers David and Johannes Fabricius (father and son) studied sunspots with a camera obscura, after realizing looking at the sun directly with the telescope could damage their eyes,

– from 1612 to at least 1630 Christoph Scheiner would keep on studying sunspots and constructing new telescopic solar projection systems called “Heliotropii Telioscopici”, later contracted to helioscope, where Scheiner built a box around the viewing/projecting end of the telescope, which can be seen as the oldest known version of a box-type camera obscura (he also made a portable camera obscura),

– Dutch inventor Cornelis Drebbel is thought to have constructed a box-type camera obscura which corrected the inversion of the projected image,

– German Orientalist, mathematician, inventor, poet, and librarian Daniel Schwenter wrote in his 1636 book Deliciae Physico-Mathematicae about an instrument that a man from Pappenheim, Germany had shown him, which enabled movement of a lens to project more from a scene through the camera obscura,

– Italian Jesuit philosopher, mathematician and astronomer Mario Bettini wrote about making a camera obscura with twelve holes in his Apiaria universae philosophiae mathematicae (1642), so when a foot soldier would stand in front of the camera, a twelve person army of soldiers making the same movements would be projected,

Illustration of a twelve-hole camera obscura from Bettini’s Apiaria universae philosophiae mathematicae” (1642)

– French mathematician and painter of anamorphic art Jean-François Nicéron (1613-1646) wrote about the camera obscura with convex lenses where he explained how the camera obscura could be used by painters to achieve perfect perspective in their work.

It’s interesting to notice above that the development of the camera obscura and its advancement was basically made in the Western Europe, during the parts of History that comprised the Renaissance, the Reformation, and the Scientific Revolution periods!  🙂

I hope you’ve enjoyed reading this article so far, and therefore, I invite you to come here next month to read the part 3 too!  😉

Works Cited

“Camera obscura.” Wikipedia. 20 Feb. 2019. Wikimedia Foundation. 28 Feb. 2019, https://en.wikipedia.org/wiki/Camera_obscura.

History of photography: the camera obscura (part 1)

Dear reader,

A long time ago (more precisely, four years ago) I wrote a very short introduction article about one of my favorite pastimes, i.e photography, in this blog. Now it’s time to start writing more about this fascinating hobby.  🙂

Before we try to understand the various techniques used through the years to take high-quality pictures, it’s advisable to know the history of photography, at least, during the last four hundred years. Since it’s a long and interesting series of past events that show the development of photography among us, I intend to write many articles as possible about it.  😉

Although not necessarily related to the history of photography, it’s worthwhile to mention one important thing that contributed immensely to the beginning of this fascinating topic: the camera obscura (in English it means “the darkened camera”).

According to the Wikipedia, the “camera obscura, also referred to as pinhole image, is the natural optical phenomenon that occurs when an image of a scene at the other side of a screen (or for instance a wall) is projected through a small hole in that screen as a reversed and inverted image (left to right and upside down) on a surface opposite to the opening. The surroundings of the projected image have to be relatively dark for the image to be clear, so many historical camera obscura experiments were performed in dark rooms.”

Example of a camera obscura

“Rays of light travel in straight lines and change when they are reflected and partly absorbed by an object, retaining information about the color and brightness of the surface of that object. Lit objects reflect rays of light in all directions. A small enough opening in a screen only lets through rays that travel directly from different points in the scene on the other side and these rays form an image of that scene when they are collected on a surface opposite the opening. In simple terms, the way your retina sees a specific image through your eye is vertically switched to the object you see and how pieces in your brain are shown to switch that object right-side up to the way you see normally” (Camera obscura).

Physical explanation about the camera obscura principle

As mentioned above, the camera obscura wasn’t necessarily related to photography. Also, according to the Wikipedia, there are a lot of examples using the principle of the camera obscura in the history of mankind:

  • 30,000 BCE to 500 BCE:

     – possible inspiration for prehistoric art and possible use in religious ceremonies and gnomon (the projecting piece on a sundial that shows the time by the position of its shadow),

  • 500 BCE to 500 CE – earliest written observations:

     – found in Chinese writings called Mozi and dated to the 4th century BCE,

     – the Greek philosopher Aristotle (384-322 BCE) or possibly a follower of his ideas touched upon the subject in the work Problems – Book XV,

     – Euclid is sometimes reported to have mentioned the camera obscura phenomenon as a demonstration that light travels in straight lines in his very influential Optics (circa 300 BCE),

     – in the 4th century Greek scholar Theon of Alexandria observed that candlelight passing through a pinhole will create an illuminated spot on a screen that is directly in line with the aperture and the center of the candle.

  • 500 to 1100 – experiments and study of light:

     – in the 6th century the Byzantine-Greek mathematician and architect Anthemius of Tralles experimented with effects related to the camera obscura,

     – in the 9th century Al-Kindi demonstrated that “light from the right side of the flame will pass through the aperture and end up on the left side of the screen while light from the left side of the flame will pass through the aperture and end up on the right side of the screen”,

     – in the 10th century Yu Chao-Lung supposedly projected images of pagoda models through a small hole onto a screen to study directions and divergence of rays of light,

     – arab physicist Ibn al-Haytham explained in his Book of Optics (circa 1027) that rays of light travel in straight lines and are distinguished by the body that reflected the rays,

     – in his 1088 book Dream Pool Essays the Song Dynasty Chinese scientist Shen Kuo compared the focal point of a concave burning-mirror and the “collecting” hole of camera obscura phenomena to an oar in a rowlock to explain how the images were inverted.

  • 1100 to 1400 – optical & astronomical tool and entertainment:

     – English philosopher and Franciscan friar Roger Bacon falsely stated in his De Multiplicatione Specerium (1267) that an image projected through a square aperture was round because light would travel in spherical waves and therefore assumed its natural shape after passing through a hole,

     – Polish friar, theologian, physicist, mathematician and natural philosopher Erazmus Ciołek Witelo wrote about the camera obscura in his very influential treatise Perspectiva (circa 1270-1278) which was largely based on Ibn al-Haytham’s work,

     – English archbishop and scholar John Peckham wrote about the camera obscura in his Tractatus de Perspectiva (circa 1269-1277) and Perspectiva communis (circa 1277-79) falsely arguing that light gradually forms the circular shape after passing through the aperture,

     – at the end of the 13th century Arnaldus de Villa Nova is credited with using a camera obscura to project live performances for entertainment,

     – French astronomer Guillaume de Saint-Cloud suggested in his 1292 work Almanach Planetarum that the eccentricity of the sun could be determined with the camera obscura from the inverse proportion between the distances and the apparent solar diameters at apogee and perigee,

     – Kamāl al-Dīn al-Fārisī described in his 1309 work Kitab Tanqih al-Manazir (The Revision of the Optics) how he experimented with a glass sphere filled with water in a camera obscura with a controlled aperture and found that the colors of the rainbow are phenomena of the decomposition of light,

     – French Jewish philosopher, mathematician, physicist and astronomer / astrologer Levi ben Gershon (1288–1344) made several astronomical observations using a camera obscura with a Jacob’s staff (a stick or pole with length markings), describing methods to measure the angular diameters of the sun, the moon and the bright planets Venus and Jupiter.

Translation of the Problems – Book XV by E.S. Forster in 1927

It’s really amazing, by reading the examples cited above, how many people around the globe had a lot of interest in the study of light and image formation through the history of mankind! Also, it’s worthwhile to mention that the name camera obscura was coined only in 1604, but this is a subject to be discussed in the part 2 of this article…  😉

See you here next month!  🙂

Works Cited

“Camera obscura.” Wikipedia. 20 Feb. 2019. Wikimedia Foundation. 28 Feb. 2019, https://en.wikipedia.org/wiki/Camera_obscura.

Rice and beans (arroz com feijão)

Dear reader,

Have you already eaten today? If not yet, then you should continue reading…  😉

This month I will introduce you to the most popular dish in my native country Brazil: arroz com feijão, i.e., rice and beans.  🙂

This very delicious dish consists basically of white rice with cooked black beans:

Rice and black beans

It can also be prepared with brown, red or even white beans (it depends on the region in the country):

Rice and brown beans

For many foreigners that never had the opportunity to eat it, the taste of the beans (basically salty) is the secret of this very delicious dish.  😉

It’s also usually served with some side dishes as for example, lettuce and tomato salad, beef, pork, etc. The following photo, taken by me on last January 19th, is a typical example of how it’s good to eat this delicious dish with some side dishes: 🙂

Rice and black beans accompanied by some side dishes

One of the most important reasons why rice and beans is a very popular dish in Brazil is because is a very nutritious dish. Both rice and beans have a great amount of protein and iron. In addition, rice is rich in starch (an excellent source of energy), consequently they provide many amino acids that are needed by the human body. Also, it doesn’t cost so much to prepare it since rice and beans can be found anywhere in Brazil at a very reasonable price. Therefore, it’s consumed by all population layers, i.e., from poor to rich families.  😉

Needless to say, rice and beans can be eaten anywhere in my country, from the southernmost state (Rio Grande do Sul, where I’m from) to the northernmost state (Roraima).  🙂

I do hope that you’ve enjoyed reading so far. As a promise, in a near future I will try to teach you how to prepare this delicious dish, OK? Thank you so much for coming here! 🙂

Bom apetite! (in Portuguese from the famous French expression, bon appétit!)

Physics

Dear reader,

As one of the most important topics (the another one is probably chemistry) related to science, physics is definitely a paramount scientific discipline.

Across the history of human civilization, from the ancient times to the present, the study of physics changed our lives in a very drastic way! From the first understanding of the motions of the Sun, Moon and stars through the formulation of quantum field theory and the advances in applied physics, the progress of mankind in terms of technological revolutions has been astonishing!

Main branches of physics

I don’t intend to write everything about physics in this blog since it will take years and thousands of articles! 🙂

However, I will try to write about the most significant concepts and interesting discoveries that have contributed to our evolution as a rational animal (although sometimes we use our knowledge to make irrational things).

Initially, it’s interesting to know what does the physics word mean. According to the Wikipedia,” it derives from the ancient Greek word  φυσική (ἐπιστήμη),  where from transliteration (romanization of Greek) it means physikḗ (epistḗmē), and from a literal translation it means ‘knowledge of nature’, from φύσις phýsis: nature. Therefore, physics is the natural science that studies matter and its motion and behaviour through space and time and that studies the related entities of energy and force.”

In a near future I intend to write more articles about physics, including its history, subdisciplines, principles, discoveries, etc. Therefore, if you really enjoy physics as I do then I invite you to take a look occasionally here at this blog, OK? 😉

Works Cited

“Physics.” Wikipedia, Wikimedia Foundation, 24 Nov. 2018, en.wikipedia.org/wiki/Physics.

Chemistry

Dear reader,

As one of the most important topics (the another one is probably physics) related to science, chemistry is definitely a paramount scientific discipline.

Across the history of human civilization, from the ancient times to the present, the study of chemistry changed our lives in a very drastic way! From the control of fire by early human through the formulation of atomic theory and the discovery of subatomic particles, the progress of mankind in terms of technological revolutions has been astonishing!

A concise timeline of history of chemistry

I don’t intend to write everything about chemistry in this blog since it will take years and thousands of articles! 🙂

However, I will try to write about the most significant concepts and interesting discoveries that have contributed to our evolution as a rational animal (although sometimes we use our knowledge to make irrational things).

Initially, it’s interesting to know what does the chemistry word mean. According to the Wikipedia, “the etymology of the word chemistry is debatable. It is agreed that the word derives from the word alchemy, which is a European one, derived from kimiya (كيمياء) and al-kīmiyāʾ (الكيمياء). The Arabic term is derived from the Ancient Greek χημία khēmia or χημεία khēmeia. However, the ultimate origin of the root word, chem, is uncertain..

Also, “there are two main views on the derivation of the word, which agree in holding that it has an Arabic descent, the prefix al being the Arabic article”:

Assuming an Egyptian origin, chemistry is defined as follows:

  • Chemistry, from the ancient Egyptian word “khēmia” meaning transmutation of earth, is the science of matter at the atomic to molecular scale, dealing primarily with collections of atoms, such as molecules, crystals, and metals.

Assuming a Greek origin, chemistry is defined as follows:

  • Chemistry, from the Greek word χημεία (khēmeia) meaning “cast together” or “pour together”, is the science of matter at the atomic to molecular scale, dealing primarily with collections of atoms, such as molecules, crystals, and metals.

In a near future I intend to write more articles about chemistry, including its history, subdisciplines, principles, discoveries, etc. Therefore, if you really enjoy chemistry as I do then I invite you to take a look occasionally here at this blog, OK? 😉

Works Cited

“Etymology of Chemistry.” Wikipedia, Wikimedia Foundation, 14 Nov. 2018, en.wikipedia.org/wiki/Etymology_of_chemistry.

Fake News

Dear reader,

From the beginnings of civilization the human being spreads false news around himself and his community. With the advent of printed paper the reach of false news has increased considerably. Later, the invention of radio and TV also contributed significantly, mainly in places where we had and still have a predominance of great conglomerates of broadcasting.

Unfortunately, things got much worse with the development of Internet!  😦 😦

I always remember one professor’s comment at my Electrical Engineering undergraduate course in Porto Alegre, Brazil. At that time (pre-Internet era) he used to say “The paper accepts everything.” with the purpose to warn his students that often a project in practice presents a completely different result from the theory …

The same applies to the Internet:  “The digital world accepts everything!”  😉

In other words, it’s extremely easy to tamper an article, a photo and even a recorded voice!  😦

Accordingly to Wardle, there are basically seven types of fake news:

  1. satire or parody (“no intention to cause harm but has potential to fool”),
  2. false connection (“when headlines, visuals or captions don’t support the content”),
  3. misleading content (“misleading use of information to frame an issue or an individual”),
  4. false context (“when genuine content is shared with false contextual information”),
  5. impostor content (“when genuine sources are impersonated” with false, made-up sources),
  6. manipulated content (“when genuine information or imagery is manipulated to deceive”, as with a “doctored” photo) and,
  7. fabricated content (“new content is 100% false, designed to deceive and do harm”)

It’s amazing, and extremely worrying at the same time, how the quantity of fake news increased exponentially with the use of social media across the globe during the last five years …

The roots of “fake news” (by UNESCO – World Trends in Freedom of Expression and Media Development Global Report 2017/2018)

For example, on last weekend we Brazilians elected our new President. Most of us were astonished by the huge quantity of fake news about the two front-runners on social media such as Facebook and WhatsApp!

Since it’s almost impossible to extinguish fake news of these chaotic times, then at least we must be able how to identify them. The picture below shows an useful method how to spot fake news:

How to Spot Fake News (By the International Federation of Library Associations and Institutions)

Therefore, dear reader:

Always be alert, open your eyes, and especially, always distrust any sources, even the reliable ones!  😉

Works Cited

Wardle, Claire. “Fake News. It’s Complicated.” First Draft News, Harvard Kennedy School’s Shorenstein Center, 16 Feb. 2017, firstdraftnews.org/fake-news-complicated/.

Previous Older Entries