Cecilia Payne, the unsung hero of astronomy

     Cecilia Payne was the first female astronomer to be granted a professorship at Harvard and the first female department chair. Her doctoral thesis was a study on stellar spectra. Stellar spectra refers to the spectrum of colors of light reflected from stellar objects. By measuring the stellar spectra and comparing it to the light reflected from known elements, Payne was able to determine the chemical composition of the stars.

Cecilia Helena Payne Gaposchkin (1900-1979),

astrophysicist at Harvard College Observatory,
 known for her research on stellar spectra.
 Photo from Smithsonian Institution Archives
(Acc. 90-105 – Science Service, Records, 1920s-1970s)

     Payne’s research was in direct conflict with the pre-eminent American physicists of her day. Geochemist Frank Wigglesworth Clarke had written a book comparing the strong spectral lines of the sun with his comprehensive sampling of minerals from the earth’s crust. Henry Norris Russell and Henry Rowland believed that the elemental abundances on the earth and in the Sun were nearly identical. Rowland’s opinion was because the spectra of the stars and the Sun were similar, that the relative abundance of elements in the universe was like that in the Earth’s crust.
     Payne had a stronger knowledge of atomic spectra than most astronomers at the time and disagreed with Rowland. She applied research by Meghnad Saha that indicated temperature had a large effect on the atomic spectra.  Payne used Saha’s equations to show that only one in 200 million of the hydrogen atoms in the Sun existed in the excited stat
e that gives off the signature spectra of hydrogen. As a result, she went on to show, the Sun as well as the stars were primarily formed of hydrogen and helium. The currently accepted values for elemental abundance in the Milky Way Galaxy (74% hydrogen, 24% helium, and 2% everything else) completely support her results. 
     Payne’s discovery brought a new view of the universe, much like the giants Copernicus, Newton, and Einstein. However, Payne was relatively unknown in the field. Many attribute this to the fact that she was a woman in the field at a time when women were denied many opportunities. Her obituary read in part, “Cecilia Helena Payne-Gaposchkin, a pioneering astrophysicist and probably the most eminent woman astronomer of all time, died in Cambridge, Massachusetts, on December 7, 1979. In the 1920s she derived the cosmic abundance of the elements from stellar spectra and demonstrated for the first time the chemical homogeneity of the universe.”

Happy Birthday World Wide Web

     It was March, 1989, when Sir Tim Berners-Lee, a researcher at CERN in Geneva, Switzerland, released a paper titled, “Information Management: A Proposal,” which outlined a method of interconnecting related documents for sharing research. His proposal was originally rejected as “Vague but exciting,” and was rejected for funding. However, Mike Sendall, Tim’s supervisor, gave him permission to work on the project unofficially.

Sir Tim, the creator of the World Wide Web, arriving at Guildhall
to receive the Honorary Freedom of the City of London.
Used under the Creative Commons Attribution-Share Alike 4.0
 International license. (https://en.wikipedia.org/wiki/Creative_Commons)

     Tim began work on the project in September 1990 and wrote three fundamental technologies that remain the foundation of World Wide Web. The first of these is HTML, the HyperText Markup Language, which consists of “tags” that allow one document on the web to link to other documents, or even other sections of the same document. The second is the URI, a Uniform Resource Identifier, which you can think of as an address for locating a file on the web, it is also commonly referred to as a URL (Uniform Resource Locator). The third and final is HTTP, the HyperText Transfer Protocol, which is the method by which the documents are shared across a network, allowing files on different computers throughout the world to link to files on other computers.
     Tim also wrote the world’s first web browser and web page editor, as well as the first web-server. The web-server is the computer where the shared files are stored and runs the HTTP services so that you can read the files. The web-browser is the application on your computer, smart-phone, game-system, or television that lets you view the files or “pages” that are stored on the server. Tim felt that it would not be right for a single entity to control the code and processes to make the web available and convinced CERN to release the tools on a royalty-free basis, forever. This made the web the first truly open-source free software. The decision to announce the public availability of the web was made in April, 1993, and sparked a wave of creativity.
     Prior to this, work files were shared via Bulletin Board Systems (BBS), which were files stored on personal computers connected to phone lines. In order to share files, there were “known” but not well advertised phone numbers that you could dial in with your computer and get a list of other computers and files with other phone numbers. Basically you had to make several phone calls to get files from what is now called the web. Tim’s system simplified the process of knowing where to find the files and created a centralized repository of file links. In 2003, companies banded together to create a new standards committee that kept the web royalty free, and in 2014, two in five people globally were connected and using the web.
     This month we celebrate 30-years of the web. None of us involved with the web in the early 1990s ever dreamed that it would be used for online interactive gaming, teleconferences with live video and even holographic-like augmented reality systems. We were just happy we didn’t have to dial multiple phone numbers and figure out which files we wanted based on people naming things the right way. Tim’s work allowed us to separate the eight character file name from the title or content of the file so we could link documents without caring what the file was named. Many times in the early days, files on the web were called file001, file002, etc. Without HTML and the URI, we would have never been able to figure out what a file contained without reading it.
   
In reference to sharing research information, Tim said, “In those days, there was different information on different computers, but you had to log on to different computers to get at it. Also, sometimes you had to learn a different program on each computer. Often it was easier to go and ask people when they were having coffee….” Just imagine having to pick up the phone and call someone every time you needed a piece of information instead of saying, “Okay Google.”

Tiny radios in your pocket

     Did you ever wonder how that hotel room key card works, when it never enters a slot and doesn’t even have to leave the cardboard sleeve? It is a technology called a Radio Frequency Identification (RFID) tag.  An RFID tag is really a tiny radio that can both transmit and receive data that is stored in a memory device on the card. 

Photo by Scott Hamilton RFID tag from laser printer toner
cartridge used to track cartridge life.

     The RFID tag is less than a hundredth of an inch in size, and usually has an antenna attached that is around a tenth of an inch in size. Sometimes the antenna is larger to make it possible to read the card from a longer distance. RFID tags can store digital information much like a USB drive or computer hard-drive. The real difference is that they are much smaller, cannot store very large amounts of information, and can be read and written to without a physical connection to the reader/writer.

     Most modern hotels use RFID cards to secure their rooms because they can modify the code on both the card and the lock randomly for every visitor to the hotel, greatly increasing the security of the rooms. Other uses of RFID tags are product tracking and security, inventory, and theft prevention. 

     The technology used in these products was originally created to assist large cattle ranches in tracking and identifying cattle. It is now used to track products in every industry and may eventually replace the bar code seen on products today. The main advantage of RFID is that a system can read multiple tags simultaneously without physically making contact with or seeing the tag. 

     RFID tags can make the future of grocery store checkout as simple as walking through a gate with your cart full of groceries and your debit card. The gate is a large RFID reader that will seemingly instantaneously read the tags in all the products in your cart and the tag in your bank card. The system will charge your card, e-mail your receipt, and you are on your way.

     RFID technology has been around since 1970, but only recently has become inexpensive enough to produce that it has come into wide use. The early technology used inductive coupling, which basically means that it used complicated metal coils that reacted in a specific way with a magnetic field, creating a specific current, or radio signal. This technology was difficult to manufacture and every tag had a unique shape and design. 

     The inductive designs were replaced by capacitive coupled tags, which used conductive carbon ink to create disposable tags that could be printed on-demand. This new technology used a microchip to store just 96-bits of information. This technology was not widely adopted and the company that developed it shut down in 2001.

     The latest innovations in RFID technology have combined the two methods to create a robust tag system that can either be constantly powered by an integrated battery (active); powered on demand with an integrated battery (semi-active); and powered by proximity to the reader (passive). 

     Active and semi-active tags are the most expensive and used to track expensive equipment like railroad cars and truckloads of inventory. They can be read from more than twenty feet away and are not considered disposable. When a product connected to an active RFID tag, like a railway car, is retired, the tag is moved to another product.

     Passive RFID tags are used in everything from your toll road pass sticker on your car windshield and your hotel room key to the bottle of shampoo you bought last week at the store. The tags can either be write-once-read-many, or read-write tags. You can get applications for your smartphone that can read, store, and simulate RFID tags. If you want to play around with RFID technology, old hotel room keys can usually be rewritten with card writer applications. You can then use them to automatically start applications on your phone, like turning on Pandora when it detects the tag in your car. You can also copy the RFID tag from your room key to your cell phone and use your phone as a room key. RFID technologies are coming en masse to our lives and I leave it to you to decide if this is good or bad.