Internet Science and Engineering Resources

What we commonly refer to as The Internet is really a diverse network of networks and machines interconnected by a common protocol known as TCP/IP. When someone comments that a piece of information was found "on the Internet", taken literally this only means that the information was retrieved from a remote computer using the TCP/IP protocol.

This is important because there are a huge number of different applications that operate over the networks using TCP/IP, and they are suited for different ways of transmitting and receiving information. In modern times, people joining the net are first introduced to graphical hypertext browser, and are unaware of many of the other available resources.

The preferred application varies depending on the sender and audience, the timeliness and importance of the data, and the nature of the information. The following are a number of common applications in widespread use over the network we know as The Internet.

Electronic Mail

One-to-One communications
Quickly prepared and retrieved
Primarily text, can be used to transfer files and images
Non-permanent information

Electronic mail is one of the most commonly used internet applications. It is easily prepared from a simple word-processor-style editor and sent within a matter of seconds or minutes to its recipient. While it is primarily used to send short text messages, Multipart Internet Mail Extensions (MIME) allow binary files such as images and data files to be sent via electronic mail. An e-mail message is originated by a single sender and generally directed to a single recipient, although multiple recipients can be specified.

Mailing lists

Few-to-few communications
Quickly prepared and sent
Almost always text
Non-permanent information (but often archived)
Ideal for small special-interest groups

A mailing list can be as simple as an individual with an "address book" who periodically sends mail to a group of friends and colleagues. Generally, however, the term refers to an e-mail "reflector" which automatically rebroadcasts all mail it receives to a pre-determined list of recipients. Modern list servers such as Majordomo and Listserv automatically take care of handling requests to be added to and removed from mailing lists as well as the actual mailing. Private mailing lists are common within a company, but there are hundreds of publicly available lists as well covering a huge variety of topics from the silly to the highly technical. A "List of lists" is posted periodically to the newsgroup news.answers and is also available on the World-Wide web at http://www.neosoft.com/internet/paml/. Mailing lists range from those with a dozen or so members and one or two messages a week to those with hundreds of members and fifty or more messages a day. Mailing lists typically have two addresses, one of which is used for administrative purposes such as subscribing and unsubscribing, and the other to actually send messages to the list. Using a mailing list is as easy as using e-mail, it's just that your message is sent by the list server to several recipients. As a rule, mailing lists are used for text-based messages only. It is not uncommon to find web sites that keep archives of popular public mailing lists available for browsing.

Usenet News

Many-to-many communications
Quickly prepared and sent
Text, images, files, sounds
Non-permanent (but often archived)

Usenet news, also called netnews, is similar to mailing lists, but on a larger scale, and with a different interface. Usenet newsgroups, as the discussion areas are called, are divided into heirarchies based on subject matter. There are literally thousands of topics available. Unlike a mailing list, one does not need to sign up ahead of time for a specific topic. While the word "subscribe" is used in much the same way as on mailing lists, in reality all of the newsgroups that your server carries are available to you at any time. The "subscription" process only flags a group as being of interest to you. This way the subjects that you are following are presented to you automatically without the need to wade through the over 10,000 subject areas every time you start your news reader. Netscape and other web browsers can be used for reading and posting news, but as a rule you'll be happier using a program designed for the purpose such as Free Agent for Windows or Newswatcher for the Mac. These and many other useful programs can be found at http://www.tucows.com .

Usenet news isn't as instantaneous as electronic mail, and a message can take anywhere from a few hours to up to a week to travel around the world. Because of the volume of information, most sites keep Usenet news items (called articles) only for a limited amount of time. That's why it's called news instead of history! However, there are web sites that keep an archive of news articles for longer periods, as well as allowing keyword searches of Usenet articles. Dejanews at www.dejanews.com is one of the better ones. AltaVista also has a searchable Usenet archive. In addition to the subject-specific newsgroups, there are a few that are worth exploring for the newcomer to Usenet. The group news.answers has periodic postings of the Frequently Asked Questions (FAQs) of many of the other newsgroups. It is always a good idea to check the FAQ before posing a question to a group that you haven't been following for a while, as it saves time for the regulars, and the answer in the FAQ is likely to be more complete than a casual answer received from someone else on the group. The news.answers group is fun to read in its own right, as the diversity of topics and trivia contained in the FAQs is incredible. Anyone who regularly reads news.answers would be a very good Jeopardy contestant. Newcomers to Usenet should also check out the group news.announce.newusers.

In most cases when you post an article to a newsgroup, it is directly posted and available to anyone else in the world to read. Some groups are moderated, which means that postings are not directly sent to the newsgroup, but first sent to a "moderator" who determines if the posting is suitable. Moderated groups tend to have a better "signal-to-noise" ratio, but can run into delays, as the moderators are volunteers who often have a life outside of netnews.

I have compiled a list of science-related newsgroups to get you started.

The World-Wide Web

One-to-many communication
Time-consuming to prepare and change
Text, images, sounds, and animation
Relatively permanent

The World-Wide Web is well-known to virtually everyone who has any kind of net connectivity. It has become the most popular application, and many people think that the Web is the internet. It is best suited for a single individual or company to get information out to the rest of the world, and for commercial applications such as online ordering. The web can be an excellent "electronic brochure", and more bells and whistles are being added to web browsers all the time, which make web sites more attention-getting (but don't necessarily add much in the way of content, that's still up to the site designer). The modern web browser clients can also handle other protocols such as File Transfer Protocol (FTP) as well as mail and Usenet news.

Streaming protocols

One-to-one, few, or many
Real-time
Sound, video, or both

Until recently, most internet applications consisted of files (be they text, sound, images, or data) of fixed length with a beginning and an end. Recently, TCP/IP applications of continuous voice and video have been developed. Information is sent in a continuous stream, much like a radio or television broadcast, and received in real time. These protocols are coming out of the realm of experiments and are finding niche applications such as voice telephony and video teleconferencing. As high-bandwidth connections become less expensive and more readily available, the "picturephone" once touted as the future product of the former Bell System is very likely to be brought to you via a TCP/IP streaming protocol.