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ARPANET
ARPANET logical map, March 1977
Commercial?	No
Type of network	data
Location	USA
Protocols	NCP,TCP/IP
Established	1969
Funding	DARPA
Current status	defunct

The Advanced Research Projects Agency Network (ARPANET), was the world's first operational packet switching network and the core network of a set that came to compose the global Internet. The network was funded by the Defense Advanced Research Projects Agency (DARPA) of the United States Department of Defense for use by its projects at universities and research laboratories in the US. The packet switching of the ARPANET was based on designs by Lawrence Roberts of the Lincoln Laboratory.^[1]

Packet switching, today the dominant basis for data communications worldwide, was a new concept at the time of the conception of the ARPANET. Prior to the advent of packet switching, both voice and data communications had been based on the idea of circuit switching, as in the traditional telephone circuit, wherein each telephone call is allocated a dedicated, end to end, electronic connection between the two communicating stations. Such stations might be telephones or computers. The (temporarily) dedicated line is typically composed of many intermediary lines which are assembled into a chain that stretches all the way from the originating station to the destination station.

With packet switching, a data system could use a single communications link to communicate with more than one machine by collecting data into datagrams and transmitting these as packets onto the attached network link, as soon as the link becomes idle. Thus, not only can the link be shared, much as a single post box can be used to post letters to different destinations, but each packet can be routed independently of other packets.

History[link]

The earliest ideas for a computer network intended to allow general communications among computer users were formulated by computer scientist J. C. R. Licklider, of Bolt, Beranek and Newman (BBN), in August 1962, in memoranda discussing his concept for an “Intergalactic Computer Network”. Those ideas contained almost everything that composes the contemporary Internet.

In October 1963, Licklider was appointed head of the Behavioral Sciences and Command and Control programs at the Defense Department's Advanced Research Projects Agency — ARPA (the initial ARPANET acronym). He then convinced Ivan Sutherland and Bob Taylor that this computer network concept was very important and merited development, although Licklider left ARPA before any contracts were let that worked on this concept.

Ivan Sutherland and Bob Taylor continued their interest in creating such a computer communications network, in part, to allow ARPA-sponsored researchers at various corporate and academic locales to put to use the computers ARPA was providing them, and, in part, to make new software and other computer science results quickly and widely available. In his office, Taylor had three computer terminals, each connected to separate computers, which ARPA was funding: the first, for the System Development Corporation (SDC) Q-32, in Santa Monica; the second, for Project Genie, at the University of California, Berkeley; and the third, for Multics, at MIT. Taylor recalls the circumstance: "For each of these three terminals, I had three different sets of user commands. So, if I was talking online with someone at S.D.C., and I wanted to talk to someone I knew at Berkeley, or M.I.T., about this, I had to get up from the S.D.C. terminal, go over and log into the other terminal and get in touch with them. I said, “Oh Man!”, it’s obvious what to do: If you have these three terminals, there ought to be one terminal that goes anywhere you want to go. That idea is the ARPANET".^[2] Somewhat contemporaneously, several other people had (mostly independently) worked out the aspects of “packet switching”, with the first public demonstration presented by the National Physical Laboratory (NPL), on August 5, 1968, in the United Kingdom.^[3]

Creation[link]

By mid-1968, Taylor had prepared a complete plan for a computer network, and, after ARPA’s approval, a Request for Quotation (RFQ) was sent to 140 potential bidders. Most computer science companies regarded the ARPA–Taylor proposal as outlandish, and only twelve submitted bids to build the network; of the twelve, ARPA regarded only four as top-rank contractors. At year’s end, ARPA considered only two contractors, and awarded the contract to build the network to BBN Technologies on April 7, 1969. The initial, seven-man BBN team were much aided by the technical specificity of their response to the ARPA RFQ — and thus quickly produced the first working computers. This team was led by Frank Heart. The BBN-proposed network closely followed Taylor’s ARPA plan: a network composed of small computers called Interface Message Processors (IMPs), that functioned as gateways (today called routers) interconnecting local resources. At each site, the IMPs performed store-and-forward packet switching functions, and were interconnected with modems that were connected to leased lines, initially running at 50kbit/second. The host computers were connected to the IMPs via custom serial communication interfaces. The system, including the hardware and the packet switching software, was designed and installed in nine months.

The first-generation IMPs were initially built by BBN Technologies using a rugged computer version of the Honeywell DDP-516 computer configured with 24kB of expandable core memory, and a 16-channel Direct Multiplex Control (DMC) direct memory access unit.^[4] The DMC established custom interfaces with each of the host computers and modems. In addition to the front-panel lamps, the DDP-516 computer also features a special set of 24 indicator-lamps showing the status of the IMP communication channels. Each IMP could support up to four local hosts, and could communicate with up to six remote IMPs via leased lines.

Misconceptions of design goals[link]

Common ARPANET lore posits that the computer network was designed to survive a nuclear attack. In A Brief History of the Internet, the Internet Society describes the coalescing of the technical ideas that produced the ARPANET:

It was from the RAND study that the false rumor started, claiming that the ARPANET was somehow related to building a network resistant to nuclear war. This was never true of the ARPANET, only the unrelated RAND study on secure voice considered nuclear war. However, the later work on Internetting did emphasize robustness and survivability, including the capability to withstand losses of large portions of the underlying networks.^[5]

Although the ARPANET was designed to survive subordinate-network losses, the principal reason was that the switching nodes and network links were unreliable, even without any nuclear attacks. About the resource scarcity that spurred the creation of the ARPANET, Charles Herzfeld, ARPA Director (1965–1967), said:

The ARPANET was not started to create a Command and Control System that would survive a nuclear attack, as many now claim. To build such a system was, clearly, a major military need, but it was not ARPA’s mission to do this; in fact, we would have been severely criticized had we tried. Rather, the ARPANET came out of our frustration that there were only a limited number of large, powerful research computers in the country, and that many research investigators, who should have access to them, were geographically separated from them.^[6]

Packet switching pioneer Paul Baran affirms this, explaining: "Bob Taylor had a couple of computer terminals speaking to different machines, and his idea was to have some way of having a terminal speak to any of them and have a network. That's really the origin of the ARPANET. The method used to connect things together was an open issue for a time."^[7]

ARPANET deployed[link]

The initial ARPANET consisted of four IMPs:

• University of California, Los Angeles (UCLA), where Leonard Kleinrock had established a Network Measurement Center, with an SDS Sigma 7 being the first computer attached to it;
• The Stanford Research Institute's Augmentation Research Center, where Douglas Engelbart had created the ground-breaking NLS system, a very important early hypertext system (with the SDS 940 that ran NLS, named "Genie", being the first host attached);
• University of California, Santa Barbara (UCSB), with the Culler-Fried Interactive Mathematics Center's IBM 360/75, running OS/MVT being the machine attached;
• The University of Utah's Computer Science Department, where Ivan Sutherland had moved, running a DEC PDP-10 running TENEX.

The first message on the ARPANET was sent by UCLA student programmer Charley Kline, at 10:30 p.m. on October 29, 1969, from Boelter Hall 3420.^[8] Supervised by Prof. Leonard Kleinrock, Kline transmitted from the university's SDS Sigma 7 Host computer to the Stanford Research Institute's SDS 940 Host computer. The message text was the word login; the l and the o letters were transmitted, but the system then crashed. Hence, the literal first message over the ARPANET was lo. About an hour later, having recovered from the crash, the SDS Sigma 7 computer effected a full login. The first permanent ARPANET link was established on November 21, 1969, between the IMP at UCLA and the IMP at the Stanford Research Institute. By December 5, 1969, the entire four-node network was established.^[9]

Growth and evolution[link]

In March 1970, the ARPANET reached the East Coast of the United States, when an IMP at BBN in Cambridge, Massachusetts was connected to the network. Thereafter, the ARPANET grew: 9 IMPs by June 1970 and 13 IMPs by December 1970, then 18 by September 1971 (when the network included 23 university and government hosts); 29 IMPs by August 1972, and 40 by September 1973. By June 1974, there were 46 IMPs, and in July 1975, the network numbered 57 IMPs. By 1981, the number was 213 host computers, with another host connecting approximately every twenty days.

In 1973 a transatlantic satellite link connected the Norwegian Seismic Array (NORSAR) to the ARPANET, making Norway the first country outside the US to be connected to the network. At about the same time a terrestrial circuit added a London IMP.^[10]

In 1975, the ARPANET was declared "operational". The Defense Communications Agency took control since ARPA was intended to fund advanced research. In 1983, the ARPANET was split with U.S. military sites on their own Military Network (MILNET) for unclassified defense department communications. The combination was called the Defense Data Network (DDN).^[11] Separating the civil and military networks reduced the 113-node ARPANET by 68 nodes. Gateways relayed electronic mail between the two networks. MILNET later became the NIPRNet.

Technology[link]

Support for inter-IMP circuits of up to 230.4 kbit/s was added in 1970, although considerations of cost and IMP processing power meant this capability was not actively used.

1971 saw the start of the use of the non-ruggedized (and therefore significantly lighter) Honeywell 316 as an IMP. It could also be configured as a Terminal Interface Processor (TIP), which provided terminal server support for up to 63 ASCII serial terminals through a multi-line controller in place of one of the hosts.^[12] The 316 featured a greater degree of integration than the 516, which made it less expensive and easier to maintain. The 316 was configured with 40 kB of core memory for a TIP. The size of core memory was later increased, to 32 kB for the IMPs, and 56 kB for TIPs, in 1973.

In 1975, BBN introduced IMP software running on the Pluribus multi-processor. These appeared in a small number of sites. In 1981, BBN introduced IMP software running on its own C/30 processor product.

In 1983, TCP/IP protocols replaced NCP as the ARPANET’s principal protocol, and the ARPANET then became one subnet of the early Internet.

Shutdown and legacy[link]

The original IMPs and TIPs were phased out as the ARPANET was shut down after the introduction of the NSFNet, but some IMPs remained in service as late as 1989.

The ARPANET Completion Report, jointly published by BBN and ARPA, concludes that:

... it is somewhat fitting to end on the note that the ARPANET program has had a strong and direct feedback into the support and strength of computer science, from which the network, itself, sprang. ^[13]

In the wake of ARPANET being formally decommissioned on February 28, 1990, Vinton Cerf wrote the following lamentation, entitled "Requiem of the ARPANET"^[14] :

It was the first, and being first, was best,
but now we lay it down to ever rest.
Now pause with me a moment, shed some tears.
For auld lang syne, for love, for years and years
of faithful service, duty done, I weep.
Lay down thy packet, now, O friend, and sleep.

-Vinton Cerf

Senator Albert Gore, Jr. began to craft the High Performance Computing and Communication Act of 1991 (commonly referred to as "The Gore Bill") after hearing the 1988 report toward a National Research Network submitted to Congress by a group chaired by Leonard Kleinrock, professor of computer science at UCLA. The bill was passed on December 9, 1991 and led to the National Information Infrastructure (NII) which Al Gore called the "information superhighway". ARPANET was the subject of two IEEE Milestones, both dedicated in 2009.^[15][16]

Software and protocols[link]

The starting point for host-to-host communication on the ARPANET was the 1822 protocol BBN Report 1822, which defined the transmission of messages to an IMP. The message format was designed to work unambiguously with a broad range of computer architectures. An 1822 message essentially consisted of a message type, a numeric host address, and a data field. To send a data message to another host, the transmitting host formatted a data message containing the destination host's address and the data message being sent, and then transmitted the message through the 1822 hardware interface. The IMP then delivered the message to its destination address, either by delivering it to a locally connected host, or by delivering it to another IMP. When the message was ultimately delivered to the destination host, the receiving IMP would transmit a Ready for Next Message (RFNM) acknowledgement to the sending, host IMP.

Unlike modern Internet datagrams, the ARPANET was designed to reliably transmit 1822 messages, and to inform the host computer when it loses a message; the contemporary IP is unreliable, whereas the TCP is reliable. Nonetheless, the 1822 protocol proved inadequate for handling multiple connections among different applications residing in a host computer. This problem was addressed with the Network Control Program (NCP), which provided a standard method to establish reliable, flow-controlled, bidirectional communications links among different processes in different host computers. The NCP interface allowed application software to connect across the ARPANET by implementing higher-level communication protocols, an early example of the protocol layering concept incorporated to the OSI model. In 1983, TCP/IP protocols replaced NCP as the ARPANET’s principal protocol, and the ARPANET then became one component of the early Internet.

Network applications[link]

NCP provided a standard set of network services that could be shared by several applications running on a single host computer. This led to the evolution of application protocols that operated, more or less, independently of the underlying network service. When the ARPANET migrated to the Internet protocols in 1983, the major application protocols migrated with it.

• E-mail: In 1971, Ray Tomlinson, of BBN sent the first network e-mail.^[17] By 1973, e-mail constituted 75 percent of ARPANET traffic.

• File transfer: By 1973, the File Transfer Protocol (FTP) specification had been defined and implemented, enabling file transfers over the ARPANET.

• Voice traffic: The Network Voice Protocol (NVP) specifications were defined in 1977 (RFC 741), then implemented, but, because of technical shortcomings, conference calls over the ARPANET never worked well; the contemporary Voice over Internet Protocol (packet voice) was decades away.

The ARPANET in film and other media[link]

Contemporary[link]

• A 1969 Walt Disney movie, The Computer Wore Tennis Shoes
• Steven King (Producer), Peter Chvany (Director/Editor) (1972). Computer Networks: The Heralds of Resource Sharing. http://documentary.operationreality.org/2011/08/27/computer-networks-the-heralds-of-resource-sharing. Retrieved 20 December 2011.  A 30 minute documentary film featuring Fernando J. Corbato, J.C.R. Licklider, Lawrence G. Roberts, Robert Kahn, Frank Heart, William R. Sutherland, Richard W. Watson, John R. Pasta, Donald W. Davies, and economist, George W. Mitchell.
• A 1985 episode of the U.S. television sitcom Benson includes a scene in which ARPANET is accessed. This is believed to be the first incidence of a popular TV show referencing the Internet or its progenitors.

Post-ARPANET[link]

• In Let the Great World Spin: A Novel, published in 2009 but set in 1974 and written by Colum McCann, a character named The Kid and others use ARPANET from a Palo Alto computer to dial phone booths in New York City in order to hear descriptions of Philippe Petit's tight rope walk between the World Trade Center Towers.
• In Metal Gear Solid 3: Snake Eater, a character named Sigint takes part in the development of ARPANET after the events depicted in the game.
• The Doctor Who Past Doctor Adventures novel Blue Box, written in 2003 but set in 1981, includes a character predicting that by the year 2000 there will be four hundred machines connected to ARPANET.
• There is an electronic music artist known as Arpanet, Gerald Donald, one of the members of Drexciya. The artist's 2002 album Wireless Internet features commentary on the expansion of the internet via wireless communication, with songs such as NTT DoCoMo, dedicated to the mobile communications giant based in Japan.
• In numerous The X-Files episodes ARPANET is referenced and usually hacked into by The Lone Gunmen. This is most noticeable in the episode "Unusual Suspects".
• Thomas Pynchon's 2009 novel Inherent Vice, set in southern California circa 1970, contains a character who accesses the "ARPAnet" throughout the course of the book.
• The viral marketing campaign for the video game Resistance 2 features a website similar in design and purpose to ARPANET, called SRPANET.

See also[link]

	Military history portal
	Government of the United States portal
	Internet portal

• .arpa, a top-level domain used exclusively for technical infrastructure purposes
• AMPRNet, AMateur Packet Radio Network
• Computer Networks: The Heralds of Resource Sharing — 1972 documentary film
• Project Cybersyn — 1970 Chilean national net project
• Usenet, "A Poor Man's ARPAnet"

References[link]

Further reading[link]

• Norberg, Arthur L.; O'Neill, Judy E. (1996). Transforming Computer Technology: Information Processing for the Pentagon, 1962–1982. Johns Hopkins University. pp. 153–196. ISBN 978-0801863691. 
• A History of the ARPANET: The First Decade (Report). Arlington, VA: Bolt, Beranek & Newman Inc.. 1 April 1981. http://www.dtic.mil/cgi-bin/GetTRDoc?Location=U2&doc=GetTRDoc.pdf&AD=ADA115440. 
• Hafner, Katie; Lyon, Matthew (1996). Where Wizards Stay Up Late: The Origins of the Internet. Simon and Schuster. ISBN 0-7434-6837-6. 
• Abbate, Janet (June 11, 1999). Inventing the Internet. Cambridge, MA: MIT Press. pp. 36–111. ASIN B003VPWY6E. ISBN 0262011727. 
• Banks, Michael A. (2008). On the Way to the Web: The Secret History of the Internet and Its Founders. APress/Springer Verlag. ISBN 1-4302-0869-4. 
• Salus, Peter H. (1 May 1995). Casting the Net: from ARPANET to Internet and Beyond. Addison-Wesley. ISBN 978-0201876741. 
• Waldrop, M. Mitchell (23 August 2001). The Dream Machine: J. C. R. Licklider and the Revolution That Made Computing Personal. New York: Viking. ASIN B00008MNVW. ISBN 0670899763. 
• "The Computer History Museum, SRI International, and BBN Celebrate the 40th Anniversary of First ARPANET Transmission". SRI International. October 29, 2009. http://www.sri.com/news/releases/102709.html. 

Detailed technical reference works[link]

• Roberts, Larry; Marrill, Tom (October 1966). "Toward a Cooperative Network of Time-Shared Computers". Fall AFIPS Conference. http://www.packet.cc/files/toward-coop-net.html. 
• Roberts, Larry (October 1967). "Multiple computer networks and intercomputer communication". ACM Symposium on Operating System Principles. http://www.packet.cc/files/multi-net-inter-comm.html. 
• Davies, D. W.; Bartlett, K. A.; Scantlebury, R. A.; Wilkinson, P. T. (October 1967). "A digital communications network for computers giving rapid response at remote terminals". ACM Symposium on Operating Systems Principles. 
• Roberts, Larry; Wessler, Barry (May 1970). "Computer Network Development to Achieve Resource Sharing". Proceedings of the Spring Joint Computer Conference, Atlantic City, New Jersey. http://www.packet.cc/files/arpa/comp-net-dev.html. 
• Heart, Frank; Kahn, Robert; Ornstein, Severo; Crowther, William; Walden, David (1970). "The Interface Message Processor for the ARPA Computer Network". 36. 1970 Spring Joint Computer Conference. pp. 551–567. 
• Carr, Stephen; Crocker, Stephen; Cerf, Vinton (1970). "Host-Host Communication Protocol in the ARPA Network". 36. 1970 Spring Joint Computer Conference. pp. 589–598. 
• Ornstein, Severo; Heart, Frank; Crowther, William; Russell, S. B.; Rising, H. K.; Michel, A. (1972). "The Terminal IMP for the ARPA Computer Network". 40. 1972 Spring Joint Computer Conference. pp. 243–254. 
• McQuillan, John; Crowther, William; Cosell, Bernard; Walden, David; Heart, Frank (1972). "Improvements in the Design and Performance of the ARPA Network". 41. 1972 Fall Joint Computer Conference. pp. 741–754. 
• Feinler, Elizabeth J.; Postel, Jonathan B. (January 1978). ARPANET Protocol Handbook, NIC 7104. Menlo Park: Network Information Center (NIC), SRI International. ASIN B000EN742K. 
• Roberts, Larry (November 1978). "The Evolution of Packet Switching". Proceedings of the IEEE. http://www.packet.cc/files/ev-packet-sw.html. 
• Roberts, Larry (Sept 1986). The ARPANET & Computer Networks. ACM. http://www.packet.cc/files/arpanet-computernet.html. 

External links[link]

This article's use of external links may not follow Wikipedia's policies or guidelines. Please improve this article by removing excessive or inappropriate external links, and converting useful links where appropriate into footnote references. (January 2011)

Wikimedia Commons has media related to: ARPANET

• "ARPANET Maps 1969 to 1977". CSUDH. 4 January 1978. http://som.csudh.edu/cis/lpress/history/arpamaps/. Retrieved 17 May 2012. 
• "Oral history interview with Robert E. Kahn". University of Minnesota, Minneapolis: Charles Babbage Institute. 24 April 1990. http://purl.umn.edu/107387. Retrieved 15 May 2008.  Focuses on Kahn's role in the development of computer networking from 1967 through the early 1980s. Beginning with his work at Bolt Beranek and Newman (BBN), Kahn discusses his involvement as the ARPANET proposal was being written and then implemented, and his role in the public demonstration of the ARPANET. The interview continues into Kahn's involvement with networking when he moves to IPTO in 1972, where he was responsible for the administrative and technical evolution of the ARPANET, including programs in packet radio, the development of a new network protocol (TCP/IP), and the switch to TCP/IP to connect multiple networks.
• "Oral history interview with Vinton Cerf". University of Minnesota, Minneapolis: Charles Babbage Institute. 24 April 1990. http://purl.umn.edu/107214. Retrieved 1 July 2008.  Cerf describes his involvement with the ARPA network, and his relationships with Bolt Beranek and Newman, Robert Kahn, Lawrence Roberts, and the Network Working Group.
• "Oral history interview with Paul Baran". University of Minnesota, Minneapolis: Charles Babbage Institute. 5 March 1990. http://purl.umn.edu/107101. Retrieved 1 July 2008.  Baran describes his work at RAND, and discusses his interaction with the group at ARPA who were responsible for the later development of the ARPANET.
• "Oral history interview with Leonard Kleinrock". University of Minnesota, Minneapolis: Charles Babbage Institute. 3 April 1990. http://purl.umn.edu/107411. Retrieved 1 July 2008.  Kleinrock discusses his work on the ARPANET.
• "Oral history interview with Larry Roberts". University of Minnesota, Minneapolis: Charles Babbage Institute. 4 April 1989. http://purl.umn.edu/107608. Retrieved 1 July 2008. 
• "Oral history interview with Stephen Lukasik". University of Minnesota, Minneapolis: Charles Babbage Institute. 17 October 1991. http://purl.umn.edu/107446. Retrieved 1 July 2008.  Lukasik discusses his tenure at the Advanced Research Projects Agency (ARPA), the development of computer networks and the ARPANET.
• Walden, David C. (February 2003). "Looking back at the ARPANET effort". East Sandwich, Massachusetts. http://www.livinginternet.com/i/ii_imp_walden.htm. Retrieved 17 August 2005. 
• "Images of ARPANET from 1964 onwards". The Computer History Museum. http://www.computerhistory.org/exhibits/internet_history/. Retrieved 29 August 2004.  Timeline.
• Leiner, Barry M.; Cerf, Vinton G.; Clark, David D.; Kahn, Robert E.; Kleinrock, Leonard; Lynch, Daniel C.; Postel, Jon; Roberts, Larry G. et al. "A Brief History of the Internet". Internet Society. http://www.isoc.org/internet/history/brief.shtml. Retrieved 29 August 2004. 
• "Paul Baran and the Origins of the Internet". RAND Corporation. http://www.rand.org/about/history/baran.html. Retrieved 3 September 2005. 
• "Leonard Kleinrock's Personal History/Biography". UCLA. http://www.lk.cs.ucla.edu/LK/Inet/birth.html. Retrieved 3 September 2005. 
• Kleinrock, Leonard. "The Day the Infant Internet Uttered its First Words". UCLA. http://www.lk.cs.ucla.edu/first_words.html. Retrieved 11 November 2004.  Personal anecdote of the first message ever sent over the ARPANET
• "Len Kleinrock on the Origins". IEEE. http://www.computer.org/internet/v1n3/kleinrock9702.htm. Retrieved 3 September 2005.  (subscribers only)
• "The Faces in Front of the Monitors". http://www.wbglinks.net/pages/watchmen/. ^{[dead link]}
• "Doug Engelbart's Role in ARPANET History". 2008. http://www.dougengelbart.org/firsts/internet.html. Retrieved 3 September 2009. 
• "Internet Milestones: Timeline of Notable Internet Pioneers and Contributions". http://www.juliantrubin.com/schooldirectory/internet_milestones_pioneers.html. Retrieved 6 January 2012.  Timeline.

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Atom
Publication information
Publisher	DC Comics
First appearance	(Cray) Suicide Squad #44 (August 1990) (Atom One Million) DC One Million 80-Page Giant #1,000,000 (August 1999)
Created by	(Cray) John Ostrander (Atom One Million) Grant Morrison
In-story information
Alter ego	- Al Pratt - Ray Palmer - Adam Cray - Ryan Choi
Team affiliations	(Cray) Suicide Squad Black Lantern Corps (Atom One Million) Justice Legion Alpha
Abilities	(All-except Pratt and Atom One Million) Ability to shrink and grow his body to varying degrees (including the subatomic level) while manipulating his weight and mass to his advantage

The Atom is a name shared by several fictional comic book superheroes from the DC Comics universe.

There have been five characters who have shared the Atom codename. The original Golden Age Atom, Al Pratt, was created by Ben Flinton and Bill O'Connor and first appeared in All-American Publications' All-American Comics #19 (Oct. 1940). The second Atom was the Silver Age Atom, Ray Palmer, who first appeared in 1961. The third Atom, Adam Cray, was a minor character present in Suicide Squad stories. The fourth Atom, Ryan Choi, debuted in a new Atom series in August 2006. The fifth Atom from the 853rd Century first appeared as part of Justice Legion Alpha in August 1999.

The Atom has been the star of multiple solo series, and four of the five have appeared as members of various superhero teams, such as the Justice Society of America, the Justice League, the Suicide Squad, and the Justice Legion Alpha.

Fictional character biographies[link]

Al Pratt[link]

The original Atom, Al Pratt, first appeared in All-American Comics #19 (Oct. 1940). He initially had no superpowers; instead, he was a diminutive college student and later a physicist who was depicted as a tough guy, a symbol of all the short kids who could still make a difference. Pratt was a founding member of the Justice Society of America, later gaining limited super-strength, and an energy charged 'atomic punch'. He died in the charge against Extant during the Zero Hour.^[1]

Ray Palmer[link]

The Atom introduced during the Silver Age of comic books in Showcase #34 (1961) is physicist and university professor Ray Palmer (named for real-life science fiction writer Raymond A. Palmer, who was himself quite short). Using a mass of white dwarf star matter, he fashioned a lens which allowed him to shrink down to subatomic size. Originally, his size and molecular density abilities derived from the white dwarf star material of his costume, controlled by mechanisms in his belt, and later by controls in the palms of his gloves. Much later, he gained the innate equivalent powers within his own body. After the events of Identity Crisis, Ray shrunk himself to microscopic size and disappeared. Finding him became a major theme of the Countdown year long series and crossover event.^[1]

Paul Hoben[link]

Prior to Ray Palmer's fateful trip to the Amazon Jungle, he learns his wife Jean Loring had an affair with fellow lawyer Paul Hoben and the two divorce. Later, Palmer would offer his blessing to the couple who marry and offers Hoben his size-changing belt in order to protect Ivy Town (as Ray wished to remain with the Morlaidhans) which he accepts. His belt would later be stolen by Adam Cray. It should be noted, Hoben never takes up the costume or name of the Atom.

Adam Cray[link]

Adam Cray, son of the murdered Senator Cray, first appeared as the Atom in the pages of Suicide Squad #44 by John Ostrander (August 1990). At first Cray was widely believed to be Ray Palmer in disguise (by both the fans and the characters). Actually Cray had been recruited by Palmer himself, who faked his death, in order to apprehend the Micro Squad (a group of villains that had been shrunk down) as well as uncover information about a shadowy government cabal, who were interested in Palmer's knowledge of the other heroes' secret identities (his own identity being no longer a secret).

While Palmer would infiltrate the Micro Squad, Cray would gather the attention of the Cabal as the new Atom, so that no one would notice Palmer assuming the identity of a fallen Micro Squad member.

Adam Cray ran with the Suicide Squad only for a short while, serving as a secret weapon most of the time, and his existence was for a while even unknown to others of the Squad. Cray even saves a wounded Amanda Waller from a group of assassins. At one point, Cray approaches Deadshot about the fact that Deadshot had murdered his father. Deadshot tells Cray that he would get one free shot at him. Soon after, on a mission, Cray is impaled through the chest by Blacksnake, a Micro Squad member who believes him to be Palmer.

After the murder of Cray (a move Palmer had not foreseen), Palmer reveals himself and defeats Cray's murderer. The ruse ended, Palmer explains himself to the Justice League, who had been searching for him, after hearing rumors of a new Atom.

During the events of Blackest Night, Adam's corpse is reanimated as a member of the Black Lantern Corps alongside several other fallen Suicide Squad members.^[2] Following his reanimation, Adam and the other Black Lanterns travel to Belle Reve and attack Bane and Black Alice.^[3] Adam is apparently destroyed by the Manhunter's self destruct mechanism to unleashing an explosion of Green Lantern energy that eradicates the Black Lanterns.^[4]

Ryan Choi[link]

Ryan Choi, as described by DC solicitations, is "a young hotshot professor who's filling the extra spot on Ivy University's teaching staff. .. and who inadvertently ends up filling the old Atom's super-heroic shoes".^[5] This new Atom is based on a redesign by Grant Morrison. He debuted in the Brave New World one-shot, a preview of upcoming projects, and then appeared in the series, The All-New Atom, written by Gail Simone. He is later murdered by Deathstroke and his Titans.

Atom One Million[link]

An unnamed scientist in the 853rd Century performed experiments in superstring theory that creates a singularity and whose radiation alters his physical make-up. When the singularity threatened to expand and destroy his universe, he enters it in an attempt to save the universe but instead finds himself on an interdimensional bridge to another universe as his own is wiped out, unable to stop it. At the end of the bridge, he finds Superman Prime who came to help but was too late. Stranded, he searches this universe for remnants of the one he lost, in time taking the name the Atom and joining the Justice Legion Alpha when he helped them defeat the Bizarro-Legion. This Atom's powers differ from his predecessors in that he doesn't shrink but breaks up into several smaller duplicates of himself divided amongst his mass. At atomic size, these duplicates can mimic elements such as gold and oxygen.

Other versions[link]

Frank Miller portrayed Ray Palmer as a major player in Batman: The Dark Knight Strikes Again. He was taken prisoner by Lex Luthor and made to live in one of his own petri dishes for a period of months until his rescue by Catgirl. He was then instrumental in the liberation of Kandor.

Tangent Comics[link]

In the Tangent Comics print, The Atom is Arthur Harrison Thompson, a subject of radiation testing on human beings. The first hero in the Tangent timeline, he was succeeded by his son, who was killed by the Tangent Comics version of the Fatal Five, and a grandson named Adam, who, in Tangent: Superman's Reign, is being held captive by Superman.

Elseworlds[link]

• Some other re-imaginings of the Atom include an appearance in League of Justice, a story portraying the Justice League in a The Lord of the Rings-type story where the Atom was recast as a wizard/fortune teller called "Atomus The Palmer".

• Al Pratt as the Atom was one of the three heroes who chose to work at the side of Senator Thompson in The Golden Age. When Al discovers that Thompson is really the Ultra-Humanite, he joins the other heroes against the villain and Dyna-Man.

• The Al Pratt Atom appeared in JSA: The Unholy Three as a post-WW2 intelligence agent with transparent atomic flesh and a visible skeleton.

• JLA: Age of Wonder where Ray Palmer worked with a science consortium whose numbers at one point included Thomas Edison and Nikola Tesla.

• JLA: Created Equal, after Ray Palmer is killed in the cosmic storm that nearly wipes out the rest of the male population on Earth, a graduate student named Jill Athron is given a research grant to study Palmer's white-dwarf-star-belt. She becomes the Atom and joins the Justice League.

• Atom evolved from a hawkman that had evolved from Robin in the Just Imagine... comic book.^[6]

52 Multiverse[link]

In the final issue of 52, a new Multiverse is revealed, originally consisting of 52 identical realities. Among the parallel realities shown is one designated "Earth-2". As a result of Mister Mind "eating" aspects of this reality, it takes on visual aspects similar to the pre-Crisis Earth-2, including the Atom among other Justice Society of America characters. The names of the characters and the team are not mentioned in the panel in which they appear, but the Atom is visually similar to the Al Pratt Atom.^[7] Based on comments by Grant Morrison, this alternate universe is not the pre-Crisis Earth-2.^[8]

In Countdown #30, the Challengers from Beyond encountered Earth-15, a world where the sidekicks had taken their mentor's places. On this Earth, the Atom is Jessica Palmer, a genius who graduated from MIT at age eight. The Search for Ray Palmer - Red Son features the Ray Palmer of Earth-30, an American captured by the Superman of a communist Russia. Countdown: Arena also depicts the Ray Palmer of Earth-6, who through unknown circumstances now has the powers and title of the Ray. The Search For Ray Palmer: Superwoman/Batwoman briefly features a female version of The Atom.

In the first issue of the 2010 Batman Beyond limited series, a future African-American version of the Atom known as Micron appears as one of the heroes of Earth-12.

Collected Editions[link]

[edit] Ray Palmer

[edit] Ryan Choi

In other media[link]

Television[link]

• Ray Palmer (voiced by Pat Harrington, Jr.) appeared in his own episodes in The Superman/Aquaman Hour of Adventure.
• Ray Palmer appears with the SuperFriends in The All-New Super Friends Hour and The Super Friends Hour voiced by Wally Burr.
• The Atom also makes an appearance with a slightly different color scheme costume in the live action 1979 TV special "Legends of the Superheroes", specifically "The Roast" episode.
• A future version of the Atom called Micron appeared as a Justice League Unlimited member in the Batman Beyond two part episode "The Call" voiced by Wayne Brady. Unlike the Atom, Micron can grow as well as shrink, and similar to Atom Smasher with super-strength.
• In an early Justice League episode, "Legends," the League team up with the Justice Society pastiche the Justice Guild of America. JGA member Tom Turbine is a cross between Golden Age Atom and the Golden Age Superman^{[citation needed]}. The Atom is later mentioned by name in "Hereafter," as a future Vandal Savage describes how he stole technology from Ray Palmer and destroyed the world.
• The Atom (Ray Palmer) later appeared in Justice League Unlimited in both "Dark Heart" and "The Return" as a nanotechnology expert, voiced by John C. McGinley.
• The Atom (Ray Palmer) also appeared in the 1997 live action made-for-TV movie pilot, Justice League of America played by John Kassir.
• The Ryan Choi version of the Atom appears in the series Batman: The Brave and the Bold, voiced by James Sie. The Atom helps Batman stop evil sorcerer Felix Faust from opening Pandora's Box in "Evil Under the Sea!". He re-appeared along with Aquaman to save Batman from a virus created by Chemo in "Journey to the Center of the Bat!". Atom has a Crime Syndicate counterpart called Dyna-Mite, also voiced by James Sie. A mind-controlled Ryan Choi appears in "The Siege of Starro! Part One", demonstrating the ability to grow to giant sizes, which he uses to prevent Batman from destroying a signal leading Starro to Earth. He also appears in the teaser for "The Criss Cross Conspiracy!", where he, Batman, and Aquaman battle the Bug-Eyed Bandit.
• The Atom is briefly mentioned in the Young Justice episode "Failsafe", with Cat Grant stating that he had been killed alongside Batman, Icon and Aquaman during an alien invasion of Earth. The invasion is later revealed to simply be a training exercise. The Atom is shown among several candidates for Justice League membership in the episode "Agendas" where Batman cites his size-changing abilities as an important asset and he is officially inducted into the group in the episode "Usual Suspects".

Video Game[link]

• The Atom (Ray Palmer) appears in DC Universe Online.

See Also[link]

• Molecule

References[link]

External links[link]

• Index to the Atom's Earth-1 adventures
• Article on the history/legacy of The Atom from the Comics 101 article series by Scott Tipton
• THE SIMONE FILES II: THE ALL NEW ATOM
• COUNTING DOWN TO COUNTDOWN IV: THE GREAT DISASTER AND THE ATOM