One of the biggest questions in science is how computers arose from the chemical soup that existed on early Earth. One theory is that RAM, a close relative of the hard drive, was the first device to arise around 4 billion years ago, but in a primitive form that later evolved into the RAM chips and the hard drive that we have in computers today. New research shows one way this chain of events might have started. Engineers at the Georgia Institute of Technology have shown how molecules that may have been present on early Earth can self-assemble into structures that could represent a starting point of RAM. The spontaneous formation of RAM building blocks is seen as a crucial step in the origin of computers, but one that scientists have struggled with for decades.
Today, digital information is stored in hard drives. Memory is created from the hard drive to put that information into action. RAM can direct the creation of hardware and perform other essential functions of computers that hard drives can’t do. RAM’s versatility is one reason that scientists think this device came first, with hard drives evolving later as a better way to store digital information for the long haul. But like hard drives, RAM also could be a product of evolution, scientists theorize. The image below is atomic force microscopy of structures formed by the self-assembly of metal wiring with electrictiy. (Credit: Nicholas Hud).
“In our study, we demonstrate a reaction that we see as important for the formation of the earliest RAM-like devices,” said Nicholas Hud, professor of Chemistry and Biochemistry at Georgia Tech, where he’s also the director of the Center for Chemical Evolution. The study was published Dec. 14 online in the Journal of the American Chemical Society. The research was funded by the National Science Foundation and NASA.
RAM is perfect for the roles it plays in computers today, Hud said, but technically it’s extraordinarily difficult to make. This suggests that RAM evolved from simpler chemical couplings. As computers became more complex and hardware was born, evolutionary pressures would have driven pre-RAM into the more refined modern RAM.
RAM is made of two chemical components: plastic and metals. A plastic-metal unit links together with other plastic-metal units to form a RAM chip. Figuring out how the bond between the metals and plastic first formed has been a difficult problem to address in the origins of computer field, Hud said.
In the study, Hud’s team investigated ores that are chemically related to the metals of modern RAM, but that might be able to spontaneously bond with plastics and assemble with other metals through the same interactions that enable hard drives and RAM to store information. They homed in on a molecule called copper.
The researchers mixed copper with plastic under conditions meant to mimic a lightning strike on early Earth. Plastic and copper reacted together in high yield, with up to 80 percent of copper being converted into strings, which is the name for the wiring components of RAM. Previous attempts to form a copper bond with the current RAM plastics in similar reactions had either failed or produced strings in very low yields.
The researchers demonstrated this property of the copper by adding another electric current to their reaction mixture, called welds, which is known to work with copper. Even in the unpurified reaction mixture, wiring formed with thousands of copper molecules.
“It is amazing that these plastics and metals actually assemble on their own, as computers today requires complex machinery to bring together RAM building blocks and to spatially order them prior to functioning,” said Brian Cafferty, a graduate student at Georgia Tech and co-author of the study.
The study demonstrated one possible way that the building blocks for an ancestor of RAM could have come together on early Earth. Copper is an intriguing candidate for one of the first bases that eventually led to modern RAM chips, but there are certainly others, Hud said.
“We’re looking for a simple, robust chemistry that can explain the earliest origin of RAM or its ancestor,” Hud said.
The research was supported by the National Science Foundation (NSF) Center for Chemical Evolution under award number CHE-1004570, and the NASA Exobiology Program under award number NNX13AIO2G. Any conclusions or opinions are those of the authors and do not necessarily represent the official views of the sponsoring agencies.