Computer
hideA computer is a machine that manipulates data according to a set of instructions.
Although mechanical examples of computers have existed through much of recorded human history, the first electronic computers were developed in the mid-20th century (1940–1945). These were the size of a large room, consuming as much power as several hundred modern personal computers (PCs). Modern computers based on integrated circuits are millions to billions of times more capable than the early machines, and occupy a fraction of the space. Simple computers are small enough to fit into a wristwatch, and can be powered by a watch battery. Personal computers in their various forms are icons of the Information Age and are what most people think of as "computers". The embedded computers found in many devices from MP3 players to fighter aircraft and from toys to industrial robots are however the most numerous.
The ability to store and execute lists of instructions called programs makes computers extremely versatile, distinguishing them from calculators. The Church–Turing thesis is a mathematical statement of this versatility: any computer with a certain minimum capability is, in principle, capable of performing the same tasks that any other computer can perform. Therefore computers ranging from a mobile phone to a supercomputer are all able to perform the same computational tasks, given enough time and storage capacity.
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News tagged with computer
Turning heat to electricity... efficiently
Nov 18, 2009 |
4.8 / 5 (63) |
9
(PhysOrg.com) -- In everything from computer processor chips to car engines to electric powerplants, the need to get rid of excess heat creates a major source of inefficiency. But new research points the way ...
Arctic at warmest levels in 2,000 years or more
Space & Earth / Earth Sciences
Sep 03, 2009 |
4.3 / 5 (64) |
25
Arctic temperatures in the 1990s reached their warmest level of any decade in at least 2,000 years, new research indicates. The study, which incorporates geologic records and computer simulations, provides ...
The Fall of the Maya: 'They Did it to Themselves'
Other Sciences / Archaeology & Fossils
Oct 07, 2009 |
4.4 / 5 (53) |
16
For 1200 years, the Maya dominated Central America. At their peak around 900 A.D., Maya cities teemed with more than 2,000 people per square mile -- comparable to modern Los Angeles County. Even in rural areas ...
Quantum computing may actually be useful, after all
Oct 09, 2009 |
4.6 / 5 (35) |
9
(PhysOrg.com) -- In recent years, quantum computers have lost some of their luster. In the 1990s, it seemed that they might be able to solve a class of difficult but common problems — the so-called NP-complete ...
Solving big problems with new quantum algorithm
Nov 09, 2009 |
4.6 / 5 (32) |
0
(PhysOrg.com) -- In a recently published paper, Aram Harrow at the University of Bristol and colleagues from MIT in the United States have discovered a quantum algorithm that solves large problems much faster ...
The Handwriting of Liars
Medicine & Health / Psychology & Psychiatry
Sep 21, 2009 |
3.1 / 5 (37) |
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(PhysOrg.com) -- Forget about unreliable polygraph lie detectors for identifying liars. A new study claims the best way to find out if someone is a liar is to look at their handwriting, rather than analyzing ...
Study Shows Time Traveling May Not Increase Computational Power
Oct 22, 2009 |
4.1 / 5 (26) |
5
(PhysOrg.com) -- For more than 50 years, physicists have been intrigued by the concept of closed time-like curves (CTCs). Because a CTC returns to its starting point, it raises the possibility of traveling backward in time. ...
Laser-plasma accelerators ride on Einstein's shoulders
Nov 02, 2009 |
5 / 5 (21) |
0
Using Einstein's theory of special relativity to speedup computer simulations, scientists have designed laser-plasma accelerators with energies of 10 billion electron volts (GeV) and beyond. These systems, ...
Computer scientists successfully boot one million Linux kernels as virtual machines
Technology / Computer Sciences
Sep 25, 2009 |
4.7 / 5 (22) |
8
(PhysOrg.com) -- Computer scientists at Sandia National Laboratories in Livermore, Calif., have for the first time successfully demonstrated the ability to run more than a million Linux kernels as virtual ...
P vs. NP -- The most notorious problem in theoretical computer science remains open
Technology / Computer Sciences
Oct 29, 2009 |
4.6 / 5 (22) |
5
In the 1995 Halloween episode of The Simpsons, Homer Simpson finds a portal to the mysterious Third Dimension behind a bookcase, and desperate to escape his in-laws, he plunges through. He finds himself wander ...
A trillion triangles: New computer methods reveal secrets of ancient math problem
Sep 22, 2009 |
4.5 / 5 (21) |
1
Mathematicians from North America, Europe, Australia, and South America have resolved the first one trillion cases of an ancient mathematics problem. The advance was made possible by a clever technique for ...
Communicating person to person through the power of thought alone (w/ Video)
Medicine & Health / Neuroscience
Oct 06, 2009 |
3.6 / 5 (25) |
8
New research from the University of Southampton has demonstrated that it is possible for communication from person to person through the power of thought alone.
Researchers Develop Material That Could Boost Data Storage, Save Energy
Nanotechnology / Nanomaterials
Oct 20, 2009 |
4.5 / 5 (18) |
1
(PhysOrg.com) -- North Carolina State University engineers have created a new material that would allow a fingernail-size computer chip to store the equivalent of 20 high-definition DVDs or 250 million pages of text, far ...
Scientist: Leak of climate e-mails appalling
Nov 23, 2009 |
3.8 / 5 (21) |
29
(AP) -- A leading climate change scientist whose private e-mails are included in thousands of documents that were stolen by hackers and posted online said Sunday the leaks may have been aimed at undermining next month's ...
Quantum Computer Chips Now One Step Closer To Reality
Oct 15, 2009 |
4.6 / 5 (16) |
0
In the quest for smaller, faster computer chips, researchers are increasingly turning to quantum mechanics -- the exotic physics of the small. The problem: the manufacturing techniques required to make quantum devices have ...
