A Matrioshka Brain Is A Computer The Size Of A Solar System

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A Matrioshka Brain Is A Computer The Size Of A Solar System

Imagine a computer the size of a solar system. For power, it would use a Dyson sphere—a solar array that completely surrounds the host star to collect almost all of its energy. That energy-collecting sphere would double as an ultra-powerful computer processor. Once the sphere had collected all the energy it needed, it would pass the excess to another larger Dyson-sphere processor that completely surrounded the first, repeating the process until all of the energy was being used. That's why this theoretical computer is called a Matrioshka brain: the nested Dyson spheres would resemble matryoshka dolls, or Russian nesting dolls. Of course, if you surround your star with Dyson spheres, it would be difficult for life on your planet to continue. That's kind of the point: this Matrioshka brain would be so powerful that a species could upload their entire consciousness into it and live within an alternate universe simulated by the computer. The species itself could die and its planet could be destroyed, but the civilization would live on in a digital world identical to the one it left behind. In fact, many people, including Elon Musk, believe we're living in a simulation like that at this very moment. This provides one answer to the Fermi Paradox—that is, the question of why we haven't encountered aliens despite the likelihood that they're out there. It's possible that any civilization advanced enough to find us has already decided to abandon reality entirely and upload themselves to a Matrioshka brain. Delve deeper into megastructures and theoretical tech with the videos below.

One Of The Most Common Passwords Is "123456"

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One Of The Most Common Passwords Is "123456"

A massive June 2016 Twitter hack suggests that it might be wise to take a course on internet security. The hack of almost 33 million users revealed that more than 120,000 of them used the foolishly simple "123456" as their passcodes. (Other popular passwords were "password," "qwerty," and "123456789.") Though simple and obvious passwords can be easy to guess and figure out, sometimes it doesn't make a difference. If a hacker is logging your keystrokes, then it doesn't matter how complicated and strong your password is. Two-step authentication is the safest way for a website to protect its users' information. For this process, an additional passcode is texted or emailed to you to ensure you're the one trying to log into your own account. We've collected some awesome videos on this topic. Watch them now to learn more.

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from Brit Lab

Key Facts to Know

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    "Password" is still the most common password, followed by "123456." 0:31

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    A hybrid attack, which combines each word with different number combinations, only takes about 1 hour and 40 minutes. 2:28

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    A 2-digit password is ten times harder to crack than a 1-digit password. 3:29

What Happens If GPS Fails?

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What Happens If GPS Fails?

One day in January 2016, the U.S. Air Force decommissioned a single satellite and accidentally uploaded an incorrect time to the clocks aboard 15 others in the process. The time difference was tiny -- only 13 millionths of a second -- but the results were significant. Police, fire, and EMS radio equipment in some parts of North America stopped functioning for more than 12 hours, and BBC digital radio went out for two days in several areas. Luckily, short-term backup systems helped ensure that the general public wasn't affected by many of the problems, but the scare posed an important question: what do we do if GPS fails completely? We might be able to go back to paper maps, but navigation is a very small part of what makes the system important. What's most essential about GPS is time: each satellite contains multiple atomic clocks that are synchronized to nanosecond precision and continually broadcast signals to Earth. For navigation, GPS units use the tiny differences in the arrival time of each of these signals to know exactly where they are in the world. But some things, like cell towers, power grids, and ATMs, rely on the time alone to stay synchronized. This means that a GPS failure could disrupt an untold number of systems essential to daily life -- and there's no backup plan.

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Key Facts to Know

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    There are 30 GPS satellites in space. To triangulate its location, a device has to receive signals from four of them at once. 0:09

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    Special Relativity tells us that moving clocks run slow, and General Relativity tells us that clocks run faster higher up in a gravitational field. 0:25

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    There are always at least four GPS satellites visible from any point on Earth. 1:15

Computers Might Never Be Able To Solve These Three Problems

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Computers Might Never Be Able To Solve These Three Problems

In computer science, an undecidable problem is one that requires a yes or no answer, but is impossible for any known computer to reliably solve. Three of these problems are the halting problem, Kolmogorov complexity, and the Wang tile problem. The halting problem refers to whether a computer can determine if a program will ever finish running, whereas Kolmogorov complexity deals with compression, and the impossibility of perfectly compressing any given file. Wang tiles are square tiles with a color on each side. Infinitely placing them next to each other so that the colors of each side match the colors on the adjacent squares is called "tiling the plane," and there is currently no computer that can predict whether a given set of Wang tiles will tile the plane. Dive deeper into these computer conundrums in the video below.

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Key Facts to Know

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    The halting problems states that no computer can always determine if a program will continue to run or eventually stop. 0:32

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    Thus far, no program can perfectly compress any given file due to Kolmogorov complexity. 1:23

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    There can be no method that can take any given set of Wang tiles and tell you whether or not it will tile the plane. 2:05

Could We All Be Living In A Computer Simulation?

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Could We All Be Living In A Computer Simulation?

In 2003, philosopher Nick Bostrom proposed the simulation hypothesis, which officially put forth the idea that our universe might be a computer simulation. Both scientists and Hollywood directors have since addressed this notion and its variants, but few people have suggested feasible tests for proving or disproving it. In 2012, a team at the University of Washington said that looking for a limitation in the energy of cosmic rays might be indicative of a simulation's "signature." Others have said that unexplained physics phenomena might be "glitches" in the simulation, which could never be a perfect copy of a real universe. Building a simulation ourselves would help us to determine what these glitches look like, and subsequently search for them in our own universe. However, the technology needed for simulating a universe (inside our own, which may or may not be a simulation itself) is not yet available.

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from DNews

Key Facts to Know

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    The idea of our reality being an illusion is as old as Buddhist and Hindu philosophy. 0:24

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    Scientists at the University of Washington have proposed running tests to determine whether our universe is a simulation. 1:00

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    Some people believe that unexplainable phenomena in physics could indicate "glitches," and provide proof that our universe is a simulation. 2:12