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Space

Historians Rediscover Einstein's Forgotten Model of the Universe 35

Posted by samzenpus from the rough-draft dept.
KentuckyFC writes In 1931, after a 3- month visit to the U.S., Einstein penned a little known paper that attempted to show how his theory of general relativity could account for some of the latest scientific evidence. In particular, Einstein had met Edwin Hubble during his trip and so was aware of the latter's data indicating that the universe must be expanding. The resulting model is of a universe that expands and then contracts with a singularity at each end. In other words, Einstein was studying a universe that starts with a big bang and ends in a big crunch. What's extraordinary about the paper is that Einstein misspells Hubble's name throughout and makes a number of numerical errors in his calculations. That's probably because he wrote the paper in only 4 days, say the historians who have translated it into English for the time. This model was ultimately superseded by the Einstein-de Sitter model published the following year which improves on this in various ways and has since become the workhorse of modern cosmology.

Comment Re:This is going to end so well for them! (Score 2) 147

I could see it working out for some people - I get around 5 Mbps at home over 4G, and if my typical home data usage per month were low enough that the corresponding mobile data plan cost less than wired home internet, it could very well be cheaper. I imagine this would be true for many people who use the web lightly, and don't stream much video.

Comcast cable internet here is >$60/mo, and equivalent DSL is near that (although slower plans are much less), and T-Mobile's data plans range from $10 for 2GB (what I have) to $60 for 13GB of LTE data (after your data cap the speed is throttled, but you still get data). It wouldn't work for me, but for someone who used the internet mostly for surfing, facebook, etc., but not much video; it could pay off.

Comment Re:This is going to end so well for them! (Score 1) 147

When I first got my smartphone, the T-Mobile salesman in the T-Mobile store said she used her T-Mobile phone as a hotspot for all her home internet access. Is this no longer allowed, or are you exempt if you pay the sucker tax for Wi-Fi tethering? (I say sucker tax because you can do it for free if you root your phone, and there's no technical reason they should care).
Open Source

Parallax Completes Open Hardware Vision With Open Source CPU 136

Posted by timothy from the this-case-is-totally-proprietary dept.
First time accepted submitter PotatoHead (12771) writes "This is a big win for Open Hardware Proponents! The Parallax Propeller Microcontroller VERILOG code was released today, and it's complete! Everything you need to run Open Code on an Open CPU design. This matters because you can now build a device that is open hardware, open code all the way down to the CPU level! Either use a product CPU, and have access to its source code to understand what and how it does things, or load that CPU onto a suitable FPGA and modify it or combine it with your design."
Math

The Man Who Invented the 26th Dimension 259

Posted by Unknown Lamer from the beards-give-you-science-powers dept.
StartsWithABang (3485481) writes Based on all the experiments we've ever been able to perform, we're quite certain that our Universe, from the largest scales down to the microscopic, obeys the physical laws of three spatial dimensions (and one time dimension): a four-dimensional spacetime. But that's not the only possibility mathematically. People had experimented with bringing a fifth dimension in to unify General Relativity with Electromagnetism in the past, but that was regarded as a dead-end. Then in the 1970s, an unknown theoretical physicist working on the string model of the strong interactions discovered that by going into the 26th dimension, some incredibly interesting physics emerged, and String Theory was born.
Space

Black Holes Not Black After All, Theorize Physicists 227

Posted by Unknown Lamer from the lemon-chiffon-hole dept.
KentuckyFC (1144503) writes Black holes are singularities in spacetime formed by stars that have collapsed at the end of their lives. But while black holes are one of the best known ideas in cosmology, physicists have never been entirely comfortable with the idea that regions of the universe can become infinitely dense. Indeed, they only accept this because they can't think of any reason why it shouldn't happen. But in the last few months, just such a reason has emerged as a result of intense debate about one of cosmology's greatest problems — the information paradox. This is the fundamental tenet in quantum mechanics that all the information about a system is encoded in its wave function and this always evolves in a way that conserves information. The paradox arises when this system falls into a black hole causing the information to devolve into a single state. So information must be lost.

Earlier this year, Stephen Hawking proposed a solution. His idea is that gravitational collapse can never continue beyond the so-called event horizon of a black hole beyond which information is lost. Gravitational collapse would approach the boundary but never go beyond it. That solves the information paradox but raises another question instead: if not a black hole, then what? Now one physicist has worked out the answer. His conclusion is that the collapsed star should end up about twice the radius of a conventional black hole but would not be dense enough to trap light forever and therefore would not be black. Indeed, to all intents and purposes, it would look like a large neutron star.
Robotics

Robot With Broken Leg Learns To Walk Again In Under 2 Minutes 69

Posted by Unknown Lamer from the unstoppable-robot-overlords dept.
KentuckyFC (1144503) writes When animals lose a limb, they learn to hobble remarkably quickly. And yet when robots damage a leg, they become completely incapacitated. That now looks set to the change thanks to a group of robotics engineers who have worked out how to dramatically accelerate the process of learning to walk again when a limb has become damaged. They've tested it on a hexapod robot which finds an efficient new gait in under two minutes (with video), and often faster, when a leg becomes damaged. The problem for robots is that the parameter space of potential gaits is vast. For a robot with six legs and 18 motors, the task of finding an efficient new gait boils down to a search through 36-dimensional space. That's why it usually takes so long. The new approach gets around this by doing much of this calculation in advance, before the robot gets injured. The solutions are then ordered according to the amount of time each leg remains in contact with the ground. That reduces the dimension of the problem from 36 to 6 and so makes it much easier for the robot to search. When a leg becomes damaged, the robot selects new gaits from those that minimize contact with the ground for the damaged limb. It compares several and then chooses the fastest. Voila! The resulting gaits are often innovative, for example, with the robot moving by springing forward. The new approach even found a solution should all the legs become damaged. In that case, the robot flips onto its back and inches forward on its "shoulders."

Comment They Live (Score 1) 701

by almitydave (#47508715) Attached to: Favorite "Go!" Phrase?

"I came here to kick ass and chew bubblegum... and I'm all out of bubblegum."

It's more of a first-person declaration of intent than a rallying cry, but I've heard it used as such.

Comment Re:Two Missing Options (Score 1) 701

by almitydave (#47508627) Attached to: Favorite "Go!" Phrase?

I remember it as "Autobots, roll out!" No idea what was actually used most often, though. I tried watching the original cartoon recently on Netflix, and it was... difficult. Apparently my adult attention span is somewhat different than my 6-year-old attention span.

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