Tuesday, May 11. 2010
Via GOOD
-----
by Mother Nature Network
It seems that time travel has captured the imaginations of people since time began. Einstein’s Special Theory of Relativity speculated that traveling close to the speed of light would physically alter time by dilating it. This means that there should be places where time slows down, and others where time speeds up. Discovery News reports that Hawking recently expanded on this theory, outlining several theoretically realistic ideas for traveling through time.
Hawking almost perfectly explains his theories in a letter to the Daily Mail in a way that non-cosmologists can understand. He encourages people to think of time as dimension just like width, height and length. Just as when you travel in a car, you can go forward, right or left. The fourth dimension would be time. And all around us are wormholes that could act as a time tunnel.
As Hawking writes, "Down at the smallest of scales, smaller even than molecules, smaller than atoms, we get to a place called the quantum foam. This is where wormholes exist. Tiny tunnels or shortcuts through space and time constantly form, disappear, and reform within this quantum world. And they actually link two separate places and two different times." The time tunnels are too small for people to travel through, but Hawking and others believe that someday a wormhole could be widened for person or ship to travel through to the future.
Hawking points out that travel backward in time may be impossible due to the cause and effect theory. (For example, if you travel backward and prevent your birth, how could you have ever been born?) Further, Hawking suspects that radiation might collapse the wormholes, rendering them useless anyway.
Another way to time travel rides on the “time as a river” theory. As Einstein proposed before him, there are places where time moves faster and where time moves slower. It depends if there are things that drag on space, much like rocks in a moving river. The Earth itself drags on space, meaning time moves slower on Earth than it does in space. Hawking points out that the Global Positioning System satellite network in space must be adjusted because of this.
Further, Hawking claims black holes may be the key to time travel. He asks us to imagine a spaceship orbiting a super-massive black hole some 26,000 miles away. To us, it would just look like the ship makes one orbit every 16 minutes. As Hawking writes, "A black hole ... has a dramatic effect on time, slowing it down far more than anything else in the galaxy. That makes it a natural time machine. … But for the brave people on board, close to this massive object, time would be slowed down. For every 16-minute orbit, they'd only experience eight minutes of time."
Hawking reminds us that nothing can travel faster than the speed of light, and that time will always slow down right before reaching this speed. Therefore, if we had a ship that could travel near the speed of light, we could also travel in time.
Katherine Butler is a TV writer who writes for the Mother Nature Network.
Personal comment:
Some ideas we've already heard or read about I feel, about time as an "architecturable" dimension. But a good short reminder by S. Hawking concerning actual scientific knowledge of time (travel).
-----
Metamaterials allow the creation of adjacent spaces with their own laws of physics, just like the multiverse.
Metamaterials are substances in which physicists have fiddled with a material's ability to support electric and magnetic fields. They can be designed to steer electromagnetic waves around, over and behind objects to create invisibility cloaks that hide objects.
If that sounds a little like the way gravitational fields can bend light, then you won't be surprised to learn that there is a formal mathematical analogy between optical metamaterials and general relativity.
The idea that anything Einstein can do, metamaterials can do too has fueled an explosion of interest in "electromagnetic space". Physicists have already investigated black holes that suck light in but won't let it out and wormholes that connect different regions of electromagnetic space.
Today, Igor Smolyaninov at the University of Maryland in College Park says that the analogy with spacetime can be taken much further. He says it is possible to create metamaterials that are analogous to various kinds of spaces dreamt up by cosmologists to explain aspects of the Universe.
In these theories, space can have different numbers of dimensions that become compactified early in the Universe's history, leaving the three dimensions of space and one of time (3+1) that we see today. In symmetries of these spaces depend on the dimensions and the way they are compactified and this in turn determines the laws of physics in these regions.
It turns out, says Smolyaninov, that it is possible to create metamaterials with electromagnetic spaces in which some dimensions are compactified. He says it is even possible to create substances in which the spaces vary from region to region, so a space with 2 ordinary and 2 compactified dimensions, could be adjacent to a space with just 2 ordinary dimensions and also connected to a 2d space with 1 compactified dimension and so on.
The wormholes that make transitions between these regions would be especially interesting. It ought to be possible to observe the birth of photons in these regions and there is even a sense in which the transition could represent the birth of a new universe."A similar topological transition may have given birth to our own Universe," says Smolyaninov.
He goes on to show that these materials can be used to create a multiverse in which different universes have different properties. In fact it ought to be possible create universes in which different laws of physics arise.
That opens up a new area for optical devices. Smolyaninov gives the example of electromagnetic universes in which photons behave as if they are massive, massless or charged depending on the topology of space and the laws of physics this gives rise to.
Just what kind of devices could exploit this behaviour isn't clear yet. If you think of any, post them here. This is clearly a field that for the moment appears to be limited only by the mind of the designer.
Ref: arxiv.org/abs/1005.1002: Metamaterial "Multiverse"
Monday, May 10. 2010
Via Rob Aid
-----
We already wrote about several 3D printers which are mostly used for rapid prototyping or creating delicious meals out, however 3D printing technology has leapt into a new realm because the Organovo NovoGen 3D bio-printer can build body parts from cells and it recently created the first “printed” human vein. The printer is meant to be used in regenerative medicine.
Instead using donor body parts or performing a surgery to transplant some of your own, the printer could just make a new part for you. The printer, developed by Invetech, is loaded with cartridges of “bio-ink” a substance that acts as a kind of scaffolding for the cells to retain their shape. A sophisticated computer is linked to the printer that is pre-programmed with the 3D blueprint of whatever is being made.
The printer fits inside a standard biosafety cabinet for sterile use. The 3D bio-printers include an intuitive software interface that allows engineers to build a model of the tissue construct before the printer commences the physical constructions of the organs cell-by-cell using automated, laser-calibrated print heads.
It includes two print heads, one for placing human cells, and the other for placing a hydrogel, scaffold, or support matrix. One of the most complex challenges in the development of the printer was being able to repeatedly position the capillary tip, attached to the print head, to within microns. This was essential to ensure that the cells are placed in exactly the right position. Invetech developed a computer controlled, laser-based calibration system to achieve the required repeatability.
Dr. Fred Davis, president of Invetech, which has offices in San Diego and Melbourne, said, “Building human organs cell-by-cell was considered science fiction not that long ago. Through this clever combination of technology and science we have helped Organovo develop an instrument that will improve people’s lives, making the regenerative medicine that Organovo provides accessible to people around the world.”
This technology could replace other toxic and carbon-heavy medicinal practices like using artificial parts in the human body if the method proves the body accepts printed parts. Invetech plan to ship a number of 3D bio-printers to Organovo during 2010 and 2011 as a part of the instrument development program. Organovo will be placing the printers globally with researchers in centers of excellence for medical research.
Friday, May 07. 2010
Via DVice
A company called PediaPress is allowing users to turn a collection of Wikipedia pages into softcover books. In theory, this would let you create your own bound volume on any damn thing, as, really, your creativity is the limit. Want to create your own science textbook? You could do that, sure. Want to create a guide for power tools? Just hit those pages up. Want a tome that covers, in detail, ancient meditation techniques and famous clowns? You can do that, too. And so it goes.
A portion of the proceeds from the books you print will go to Wikipedia, to boot. Prices vary depending on how big your book will be (a book simply titled "Wikipedia," for instance, would probably be pretty expensive), though they start at $8.90. If you're really looking for Wikipedia on the go, though, there's already a gadget for that — the WikiReader.
Monday, May 03. 2010
-----
The 'Living Earth Simulator' will mine economic, environmental and health data to create a model of the entire planet in real time.
When it comes to global crises, we're not short of complex systems that look close to the edge: the climate, the food supply, energy security, the banking system and so on. Add to this the threat of war in many parts of the world and the possibility of global pandemics and it's a wonder that anybody gets out of bed in the morning.
Science has certainly played an important role in understanding aspects of these systems but could it do more?
Today, Dirk Helbing at the Swiss Federal Institute of Technology in Zurich outlines an ambitious project to go further, much further.
Helbing's idea is to create a kind of Manahattan project to study, understand and tackle these techno-socio-economic-environmental issues. His plan is to gather data about the planet in unheard of detail, use it to simulate the behaviour of entire economies and then to predict and prevent crises from emerging.
Think of it as a kind of Google Earth for society. We've all played with Google's 3D map of the Earth that uses real data to reveal not only the town where you live and work but your home and back garden too.
Imagine a similar model that uses in real time things like financial transactions, health records, travel details, carbon dioxide emissions and so on to build a model of not just the planet but the entire society that populates it. Helbing calls it 'reality mining'.
This model will be capable not only modelling the planet in real time but of simulating the future, rather in the manner of weather forecasters.
Helbing's simulator will look for economic bubbles and collapses, warn of global pandemics and suggest how to tackle them, it will model and predict the outcome of regional conflicts and determine the effect of our behaviour on the climate. He even wants to create 'situation rooms' in which global leaders can view and manage crises as they occur.
This Google-Earth-on-steroids is to be called the Living Earth Simulator and Helbing's plan is to have it working by 2022 at a cost of a cool EUR 1 billion, funded by the European Commission. He's even assembled an impressive team to help, including partners from most of the top universities in Europe.
So what to make of this plan and it's ambition. At first glance, it seems a somewhat worrying, even frightening, vision of the future. A Living Earth Simulator will change how we see ourselves and our planet in ways that are hard to imagine right now.
There's no question that we need to better understand the global nature of the society we live in and the effects that it has on the planet. We also need to know how to leverage the benefits of these global systems while limiting the downsides they can generate.
This capability is coming whether we like it or not. Clearly, the computing infrastructure of the near future will be increasingly capable of such a task.
The great worry, of course, is that it will not be the great public universities and government-funded research institutes that complete this task. The huge benefits of a Living Earth Simulator will make it a valuable tool for insurance companies, financial traders, global businesses and even search engines.
It's not hard to imagine a company like Google wanting and even building such a model. And if that seems hard to swallow, there are plenty of organisations that may be even less palatable operators of such a system. Imagine a Goldman Sachs Earth Simulator or one run by the People's Liberation Army. EUR 1 billion is just a small fraction of the money these organisations play with.
When viewed through that prism, it seems clear and even necessary that such a project is publicly funded and managed. Should the European Commission agree, Helbing, who is a world leader in the new science of techno-socio-economic studies, may well be the man who leads it.
A Living Earth Simulator is coming, one way or another, perhaps even to your living room or mobile communicator. The only question is who builds it.
Ref: arxiv.org/abs/1004.4969: The FuturICT Knowledge Accelerator
|