Tag Archives: astrophysics

The Emperor and/is the Butterfly

In an earlier post I touched on the notion proposed by some cosmologists that our entire universe is some kind of highly advanced simulation. The hypothesis is that perhaps we are merely information elements within a vast mathematical fabrication, playthings of a much superior consciousness. Some draw upon parallels to The Matrix movie franchise.

Follow some of the story and video interviews here to learn more of this fascinating and somewhat unsettling idea. More unsettling still: did our overlord programmers leave a backdoor?


Video: David Brin – Could Our Universe Be a Fake? Courtesy of Closer to Truth.

You May Be Living Inside a Simulation


Some theorists posit that we are living inside a simulation, that the entire universe is one giant, evolving model inside a grander reality. This is a fascinating idea, but may never be experimentally verifiable. So just relax — you and I may not be real, but we’ll never know.

On the other hand, but in a similar vein, researchers have themselves developed the broadest and most detailed simulation of the universe to date. Now, there are no “living” things yet inside this computer model, but it’s probably only a matter of time before our increasingly sophisticated simulations start wondering if they are simulations as well.

From the BBC:

An international team of researchers has created the most complete visual simulation of how the Universe evolved.

The computer model shows how the first galaxies formed around clumps of a mysterious, invisible substance called dark matter.

It is the first time that the Universe has been modelled so extensively and to such great resolution.

The research has been published in the journal Nature.

Now we can get to grips with how stars and galaxies form and relate it to dark matter”

The simulation will provide a test bed for emerging theories of what the Universe is made of and what makes it tick.

One of the world’s leading authorities on galaxy formation, Professor Richard Ellis of the California Institute of Technology (Caltech) in Pasadena, described the simulation as “fabulous”.

“Now we can get to grips with how stars and galaxies form and relate it to dark matter,” he told BBC News.

The computer model draws on the theories of Professor Carlos Frenk of Durham University, UK, who said he was “pleased” that a computer model should come up with such a good result assuming that it began with dark matter.

“You can make stars and galaxies that look like the real thing. But it is the dark matter that is calling the shots”.

Cosmologists have been creating computer models of how the Universe evolved for more than 20 years. It involves entering details of what the Universe was like shortly after the Big Bang, developing a computer program which encapsulates the main theories of cosmology and then letting the programme run.

The simulated Universe that comes out at the other end is usually a very rough approximation of what astronomers really see.

The latest simulation, however, comes up with the Universe that is strikingly like the real one.

Immense computing power has been used to recreate this virtual Universe. It would take a normal laptop nearly 2,000 years to run the simulation. However, using state-of-the-art supercomputers and clever software called Arepo, researchers were able to crunch the numbers in three months.

Cosmic tree

In the beginning, it shows strands of mysterious material which cosmologists call “dark matter” sprawling across the emptiness of space like branches of a cosmic tree. As millions of years pass by, the dark matter clumps and concentrates to form seeds for the first galaxies.

Then emerges the non-dark matter, the stuff that will in time go on to make stars, planets and life emerge.

But early on there are a series of cataclysmic explosions when it gets sucked into black holes and then spat out: a chaotic period which was regulating the formation of stars and galaxies. Eventually, the simulation settles into a Universe that is similar to the one we see around us.

According to Dr Mark Vogelsberger of Massachusetts Institute of Technology (MIT), who led the research, the simulations back many of the current theories of cosmology.

“Many of the simulated galaxies agree very well with the galaxies in the real Universe. It tells us that the basic understanding of how the Universe works must be correct and complete,” he said.

In particular, it backs the theory that dark matter is the scaffold on which the visible Universe is hanging.

“If you don’t include dark matter (in the simulation) it will not look like the real Universe,” Dr Vogelsberger told BBC News.

Read the entire article here.

Image: On the left: the real universe imaged via the Hubble telescope. On the right: a view of what emerges from the computer simulation. Courtesy of BBC / Illustris Collaboration.

NASA’s 30-Year Roadmap

NASA-logoWhile NASA vacillates over any planned manned missions back to the Moon or to the Red Planet, the agency continues to think ahead. Despite perennial budget constraints and severe cuts NASA still has some fascinating plans for unmanned exploration of our solar system and beyond to the very horizon of the visible universe.

In its latest 30 year roadmap, NASA maps out its long-term goals, which include examining the atmospheres of exoplanets, determining the structure of neutron stars and tracing the history of galactic formation.

Download the NASA roadmap directly from NASA here.

From Technology Review:

The past 30 years has seen a revolution in astronomy and our understanding of the Universe. That’s thanks in large part to a relatively small number of orbiting observatories that have changed the way we view our cosmos.

These observatories have contributed observations from every part of the electromagnetic spectrum, from NASA’s Compton Gamma Ray Observatory at the very high energy end to HALCA, a Japanese 8-metre radio telescope at the low energy end.  Then there is the Hubble Space Telescope in the visible part of the spectrum, arguably the greatest telescope in history.

It’s fair to say that these  observatories have had a profound effect not just on science , but on the history of humankind.

So an interesting question is: what next?  Today, we find out, at least as far as NASA is concerned, with the publication of the organisation’s roadmap for astrophysics over the next 30 years. The future space missions identified in this document will have a profound influence on the future of astronomy but also on the way imaging technology develops in general.

So what has NASA got up its sleeve? To start off with, it says its goal in astrophysics is to answer three questions: Are we alone? How did we get here? And how does our universe work?

So let’s start with the first question. Perhaps the most important discovery in astronomy in recent years is that the Milky Way is littered with planets, many of which must have conditions ripe for life. So it’s no surprise that NASA aims first to understand the range of planets that exist and the types of planetary systems they form.

The James Webb Space Telescope, Hubble’s successor due for launch in 2018, will study the atmospheres of exoplanets, along with the Large UV Optical IR (LUVOIR) Surveyor due for launch in the 2020s. Together, these telescopes may produce results just as spectacular as Hubble’s.

To complement the Kepler mission, which has found numerous warm planets orbiting all kinds of stars, NASA is also planning the WFIRST-AFTA mission which will look for cold, free-floating planets using gravitational lensing. That’s currently scheduled for launch in the mid 2020s.

Beyond that, NASA hopes to build an ExoEarth Mapper mission that combines the observations from several large optical space telescopes to produce the first resolved images of other Earths. “For the first time, we will identify continents and oceans—and perhaps the signatures of life—on distant worlds,” says the report.

To tackle the second question—how did we get here?—NASA hopes to trace the origins of the first stars, star clusters and galaxies, again using JWST, LUVOIR and WFIRST-AXA. “These missions will also directly trace the history of galaxies and intergalactic gas through cosmic time, peering nearly 14 billion years into the past,” it says.

And to understand how the universe works, NASA hopes to observe the most extreme events in the universe, by peering inside neutron stars, observing the collisions of black holes and even watching the first nanoseconds of time. Part of this will involve an entirely new way to observe the universe using gravitational waves (as long as today’s Earth-based gravitational wave detectors finally spot something of interest).

The technology challenges in all this will be immense. NASA needs everything from bigger, lighter optics and extremely high contrast imaging devices to smart materials and micro-thrusters with unprecedented positioning accuracy.

One thing NASA’s roadmap doesn’t mention though is money and management—the two thorniest issues in the space business. The likelihood is that NASA will not have to sweat too hard for the funds it needs to carry out these missions. Much more likely is that any sleep lost will be over the type of poor management and oversight that has brought many a multibillion dollar mission to its knees.

Read the entire article here.

Image: NASA logo. Courtesy of NASA / Wikipedia.