Our Universe in a Black Hole Within a Larger Universe?

Einstein-Rosen Bridges like the one visualized 

Could our universe be located within the interior of a wormhole which itself is part of a black hole that lies within a much larger universe?

Such a scenario in which the universe is born from inside a wormhole (also called an Einstein-Rosen Bridge) is suggested in a paper from Indiana University theoretical physicist Nikodem Poplawski in Physics Letters B. The final version of the paper was available online March 29 and will be published in the journal edition April 12.

Poplawski takes advantage of the Euclidean-based coordinate system called isotropic coordinates to describe the gravitational field of a black hole and to model the radial geodesic motion of a massive particle into a black hole.

In studying the radial motion through the event horizon (a black hole’s boundary) of two different types of black holes — Schwarzschild and Einstein-Rosen, both of which are mathematically legitimate solutions of general relativity — Poplawski admits that only experiment or observation can reveal the motion of a particle falling into an actual black hole. But he also notes that since observers can only see the outside of the black hole, the interior cannot be observed unless an observer enters or resides within.

“This condition would be satisfied if our universe were the interior of a black hole existing in a bigger universe,” he said. “Because Einstein’s general theory of relativity does not choose a time orientation, if a black hole can form from the gravitational collapse of matter through an event horizon in the future then the reverse process is also possible. Such a process would describe an exploding white hole: matter emerging from an event horizon in the past, like the expanding universe.”

A white hole is connected to a black hole by an Einstein-Rosen bridge (wormhole) and is hypothetically the time reversal of a black hole. Poplawski’s paper suggests that all astrophysical black holes, not just Schwarzschild and Einstein-Rosen black holes, may have Einstein-Rosen bridges, each with a new universe inside that formed simultaneously with the black hole.

“From that it follows that our universe could have itself formed from inside a black hole existing inside another universe,” he said.

By continuing to study the gravitational collapse of a sphere of dust in isotropic coordinates, and by applying the current research to other types of black holes, views where the universe is born from the interior of an Einstein-Rosen black hole could avoid problems seen by scientists with the Big Bang theory and the black hole information loss problem which claims all information about matter is lost as it goes over the event horizon (in turn defying the laws of quantum physics).

This model in isotropic coordinates of the universe as a black hole could explain the origin of cosmic inflation, Poplawski theorizes.

Poplawski is a research associate in the IU Department of Physics. He holds an M.S. and a Ph.D. in physics from Indiana University and a M.S. in astronomy from the University of Warsaw, Poland.

Future spaceships powered by black holes and dark matter

The radical proposals, put forward by physicists in two American universities, are hoped to make visits to other stars in our galaxy plausible.

At the moment, the fastest-moving spacecraft mankind has made is Voyager 1, which is just leaving the solar system at an impressive 17km (10.6 miles) a second. However, even at that dizzying – to us – speed, it would take it another 74,000 years to reach even our nearest stellar neighbour, Proxima Centauri, 4.2 light years away.
Chemical rockets are not suitable for travelling these sort of distances, as they only convert 0.000000001 per cent of their mass into energy. They would require billions of tons of fuel to get up to the required speed. Even nuclear fusion reactors would be less than 1 per cent efficient.
Other suggestions have included using vast sails to collect light energy, either from stars or from laser beams, or using antimatter reactions. But both of these have practicality problems: sails need a nearby power source, while antimatter is hugely difficult to make and equally difficult to store.
But a New York University physicist, Jia Liu, has suggested using a dark matter “jet engine” to power spacecraft, while two mathematicians at Kansas State University, Louis Crane and Shawn Westmoreland, have claimed that using an artificial black hole as a power source is feasible.
Surprisingly, there seems to be nothing in the present understanding of physics that would rule these proposals out, 

according to New Scientist.
The black hole proposal would involve building a spaceship with a large parabolic reflector behind it, and then putting a small (at a mere million tons) black hole in its focus. The “Hawking radiation” given off by the black hole as it slowly converts its mass into energy (or “evaporates”) would push the spacecraft to near light speed within a few decades, bringing Proxima Centauri into a more reasonable reach.
More than that, at the relativistic near-light-speed velocities, the travellers’ experience of time would slow down, making them age slower than those left on Earth. At very high speeds, says Mr Crane, "it might be possible to reach the Andromeda galaxy 2.5 million light years away within a human lifetime."
Mr Liu’s idea is more speculative, relying on one possible theory of what dark matter really is. He suggests building a spacecraft with a large intake at the front which would scoop up dark matter particles. If, as is theorised, those particles are “neutralinos”, which annihilate each other on contact, they could be forced into a box at the back of the craft which would fire the energy rearwards like a jet engine.
The faster the spacecraft travelled, the more neutralinos it would pick up, and the faster it would accelerate. If his calculations are correct, Mr Liu suggests that the ship could reach near-light speed in just days.
However, even if dark matter does consist of neutralinos, there are other problems. First, to work well, it would need densely concentrated dark matter, and as far as we know the nearest dense area is 26,000 light years away in the centre of the Milky Way. Second, neutralinos barely interact with ordinary matter. To make a “box” to keep it in would require some new, unknown material. As Mr Crane says, “this is the idea’s Achilles heel.”

Planning for Mars sample return starts here

I think we were all inspired by the Japanese adventure in bringing samples of asteroid Itokawa back to Earth. The Hayabusa capsule which landed in Australia is now safely installed in the Sagamihara curation facility in Kanagawa.
We await news of the opening of the canister and confirmation that asteroid dust is inside.
Of course, the really big prize would be to return samples of surface material from mars, a planet where microbial life may once have thrived (and may still in some corner).
And I've had an opportunity in recent days to discuss the topic with top Nasa officials who've been on a tour of Europe to review progress on the European Space Agency's (Esa)  ExoMars rover.
As previously mentioned in this blog, all US and European activity at the Red Planet will become a combined effort from mid-decade onwards.
This joint initiative will start in 2016 with an orbiting spacecraft that will investigate trace gases such as methane in the Martian atmosphere, and then progress on to a double rover mission that will launch in 2018.

The Americans plan on using a "skycrane" to land both the ExoMars vehicle and a robotic rover of their own design.
This will be an extraordinary sight - if only you could be on Mars to see it!
The skycrane is a kind of rocket-powered cradle. The crane will lower a pallet containing the two rovers on to the surface before moving itself clear and dropping to the ground at a safe distance.
We'll be able to assess how well this technology works in 2012 because the exact same system is being used to land the next US rover, MSL-Curiosity.

 

The one big difference is that MSL will be put down directly on to its wheels; there will be no pallet involved.

The crane should be capable of landing a tonne or so, which means ExoMars and its co-passenger American vehicle will be allocated 300kg each.
But what will the US robot actually do? I've written a lot about ExoMars and how it will drill below the surface looking for extinct or extant life, but I must confess I've been a little vague on the American side of things.
Their vehicle will be what's termed a caching rover. Its working name is Max-C Mars Astrobiology Explorer-Cacher. It will seek out interesting rocks on the surface of the planet, study them with a suite of instruments and then bag samples. Charles Whetsel, a spacecraft systems engineer at Nasa's Jet Propulsion Laboratory, described the US rover's mission to me this way:

"The concept right now is that it will have a coring tool able to go about five centimetres in, about a centimetre in diameter. It will be able to go up to the rocks we find most interesting and take a 'biopsy', if you will, to lift the core out and start building up a library onboard the rover. If we can do one of those every week or so, and we plan on being there for the better part of a year, at the end of that year we could have a little 'backpack' of about 30 samples."

Nasa now says these cores gathered by Max-C will be the same ones that a later mission, perhaps in the 2020s, will attempt to retrieve and bring back to Earth. Doug McCuistion, the director of the Mars Exploration Program at Nasa Headquarters in Washington DC, told me:

"Our expectation is that these samples will be acquired with the intention to go get them, unless something significant occurs that prevents us from doing that."

So, the Mars sample return project starts in earnest with the launch of ExoMars and Max-C in 2018. This makes it a hugely significant venture.

 It raises some interesting questions, too, which Nasa and Esa planners have really only just started to grapple with [PDF].
Can a landing location be identified that is optimal for both drilling into the sub-surface and for finding the right type of rocks you might want to bring back to Earth?
Also, when the two rovers drive off their pallet, do they go in the same direction or do they stick close together? Charles Whetsel:

"We're still talking about that. For us, getting those 30 cores is going to involve some hoping about on our part, whereas ExoMars's theme will be about getting below the surface and exploring Mars with vertical mobility instead of horizontal mobility. That means ExoMars will tend to go to a relatively small number of sites and camp out. The science community has started thinking about how you might reconcile those different modes of operation. One possibility is that you could use the rock-hopping approach of the American rover to scout out locations for ExoMars."

One question that comes into my mind: is there any possibility that ExoMars could pass some of the material it has drilled from two metres below the surface over to Max-C? After all, we know the ultraviolet conditions on the surface today would make it a tough environment for any Martian microbes. There's more chance of them existing deeper in the dirt.

Well, the engineers are apparently considering this one, too.
Max-C's backpack will need to be easily accessible to the later retrieval mission. One idea is that the rover simply dumps a canister on the ground that can be picked up and then blasted into orbit for capture and boosting back to Earth.
But we're getting a little bit ahead of ourselves here. First, ExoMars and Max-C have got to be made to work before we can start dreaming of what might be in the 2020s.
I tell you what I am looking forward to, though - seeing the pictures the rovers take of each other.
The static Mars Pathfinder lander imaged the little Sojourner rover on the Red Planet in 1997, but this would be something different altogether - an album of snaps from a fly-drive excursion on another planet.
Watch this space.