Category Archives: Space

Breaking the warp barrier for faster-than-light travel

Artistic impression of different spacecraft designs considering theoretical shapes of different kinds of “warp bubbles”.
CREDIT: E Lentz

Astrophysicist at Göttingen University discovers new theoretical hyper-fast soliton solutions

If travel to distant stars within an individual’s lifetime is going to be possible, a means of faster-than-light propulsion will have to be found. To date, even recent research about superluminal (faster-than-light) transport based on Einstein’s theory of general relativity would require vast amounts of hypothetical particles and states of matter that have “exotic” physical properties such as negative energy density. This type of matter either cannot currently be found or cannot be manufactured in viable quantities. In contrast, new research carried out at the University of Göttingen gets around this problem by constructing a new class of hyper-fast ‘solitons’ using sources with only positive energies that can enable travel at any speed. This reignites debate about the possibility of faster-than-light travel based on conventional physics. The research is published in the journal Classical and Quantum Gravity.

The author of the paper, Dr Erik Lentz, analysed existing research and discovered gaps in previous ‘warp drive’ studies. Lentz noticed that there existed yet-to-be explored configurations of space-time curvature organized into ‘solitons’ that have the potential to solve the puzzle while being physically viable. A soliton – in this context also informally referred to as a ‘warp bubble’ – is a compact wave that maintains its shape and moves at constant velocity. Lentz derived the Einstein equations for unexplored soliton configurations (where the space-time metric’s shift vector components obey a hyperbolic relation), finding that the altered space-time geometries could be formed in a way that worked even with conventional energy sources. In essence, the new method uses the very structure of space and time arranged in a soliton to provide a solution to faster-than-light travel, which – unlike other research – would only need sources with positive energy densities. No “exotic” negative energy densities needed.

If sufficient energy could be generated, the equations used in this research would allow space travel to Proxima Centauri, our nearest star, and back to Earth in years instead of decades or millennia. That means an individual could travel there and back within their lifetime. In comparison, the current rocket technology would take more than 50,000 years for a one-way journey. In addition, the solitons (warp bubbles) were configured to contain a region with minimal tidal forces such that the passing of time inside the soliton matches the time outside: an ideal environment for a spacecraft. This means there would not be the complications of the so-called “twin paradox” whereby one twin travelling near the speed of light would age much more slowly than the other twin who stayed on Earth: in fact, according to the recent equations both twins would be the same age when reunited.

“This work has moved the problem of faster-than-light travel one step away from theoretical research in fundamental physics and closer to engineering. The next step is to figure out how to bring down the astronomical amount of energy needed to within the range of today’s technologies, such as a large modern nuclear fission power plant. Then we can talk about building the first prototypes,” says Lentz.

Currently, the amount of energy required for this new type of space propulsion drive is still immense. Lentz explains, “The energy required for this drive travelling at light speed encompassing a spacecraft of 100 meters in radius is on the order of hundreds of times of the mass of the planet Jupiter. The energy savings would need to be drastic, of approximately 30 orders of magnitude to be in range of modern nuclear fission reactors.” He goes on to say: “Fortunately, several energy-saving mechanisms have been proposed in earlier research that can potentially lower the energy required by nearly 60 orders of magnitude.” Lentz is currently in the early-stages of determining if these methods can be modified, or if new mechanisms are needed to bring the energy required down to what is currently possible.

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Original publication: Erik W Lentz, Breaking the Warp Barrier: Hyper-Fast Solitons in Einstein-Maxwell-Plasma Theory, Classical and Quantum Gravity, March 2021. DOI: 10.1088/1361-6382/abe692

SOURCE: EurekaAlert

New data locates hundreds of millions of objects throughout space

Survey has mapped one-eighth of the skies, studying dark energy

This irregular dwarf galaxy, named IC 1613, and discovered through the Dark Energy Survey, contains some 100 million stars (bluish in this portrayal). It is a member of our Local Group of galaxy neighbors, a collection which also includes our Milky Way, the Andromeda spiral and the Magellanic clouds.Credit: DES/NOIRLab/NSF/AURA. Acknowledgments: Image processing: DES, Jen Miller (Gemini Observatory/NSF’s NOIRLab), Travis Rector (University of Alaska Anchorage), Mahdi Zamani & Davide de Martin

A longstanding project designed to study dark energy throughout the cosmos has released a second data set showing 300 million objects throughout space, one of the largest data releases of its kind. Combined with an initial release, the survey has now cataloged about 700 million objects in the universe.

The data was released by the Dark Energy Survey, an international collaboration of about 500 scientists from the U.S., Europe and South America, to map hundreds of millions of galaxies and thousands of supernovae in an attempt to understand more about dark energy, the force that is causing the universe to expand. The Ohio State University has played a primary role in the survey from the beginning.

The survey, started in 2013, has so far mapped about one-eighth of the skies.

The release was announced Friday, Jan. 15, at the American Astronomical Society’s annual meeting, held virtually this year.

Klaus Honscheid

“This release tells the world, ‘If you ever want to see any of these galaxies, here’s where they are and here’s what they look like,’ said Klaus Honscheid, a physics professor at Ohio State and member of Ohio State’s Center for Cosmology and Astroparticle Physics. “And people can use this info and do their own analysis – look for objects of a certain property or compare to theoretical models. This is really enabling a lot of people to do work now outside the DES collaboration.”

Last week’s release is the second from the Dark Energy Survey. The data builds on the 400 million objects cataloged in the survey’s previous data release, and improves on the first release by refining calibration techniques and including deeper combined images of the objects throughout space. That combination, scientists say, led to improved estimates of the amount and distribution of matter in the universe.

The data allows researchers to determine the size, shape and location of objects – most of them galaxies, but also quasars, stars, interstellar gas clouds and asteroids – throughout space, and to build a catalog of those objects

“These images combine data from the same locations in the skies – images of the same spot, multiple times,” said Ami Choi, co-convener of the DES science working group on weak gravitational lensing and a CCAPP fellow. “And it’s three-dimensional, so it allows us to build a map that looks deep into this one part of the universe.”

The new data should make it easier for astronomers, astrophysicists and cosmologists – both professional and amateur – to locate those objects in the night skies, and to build models around the distance those objects may have moved away from one another over time.

“The catalog contains these objects with their properties and their location, and anyone else who has this information and a big enough telescope can go look at the location we specified and repeat these observations,” Honscheid said.

The expansion of the universe is the key to understanding dark energy. Previous work has shown that the universe has been expanding since its birth some 13.8 billion years ago, and that for approximately the last 7 billion years the universe’s expansion is accelerating.

The next set of results from the survey is expected later this spring, said Jack Elvin-Poole, co-convener of the DES science working group on large scale structure and a CCAPP fellow.

Scientists at the Dark Energy Survey, including those at Ohio State, are still analyzing data released last week to discern what it might say about dark energy and the expansion of the universe. The data are online and available to the public; the survey’s scientists will make their analysis available after it is complete.

“We are very interested in cosmology – the history of the universe – so we are looking for these dark energy signatures in this data,” Honscheid said. “If you think about dark energy, it’s something that pulls the universe apart, that pushes objects further apart.”

The survey involves taking photographs of light produced by each object and analyzing the wavelengths of that light.

This analysis is built on a concept called “redshifting,” which gets its name from the way wavelengths of light lengthen as they travel through the expanding universe.

“The farther away something is in the universe, the longer its wavelength of light – and longer wavelengths appear red, while shorter wavelengths appear blue,” said Anna Porredon, a CCAPP fellow who worked on the survey. “Scientists who study the cosmos call that lengthening the redshift effect.”

There are a number of other researchers at Ohio State who have worked on the DES project, including David Weinberg, Paul Martini, Chris Hirata and Ashley Ross.

SOURCE:NEWS.OSU.EDU Credit: Laura Arenschield