Let’s Explore Quantum Teleportation

quantum teleportation2

Quantum teleportation is perhaps the closest that modern technology has come to developing a sort of teleporter for transmitting physical objects across distances without the use of some physical method of moving them. Quantum teleportation involves transmitting the exact state that an atom or photon exists in, and then using this data at a different site to reassemble it. This quantum information cannot travel faster than the speed of light, since it depends on classical communication. Read More →

Will We Ever Really Travel to the Stars?

Image Credit: Paramount

Image Credit: Paramount

Interstellar space travel is one of the most common themes of science fiction, but the question is, will it ever become reality?

With our current understanding of physics, propulsion methods and the limits of our technology, there is currently no practical way to travel to other stars and solar systems. NASA terminated its Breakthrough Propulsion Physics Program in 2003, stating that no further breakthroughs appeared to be imminent. What this ultimately means is that we should not be expecting to see travel to other stars become reality any time soon, if ever. NASA did recently announce that they will begin work on a Warp Drive…whether anything will come of that, only time will tell. I personally would like to see this happen in the private-sector but that’s certainly unlikely for the immediate future.

In most sci-fi stories, starships zip around the galaxy at speeds far exceeding that of light, the universal speed limit of roughly 186,000 miles per second. The problem however is that the laws of physics state that absolutely nothing in the universe can travel faster than this (even though folks are trying to prove otherwise).

The Primary Issue – Distance

We know our own star simply as the Sun. The Sun is a star no different than billions of others in the Milky Way galaxy. To provide some important figures for reference, the Sun lies 93 million miles from away from Earth and it takes light eight minutes and twenty seconds to reach us.

Source: NASA

Source: R. Mewaldt & P. Liewer, JPL

The nearest star to Earth, other than the Sun, is Proxima Centauri of the Alpha Centauri triple-star system. It lies 4.24 light-years away, meaning that it takes 4.24 years for the star’s light to reach us.

The fastest launch speed achieved by mankind was that of the New Horizons robotic spacecraft which was launched at 36,373 miles per hour on its mission to the dwarf planet Pluto. The fastest man-made object is currently the Helios 2 solar space probe, traveling at 157,100 miles per hour. This speed was achieved by using gravitational assistance from the Sun. If the Helios 2 solar probe were to be sent directly towards Proxima Centauri, it would reach the star in approximately 18,000 years.

How Fast Can We Go?

There are technologies that exist which can achieve far greater speeds than those of space probes like Helios 2 or New Horizons.

One of these is nuclear pulse propulsion which basically uses nuclear explosions to power a rocket to incredibly high speeds. It seems plausible that such a spacecraft could reach speeds of around 5 percent of the speed of light, yet this would still take about 85 years to reach the nearest star. As demonstrated by the Project Orion effort of the mid-twentieth century, it is possible using only currently available technology. Of course, this speed is still too low, making it highly impractical. It is generally considered that, if a journey cannot be completed in considerably less than a human lifetime, it should not be started at all.

The only thing that is possible is to send out radio waves, traveling at the speed of light, to the stars. This allows us to send a message to Proxima Centauri for example, which would arrive in 4.24 years. Perhaps some day we will be able to send physical objects there at this rate.

Faster-than-Light (FTL)

Image Source: Nextbigfuture

Image Source: Nextbigfuture

Nothing can travel faster than light, as dictated by Einstein’s theories on relativity. Roughly 186,000 miles per second is the absolute speed limit. If practical interstellar travel is ever to become a possibility, we need to find a way around this speed limit.

To get around the FTL issue, sci-fi shows/movies/books often use things like warp drives that are capable of warping spacetime in such a way that it folds space. If this were possible, it would effectively enable FTL travel between two points. The Alcubierre drive, proposed in 1994, is the only serious attempt at theorizing a starship which travels faster than light. It does this by expanding space behind it and contracting space before it. The spacecraft travels in its own bubble at speeds slower than light. To put this in perspective, imagine a piece of paper with a point marked at each end. The shortest distance between these two points is a straight line, unless you fold the paper in half so that the two points meet each other directly.

The Alcubierre drive is highly theoretical and has one deal-breaking flaw – it requires something called exotic matter with negative mass, and this isn’t even known to exist.

The Bottom Line

Space Travel ConceptIf you could go back in time to the mid-nineteenth century and tell people that humanity was going to land on the moon in 1969, they would probably laugh at you. Since then, we have launched probes all over the Solar System and landed robotic spacecraft on the surfaces of Venus, Mars and Saturn’s moon, Titan. One thing is clear: Humanity’s potential is immense and science and technology are full of surprises. Interstellar travel may seem like a very long way off, but it will never become a reality if we don’t try.

One thing that is preventing many scientists from taking interstellar travel seriously is also the fact that we don’t really know where to start. There are countless stars out there, but until something truly interesting and worth visiting shows up, interstellar travel will remain a thing of science fiction. That being said, more than 850 planets have been discovered orbiting other stars and more are being confirmed every week. We are now learning that every star “up there” likely has a number of planets rotating around them (the same thing that happens in our neck of the universe). That’s a very, very large number of planets. It is likely just a matter of time before we find an Earth-like world out there in the lonely depths of space. Perhaps that will truly give humanity something to aim for resulting in a renewed interest in reaching the stars.

Reference:

Ford, L., & Roman, T. (2000). Negative Energy, Wormholes and Warp Drive Scientific American, 282 (1), 46-53 DOI: 10.1038/scientificamerican0100-46

Hill, J., & Cox, B. (2012). Einstein’s special relativity beyond the speed of light Proceedings of the Royal Society A: Mathematical, Physical and Engineering Sciences, 468 (2148), 4174-4192 DOI: 10.1098/rspa.2012.0340

González-Díaz, P. (2000). Warp drive space-time Physical Review D, 62 (4) DOI: 10.1103/PhysRevD.62.044005

Hansson, A. (2003). Project Orion: The Atomic Spaceship 1957–1965 Space Policy, 19 (2), 149-150 DOI: 10.1016/S0265-9646(03)00011-0

Endl, M., & Kürster, M. (2008). Toward detection of terrestrial planets in the habitable zone of our closest neighbor: proxima Centauri Astronomy and Astrophysics, 488 (3), 1149-1153 DOI: 10.1051/0004-6361:200810058

ResearchBlogging.org

Holistic Design Factors in Space Colonies

Assuming that we never achieve FTL travel, generational colony ships may become a necessary method used to traverse great distances. Inherent in the term generational, individuals will live their entire lives on these massive spaceships as will their descendants. In other words, these space ships will be the only home many generations of inhabitants will ever know. This of course means that the ships would have to be designed in the best way possible to ensure the survival of travelers. Inhabitants would need to feel at home. That’s definitely a big challenge, but new techniques being used to design oceangoing vessels today could provide a roadmap to achieve these difficult gains in the years ahead.

Holistic design seems to be a buzzword today, but taking this approach means that people are more likely to enjoy the surroundings that they’re in. The Earth’s growth was not the result of careful human engineering. While gardens might be planned, forests are not. It’s difficult for people to be truly random. However, they’ll need to at least simulate randomness in order to build a craft that was as holistic as the planet that people have already called home for so long.

Design optimization plans are already in place with the intent of increasing safety and cargo space, but habitability seems to be all but forgotten. In the future, this will have to change if people are going to be able to run their own space dwelling civilizations on interstellar missions.

Considering emerging conditions on Earth today, if you were given a chance to spend the rest of your life on one of these generational colonies, would you leave behind our planet forever in the name of human survival/exploration/discovery? What must-have features would the ship have to include if you were to go?

Reference:

Apostolos Papanikolaou (2010). Holistic ship design optimization Computer-Aided Design, 42 (11), 1028-1044 : 10.1016/j.cad.2009.07.002

Cooper RA (2008). Quality-of-life technology. A human-centered and holistic design. IEEE engineering in medicine and biology magazine : the quarterly magazine of the Engineering in Medicine & Biology Society, 27 (2), 10-1 PMID: 18472458

Image Credit: G4

ResearchBlogging.org

Future Mission to 51 Pegasi

Due to their proximity to Earth, many of the closest star systems have been extensively studied. When the mass media gets their hands on research, they go wild with it. This is a very human response. Naturally, many individuals want to find proof of extraterrestrial life. Other people want to find places where humanity can expand. Some people might simply have some sort of fantasy fulfilled by being an armchair astronaut.

In 1995 astronomers announced that they had discovered a planet, 51 Pegasi B, in orbit around its star, 51 Pegasi – the first exoplanet found orbiting a star similar to the Sun. If one were to travel 48 light-years from this world, they might happen upon a fifth-magnitude star with a mass that’s almost 47 percent higher than that of Jupiter. The planet in that system orbits extremely close to the stellar body. This might very well suggest that the world could never have supported life.

However, that means very little and long-range planning and missions to these systems should still be planned. Though faster than light travel is still out of reach, even conventional systems could theoretically take an artificial intelligence unit to another star system. While it might take decades to reach another world, the whole of humanity would be better for it – especially if life were discovered.

I’m all for going back to the moon (human exploration). It’s a feasible idea (given that we’ve done it before) and certainly a candidate for early space colonization. That being said, I think we should stop focusing on manned missions to Mars [PDF] for now, and focus instead on sending machines to conduct long-term planetary exploration and discovery missions. Ancestors of today’s scientists will surely reap the benefits of such journeys in the far future as a result of our efforts right now.

Image Credit: BBC