Can we go to Alpha Centauri?

Alpha Centauri

This artist’s impression made available by the European Southern Observatory on Tuesday, shows a planet, right, orbiting the star Alpha Centauri B, center, a member of the triple star system that is the closest to Earth. Alpha Centauri A is at left. The Earth’s Sun is visible at upper right. Searching across the galaxy for interesting alien worlds, scientists made a surprising discovery: a planet remarkably similar to Earth in a solar system right next door. Other Earth-like planets have been found before, but this one is far closer than previous discoveries. Unfortunately, the planet is way too hot for life, and it’s still 25 trillion miles away. (AP/ESO, L. Calcada)

The recent confirmation of a planet circling our nearest stellar neighbour is nothing short of thrilling.  Sure, it isn’t habitable, circling Alpha Centauri B in something like 3.2 days, but the fact it exists at all is a major breakthrough.  If we can find a few more planets over there, we might seriously start thinking about actual space exploration.  Kudos to the European Southern Observatory team for making the discovery, and having the scientific self-discipline to spend three years confirming it before the announcement.

So, what are the realistic considerations of a potential interstellar mission?  In my opinion, the barriers are enough that we won’t be doing it for a very long time, if at all – barring some black swan scientific discovery like a warp drive or other FTL technology.  No doubt we have much to learn about physics and the universe, but we cannot assume that future scientific discoveries will help us indulge our urge to explore.

Time

One of the biggest barrier to such travel is time.  If it takes 100 years to reach another star, nobody is going to want to go.  And if we might find nothing of worth and have to set off somewhere else, the incentive is too small to bother, especially assuming a significant cost in energy and resources to send a viable ship that far and for that long.

So, how can we address the time barrier?  Nobody wants to live our their lives (and the lives of the next 40 generations) in a spaceship – there haven’t been many human societies that have lasted anywhere near that long.  But what if a human lifespan was dramatically longer, even functionally immortal?  It seems unlikely now, but no more so than warp drives and wormholes.  In fact, we spend significantly more resources and energy studying health than we do on space.

A thousand-year old person, or a person who might live for 10,000 years, might be much more willing to undertake an interstellar voyage.  It is hard to know what humans would be like if they had lifespans on that scale, but I imagine patience would be much more common.  Some people would no doubt appreciate an opportunity to spend a few centuries working on something that interests them.  Maybe they could finally finish the Harry Potter novels, or read those impenetrable Tolkein books that aren’t LOTR.

Resources

The other big barrier to interstellar travel is cost.  Not in dollars but in resources and energy.  It will take a lot of energy to send even a tiny ship to another star, and a lot of resources to support even a tiny crew for thousands of years.  And the more resources needed, the more energy as well, a vicious cycle that could well make interstellar travel impossible.

However, there are some resources that weigh nothing, like technical and scientific knowledge.  Far better to send a few small machines capable of making anything on arrival as needed than to try to send everything in advance.  Similarly, it would be a lot easier to send some raw materials for the manufacture of humans on arrival (i.e. genetic material and the means to grow and educate people when they get there).  Trying to send actual grown humans might be impossible and absurdly expensive, but sending a tiny ship with all it need to build on arrival might actually be viable.

Of course, we don’t have the scientific knowledge to build a person from scratch right now, but we much closer than we are to an FTL drive (if such a thing is possible).  It may be that humans who arrive at another star will be born of that star, and any further exploration would be similarly done by their descendents.  Von Neumann Machines, but organic.

All of this is a long way off, barring the black swan event that changes everything.  (My personal favourite would be friendly contact from somewhere else once we reach a certain level of development).  Nonetheless, the discovery of planets in the neighbourhood makes me optimistic that someday, someone will go for a closer look.

 

 

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Search for Exomoons finds a Planet – Crowdfunded science

New Discovery Funded by Petridish Published in Science! | The Petridish Blog.

Remember the Petridish crowdfunded science site?  This blog donated a few dollars to the Search for Exomoons research awhile ago.  Well, they haven’t found an exomoon yet, but they did just publish a newly discovered planet in Science, a happy byproduct of the successfully crowdfunded research.

When the team looked at the data that Kepler has made public, they found something unusual with the planetary candidate KOI-872.01 (KOI stands for “Kepler Object of Interest”). It had some of the largest timing variations ever detected—about two-hour variations in an orbit that takes a bit under 34 days. But there was no sign of any transit duration variations, which should be present if there was a moon. All of which suggests that the planet was being pulled around by another planet Kepler hadn’t detected.

 

Hooray.  Though our contribution was relatively tiny, it feels really fantastic to have contributed at all.  Petridish has a number of exciting looking projects currently seeking funding, though I am personally holding out for another SF/space related idea.

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The Plausibility of a Dyson Sphere.

George Dvorsky over at IO9 has a thought-provoking article outlining how humans might go about building a Dyson Sphere in our solar system.  Given the implausibility of long-distance space travel in anything like the near future, Dyson spheres are one of the most probable options available to humans wishing to expand beyond our fragile Earth.

This hypothetical megastructure, as envisaged by Dyson, would be the size of a planetary orbit and consist of a shell of solar collectors (or habitats) around the star. With this model, all (or at least a significant amount) of the energy would hit a receiving surface where it can be used. He speculated that such structures would be the logical

consequence of the long-term survival and escalating energy needs of a technological civilization.

For the purposes of this discussion, I’m going to propose that we build a Dyson swarm (sometimes referred to as a type I Dyson sphere), which will consist of a large number of independent constructs orbiting in a dense formation around the sun. The advantage of this approach is that such a structure could be built incrementally. Moreover, various forms of wireless energy transfer could be used to transmit energy between its components and the Earth.

 

The practicalities of such a massive undertaking seem remote given our current inability to agree on anything even remotely as large, but change is a rapid and constant thing.  Technological advancement is accelerating at alarming rates, and the impossible one year becomes the merely difficult a few years later.  I am an SF optimist, but I think 50 years to begin is a bit pessimistic.  It could happen sooner, assuming we don’t enact any of our collapse/apocalypse scenarios.

Of course, it will be awhile before we develop the capacity to mine or dismantle any planets, but the nascent beginnings of asteroid mining are a definite start.  Technological change happens quickly and decisively, making old arguments quaint and silly seeming very quickly.  I suspect this will be one of those cases.

Of course, sign me up to live in the new Dyson swarm (ideally in my cloned new 20-year-old body).

Link to original article.

 

 

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Your Last Chance to see Venus Transit the Sun

2004 Transit of Venus, courtesy of Wikipedia.

On June 6, 2012 Venus will transit the Sun.  Pacific Islanders will see it best, but most of the world will see part of it.

Transits of Venus occur only on the very rare occasions when Venus and Earth are in a line with the Sun. At other times Venus passes below or above the Sun because the two orbits are at a slight angle to each other. Transits occur in pairs separated by eight years, with the gap between pairs of transits alternating between 105.5 and 121.5 years — the last transit was in 2004.

In other words, the next transit will be in a month, and then you’ll have to wait 115 years to see it again.  I am optimistic about the scientific advancement of health and extension of life, but even an SF-soaked optimist like myself doesn’t seriously expect to live for another 115 years (not that I would mind).

Edmond Halley proposed using a transit of Venus to predict the precise distance between Earth and the Sun, known as the astronomical unit. As a result, hundreds of expeditions were sent all over the world to observe the 1761 and 1769 transits. A young James Cook took the Endeavour to the island of Tahiti, where he successfully observed the transit at a site that is still called Point Venus.

Hopefully most of us won’t manage to witness the transit of Venus and get killed by cannibals in the same lifetime, but if we take the time to look for it we will be walking in the footsteps of giants.  Modern astronomers will use the transits to refine theories about observed transits in other solar systems, furthering our understanding about what we see far into space.

Via Science Daily and Geekosystem.  Quotes from Science Daily.

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Robot Surgeons

IO9 has an article about robot assisted surgery showing better outcomes that straightforward human-only surgery (specifically on the prostate).  While our natural inclination might be to prefer a human surgeon, I think that surgery (like car driving) is something that will likely be done better by a machine with an unlimited attention span.

Read the IO9 article here.  Read the original research here.

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