In science fiction it’s easy to hop into your spaceship and blast off for other stars. But the true distances between stars, and the limits of relativity make interstellar travel almost impossible with our current technology. What would it really take to travel from star to star, exploring the galaxy?
Tagged with “astronomy” (29)
We now know, Schwartz began, that nearly all of the billions of stars in our galaxy have planets. If we can master interstellar travel, "there’s someplace to go." Our own solar system is pretty boring—-one planet is habitable, the rest are "like Antarctica without ice" or worse.
So this last year a number of researchers and visionaries have begun formal investigation into the practicalities of getting beyond our own solar system. It is an extremely hard problem, for two primary reasons—-the enormous energy required to drive far and fast, and the vast amount of time it takes to get anywhere even at high speed.
The energy required can be thought of in three ways. 1) Impossible—-what most scientists think. 2) Slow. 3) Faster than light (FTL). Chemical rockets won’t do at all. Nuclear fission rockets may suffice for visiting local planets, but it would take at least fusion to get to the planets of other stars. Schwartz showed Adam Crowl’s scheme for a Bussard Ramjet using interstellar ions for a fusion drive. James Benford (co-author of the book on all this, Starship Century) makes the case for sail ships powered by lasers based in our Solar System.
As for faster-than-light, that requires "reinventing physics." Physics does keep doing that (as with the recent discovery of "dark energy"). NASA has one researcher, Harold White, investigating the potential of microscopic wormholes for superluminal travel.
Standard-physics travel will require extremely long voyages, much longer than a human lifetime. Schwartz suggested four options. 1) Generational ships—-whole mini-societies commit to voyages that only their descendents will complete. 2) Sleep ships—-like in the movie "Avatar," travelers go into hibernation. 3) Relativistic ships—-at near the speed of light, time compresses, so that travelers may experience only 10 years while 100 years pass back on Earth. 4) Download ships—-"Suppose we learn how to copy human consciousness into some machine-like device. Such ‘iPersons’ would be able to control an avatar that could function in environments inhospitable to biological humans. They would not be limited to Earthlike planets."
Freeman Dyson has added an important idea, that interstellar space may be full of objects—-comets and planets and other things unattached to stars. They could be used for fuel, water, even food. "Some of the objects may be alive." Dyson notes that, thanks to island-hopping, Polynesians explored the Pacific long before Europeans crossed the Atlantic. We might get to the stars by steps.
Futurist Schwartz laid out four scenarios of the potential for star travel in the next 300 years, building on three population scenarios. By 2300 there could be 36 billion people, if religious faith drives large families. Or, vast wealth might make small families and long life so much the norm that there are only 2.3 billion people on Earth. One harsh scenario has 9 billion people using up the Earth.
Thus his four starship scenarios… 1) "Stuck in the Mud"—-we can’t or won’t muster the ability to travel far. 2) "God’s Galaxy"—-the faithful deploy their discipline to mount interstellar missions to carry the Word to the stars; they could handle generational ships. 3) "Escape from a Dying Planet"—-to get lots of people to new worlds and new hope would probably require sleep ships. 4) "Trillionaires in Space"—-the future likes of Elon Musk, Jeff Bezos, and Richard Branson will have the means and desire to push the envelope all the way, employing relativistic and download ships or even faster-than-light travel.
Schwartz concluded that there are apparently many paths that can get us to the stars. In other words, "Galactic civilization is almost inevitable."
Time’s a mystery, yet we’ve invented clever ways to capture it. From sundials to atomic clocks, trace the history of time-keeping. Also, discover the surprising accuracy of nature’s dating schemes - from the decay of carbon to laying down tree rings.
Plus, why the "New York minute," stretches to hours in Rio de Janeiro: cultural differences in the perception of time.
* Chris Turney - Geologist at the University of Exeter, UK, and the author of Bones, Rocks and Stars: The Science of When Things Happened * Demetrios Matsakis - Head of the U.S. Naval Observatory’s Time Service * Steven Jefferts - Physicist at the National Institute of Standards and Technology in Boulder, Colorado * Robert Levine - Psychologist at California State University in Fresno and the author of The Geography of Time * Norman Mohr - Owner, Mohr Clocks, Mountain View, California
"Someone described my office as an eight-year-old’s daydream," says astronomer Jill Tarter, who has been collecting E.T.-themed office ornaments for 30 years. Tarter was the SETI (Search for Extraterrestrial Intelligence) Institute’s first employee, and the inspiration for the character in Carl Sagan’s Contact.
Ed Lu: Anthropocene Astronomy: Thwarting Dangerous Asteroids Begins with Finding Them - The Long Now
This talk was given at Marines’ Memorial Theater in San Francisco, California on Tuesday June 18, 02013.
Are humans smarter than dinosaurs? We haven’t proved it yet.
In the long now, the greatest threat to life on Earth, or (more frequently) to civilization, or (still more frequently) to cities, is asteroid impact. The technology exists to eliminate the threat permanently. It is relatively easy and relatively cheap to do. However to date, government organizations have not made this a priority. That leaves nonprofits and private funding. Considerable efficiency may be gained by going that route.
Ed Lu is CEO and Chairman of the B612 Foundation, which, in partnership with Ball Aerospace is building an asteroid-detection system called Sentinel, aiming for launch in 2018. A three time NASA astronaut, Lu is also the co-inventor of the “gravity tractor” — one of the several techniques that can be used to nudge threatening asteroids out their collision paths with Earth.
Asteroid threat is an attention-span problem blended with a delayed-gratification problem—-exactly the kind of thing that Long Now was set up to help with. Taking the extreme danger of asteroids seriously requires thinking at century and millennium scale. Dealing with the threat requires programs that span decades, because asteroids can only be deflected if they are found and dealt with many years before their potential impact. The reality is that the predictability of orbital mechanics makes cosmic planetary defense completely workable. Sometimes real science is more amazing than science fiction.
On February 15th of this year, civilization got a wake-up call. A 45 meter asteroid, large enough to completely obliterate a major city, missed Earth by only 17,000 miles, and hours later a smaller rock, 17 meters in diameter, exploded in the air over Chelyabinsk, Russia, injuring 1500 people. Interest in B612’s asteroid detection mission spiked accordingly.
As senior astronomer of the S.E.T.I. Institute in California tells Dick he has no doubt life exists in other parts of the universe, and believes scientists are getting closer to finding it â itâs just a matter of time.
Jim al-Khalili talks to the astronomer Jocelyn Bell Burnell about missing out a Nobel Prize, sexism in science and a strange smudge in the data from a radio telescope. While others dismissed this smudge as insignificant, Jocelyn revealed a series of strange flashing signals. They might have been evidence of faulty radio telescope or even messages from a little green man; but Jocelyn thought otherwise and her determination to get to the bottom of it all, led to one of the most exciting discoveries in 20th century astronomy, the discovery of pulsars, those dense cores of collapsed stars.
Our science team takes stock of the textbook landing of Nasa’s Curiosity rover on Mars. Plus, we discuss why science in film works – and why it sometimes doesn’t.
This week we’ve assembled a panel of experts to feed your appetite for information about Nasa’s new star, the Mars Curiosity rover.
The plucky robot landed on the red planet at 6:14am UK time and immediately sent back images of its surroundings. Guardian science correspondent Ian Sample takes us through the complex landing procedure; planetary scientist Geraint Jones from University College London tells us what it’s like to be in the control room back on Earth when your lander reaches another planet; and our new astronomy blogger, Stuart Clark, walks us through Curiosity’s scientific goals.
Talking of alien worlds, science fans will be pleased to know that the Wellcome Trust has launched a new prize to encourage the production of high-quality feature films inspired by biology and medicine: from genetics and infectious diseases to consciousness and mental health.
Here to discuss good and bad science on the big and small screen are the Wellcome Trust media fellow and podcast regular, Kevin Fong, and the Wellcome Trust’s games and film expert Iain Dodgeon.
We also have the space junkie and self-confessed geek Helen Keen on the show. She’s hoping to win audiences at this year’s Edinburgh Fringe festival with a show that exposes her love for all things robotic. We’ll talk to her about her new show – Robot Woman of Tomorrow – and get her thoughts on the Curiosity rover too.
Astronomer Roger Angel completely revolutionized the large telescopes that scientists use to look at the stars. Now he wants to use his mirror technology to make solar energy cheaper and more efficient.
Astronomer, physicist and the first director of the Jodrell Bank Experimental Observatory Professor Bernard Lovell explores the continuous creation theory of the universe in the final lecture of his Reith Lectures series ‘The Individual and the Universe’.
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