Telepresence — Our Best Bet For Exploring Space 309
Seth Shostak of the SETI Institute recently wrote an opinion piece for the NY Times discussing the limitations of our space technology. He makes the harsh point that transporting human beings to other star systems isn't a reasonable goal even on a multi-generational time frame. However, advances in robotics and data gathering could instead bring the planets and stars to us, and do it far sooner. Quoting:
"Sending humans to the stars is simply not in the offing. But this is how we could survey other worlds, around other suns. We fling data-collecting, robotic craft to the stars. These proxy explorers can be very small, and consequently can be shot spaceward at tremendous speed even with the types of rockets now available. Robot probes don't require life support systems, don't get sick or claustrophobic and don't insist on round-trip tickets. ... These microbots would supply the information that, fed to computers, would allow us to explore alien planets in the same way that we navigate the virtual spaces of video games or wander through online environments like Second Life. High-tech masks and data gloves, sartorial accessories considerably more comfortable than a spacesuit, would permit you to see the landscape, touch objects and even smell the air."
Re:Latency (Score:2, Informative)
Comment removed (Score:4, Informative)
Re:Latency (Score:3, Informative)
Re:Latency (Score:5, Informative)
Wow, I can't believe you've been moderated "Informative" with completely wrong information. Light travels from the Sun to the Earth in a little over 8 minutes, not 8 seconds. You are a little closer on the delay between the Earth and the Moon, but it is about 1.25 seconds, not .25.
Also, anything interactive requires a round trip, so for practical purposes, the delay is double that (about 16.5 minutes for the Sun and 2.5 seconds for the Moon).
Re:Latency (Score:2, Informative)
The author would have a much easier time making his case if he called it computer simulation instead of telepresence (which sort of implies a near real time experience) and referred to experiencing other worlds, rather than exploring them.
I would say blame the journalist, but the author of the Op-ed works at the Seti Institute, so he probably knew exactly what he was doing.
Re:Latency (Score:1, Informative)
Except that quantum entanglement doesn't allow instantaneous communication.
http://en.wikipedia.org/wiki/Action_at_a_distance_(physics)#Quantum_mechanics [wikipedia.org]
Re:Latency (Score:1, Informative)
That said, it wouldn't be too difficult to send humans on that trip. From the perspective of the people on the ship, very little time would have passed. They merely would have accrued a very large time-debt compared to us. So we don't have to worry about the colonists evolving into something unrelated from us. We have to worry about us evolving away from the colonists.
Re:Ignores time dilation (Score:5, Informative)
Who cares, we're not going to be accelerating at much more than 1g in any case, and probably a great deal less.
(B) At that acceleration, how long does it take to reach a significant fraction of c?
0.95c is about turnover speed for a 1g trip to Alpha Centauri. It'll take about 21 months to reach that speed, and another 21 months to stop. So Alpha Centauri at 1g is about 3.5 years away.
Everything else is farther, of course. But not a lot farther, since you've done the slow part already. Twenty years can get you anywhere in the galaxy at one g.
Re:Ignores time dilation (Score:3, Informative)
Humans can sustain an acceleration of 10m/s^2 (a little more than 1g). One day (86,400s) would lead to a speed of 864,00m/s. To reach a speed of .9c (270,000,000m/s) would require about a year. It would require the same amount of time to decelerate. The problem is that even a speed of .9c does not give you much time dilation. We have gamma=1/sqrt(1-.9^2), which is 1/sqrt(1-.81) or 1/sqrt(.19), which is 1/.44, or about 2.3. Hence, one would age 44 years on a 100-light-year voyage.
Re:Latency (Score:1, Informative)
except, unless our understanding of quantum entanglement is completely off (always a valid possibility, of course...), entanglement can't be used to communicate info at FTL speeds.
someone posted this above:
http://en.wikipedia.org/wiki/Action_at_a_distance_(physics)#Quantum_mechanics [wikipedia.org]
Re:'Human' (Score:2, Informative)
For an interesting and entertaining take on this concept (and other singularity-related ideas) check out the novel Accelerando [accelerando.org] by Charles Stross [antipope.org].
It's a great book by a fellow Slashdot user [slashdot.org], and you can download it free!
(Then go buy some of his other fine works)
Re:Ignores time dilation (Score:3, Informative)
A: For extremely short durations, a small sample size of humans have survived 150G. However, the green 50G shock stickers are commonly used on dummies to equate to major injury. 9G is about the most anyone can take without blacking out, even lying down. I suspect for long-term endurance you may be limited to 2 or 3G and even that would require extreme physical training.
B: Google calculator can easily answer this one: http://www.google.com/search?q=c%2F(9.8m%2Fs^2*3) [google.com]. Replace the 3 with whatever acceleration rate in G's you want.
The hard part, of course, is finding a powerplant that could actually do that.
Erm (Score:2, Informative)