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81 Comments
- iCosmos84, on 09/30/2009, -0/+27"The size and age of the Cosmos are beyond ordinary human understanding. Lost somewhere between immensity and eternity is our tiny planetary home. In a cosmic perspective, most human concerns seem insignificant, even petty. And yet our species is young and curious and brave and shows much promise. In the last few millennia we have made the most astonishing and unexpected discoveries about the Cosmos and our place within it, explorations that are exhilarating to consider. They remind us that humans have evolved to wonder, that understanding is a joy, that knowledge is prerequisite to survival. I believe our future depends on how well we know this Cosmos in which we float like a mote of dust in the morning sky."
/carl - Chairboy, on 09/30/2009, -0/+22On the subject of "total fail", we must discuss your understanding of relativistic physics and the subjective flow of time as you approach c.
kthxbai - appleseed1234, on 09/30/2009, -0/+16Well at this point, they're restricted to Low Earth Orbit. Once the shuttles are decommissioned, America won't even be able to reach that and doesn't even have a solid plan to get at least that high. So nowhere soon. Had we actually actually given a ***** about NASA after Apollo I feel as though this article would be a little more than theoretical.
- funkedup, on 09/29/2009, -2/+17This is an interesting article. Without extremely advanced technologies, it would be very difficult to get cosmonauts to Mars, let alone outside of our solar system. I suppose that we currently have the technology to propel someone outside of the solar system, but it would be a one way ticket to radiation, possible solar storms, and the barbaric exposures of space. If someone could find some type of exotic matter to stabilize a black hole though, then we may be in business.
- mas6700, on 09/30/2009, -1/+13Interesting with regard to the concept of expanding space, but also sort of a pointless argument about coming back to Earth since it would be hundreds of thousands if not millions of years later due to the relativistic effects of traveling at nearly the speed of light. What would you be coming back to on Earth assuming its even still hospitable?
- murocan, on 09/30/2009, -0/+12A planet of apes.
- inactive, on 09/30/2009, -2/+10Oh, hi. I'm Zephram Cochrane and I have a cunning plan.
- TheEngineer2008, on 09/30/2009, -0/+7Not for the reference frame of the ship.
- LarkStew, on 09/30/2009, -0/+6I'm sure I read somewhere that at Earth acceleration, ie 1g, then a ship would need to accelerate continuously for just one year to reach 99% light speed. Of course, where it would get the energy from is a different problem...
- Bobby1978, on 09/30/2009, -2/+8Shouldn't you be making sandwiches in the kitchen?
- chrisdodges, on 09/30/2009, -0/+6You have a fundamental misunderstanding of space/time. Space can expand faster than the speeed of light, because it is space itself, not a particle travelling through space. Time is relative to perspective. As an object travels near or at the speed of light, time effectively slows down relative to someone not travelling at those speeds.
To sum it up, if you are travelling at the speed of light, it would only seem like 30 years to travel billions of light years while here on Earth tens of billions of years would pass during that same travel period. - iCosmos84, on 09/30/2009, -0/+5[Why a mote of dust in the morning sky?]
I think he was trying to remediate the image of the "pale blue dot" (when Voyager imaged the inner solar system from Neptune's orbit and Earth appeared as 1/12th of a pixel). It is simply meant to illustrate how, to our current knowledge, and particularly within the context of our solar system, that life is rare and should be cherished. I think it also gives a sense of scale. A mote of dust is minuscule in comparison to several hundred miles of atmosphere that envelope the Earth.
[And yet our species is young and curious and brave and shows much promise.]
Sagan wrote books in which he examined intelligence in other species and its gradual rise within the human species. I don't think he had any delusions that we are the only intelligent beings on this planet. I think that when he wrote this he wasn't trying to compare us to other species but rather to point out that we happen to have the capacity to contemplate the universe.
[Somewhere between immensity and eternity]
I have often wondered about this line as well. It sounds beautiful, but alas, it serves as more of a poetic device than a scientific observation. I think much of what Sagan was doing was to get the general public excited about astronomy. Sometimes words and phrases like "somewhere between immensity and eternity" achieve that end.
[Beyond ordinary human understanding[
I don't think it's outlandish to say that, confined to three dimensions and a small terrestrial planet for 4.5 billion years, we have difficulty understanding the sheer scale of the universe. Have you seriously sat down before and contemplated infinity? I know I have, and no matter how many books, formulas, documentaries, or lectures I absorb, it has never quite sunk in. Maybe it has for you--that would be quite an incredible leap in human consciousness.
[Explorations that are exhilarating to consider]
Perhaps they are not exhilarating to you, but I think some of our discoveries are absolutely fascinating. Moreover, this idea of "explorations in the proper sense" seems unfounded. What is "the proper sense?" On the timescale of mass extinctions and stellar explosions, I think these discoveries are rather drastic and compelling.
[This statement was benign, though stupid...]
I too am a bit disappointed, but not by the quote. Although I was a little offed by the tone of your comment, I do respect your opinion and hope that my responses were meaningful. - JBregard, on 09/30/2009, -0/+5FTA: "Despite the vast distance, this would take only about 50 years in the astronaut's reference frame, because time would pass slower than on Earth due to relativity."
That's the point of the article. Time will pass slower for the astronaut than on Earth. - Hydrochloric, on 09/30/2009, -0/+4I read that in Carl Brutananadilewski's voice.
- FearlessFreep, on 09/30/2009, -0/+4The Last Question -
http://www.multivax.com/last_question.html - Magnes, on 09/30/2009, -0/+4Yes.
- Bobby1978, on 09/30/2009, -2/+6Get rich and live with naked women.
- feignNU, on 09/30/2009, -0/+4actually it would be billions of years, according to the article. There probably wouldn't even be an earth to come back to.
- iCosmos84, on 09/30/2009, -0/+4You're either being sarcastic or are seriously misinformed. Do you really believe a government agency comprised of hundreds of thousands of employees could silence a fake moon landing for over four decades? Moreover, the footage in the moon landings proves that we were there. The way in which particulates, kicked up by astronauts, fell to the lunar soil was how particulates should behave in a zero gravity environment. We even have images of the landing sites from satellites orbiting the Moon today.
- lead2thehead, on 09/30/2009, -0/+4I doubt that's even possible. As you approach the speed of light, the amount of energy necessary to accelerate you approaches infinity. So to get close to the speed of light, you'd need a nearly infinite supply of energy. A better option may be to warp space in order to travel faster than light. NASA is researching a propulsion system to do that.
http://www.grc.nasa.gov/WWW/bpp/index.html - Chairboy, on 09/30/2009, -0/+4Ad TheEngineer2008 said, a ship traveling at exactly c wouldn't perceive any passage of time. As far as the pilot would be concerned, he would travel an infinite distance in zero time.
Now, let's take reduce the speed very slightly to, say, .9999999~c. To the pilot, his view out the window would make it look like he's at freaking warp speed, he'd be eating up the space miles like crazy at an enormous subjective speed. His ACTUAL speed, however, would be just below the speed of light. So while he might get from here to Proxima Centauri in a few hours by his clock, 4 years would pass back on Earth.
So, just make sure you're paid hourly, it's a sweet way to clock up the overtime. - DirtPile, on 09/30/2009, -1/+4"Come on, Lily, one more round!"
- topcat5, on 09/30/2009, -1/+4Best post in this topic.
- PeterBassett, on 09/30/2009, -0/+3This is why your application to NASA was turned down "Darth".
- LarkStew, on 09/30/2009, -1/+4Special Relativity is simple if you look at it the right way. EVERYTHING moves at light speed through spacetime. It's just that massive objects have most of their speed directed through time. If an object accelerates through space, it must decelerate through time to maintain a constant speed. Imagine an arrow rotating from a vertical time axis to a horizontal space axis. The limitation is that massive objects can't travel purely through space, they must always travel slightly through time. Whereas massless objects like photons always travel purely through space and thus experience no time at all.
- iCosmos84, on 09/30/2009, -0/+3You are making a fundamental error here. If light travels from the Andromeda Galaxy (2.2 million light years away), it will take 2.2 million light years to reach Earth. That is from our own perspective. From the perspective of the light particle, as exotic as that might seem, the journey did not take 2.2 million light years. It all has to do with time dilation and The Special Theory of Relativity. I can certainly understand where you'd be confused by this concept though--relativity is an absolutely bizarre concept.
- prufrock123, on 09/30/2009, -0/+3whoa. icosmos84. Please do not interpret this response as sarcasm. I actually am very encouraged by your comment and do find them meaningful. It's very uncommon to have someone respond in such a way on digg. I really do appreciate it.
I agree, my tone was too much. I sometimes get exhausted by the tone of diggers and have, instead of offering any counter-example, have merely imitated the ones I find offensive.
I think perhaps you misunderstood some of my comment, but that is well enough. You disagreed in a civil and fair manner, particularly considering my unrestrained statements.
I do find the universe incomprehensible, I think the scope of the stellar narrative is nothing if not exhilarating, and the infinitude of our smallness is utterly humbling.
My comment was a (poor) way of dealing with how I (arrogantly) view other people and our current culture. I simply get frustrated sometimes that science has in many ways become a sort of pseudo-cult that has exchanged artistic beauty for doctrinal purity. Carl Sagan was a brilliant guy and wrote great sci-fi. But... he's not a poet. And I get upset seeing people fawn over a paragraph of words that are in no way as remarkable as the object he is encountering.
But I'm not any better, though my pride will endlessly tell me otherwise.
Nevertheless, and in summary, I do appreciate your response, I do find them meaningful, and I likewise thoroughly respect your opinion.
Have a fine day!
Also, if you found something artistically wonderful about Sagan's words or were inspired by them, then that is great! I am not knocking it. I do not mean to attack something you hold dear. I am in no way the final authority of something's relevance.
Rather, time and continual opinion is a better arbiter and so far, his words have done very well. So that's something I ought to consider. - sproket, on 09/30/2009, -0/+3@brodimus right but due to the time dilation effect that 1 year might be only a couple of hours on your clock.
- moofree, on 09/30/2009, -0/+3Gunbuster + Ender's... sequels.
They'll get back to a dark earth billions of years later, but with a burning sun. And then the lights turn on.
WELCOME HOME! - miketejera, on 09/30/2009, -0/+3you my friend are a f-ing airhead....
- hughesj919, on 09/30/2009, -2/+5That's cute honey. Back to the kitchen please.
- BetaUser, on 09/30/2009, -0/+2@prufrock123
I read iCosmos's post after i responded to you and I agree with you. iCosmos is a class act in the way he/she responded to you.
Myself, i still think you're an ass, but your response to iCos does show some humility. My only suggestion would be to look at the effect words can have no matter how simple or banal they may be. Carl Sagan's words in no way come close to fully describing the great unknown outside of our small rock, but they put into words for some the wonders of the universe. So for that, they carry meaning.
And isn't that the purpose of any spoken or written word....to carry meaning?
In that sense, they are more than appropriate even if simple. - iCosmos84, on 09/30/2009, -0/+2I think you're on to something though. Too often, discussion about astronomy gets mired in "gee whiz" facts and top 10 lists. Although I love the series because of its pursuit of popularizing astronomy, the History Channel's "Universe" too often falls into this trap. Episodes like "10 Ways to Destroy Earth" are more sensationalist than educational. Such messages are good at inspiring interest in those who would otherwise be disinterested; however, I think it should not end there and it cheats the viewer out of a truly educational experience. This is not a condemnation of the History Channel's series; I have seen a few episodes to dig deeper and do a masterful job of communicating science in a modern format.
There is an ongoing and serious debate within academia and science advocacy groups about the methods a science communicator should employ to convey information to a general audience. Like a good journalist, capture the audience in the first 40 words, then get to the meat of it. I think that modern science communication lacks the meat.
Sagan's "Cosmos" was unusual in that it interwove history, culture, art, and astronomy into one medium. While the "The size and age of the Cosmos..." serves as an attention-getter for readers, the real arguments come further in the literature. And many astronomers I have met in my life got their start on Cosmos. Sagan was their spark.
Your latter response was about as civil as a response can be. It heartens me to know that my own response was meaningful. - TheInformer, on 09/30/2009, -1/+3Hi, I'm Uhuru and I am a Cunning Linguist.
- eriqc, on 09/30/2009, -0/+2And you know this because you've really studied our current technology enough to know that we're not capable? These "fake moon landing" websites were started by a small minority of [ignorant] people who won't give mankind credit for advancements in technology because they don't understand it. Like you. Something human beings have done since the beginning of time. If they don't understand something, they call it a lie (or kill it lol). Why don't you pick up a real book other than Enquirer magazine for a change.
My 108 year old great-grandmother refuses to believe we landed on the moon because she doesn't understand how technology can advance so fast in 100 years. My grandmother on the other hand has seen technology advance so fast over the last 50 years and knows that mankind is capable of at least visiting our closest moon. It's really no big deal anymore. We've already done it. - dawgma, on 09/30/2009, -0/+2Yep. They are all wrong.
- Nerys, on 09/30/2009, -0/+2Nono just make sure your paid EARTH TIME not SHIP TIME :-) hehe
- iCosmos84, on 09/30/2009, -0/+2The author is popularizing the concept. It is not meant to be an in-depth description of light travel. As astonishing as "billions of light years" may seem for someone to travel within a light time, it is not mathematically unfounded. As you approach light speed, space-time warps tremendously. The hypothetical example I can give you is the Twins Paradox. There is an excellent Wiki on this concept here: http://en.wikipedia.org/wiki/Twin_paradox. It is a fundamental concept in the Theory of Special Relativity.
- PeterBassett, on 09/30/2009, -0/+2Since when has common sense had anything to do with exotic physics? Not since the block and tackle was the most powerful machine on earth.
Special Theory Of Relativity : All will become clear.
http://en.wikipedia.org/wiki/Special_relativity
We can (theoretically, not practically) send astronauts off at the just under the speed of light and they can go 15B LR within their own lifetimes, just not in the lifetimes of those they leave behind. - prufrock123, on 09/30/2009, -0/+2whoa. icosmos84. Please do not interpret this response as sarcasm. I actually am very encouraged by your comment and do find them meaningful. It's very uncommon to have someone respond in such a way on digg. I really do appreciate it.
I agree, my tone was too much. I sometimes get exhausted by the tone of diggers and have, instead of offering any counter-example, have merely imitated the ones I find offensive.
I think perhaps you misunderstood some of my comment, but that is well enough. You disagreed in a civil and fair manner, particularly considering my unrestrained statements.
I do find the universe incomprehensible, I think the scope of the stellar narrative is nothing if not exhilarating, and the infinitude of our smallness is utterly humbling.
My comment was a (poor) way of dealing with how I (arrogantly) view other people and our current culture. I simply get frustrated sometimes that science has in many ways become a sort of pseudo-cult that has exchanged artistic beauty for doctrinal purity. Carl Sagan was a brilliant guy and wrote great sci-fi. But... he's not a poet. And I get upset seeing people fawn over a paragraph of words that are in no way as remarkable as the object he is encountering.
But I'm not any better, though my pride will endlessly tell me otherwise.
Nevertheless, and in summary, I do appreciate your response, I do find them meaningful, and I likewise thoroughly respect your opinion.
Have a fine day! - lead2thehead, on 09/30/2009, -0/+2Ah, I see. I retract my previous statement. :)
- subliminalurge, on 10/01/2009, -0/+2"and gravity dampening systems"
Gravity isn't really much of a problem. The ability to dampen inertia, on the other hand, would be extremely useful in the scenario you're talking about. - Bobby1978, on 09/30/2009, -0/+2Actually in this instance, space isn't necessarily expanding at or faster than light-speed. It could even be expanding a few nanometers per hour over a certain large distance. It's just that over vast distances, all this adds up to a point where at the farthest point, the total accumulated expansion exceeds that of light.
Space doesn't appear to be able to warp faster than the speed of light. - feignNU, on 09/30/2009, -0/+2@brodimus
Don't worry, I was a bit confused at first too. The problem is that the article doesn't make the idea of reference frames very clear. To put it simply: there is no universal metronome ticking away time at a constant rate that everyone in the universe can refer to. This means that whenever you talk about a duration of time, you have to talk about who or what that duration is relative to.
So let's take your question, "traveling at c for 1 year only gets you 1 lightyear away, no?" The question is, one year for whom? One year for the people on earth, or one year for the astronaut? If you observed, from earth, an astronaut traveling at c for one year, then at the end of that time the astronaut would have traveled one lightyear, yes. But a year for an earthling is not the same as a year for an astronaut traveling at c. It would be much less time for the astronaut, just like a year for the astronaut would be much MORE time for the earthling. It's tempting to want to ask who's clock is "right", or how much time it "really" took, but this question is meaningless. We can only talk about how much time it took for a person in one of the two reference frames. There is no universal metronome outside of those reference frames to which we can appeal.
Why does this happen? The answer is actually not all that complicated as long as you can grasp the idea that space and time are one manifold. What do I mean by that? They are merely aspects of one entity, sort of like the X and Y axes of a coordinate plane are different (and mutually irreducible) aspects of the same coordinate plane. Imagine if you will a coordinate plane in which the x-axis represents the three dimensions of space and the y-axis represents time. Any vector in this coordinate plane represents a velocity through space-time. It turns out that the component vectors of one of these space-time velocity vectors always sum to the speed of light. In other words, anything that moves through space-time (which is everything) is always actually moving at the speed of light...just not necessarily in the SPACE component of the space-time manifold.
If you can visualize this coordinate plane that I've tried to describe, it should be fairly simple to see why time dilation occurs. As you travel faster through space (ie, your space-time vector leans closer to the space axis), the space component of your space-time velocity vector becomes larger, and the time component gets smaller. In other words, because you're always moving through space-time at c, if you start shifting more of that velocity in to the space component of your space-time velocity, then it's gotta come out of your time component. Likewise if you went slower and slower and slower in space (ie, leaned your space-time vector toward the time axis), you'd be shifting more of your space-time velocity into the time component, and thus traveling through time faster than someone who was moving through space at a higher velocity than you.
This means that a photon which has traveled through space at c since the beginning of the universe has actually not traveled through time AT ALL from its perspective, even though from ours it has been on a 13 billion year journey across the universe. Likewise, 50 years for an astronaut traveling at .99c would be billions of years for us here, and thus he would have traveled billions of light years in that time. - subliminalurge, on 10/01/2009, -0/+2"but alas, it serves as more of a poetic device than a scientific observation."
And there's nothing wrong with that. That's one of the things that I admire about Sagan. He was able to take the science and present it in a way that incorporated the concepts of awe, beauty, and amazement. Things that all too often get completely left out.
"They should have sent a poet." - 4degrees, on 09/30/2009, -0/+2not really, it will just poof up and fizzle into a brown dwarf.
- prufrock123, on 09/30/2009, -0/+2Also, if you found something artistically wonderful about Sagan's words or were inspired by them, then that is great! I am not knocking it. I do not mean to attack something you hold dear. I am in no way the final authority of something's relevance.
Rather, time and continual opinion is a better arbiter and so far, his words have done very well. So that's something I ought to consider. - BetaUser, on 09/30/2009, -0/+2What a *****' pompass ass. Carl Sagan inspired many to study the wonders that space had to offer and for that he is respected and revered. He took complex ideas and made them understandable and exciting to the children and young adults of that time.
What have you done other than become a self-important jackass snob? - jamdogg, on 09/30/2009, -0/+1The Carina Nebula bears a striking and worrying resemblance to an ape with a swollen right eye giving everyone the finger... maybe it's just me.
- subliminalurge, on 10/02/2009, -0/+1I don't know if this is where you read it but Stanton Friedman has a pretty good page on his web site explaining just that.
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