# How Far away was the planet they travelled to?

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Posted Jun-09-2012 2:19 PM

I'm trying to remember how far away the planet was, I think it was 3.10x 10^14 miles away, because I was trying to calculate how long it would take for a message to get from the planet back to earth.

# 13 Replies

Unless I'm mistaken, LV-223 was 2 years out. If they were traveling at light speed, then it was 2 light years away. It's supposed to be in the real zeta 2 reticuli, so if anyone is well-versed in astronomy, they could give you a pretty accurate distance.

I calculated the distance at a little over 300 light years based on the distance provided in the movie. The real zeta 2 reticuli star system where alien took place is 39 light years from earth. The prometheus was traveling much faster than the speed of light to get there in two years.

You got your maths wrong. The did put this info on the screen when the Prometheus ship is first shown to us. The tell us the date, the crew number, and distance from Earth. All three of these are actually important to themes or sub themes and plot. it says 3.27 * 10 ^14 which is 34.5 light years. They travelled that distance in 28.5 months, so that's 14.5 times the speed of light. Zeta 2 Reticuli is 39 light years out. but is fairly close to Glies 86, which is the star that these guys aimed for. Do you realise that if they went to Zeta 2 Reticuli, they still would have found a space jockey and a bunch of nasty cretures? That's the solar system where LV 426 is located. Check out a star map of that system... it's the same pattern that they show in the caves.

I'm busy having a look at the project prometheus wesite - the active 'new worlds' section. it's over here - http://www.projectprometheus.com/newworlds/ Now reading what you folks have been writing in this post, i can only deduce that either the LV bodies have been left out of the above advertising campaign completely, or they have, unfortunately, cocked up their intel. I can't find any LV references on the official site, or even any 'mystery planet' references in there. Am i missing something? :/

To answer the original question. It would take a message roughly 39 years to reach the Earth from the planet they arrived on. For the ship to travel 39 light years away in only 2 years is possible without exceeding the speed of light, which is impossible (according to Einstein's Special Theory of Relativity). Time dilation occurs as something with mass approaches the speed of light. The calculation looks like: 1/(√(1-(v^2/c^2))) where v=velocity and c=speed of light. When time dilation occurs, the crew aboard the Prometheus will age much slower relative to their counterparts back on earth. This allows an organic crew to travel very far in a relatively short period of time. The closer one gets to the speed of light, the greater the factor increases. If one was to reach the speed of light (which in theory is impossible) than the factor would become infinite, just imagine someone exploding. So if the Prometheus took 2 years to travel 39 light years it would mean that they underwent a factor change of 19.5 (39ly /2 ship years) which would occur at 0.9986842099564331 the speed of light. On the downside, with a factor change of 19.5 it would also entail that the mass of the Prometheus and the crew would increase by a factor of 19.5. So a 180 lb man would now weigh 3,510 lbs, but hopefully they would have invented some means of mitigating that little issue. Just as a side note, to reach a factor change of 50,000,000 one "only" need to attain 0.9999999999999998 the speed of light. A two year round trip from Earth at that speed would mean that you would have only aged 2 years but 100,000,000 years would have passed on Earth. Mind blowing!....to me at least.

To "Irish" Tá cúpla ceisteanna agam.... why do you say it's 39 light years away? [i]To answer the original question. It would take a message roughly 39 years to reach the Earth from the planet they arrived on. [/i] It's 34.5 light years away. Do the math, using the figures that appeared on screen. 3.27 * 10^14 km and 1 lightyear is 9,460,730,472,580.8 km [i]For the ship to travel 39 light years away in only 2 years is possible without exceeding the speed of light, which is impossible (according to Einstein's Special Theory of Relativity). Time dilation occurs as something with mass approaches the speed of light. The calculation looks like: 1/(√(1-(v^2/c^2))) where v=velocity and c=speed of light. [/i] They travelled 34.5 light years in 28 and a half months. In other words 14.5 times the speed of light. That's why Science Fiction sometimes has to 'assume' that some barriers are 'overcome' in the future.... otherwise space adventures can't happen, because if someone spend a few years travelling to Jupiter, and reported landing it would take hours to hear "message received" and that kind of slow pace doesn't work well in movies. [i]When time dilation occurs, the crew aboard the Prometheus will age much slower relative to their counterparts back on earth. [/i] Have you noticed that they are in stasis? They're not going to age much regardless. [/i] If one was to reach the speed of light (which in theory is impossible) than the factor would become infinite, just imagine someone exploding. [/i] They've taken a liberty with this obviously [i]So if the Prometheus took 2 years to travel 39 light years it would mean that they underwent a factor change of 19.5 (39ly /2 ship years) which would occur at 0.9986842099564331 the speed of light. On the downside, with a factor change of 19.5 it would also entail that the mass of the Prometheus and the crew would increase by a factor of 19.5. So a 180 lb man would now weigh 3,510 lbs, but hopefully they would have invented some means of mitigating that little issue. Just as a side note, to reach a factor change of 50,000,000 one "only" need to attain 0.9999999999999998 the speed of light. A two year round trip from Earth at that speed would mean that you would have only aged 2 years but 100,000,000 years would have passed on Earth. Mind blowing!....to me at least.[/i] Your maths is wrong throughout, the mass of the ship would not increase by 19.5 times if they travelled 19.5 times the speed of light. It would have hit as velocity approached "c".

To Hadley's Hope: [i]Your maths is wrong throughout, the mass of the ship would not increase by 19.5 times if they travelled 19.5 times the speed of light. It would have hit as velocity approached "c"[/i] I was trying to give a basic understanding of how time dilation works. The math is not wrong. Sci-Fi is not needed to make an expedition like that happen. I used 39 ly because I thought somebody said that it took place in the zeta 2 reticuli. So in that regard I was wrong. I don't think you understand the principal behind what I was explaining. I never said the Prometheus was traveling 19.5 times the speed of light I said they were traveling at 0.9986842099564331 times the speed of light which would be SLOWER than the speed of light. Traveling at that speed, one would have a relativistic factor of change of 19.5 With a basic understanding of special relativity you would know that mass DOES increase as one approaches the speed of light. E=mc2, or m=c2/E. The speed of light is a constant, so as more energy is applied, the mass increase is directly proportional. Meaning that with a relativistic factor of change of 19.5 which occurs at LESS than the speed of light, three things happen: -Mass increase (19.5 times) -Contraction in the direction of travel (19.5 times) -Slowing of time (19.5 times) Again, this occurs as one APPROACHES the speed of light, not when one exceeds it, which in theory is impossible. As I stated in the previous post, at the speed of light "c" the factor becomes infinite. So even if it were possible to travel 19.5 times "c" you would have 19.5 times infinity....which is still infinity, I think you were confused. So basing the distance on what you gave me (34.5 ly in 28.5 months) 14.526 is the relativistic factor of change. Meaning that the ship was traveling at 0.9976275700550126 times "c" not 0.9986842099564331 times "c", my mistake. When it all boils down the ship was going 185840.455 miles per second which is very fast. End of story. Before you accuse someone else of being wrong, you should be well versed in the subject matter. In this case relativity.

Hadleys: I believe you are getting confused not accounting for the reference frame, time is not fixed. They traveled 34.5 light years in 2 [i]ship[/i] years. If the ship could travel at the speed of light, they would make a return journey in 69 earth years, but it would take zero time for them in ship years. Also they would have the pesky problem of being infinitely heavy because they divided by 0. No faster than light travel here.

Irish, I don't understand your relativity computations. The relavant equations are those for time dilation -> t = t(proper) ( 1 - v^2/c^2)^(-1/2) ... of which we know the proper time: 28.5 months... Next, we know the distance is 34.6 ly (note incorrect rounding in prev posts). The relavant eq here is Lorentzian length contraction --> L = L0 (1 - v^2/c^2)^(1/2) ... (note that (1 - v^2/c^2)^(1/2) = gamma, the 'lorentz' factor and appears often in relativity computations). We know the L = 34.6 ly. I'll post a detailed solution if someone is interested. Their speed is 0.99765 that of light... That would result in an 'on-board' time of flight of 28.5 months. This simple computation assumed they traveled at that speed from the start... Note that relativity provides the seemingly disparate explanations for the 'paradox' here: onboard, length contraction means the distance is significantly foreshortened.... Time dilation means that the clocks on the ship "run slow" (from earths perspective). Both effects precisely account for the duration of the trip from the frame of the ship. Also, I do not know what this means: "(34.5 ly in 28.5 months) 14.526 is the relativistic factor of change" ... That relationship is meaningless in SR. Linear approximations are only valid if v < 0.1c ... which, of course, it is not.

I'm perplexed. Every time I convert 3.27*10exp14km to ly, I get 354.6. 3,270,000,000,000,000km/ 9,460,730,472,580.8km= 354.6 (rounded)

Ah. MS Calculator. 10Exp14 doesn't equal 10x(superscript)y14. Carry on.

4g constant acceleration they would need to make 34.5 ly distance in 29 months

This is why I am going to college to become an archaeologist not a physicist!

The Anunnaki were on the earth in those days--and also afterward--when the sons of God went to the daughters of humans and had children by them. They were the heroes of old, mighty men of high reno