How unique is 'Earth-like' life in the universe?

Discussion in 'Science' started by Medieval Man, Nov 5, 2017.

  1. OldManOnFire

    OldManOnFire Well-Known Member

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    If we are to trust in the theory of evolution we should surmise that humans today are near-perfect life forms regarding Earth's water, atmosphere, and terrain...humans as we know them today are the survival of the fittest...we have adapted quite well. Therefore, I would expect on similar planets to Earth, that their evolutionary path would create beings very similar to humans. I can accept slight differences in eye sight, hearing, the digestive track, and skin/hair, but not much different than we can find on Earth say between a Minnesotan and a Kenyan. Of course modern humans have not been around that long so it's interesting to speculate how much more evolution the human will see? But we'll never know this answer because we don't know the challenges humans will face in the future...other than themselves...
     
  2. CCitizen

    CCitizen Well-Known Member

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    hopefully by the end of the century Space Travel will be less expensive.
     
  3. Nightmare515

    Nightmare515 Ragin' Cajun Staff Member Past Donor

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    Space travel will undoubtedly be less expensive by then, SpaceX had already figured out how to reuse rockets which has cut the cost down dramatically. Advanced space travel will more than likely be taken over by private organizations like SpaceX and leave NASA behind simply because NASA is bound by the federal government's willingness to give them money which private companies are not.

    The problem is that the general public just doesn't care very much about space and neither does the federal government. NASA has gotten to the point where they can't really show the average joe anything "cool" anymore. The public wants pretty pictures and stuff, or to send people places. Hubble wow'd the masses a couple decades ago with it's pretty unseen pictures of deep space and the discovery of Exoplanets made the public excited as well but after that nothing really exciting has happened to the average person. The next thing the public will care about will be landing humans on Mars. Although tons of amazing discoveries have been made over the years, including the recent incredible measuring of confirmed gravity waves, those are the types of things that the general public couldn't give less of a damn about.

    Those are also the sentiments of the government who serves the people here in the US. Basically it has become either show us HD pictures of something cool or show us aliens or we don't care.

    James Webb is going to piss off a lot of people when it launches next year because people don't understand how Astronomy works and many are expecting this telescope to snap HD pictures of Exoplanets or something. When the first images come back from the IR telescope designed for scientists and not for wow'ing the average joe then a lot of folks are going to be mad that we spent over 8 billion bucks of taxpayer money building that thing.

    If common folks shared the same fascination about Astronomy as you or I do then it would be much easier to convince Congress to give NASA more money. But the sad reality is that most folks really couldn't care less. Once we launch the first humans to Mars then the public will get excited again, but until then, unless we confirm alien life on another planet then the public isn't really going to care about anything else NASA does.
     
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  4. CCitizen

    CCitizen Well-Known Member

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    We do not know. Space travel today is as expensive as it was in 1970. And in 1970 almost all experts believed that space travel will be common and inexpensive in 2017.
     
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  5. Nightmare515

    Nightmare515 Ragin' Cajun Staff Member Past Donor

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    I disagree, the mere fact that humans have developed reusable rockets has cut costs considerably. However, we are also venturing further out than we did back then. In the late 60's and 70's our target was the Moon. Nowadays our target is Mars. Even cutting space costs down will still cost us more to send humans to Mars than it did the Moon given the required technology and sheer distance.

    In the 70s we believed space travel would be common in 2017 because they figured NASA would have the same percentage of the budget as it did in the 60's and 70's. When humans were researching technology to get to to the Moon NASA was allocated between 3-4% of the budget. Nowadays when humans are trying to get to Mars NASA is allocated less than half of 1% of the budget.

    So basically right now we are trying to do a hell of a lot more with a hell of a lot less money.
     
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  6. CCitizen

    CCitizen Well-Known Member

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    We never know the future, but I hope you are right. I am a 47 year old man. I eat lots of fried food, I do not drink, do not smoke and do not use drugs. I hope to see some changes during my life.
     
  7. Bear513

    Bear513 Banned

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    I don't get your post because the facts say other wise, for some reason Obama cut the mars program , instituted by Bush Jr ( for some reason Obama wanted to go to an asteroid instead ( big fan of popular mechanics and popular science) all I read now is the USA is letting China and Russia have the moon and now finnaly with Trump we are going back to Mars , unless Elon beats nasa first.

    Just my two cents in this informative thread
     
  8. Bear513

    Bear513 Banned

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    * conspiracy alert *

    For some reason nasa doesn't want to go back to the moon for some reason..?
     
  9. Nightmare515

    Nightmare515 Ragin' Cajun Staff Member Past Donor

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    Me too!

    Not to be pessimistic but I believe the more you study and understand Astronomy and Astrophysics then more fascinated you will be with the more subtle discoveries being made. If you don't set your expectations too high the way the average joe does, based on not really understanding science, then the more excited you will be when discoveries are made.

    I followed Juno from the day it was a blueprint up until the day it launched and counted down the days when it finally arrived at Jupiter. Went to work that day super happy and excited with my co-workers poking fun at me when I told them the smile on my face was because our probe finally arrived at Jupiter. Their responses were "Uh ok? Don't we already have pictures of Jupiter?"

    When the announcement was made that we discovered concrete evidence of gravity waves I was in shock.

    When I got my first telescope decades ago and first saw Saturn with my own eyes I will in absolute awe. The tiny fuzzy image that I saw with little detail was completely uninspiring to any of my friends at the time because they'd of course seen nice pictures of Saturn taken by Cassini or Hubble. But I sat there for hours just staring at this thing, I was seeing Saturn! With my OWN eyes!

    And I sit here counting down the days until James Webb launches next year which will be a bigger celebratory day for me than Christmas.

    Point is, at your age and my age we will likely not see anything mind blowing getting made before we die. We MIGHT see the beginning of the construction of a colony ship bound for Mars or something in the next 30-40 years but that will be about it. We will likely see private companies building asteroid mining ships. And of course we SHOULD see humans first land on Mars. We will get more pictures of Exoplanets but they will not be Hubble quality they will be pixelated dots. But if you understand even the basics of Astronomy you will understand just how absolutely awesome it is to see a grainy 4 pixel dot of a planet outside of our own Solar System. And that will fascinate you.

    Don't expect to see humans building the USS Enterprise before you die. Just like don't buy a telescope and expect to get Hubble quality images of things when you look through it from your backyard. But understanding Astronomy would make the blurry tiny image of Saturn that you can see with your own eyes 100x more fascinating than the HD quality one you can see from Cassini.

    At least it does for me anyway.
     
  10. Nightmare515

    Nightmare515 Ragin' Cajun Staff Member Past Donor

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    Well its a budget issue as well as an issue with Congress changing their damn minds all the time. NASA's biggest problem is that fact that they are federally funded and are subjected to the will of those who fund them, IE Congress which represents the people.

    So basically we have the financiers of a company directing how a company should operate when they have absolutely no understanding whatsoever of what's actually involved for the company to adhere to their wishes.

    Astronomy, Astrophysics, Space Exploration, etc is one of the most complex fields of science there is. Meanwhile the federal company tasked with carrying out these programs is funded by those who have virtually no knowledge whatsoever about any of the aforementioned. An Administration, Congress, etc can say "I want to go to Mars" but they don't know exactly what that entails or how long it takes to even begin to research a project like that. Then a few years later Congress can change and say "I want to go to the Asteroid Belt" completely oblivious to the fact that you can't just change your mind like that because it takes years to even draw up the plans for any project they come up with.

    The Federal Government has to make a decision and they have to stick with it. It takes YEARS to even draw up the blueprints for space missions and the government just changes their mind on what they think is important every few years which screws NASA all up because they can't make up their minds.

    Bottom line is that Congress has no idea how space exploration works or the planning and funding required to do it. Yet they are the ones who make the decisions about space exploration which is why it takes so long for anything to ever get done.

    Basically the folks at NASA are smarter on space exploration stuff than Congress. So Congress needs to just allocate them a budget and leave them alone and let them do what THEY think is important with that money. But they can't do that because NASA is funded via tax payer money and the public has a right to have input on what NASA does via Congress even though neither have any real idea of what they are talking about.
     
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  11. Bear513

    Bear513 Banned

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    Yup. I hate this flipp flopping on our space program , I know our military space program is huge compared to NASA..

    A president comes in and cancels out another presidents orders, then another president comes in and flip flops..

    Yet the military space budget remains in tack under dark funding
     
  12. Nightmare515

    Nightmare515 Ragin' Cajun Staff Member Past Donor

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    Thats the way the world works unfortunately. A whole lot of technological advancements are made during war and/or when humans are trying to figure out more efficient ways to kill each other. Even our most valuable technological advancement in regards to space travel wasn't designed for space exploration, rockets were developed as a way for humans to kill each other better.

    Humans will always, at least for the foreseeable future put military power over exploration because we view the former as more important than the latter. While space exploration is "interesting", military might is "necessary" and we will always dump way more funding into that. Which is the the US Air Force's Space Command is bigger than NASA.

    You want to see space get decent funding? Dissolve that non militarization of space treaty and have America's enemies start trying to build space weapons. You'd see an entire fighter squadron of US X-Wings flying around in orbit by the year 2025.
     
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  13. Bear513

    Bear513 Banned

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    Ok you seem like a really knowledgeable person on a wide variety of subjects like I try to be, I tried to refer to this before in this topic, what's your take on astronauts claiming their is aliens on the moon? Do you believe it or it's just imagination , some one being scared in a dark and lonely space ship?

    I love to fish and all, so I sit back and look up at the stars on my days off for years and decades I never seen a UFO in 52 years ..not once ..
     
  14. Nightmare515

    Nightmare515 Ragin' Cajun Staff Member Past Donor

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    Well I'm not one who will every say with 100% certainty that something didn't happen. But I personally do not believe Aliens have ever visited the Earth nor do I believe that any Aliens live on the Moon. Perhaps maybe there are some microorganisms or something deep in the crust of the Moon but as far as the claims of little green men walking around I find those claims to be pure imagination.

    Many of the things that folks claim to see are natural phenomena or man made objects. During the height of whole UFO craze in the 50s the flying saucers were quickly debunked to be US military hardware that just happened to look like nothing anybody had ever seen before so they concluded it must be Aliens.

    I am an Astronomy lover who stares up at the heavens almost daily with everything from my own eyes to binoculars to telescopes, have been doing this for decades and I too have never seen anything that I even remotely thought was an alien spaceship. I was even living in Phoenix Arizona in 1997 when the supposed Phoenix Lights UFO's were flying around. I saw them with my own eyes as did everyone else there. While my neighborhood ran around screaming about an alien invasion I simply walked back inside and turned on the news for some comic relief to watch the city panic. To me they looked like airplanes, perhaps weather balloons or possibly some type of illumination rounds or flares. Not quite sure what they were and haven't done much more research on the subject, but what I do is that it wasn't an alien spaceship formation. The southwest US is where the military tests all sorts of experimental stuff. That's why so many folks in that area claim to keep seeing weird stuff flying around.

    I am a skeptic by nature. Aliens having visited Earth and the government being able to keep such a thing a secret is a virtual impossibility in both aspects. That would be the biggest news story in the history of humanity and there are no threats out there grave enough for the government to keep EVERYBODY quiet. There would be at least a handful of folks working at Area 51 or whatever who would believe that the world had the right to know of the greatest discovery in the history of mankind and would have leaked that out with actual evidence by now. Plus it's also the year 2017, there are super nerds living in their parents basements who can literally hack the Pentagon. In this grand age of computers and technology if there were databases of aliens out there then somebody would have leaked that information out.

    So to me, I believe all of these supposed alien sights are the result of folks with overactive imaginations who are seeing what they want to see. I've been alive for a while now and I have never once even remotely thought I've seen a ghost, a zombie, bigfoot, or aliens or anything else along those lines. I am also a pilot by profession who has flown in many places around the US and the world and I have never once seen anything weird up there that I couldn't explain.

    Not saying with 100% certainty that there aren't aliens living on the moon or have come to visit Earth....But I HIGHLY doubt it.
     
  15. Bear513

    Bear513 Banned

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    I remember that night like yesterday in 1997 , I was working night shift up in Chicago listening to Art bell on WLS am .. it was one messed up night, lol

    I lived for like 6 months in queen creek Arizona area afterwards and I always would check the night sky because of that incident I never seen anything except a military satellite out west right before night fall.
     
  16. Nightmare515

    Nightmare515 Ragin' Cajun Staff Member Past Donor

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    I remember it quite comically because my sister called me freaking out because shes one of those people who believes in everything. I'm talking literally everything, bigfoot, abominable snowman, loch ness monster, aliens, ghosts, demons, zombies, Hellraiser, and whatever else you could even think of. So she calls me screaming bloody murder because Independence Day was happening in real life apparently and she was convinced that out of all the folks in the world they had come specifically for her lol....

    Watching that unfold in real life was hilarious. Folks were rushing to the stores and emptying the shelves and everything. Neighbors were inside calling loved ones. Weirdos were on their roofs with signs and all types of **** lol. Meanwhile my neighbor who is also a big Astronomy guy and myself just walked outside stared at them for a few mins then went inside and sat on the couch.

    Human beings have some pretty extensive imaginations to say the least. Which is funny to me because you would think behind the hysteria some logic would prevail. Seeing how these mysterious flying orbs flew around for like 3 hours you would think that if it was something out of the ordinary then the US Air Force who has a fully operational base in Phoenix would have probably scrambled some jets over there to take a look at it.

    The Air Force will scramble fighters to intercept you if you accidentally fly your Cessna too close to their base or training area. I'm pretty sure they would have launched some fighter jets after a formation of alien spaceships flying around Phoenix for 3 hours scaring the crap out of everybody lol.
     
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  17. OldManOnFire

    OldManOnFire Well-Known Member

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    If Earthlings were to ever travel to another solar system, or ET's traveling to Earth, is it fathomable to achieve this in small spacecraft (2-3 people) or spacecraft the size of a small city (100's of people)? I'm guessing it will require an entirely self-sustaining biosphere capable of multigenerational travel. Therefore, unless it can dock outside of a solar system, and be undetectable, it is unlikely they can exist without us fully knowing they are ET's.

    I can imagine this type of ET craft because it's actually something Earthlings could build today. The ONLY problem is there's not enough money on Earth to fund such a venture! I think the idea of ET spacecraft on small scale that can keep up with one of our military jets is not likely...
     
  18. FreshAir

    FreshAir Well-Known Member Past Donor

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    the real question is how long does human like life last on a planet before it destroys itself, what percent avoids that destruction....
     
  19. OldManOnFire

    OldManOnFire Well-Known Member

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    You're going to get your answer regarding Earth...soon...
     
  20. Nightmare515

    Nightmare515 Ragin' Cajun Staff Member Past Donor

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    Given current technology and even proposed technology it's not really fathomable for humans to conduct interstellar travel in anything but huge generation ships. As of right now we have no technology capable of reaching even the nearest star in anything less than literally thousands of years. There are a few theoretical propulsion systems on the table being researched that could cut that time down significantly, fusion drives, ramjet's, laser sails, etc. These theorized systems could propel a spacecraft to Alpha Centauri between 10-50 years or so, but the energy requirements are astronomical (pun intended), and they are still just theories.

    Here's the basic breakdown of how this works. Thrust requires fuel, more thrust requires more fuel, accelerating a huge sci-fi sized spaceship to the speeds necessary to get anywhere in a reasonable amount of time (a decent fraction of the speed of light) would require a lot of fuel. One of the biggest problems facing scientists and engineers is figuring out how to take that much fuel with you. So you build a huge spaceship weighing thousands or hundreds of thousands of tons, then you need fuel to move it, to move something that massive you need hundreds of times more fuel in weight than the spaceship itself, which makes the whole thing even more massive requiring even more fuel to move it.

    Think of it this way, the Alcubierre Drive (warp drive) is theoretically possible to build within the laws of physics. Sort of....but in order to power that thing to "warp speeds" to get to the nearest star in 4 years you would have to build a huge spaceship....and take the entire planet of Jupiter with you as fuel to power the engines.

    It's not just the money that's the problem it's our current limited technology. We basically just don't know how to build engines that can propel anything very fast yet. We're getting there though. ET may not be limited by our own technological handicaps though, they may very well have figured out how to achieve Star Trek levels of speed at like 1000x the speed of light or something and can zip around the galaxy in days or weeks. So them having a small 2 or 3 person spacecraft that can visit Earth as routinely as quickly as I can fly from New York to LA in a commercial jet isn't out of the question. We simply don't know what they can do, if they even exist, we've never met them before.
     
  21. tecoyah

    tecoyah Well-Known Member Past Donor

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    It should be obvious to anyone who seriously contemplates these issues that interstellar travel is unlikely to involve organic entities of any kind. Likely even we have been investigated by micro probe and do not even know it, which is how they intended it. Considering the advances we little humans have made in nano technology I find it extremely doubtful that an alien would build a big spacecraft and fly around here at night with its lights on...what the hell would it need those lights for anyway?
    By the time WE decide to check out our nearest star it will likely be with a tiny little probe the size of a bumblebee that gets there in a decade or less and any images take longer to get here than it took to get there.
     
  22. Durandal

    Durandal Well-Known Member Donor

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    That's forward thinking! However....

    I think that macroscopic life is much less common than microscopic life, and that anything resembling tetrapods or other animals is less common still, especially when you factor in time. While other life might arise that bears some resemblance to terrestrial animal life, it may happen at such a distance and such a difference in time (star systems are still being born even as ours is middle-aged and we sit here contemplating the universe, while others are long dead) that we would be lucky indeed even to coexist. I mean, it's freaky to think about just how short a time humans in particular have been around, and just how briefly we have had the technology to study the cosmos in a meaningful way. The next civilization could be not only hundreds, thousands, millions of light years away, but as many earth years separated as well.

    So, have we ever been observed by other intelligent life? Ever been visited by a probe of any kind? Chances are, no way, Jose.
     
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  23. tecoyah

    tecoyah Well-Known Member Past Donor

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    I like the beach analogy:

    Imagine a beach full of sand as big as the Earth. Now paint one hundred grains of sand neon blue. Take these grains and spread them randomly across the beach. Find one of these grains in a day with just your eyes and hands. keep in mind the waves are coming in and the sand is twenty feet deep. Oh..... and the paint will wash off in an hour,
     
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  24. OldManOnFire

    OldManOnFire Well-Known Member

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    We don't have the technology to go super-fast and maybe never will but we can go 50K/60K mph which means if we set out on a course towards Alpha Centauri it's going to be a very, very, very long time which is fine as long as the ship can sustain it's crew.

    When people talk about traveling at or near the SOL I can't help but think about the movie Spaceballs when they need to go fast and choose Ludicrous Speed...the people in the ship must deal with the acceleration and braking from SOL. How long will it take to accelerate without compromising the passengers to near SOL? How is it possible to navigate objects when traveling near SOL? How long does it take to go from SOL to 50K mph speed? Never mind the physiological effects on humans traveling at high speeds...just consider the acceleration and braking. Unless we discover new physics or whatever I just don't see an 'object' and it's passengers being able to travel at near SOL...
     
  25. Nightmare515

    Nightmare515 Ragin' Cajun Staff Member Past Donor

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    Going 50/60k mph is nowhere near "fast" when talking about interstellar distances. Just doing quick math it would take a spaceship around 50,000 years going 60,000mph to travel to Alpha Centauri...

    It sounds fast to us here on Earth, but not when your destination is roughly 25,000,000,000,000 miles away.

    You're talking about building a "generation ship" where the "generation" that actually arrived at Alpha Centauri would be well over 500 generations away from the ones who started off. Star Trek was supposedly set in the 2300's. This ship would arrive there in the year 52017 lol. We need to go WAY faster than that.

    What you are talking about is actually a pretty interesting discussion that is very real in the space industry. Think of it this way. Lets say we can somehow build the generation ship you mentioned and somehow it would actually be able to keep 500+ generations of humans alive on it for the next 50,000 years and it travels at 60,000mph and we launch it in 2020. Then 20 years later we develop faster engines that can go twice as fast and travel at 120,000mph and we launch that one to Alpha Centauri. Those folks who launched after the first ones zip right by them and get there twice as fast. Then 200 years later we develop super engines that can travel at 25% the speed of light and we launch that ship in 2240 and it can get to Alpha Centauri in 20 years. It gets to Alpha Centauri before the first ship even gets 1/10000th of the way there. Then we develop even faster engines that can go 50% light speed and launch those and they can get to Alpha Centauri in 10 years. Etc, etc.

    So the original "generation ship" we sent off to colonize the stars will arrive at it's destination about 47,720 years after the first humans actually got there and likely see a full blown Terraformed Alpha Centauri solar system with billions of humans all over the place. Pretty much negating their purpose for showing up.

    Point is technology moves too fast. In layman's terms, before we launch anything to the stars we have to get to the technological point of propulsion advancements to where the next thing we launch to the stars isn't going to beat the first thing we launched to the stars there.

    The fastest thing humans have ever launched into space was the New Horizons probe which travels at over 36,000mph. If it were pointed at Alpha Centauri it wouldn't get there for over 78,000 years. If we want to send humans to Alpha Centauri we're going to have to figure out how to propel a huge spaceship and some very significant percentage of light speed. If we want to get there in any reasonable amount of time (less than 100 years) then we are going to have to develop engines that can propel a spaceship at around 33,500,000mph.

    60,000mph ain't gonna cut it.

    The acceleration aspect is a good one to discuss and is often left out simply for the sake of making things easier to understand using raw numbers that regular folks can multiply and divide by. A ship traveling to Alpha Centauri would likely spend the first part of its journey accelerating to it's speed, then cut the engines and just coast at that speed (no friction in space), then turn around and blast the engines at the halfway point to decelerate until it arrived. Or it would have to spend the entire first half of the journey accelerating and the second half decelerating with no cruise inbetween depending on how fast it could accelerate.

    As far as how much acceleration people can handle. The average person can withstand around 5gs for a short amount of time before passing out. Fighter pilots and astronauts that wear pressure suits can withstand up to around 9gs briefly. So without any sort of dampening technology aboard the spaceship then the acceleration would have to be sustained at around 1g. Any higher sustained g's would screw the crew up. But when talking about the technology required to even build a generation starship I'm pretty sure a whole lot of g dampeners and whatnot would be involved to negate the effects of high g's to keep the crew from feeling it themselves. Some sci fi books discuss this talking about how their big star battle ships have g dampeners that allow the ship to accelerate at like 60gs but the crew only feels 6gs or something.

    Navigating in space isn't something to worry about. Space is extremely empty. Even our Solar System is mostly empty. The Sun holds 99.8% of all the mass in the solar system. Meaning 99.8% of all the "stuff" in the solar system, dust, planets, asteroids, moons, etc, is the Sun. After that is Jupiter which takes up a huge chunk of the other 0.2% The rest of it is basically just empty space. The solar system is so "empty" that NASA doesn't even calculate whether or not it's probes will smack into an asteroid or something when passing through the asteroid belt on their way to the outer planets because the odds of it hitting anything are virtually zero. If you think the Solar System is empty then interstellar space is REALLY empty. We at least have planets and asteroids and stuff in the solar system, there is virtually NOTHING between the stars.

    Basically you could draw a theoretical straight line from Earth to the other side of the whole Milky Way Galaxy with it's billions of stars and planets and comets and whatever else is out there and you wouldn't hit anything. Our pictures of space are always from a perspective that make stuff look really close together. Our solar system models do the same thing. But remember, our closet neighboring star is 25,000,000,000,000 miles away from us. Even things as huge as stars, you'd have to be trying if you wanted to run into one with a spaceship.

    That's why Project Starshot is talking about launching a bunch of tiny stamp sized micro spaceships at Alpha Centauri. They aren't worried about anything in space messing up the trajectory of their little stamp starships, there's almost nothing out there.

    Hope this all helps :wink:
     

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