Space Travel Purpose?

[Quetzal]

and at these lesser speeds.....how many years to the edge of our system?
Voyager took how long?
and the next solar system is how many light years?

This is a fair point and a very big challenge for us if we want to ever visit other galaxies. We have to survive the very lengthy journey!

 

[Demonslayer]

Yeah, poor little guy.

I did see a cool movie at the planetarium called Moons: Worlds of Mystery. Interesting stuff. Did you know (of course YOU did ) that Jupiter now has 65 moons? They are finding them so fast that the information card next to Jupiter in the display still says 63 and the movie said 65...they found two more just in the time it took to film and get the movie to production!

Crazy stuff going on just in our solar system.

 

[Thief]

I have questions, isn't the most efficient way to travel through space by taking advantage of the gravity of other bodies? In that case, you don't want to be shot into space like a bullet. You want to use archs and apexes to sling shot your way out.


I don't get this either. Where would that force come from? We have folks in the ISS cruising around the earth at a humble 17,150 miles per hour, so it doesn't have to do with speed, right?

right.....acceleration is the problem
but on the scheme of touching down on other worlds......

you need to go.....really really fast

Star Trek is soooooo cool
instant light speed and you don't turn to goo!

 

[Quetzal]

right.....acceleration is the problem

Right, it would have to be a gradual process, I agree with that.

you need to go.....really really fast

Correct, but without an atmosphere to interfere with resistance, it wouldn't take very long at all to get truckin!

 

[Quetzal]

I did see a cool movie at the planetarium called Moons: Worlds of Mystery. Interesting stuff. Did you know (of course YOU did ) that Jupiter now has 65 moons? They are finding them so fast that the information card next to Jupiter in the display still says 63 and the movie said 65...they found two more just in the time it took to film and get the movie to production!

Crazy stuff going on just in our solar system.

But there is MORE! In fact, I believe there is a mission in progress to do a flyby of Io (I think?) and take a sample from an ice volcano (YES, ICE!) on the moon. In short, when it coughs up ice dust, we want to vacuum it up! Jupiter has a lot to share with us.

 

[beenherebeforeagain]

and at these lesser speeds.....how many years to the edge of our system?
Voyager took how long?
and the next solar system is how many light years?

That is a different question--you were saying that in order to leave earth you MUST HAVE 18 gs and to leave the system, 44gs. That is incorrect; to do so WITHIN A GIVEN SHORT PERIOD OF TIME, you might have to accelerate like that, sure, that's the case, but there is no reason to limit your time period--unless you want to make it appear impossible to people who don't know better.

Sure, at these lesser speeds (which are achieved either with a brief burst of acceleration, or by using continuous-thrust technology, such as ion rockets), it takes a long time even to get around the solar system. But if we could upgrade to more powerful versions (which we should be able to do over the next couple centuries), we should be able to easily overcome the solar escape velocity without high g accelerations.

That it will still take a long time to go anywhere, even in the solar system, is the nature of our cosmos--but it certainly doesn't preclude humanity from doing so, just puts limits on how quickly we can.

 

[Quetzal]

That is a different question--you were saying that in order to leave earth you MUST HAVE 18 gs and to leave the system, 44gs. That is incorrect; to do so WITHIN A GIVEN SHORT PERIOD OF TIME, you might have to accelerate like that, sure, that's the case, but there is no reason to limit your time period--unless you want to make it appear impossible to people who don't know better.

Sure, at these lesser speeds (which are achieved either with a brief burst of acceleration, or by using continuous-thrust technology, such as ion rockets), it takes a long time even to get around the solar system. But if we could upgrade to more powerful versions (which we should be able to do over the next couple centuries), we should be able to easily overcome the solar escape velocity without high g accelerations.

That it will still take a long time to go anywhere, even in the solar system, is the nature of our cosmos--but it certainly doesn't preclude humanity from doing so, just puts limits on how quickly we can.

If we want to expand the timeline even further, for satellites and unmanned missions, we are also developing solar sails! I don't think they even use engines once they deploy. The downside is it takes a long time for them to get moving.

 

[Thief]

Right, it would have to be a gradual process, I agree with that.


Correct, but without an atmosphere to interfere with resistance, it wouldn't take very long at all to get truckin!

well that's where the number came from in my previous post
that professor claimed you would need to accelerate with endurance
or you simply end up in a larger orbit

he did not demonstrate the equation
the course offered had a lot of territory to cover
it was a notation ....so to speak

perhaps someone here has a computation.....?
how long to reach the speed of light?
when allowing only 18g's constant

 

[Thief]

That is a different question--you were saying that in order to leave earth you MUST HAVE 18 gs and to leave the system, 44gs. That is incorrect; to do so WITHIN A GIVEN SHORT PERIOD OF TIME, you might have to accelerate like that, sure, that's the case, but there is no reason to limit your time period--unless you want to make it appear impossible to people who don't know better.

Sure, at these lesser speeds (which are achieved either with a brief burst of acceleration, or by using continuous-thrust technology, such as ion rockets), it takes a long time even to get around the solar system. But if we could upgrade to more powerful versions (which we should be able to do over the next couple centuries), we should be able to easily overcome the solar escape velocity without high g accelerations.

That it will still take a long time to go anywhere, even in the solar system, is the nature of our cosmos--but it certainly doesn't preclude humanity from doing so, just puts limits on how quickly we can.

I've seen that discussion on tv.
and the acceleration problem comes up again

unless we find a means to hold our minds in a frozen body......for centuries
we are not going anywhere

but maybe the warp engine will not be science fiction forever
and maybe we can somehow NOT turn into goo on the back wall of the stern!

 

[Demonslayer]

But there is MORE! In fact, I believe there is a mission in progress to do a flyby of Io (I think?) and take a sample from an ice volcano (YES, ICE!) on the moon. In short, when it coughs up ice dust, we want to vacuum it up! Jupiter has a lot to share with us.

When the showed Jupiter with all of the moon orbit lines, it was dizzying. Most of the moons are far out and not much more than little chunks of rock, but the major ones are as big as planets but all with very different traits. I mean I know I read about this stuff back in the day in school, but it was very cool to hear the updated information. High school was an unfortunately long time ago...

Hmmm, Wikipedia says 67 moons...they found too more since my last post.

 

[Demonslayer]

unless we find a means to hold our minds in a frozen body......for centuries
we are not going anywhere

If you could create a large enough self-sustaining space craft you could travel over generations, with some generations being ship-bound for their entire lives, Battlestar Galactica style.

Alpha Centauri is only 4+ light years away and there is a group doing a proof of concept study trying to show we could get there in 20 years. I don't really get the science behind it, but that's why I'm here at this desk job and not planning to fly around in space.

 

[Thief]

If you could create a large enough self-sustaining space craft you could travel over generations, with some generations being ship-bound for their entire lives, Battlestar Galactica style.

Alpha Centauri is only 4+ light years away and there is a group doing a proof of concept study trying to show we could get there in 20 years. I don't really get the science behind it, but that's why I'm here at this desk job and not planning to fly around in space.

yeah....when I was soooooooo much younger
space travel science fiction was really en vogue

a common theme was multi generation voyage
which then digressed to the people on board not keeping to the 'plan'

but more to reality......
our bodies digress badly for lack of earth style input
gravity at 1g for example
by the time we get anywhere.....we loose our bones

I think the octopus is an alien that crash landed
could not recover space flight
and the ancestors are what we now know!
their bold is copper based

 

[Quetzal]

unless we find a means to hold our minds in a frozen body......for centuries
we are not going anywhere

You and me? Probably not. Our species? You bet we are going somewhere!

 

[Demonslayer]

I think the octopus is an alien that crash landed
could not recover space flight

Makes sense, their 8 arms would be good for pulling levers and gizmos required to run the spaceship.

 

[Demonslayer]

You and me? Probably not. Our species? You bet we are going somewhere!

I just want to live long enough to see people on Mars. I'm 45 now, I think I'll see it don't you?

 

[Quetzal]

I just want to live long enough to see people on Mars. I'm 45 now, I think I'll see it don't you?

Yep! My model puts us about 10 years shy of putting foot prints on it. Then about 20 from trying to inhabit it.

 

[jonathan180iq]

I got it from a physics course I took (college)

Ah ha! Here we go!
http://www.universe-galaxies-stars.com/Escape_velocity.html

Also important to point out that increasing speed is relatively easy and doesn't require much energy via the gravity sling shot technique. See: Voyager who just high fived Pluto and is still going!

I did some digging and I find the equation a bit over my head....
but I did not forget the number provided at the classroom.

wiki does explain escape velocity
and also notes, if your vehicle can maintain a course with sufficient fuel....
you need not be shot into space like a bullet

still there's that problem of getting crushed in your seat.....
for a very long time

Escape velocity and G's experienced are not the same thing at all. You're forgetting the difference in expression of force. There's no real correlation between the two, once you've left a planetary surface.
Our rockets gain the most speed once they've officially crossed into space (which happens somewhere between 62-73 miles from the surface). The G-forces experienced during this period are basically nonexistent...

Given enough fuel, a ship could accelerate almost indefinitely in space with little-to-no-effect on it's occupants. The only time that that G-forces would become a concern would be when the predominant acting force on the body becomes the gravity of a new planetary object (like entering the atmosphere or gravitational pull of wherever you're traveling). Deceleration in space works the same way. Until you are predominantly affected by the pull of some other thing, you could basically stop and speed up as much as you like and the little spacemen inside would barely know that anything was happening.

Relativity, man. Relativity.

To be totally fair, we don't really know what it will feel like if/when humans ever cross over the heliopause as even our best understanding of the forces in space are constantly being influenced by the Sun, either gravitationally or via solar wind. But until we are given reason to think otherwise, what happens juts beyond the Sun's gravity won't vary too much from what happens within it.

 

[jonathan180iq]

I just want to live long enough to see people on Mars. I'm 45 now, I think I'll see it don't you?

Humans will at least have stepped foot on Mars by 2040. You'll see it.

 

[beenherebeforeagain]

I've seen that discussion on tv.
and the acceleration problem comes up again

unless we find a means to hold our minds in a frozen body......for centuries
we are not going anywhere

but maybe the warp engine will not be science fiction forever
and maybe we can somehow NOT turn into goo on the back wall of the stern!

As one accelerates to near the speed of light, time perceived on the ship slows down...at 1g, while it takes almost a year earth-time to get to 99.99c, it's only about 270 days--nine months--onboard; and at that velocity, light-years go by in only hours or days. Thus, a 10 light-year trip (Tau Ceti, for example), would take about 10 earth-years, but only about 1.5 years on the ship. For 100 light-years, 100 years on earth, but less than 3 years on board (if my calculations are right). Time dilation moves interstellar travel into the possible...

The problem is accelerating continuously to that velocity very close to c--that's very difficult and may take humans hundreds or thousands of years to develop--maybe never...

If you can only accelerate to ten percent of the speed of light, you don't get the benefit of time dilation, so it does take a long time to go anywhere--Tau Ceti would take over a century aboard ship, just as long as on earth (for all practical purposes--there's a LITTLE dilation involved, but not much). Even 10 percent of c is going to be a tremendous technological achievement...

 

[Quetzal]

As one accelerates to near the speed of light, time perceived on the ship s lows down...at 1g, while it takes almost a year earth-time to get to 99.99c, it's only about 270 days--nine months--onboard; and at that velocity, light-years go by in only hours or days. Thus, a 10 light-year trip (Tau Ceti, for example), would take about 10 earth-years, but only about 1.5 years on the ship. For 100 light-years, 100 years on earth, but less than 3 years on board (if my calculations are right). Time dilation moves interstellar travel into the possible...

I wish I could wrap my little head around this kind of stuff!