# Size a solution to Fermi Paradox?

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1 hour ago, Moontanman said:

I suggest you do some research...  Your assertion still sounds like someone standing on an iron ore deposit and says it's impossible to use it to make cars...

You were asked for supporting evidence. Saying, in effect, "Go dig it up yourself" isn't really an acceptable response, especially in light of it being in the context of things that nobody has ever done.

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They've electromagnetic imagining probability of the aliens, maybe we can communicate. We can think of the ways of the capturing variable. We can draw wavelength art and we can teach the communicate devices. I guess the alien have an vectorical logic on the own neurons.

Edited by hydrox

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46 minutes ago, hydrox said:

They've electromagnetic imagining probability of the aliens, maybe we can communicate. We can think of the ways of the capturing variable. We can draw wavelength art and we can teach the communicate devices. I guess the alien have an vectorical logic on the own neurons.

Yeah, this makes no sense.

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2 hours ago, swansont said:

I've seen arguments that take a distance and argue that there is this very small speed that expansion requires, but the problem with that is it ignores the discrete nature of the travel. There is no place to stop and resupply in the middle of nowhere. It's not a matter of only going some speed. It's a matter of surviving until you get to the next habitable planet.

You can argue it took 10,000 years to expand across the ocean to the new world, and that's 10,000 km (just for sake of argument), so the speed was just 1 km/year, but you don't just go 1 km out into the ocean that first year. At the very minimum you have to go to the next island.

Again, I'm not convinced this is true. It's just an assertion. Not an actual argument.

The situation is more akin to being able to refuel and build more boats as you go. Even tiny islands would be exploited to refuel, repair, and reproduce more boats.

We used to think the asteroids were natural islands for resources of a kind but volatiles would be a problem now we know that asteroids contain volatiles. We used to think that metals were the limit but we now think that carbon fibers and such will be the majority of construction materials with metals having a much smaller role. We used to think that self contained habitats were a necessity but now we know that ices and other volatiles are available in space. Space is not empty, gas dust and even chucks exist in reasonable numbers even in interstellar space.

It's not a matter of building a ship to travel to the new world, its a matter of colonizing the ocean by removing the raw materials we need form the water. Oort clouds extend far from a star and do not suddenly stop but slowly become the interstellar medium, which is not a vacuum but contains significant quantities of various materials from the size of dust grains to planetoids.

The expansion would proceed from the asteroids to the kuiper belt to the oort cloud to oort to objects in the interstellar medium to other oort clouds and onward. Planets and deep gravity wells would be avoided for the most part.

Single forays to the next star would be difficult to improbable but tiny steps out by millions of habitats would be inevitable...

1 hour ago, swansont said:

You were asked for supporting evidence. Saying, in effect, "Go dig it up yourself" isn't really an acceptable response, especially in light of it being in the context of things that nobody has ever done.

If no one had ever used iron ore to make cars how would you even know there is supporting evidence? he was as much as saying there are no raw materials and so it can't be done. Do I really have to demonstrate the existence of resources in space?

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13 minutes ago, Moontanman said:

gas dust and even chucks exist in reasonable numbers even in interstellar space.

For the love of...

Will you PLEASE provide a citation for this claim?

Quote

It's not a matter of building a ship to travel to the new world, its a matter of colonizing the ocean by removing the raw materials we need form the water. Oort clouds extend far from a star and do not suddenly stop but slowly become the interstellar medium, which is not a vacuum but contains significant quantities of various materials from the size of dust grains to planetoids.

The expansion would proceed from the asteroids to the kuiper belt to the oort cloud to oort to objects in the interstellar medium to other oort clouds and onward. Planets and deep gravity wells would be avoided for the most part.

Single forays to the next star would be difficult to improbable but tiny steps out by millions of habitats would be inevitable...

The interstellar medium has about 10^6 atoms per cm^3 (mostly Hydrogen. Some Helium. A smattering of heavier elements) as a maximum. Minimum is much smaller.

If you have better information, provide a link to it

Now, what does that mean. That's 10^12 atoms per cubic meter. Sounds like a lot. We put a 1 square meter scoop on our craft and collect everything. We go really fast: 1000 km/s, or 0.01c (we'll ignore all the problems associated with going this fast)

That's 10^6 m/s, meaning we collect 10^18 atoms per second, once we're going that fast. It takes us a week (6 x 10^5 s /86400 s/day = 7 days) to harvest Avogadro's number of atoms. A gram of hydrogen per week. And only if we go really, really fast.

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3 hours ago, swansont said:

Citation needed

A cursory look only found listings of objects like oumuamua and or gas and dust but I have recently seen estimates of smaller ice and rock objects occuring in interstellar space, enough to be useful but I can't find them right now. I am unable to be online for long due to heath problems. I'll continue to look for the specifics at later date or with draw my claim your call...

7 minutes ago, swansont said:

For the love of...

Will you PLEASE provide a citation for this claim?

The interstellar medium has about 10^6 atoms per cm^3 (mostly Hydrogen. Some Helium. A smattering of heavier elements) as a maximum. Minimum is much smaller.

If you have better information, provide a link to it

Now, what does that mean. That's 10^12 atoms per cubic meter. Sounds like a lot. We put a 1 square meter scoop on our craft and collect everything. We go really fast: 1000 km/s, or 0.01c (we'll ignore all the problems associated with going this fast)

That's 10^6 m/s, meaning we collect 10^18 atoms per second, once we're going that fast. It takes us a week (6 x 10^5 s /86400 s/day = 7 days) to harvest Avogadro's number of atoms. A gram of hydrogen per week. And only if we go really, really fast.

You do realise you are quoting an average of gas not objects right? And the oort cloud extends almost a light year away from the sun at least?

3 hours ago, Bufofrog said:

I really think you are minimizing the incredible difficulty in making your own little world that flies around space!

"your own little world" would be many miles long and miles wide, rotate for internal gravity and house thousands of people. The asteroids would be the construction materials along with trojan asteroids, kuiper belt objects and or oort cloud objects. I'm not saying it would be easy but the task is well within the realm of possibility. Engineering studies were done decades ago.

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58 minutes ago, hydrox said:

They've electromagnetic imagining probability of the aliens, maybe we can communicate. We can think of the ways of the capturing variable. We can draw wavelength art and we can teach the communicate devices. I guess the alien have an vectorical logic on the own neurons.

11 minutes ago, swansont said:

Yeah, this makes no sense.

"Perhaps we can communicate with the aliens if they are aware of the EM spectrum."

"We can develop the technology to capture what we need from space along the way to another system"

"We can figure out new ways to communicate with alien cultures."

"Aliens probably think differently."

It's been a long time since I spoke any Hydrox. It's an older form of Oreo, where the middle is stressed before either end is considered.

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23 hours ago, beecee said:

Isn't this  at least partly due to DE? What I'm saying is that the gravity from the denser regions of space, are acting to pull galaxies together, and so making the voids larger due to the effects of the expansion over larger scales.

I would be foolish to rule out your possibility. DE is an area of science that offers explanations for so many things...unfortunately none can be overwhelmingly considered, "absolutely true, or correct".

I try to keep an open mind. It tires me at the end of day...brain crunching...thought experiments...reading opinions from astute others. Wish I (we?) had conclusive answers:(

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5 hours ago, Moontanman said:

A cursory look only found listings of objects like oumuamua and or gas and dust but I have recently seen estimates of smaller ice and rock objects occuring in interstellar space, enough to be useful but I can't find them right now. I am unable to be online for long due to heath problems. I'll continue to look for the specifics at later date or with draw my claim your call...

Oort clouds are as yet unconfirmed and even if the do extend that far,  this does not claim they fill space. So you could still find yourself going LY stretches not inside them.

interstellar objects do not fill space.

the third link quotes a density a million times smaller than my example.

Quote

You do realise you are quoting an average of gas not objects right?

If you can find data telling how often you might find a more massive object, please share it.

But I’m guessing you don’t want to encounter one, because they would be hard to detect and hitting it will ruin your day.

5 hours ago, Moontanman said:

"your own little world" would be many miles long and miles wide, rotate for internal gravity and house thousands of people. The asteroids would be the construction materials along with trojan asteroids, kuiper belt objects and or oort cloud objects. I'm not saying it would be easy but the task is well within the realm of possibility. Engineering studies were done decades ago.

Are you simply allergic to providing citations?

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13 hours ago, swansont said:

Oort clouds are as yet unconfirmed and even if the do extend that far,  this does not claim they fill space. So you could still find yourself going LY stretches not inside them.

interstellar objects do not fill space.

the third link quotes a density a million times smaller than my example.

If you can find data telling how often you might find a more massive object, please share it.

But I’m guessing you don’t want to encounter one, because they would be hard to detect and hitting it will ruin your day.

Are you simply allergic to providing citations?

I gave a link to Mckendree Cylinders, lots of variations, take two counter rotating cylinders, energy via controlled fusion, make them 10 miles long 2 miles thick. rotate them within a non rotating metal scaffold, cover the scaffold with the construction debris. Things like rock, ice, regolith and minerals that contain other valuable materials. as thick or massive as you are willing to have if you have to slow down any acceleration you may have planned.

You might decide to stay hear where your house was built, say Jupiter's lagrange points, but most would eventually decide to move out, very slowly at first, building up speed with gravitational assists when ever possible.

A huge amount of fuel, hydrogen, can be stored in the construction debris layer as ices which would protect from small meters.Keep you speed low so that when you detect an object ahead you can decelerate to take on volatiles if needed but using this method you should be able to cary many times the mass of volatiles you would lose over the time it took to semi drift to the next oort cloud.

The only analogy we might make it RV travel, taking your home with you, it might take a million years but eventually things like gas stations might pop up on widely separated objects and chucks of icies or other necessities could be EM accelerated to the speed of the space RV to be captured so they don't even have to slow down.

14 hours ago, swansont said:

Oort clouds are as yet unconfirmed and even if the do extend that far,  this does not claim they fill space. So you could still find yourself going LY stretches not inside them.

interstellar objects do not fill space.

the third link quotes a density a million times smaller than my example.

If you can find data telling how often you might find a more massive object, please share it.

But I’m guessing you don’t want to encounter one, because they would be hard to detect and hitting it will ruin your day.

Are you simply allergic to providing citations?

Best I could do on short notice, now I have go and pass some more kidney stones hallelujah!!!!!

Edited by Moontanman

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18 minutes ago, Moontanman said:

I gave a link to Mckendree Cylinders, lots of variations, take two counter rotating cylinders, energy via controlled fusion, make them 10 miles long 2 miles thick. rotate them within a non rotating metal scaffold, cover the scaffold with the construction debris. Things like rock, ice, regolith and minerals that contain other valuable materials. as think as you are willing to slow down any acceleration you may have planned.

You might notice that the only critique directed at the Mckendree Cylinders was that they are unproven.

Quote

You might decide to stay hear where your house was built, say Jupiter's lagrange points, but most would eventually decide to move out, very slowly at first, building up speed with gravitational assists when ever possible.

It's almost like you haven't read my objections. Jupiter is inside the solar system.

Quote

A huge amount of fuel, hydrogen, can be stored in the construction debris layer which would protect from small meters.Keep you speed low so that when you detect an object ahead you can decelerate to take on volatiles if needed but using this method you should be able to cary many times the mass of volatiles you would lose over the time it took to semi drift to the next oort cloud.

Now all you have to do is some kind of analysis. Without it, this is just hand-waving. "Then a miracle occurs" of Sidney Harris fame.

I mentioned in another thread that to get a mass M up to a speed v and stop it again requires a minimum of Mv^2 of energy, and in likelihood many times that. Decelerating to take on volatiles is a much more complex scenario than you are acknowledging. I doubt you would do that with the main ship; M is very large, and therefore the energy cost would be, too.  That raises the lower limit of how big and complex a system you need to build.

At the very least this limits you to not trying to retrieve volatiles unless you encounter a rock of some minimum size, because it would cost more resources than you would gain.

Quote

The only analogy we might make it RV travel, taking your home with you, it might take a million years but eventually things like gas stations might pop up on widely separated objects and chucks of icies or other necessities could be accelerated to the speed of the space RV to be captured so they don't even have to slow down.

And my point, yet again, is that "Last gas for 1 light year" is not a problem you can deal with if you can e.g. only go 0.001 LY between refueling.

IOW, your RV can go 500 miles on a tank, but you are trying to travel all the way across Europe and Asia on a route with no gas stations. Stop treating the latter half of this problem like it's a triviality. You skirt around this every time I point it out.

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15 minutes ago, swansont said:

You might notice that the only critique directed at the Mckendree Cylinders was that they are unproven.

It's almost like you haven't read my objections. Jupiter is inside the solar system.

Now all you have to do is some kind of analysis. Without it, this is just hand-waving. "Then a miracle occurs" of Sidney Harris fame.

I mentioned in another thread that to get a mass M up to a speed v and stop it again requires a minimum of Mv^2 of energy, and in likelihood many times that. Decelerating to take on volatiles is a much more complex scenario than you are acknowledging. I doubt you would do that with the main ship; M is very large, and therefore the energy cost would be, too.  That raises the lower limit of how big and complex a system you need to build.

At the very least this limits you to not trying to retrieve volatiles unless you encounter a rock of some minimum size, because it would cost more resources than you would gain.

And my point, yet again, is that "Last gas for 1 light year" is not a problem you can deal with if you can e.g. only go 0.001 LY between refueling.

IOW, your RV can go 500 miles on a tank, but you are trying to travel all the way across Europe and Asia on a route with no gas stations. Stop treating the latter half of this problem like it's a triviality. You skirt around this every time I point it out.

You keep assuming we are only talking about interstellar space. This would have to start inside the solar system, be perfected inside the solar system. In fact I would think millions of these things would be build inside the solar system for use inside the solar system before the tech developed to allow longer voyages.

McKendree cylinders might be unproven but there is no reason to think they could not be built

Edited by Moontanman

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Edit removed overtired wrong thread post

Edited by Mordred

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Time to go to bed and get some sleep, Mordred.
( you have a choice, I'm working till 7 am )
The above post is obviously meant for the
'Resistance leads to mass and time in 3 dimensions'

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So that's where it went lol must be tired. Edited it out roflmao

Edited by Mordred

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21 hours ago, Moontanman said:

You keep assuming we are only talking about interstellar space.

Yes, I am. The topic is the Fermi Paradox, so it is necessarily involving interstellar space.

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5 hours ago, swansont said:

Yes, I am. The topic is the Fermi Paradox, so it is necessarily involving interstellar space.

So these things must start in interstellar space?

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I never understand why people continuously consider the future without intelligent machines. Like if it won't happen.

I cannot even imagine an advanced civilization that does not almost exclusively consist of intelligent machines. Machines that copy and redesign themselves in millions of different directions - some large as moonlets, but most as small as sand particles. Enormous amount of them, billions of billions.

This is how I understand Fermi's question: where are those intelligent machines, vast swarms of them that are spreading thought the galaxy in a diffusion like manner (not where are those 'bags of protoplasm' with their rockets)?

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1 hour ago, Moontanman said:

So these things must start in interstellar space?

No. Why would you think it would?

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Intelligent machines depend on the 'bags of protoplasm' having achieved an intelligence level facilitating their construction.
As such, they would be even more scarce ( being equivalent to a subset ).

Not all intelligent life will develop intelligent machines.
Not all will develop space travel.
Not all will be able to communicate with EMR.

Imagine if we had evolved underwater like dolphins/whales.
Or on a gaseous giant planet and floated in the upper atmosphere.
Or silicon based life, on a hot planet.
What kind of challenges would we have developing the technology we take for granted ?

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I don’t think it unreasonable to posit that an intelligence capable of interstellar travel would develop AI, and the former is a premise of the paradox

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26 minutes ago, MigL said:

Intelligent machines depend on the 'bags of protoplasm' having achieved an intelligence level facilitating their construction.
As such, they would be even more scarce ( being equivalent to a subset ).

Not all intelligent life will develop intelligent machines.
Not all will develop space travel.
Not all will be able to communicate with EMR.

Imagine if we had evolved underwater like dolphins/whales.
Or on a gaseous giant planet and floated in the upper atmosphere.
Or silicon based life, on a hot planet.
What kind of challenges would we have developing the technology we take for granted ?

All true, I agree...but the essence of the Fermi paradox ,as I see it, is: if at least one civilization managed to develop a method of interstellar spreading, there is nothing to stop it until it takes the whole galaxy. So it should be here too. (Interestingly, such spreading machines do not even have to be intelligent - they only have to have a 'will' and the ability to spread)

I am not a very optimistic guy, but I still think that, according to our current course, within 200 years we should have self-optimizing machines capable to overrun biological evolution.I don't know what might follow, but I suspect that for a machine, the interstellar travel is not such an unthinkable endeavor as it is for humans.

[Well, because no other civilization seem to be present here, I might speculate that either human-type tech civilizations are very rare, or something very bad will very likely happen to our civilization in next several hundred years..]

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On 7/13/2019 at 3:46 PM, swansont said:

No. Why would you think it would?

Because you seem to be dismissing my assertions of the beginning taking place in the solar system...

On 7/13/2019 at 4:05 PM, MigL said:

Intelligent machines depend on the 'bags of protoplasm' having achieved an intelligence level facilitating their construction.
As such, they would be even more scarce ( being equivalent to a subset ).

Not all intelligent life will develop intelligent machines.
Not all will develop space travel.
Not all will be able to communicate with EMR.

Imagine if we had evolved underwater like dolphins/whales.
Or on a gaseous giant planet and floated in the upper atmosphere.
Or silicon based life, on a hot planet.
What kind of challenges would we have developing the technology we take for granted ?

The silicone based life on a hot planet, organo-metallic based organisms might be more likely, but we know so little about what that might be like it's limitations are totally unknown..

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3 minutes ago, Moontanman said:

Because you seem to be dismissing my assertions of the beginning taking place in the solar system...

I don't see the relevance of it. Stopping for gas after ~0.01% of your trip is over doesn't seem like it's in the critical path of success.

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14 hours ago, swansont said:

I don't see the relevance of it. Stopping for gas after ~0.01% of your trip is over doesn't seem like it's in the critical path of success.

The relevance is that no one is saying we will build a star ship in earth orbit and take off for the nearest earth like planet. It's like expecting European humans who were building log rafts to suddenly build 747's and fly to north america. We will build movable habitats for centuries all over the solar system before we even think of the oort cloud. The idea of a generational ship is not impossible and if you are taking your home with you stopping at some point to build more habitats is hardly stopping for gas in fact gas and dust could be harvested with out stopping and going from our Oort cloud to the next is not unreasonable. Why would you stop for gas at 0.01% of your trip? I don't get that.

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