The aliens are silent because they're dead

We are the Borg.
Anaxagoras
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Re: The aliens are silent because they're dead

Post by Anaxagoras »

Yeah, but it's no more far-fetched today than it was back then. Whether you think it would be awesome if aliens found it or a problem, it doesn't really change the odds that anyone besides us might accidentally find it.
Rob Lister
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Re: The aliens are silent because they're dead

Post by Rob Lister »

Anaxagoras wrote:Yeah, but it's no more far-fetched today than it was back then. Whether you think it would be awesome if aliens found it or a problem, it doesn't really change the odds that anyone besides us might accidentally find it.
It was a stupid idea to begin with. Not because of the danger but because of the wasted cost. Okay, it made us feel all warm and squishy so maybe that was worth the cost. Well, I'm not actually sure SETI had fully surveyed the nearby stars by then so maybe we didn't know just how quiet it was out there.

Nay, it was stupid.
gnome
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Re: The aliens are silent because they're dead

Post by gnome »

When P'neer comes and demands to meet its makers and assimilates the Earth, you'll have to change your avatar to Stephen Collins for 17 days.
ed
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Re: The aliens are silent because they're dead

Post by ed »

Harte wrote:
Anaxagoras wrote:
Harte wrote:A guy on ATS just forced me to do the calculation. A 20 gigawatt signal one light year away would reach us with the undetectable power of around 20X10^-22 watts.

IOW, no way Jose.

Try it yourself: link

Don't forget to:
1) convert light years to meters,
2) square the distance

Harte
Plus, wouldn't stuff like the nearby star also mask this signal with lots of electromagnetic noise?
Absolutely. But it could be handled by using frequencies that can stand out from the nearby star.

Everyone should stop and think about a signal strength of 20 GW. The highest powered signal we use to my knowledge is with certain high power radars which are directed but have a power density of one to five gigawatts.
Anaxagoras wrote: I forget, but isn't SETI looking for aliens that might be intentionally sending us a message? It might be hard to pick up their signals if they aren't pointing them right at us, right? Because, why do that anyway? Yeah, perhaps we've done it once or twice ourselves, but we're weird.
I guess they do it because there isn't anything else we can do at the present time and (apparently) we don't want to just sit around wondering and not trying in some way to find out.

Harte
This negative screed got me thinking. Back in pre-cambrian days, when I was in grad school, we used a thing called a Computer of Average Transients".
https://ub.fnwi.uva.nl/computermuseum/p ... 0front.gif

Idea was that if a signal was lost in noise and was repeatable and could be synced, all you had to do was create intervals within which the power of the signal was averaged.

So, if you were using scalp electordes to measure an evoked visual potential, the eeg on each trial was random, noise. But the evoked response was not, it was the same each time. When you average random you get a constant, when you average the signal you get
http://www.frca.co.uk/images/vep.jpg
seems to me that the same sort of thing might apply with signals from ... space :shock:
Yes?
Anaxagoras
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Re: The aliens are silent because they're dead

Post by Anaxagoras »

ed wrote:
Harte wrote:
Anaxagoras wrote:
Harte wrote:A guy on ATS just forced me to do the calculation. A 20 gigawatt signal one light year away would reach us with the undetectable power of around 20X10^-22 watts.

IOW, no way Jose.

Try it yourself: link

Don't forget to:
1) convert light years to meters,
2) square the distance

Harte
Plus, wouldn't stuff like the nearby star also mask this signal with lots of electromagnetic noise?
Absolutely. But it could be handled by using frequencies that can stand out from the nearby star.

Everyone should stop and think about a signal strength of 20 GW. The highest powered signal we use to my knowledge is with certain high power radars which are directed but have a power density of one to five gigawatts.
Anaxagoras wrote: I forget, but isn't SETI looking for aliens that might be intentionally sending us a message? It might be hard to pick up their signals if they aren't pointing them right at us, right? Because, why do that anyway? Yeah, perhaps we've done it once or twice ourselves, but we're weird.
I guess they do it because there isn't anything else we can do at the present time and (apparently) we don't want to just sit around wondering and not trying in some way to find out.

Harte
This negative screed got me thinking. Back in pre-cambrian days, when I was in grad school, we used a thing called a Computer of Average Transients".
https://ub.fnwi.uva.nl/computermuseum/p ... 0front.gif

Idea was that if a signal was lost in noise and was repeatable and could be synced, all you had to do was create intervals within which the power of the signal was averaged.

So, if you were using scalp electordes to measure an evoked visual potential, the eeg on each trial was random, noise. But the evoked response was not, it was the same each time. When you average random you get a constant, when you average the signal you get
http://www.frca.co.uk/images/vep.jpg
seems to me that the same sort of thing might apply with signals from ... space :shock:
Yes?
That's obviously some sort of prop from a bad 60's sci-fi movie. You can't fool me Ed.
ed
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Re: The aliens are silent because they're dead

Post by ed »

Sort of a palimpsest is what I'm thinking. Not quite though.
Doctor X
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Re: The aliens are silent because they're dead

Post by Doctor X »

gnome wrote:When P'neer comes and demands to meet its makers and assimilates the Earth, you'll have to change your avatar to Stephen Collins for 17 days.
So long as we do not have to rape children.







Too soon?

--J.D.
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Re: The aliens are silent because they're dead

Post by gnome »

I could be missing some context here.

So probably not soon enough--remind me?
Rob Lister
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Re: The aliens are silent because they're dead

Post by Rob Lister »

gnome wrote:I could be missing some context here.

So probably not soon enough--remind me?
https://en.wikipedia.org/wiki/Stephen_C ... llegations
gnome
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Re: The aliens are silent because they're dead

Post by gnome »

Well, fuck.

Ok, use bearded McCoy instead.
Rob Lister
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Re: The aliens are silent because they're dead

Post by Rob Lister »

Here's a cute infographic of Voyager.
Spoiler:
https://i.imgur.com/4npMe6y.jpg
In about a dozen years the Pu battery will be useless for sending data back. Most of the instruments will be shut down within the next 5 years.

In 40,000 years it will approach Gliese 445, a red dwarf, about 18 ly from Earth. Of course by then it will long be a lump of metal indistinguishable from any other rock.

But lets worry about it nonetheless.
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Re: The aliens are silent because they're dead

Post by sparks »

But we had to start somewhere.
Rob Lister
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Re: The aliens are silent because they're dead

Post by Rob Lister »

LIvE AliaNs !!!
Distant galaxy sends out 15 high-energy radio bursts

By Robert Sanders, Media relations | August 30, 2017

Breakthrough Listen, an initiative to find signs of intelligent life in the universe, has detected 15 brief but powerful radio pulses emanating from a mysterious and repeating source – FRB 121102 – far across the universe.

Fast radio bursts are brief, bright pulses of radio emission from distant but largely unknown sources, and FRB 121102 is the only one known to repeat: more than 150 high-energy bursts have been observed coming from the object, which was identified last year as a dwarf galaxy about 3 billion light years from Earth.
http://news.berkeley.edu/2017/08/30/dis ... io-bursts/

The interesting thing about this is that the signals are not regular or periodic.

https://i.imgur.com/NFeuCDy.gif
A sequence of 14 of the 15 detected bursts illustrate their dispersed spectrum and extreme variability. The streaks across the colored energy plot are the bursts appearing at different times and different energies because of dispersion caused by 3 billion years of travel through intergalactic space. In the top frequency spectrum, the dispersion has been removed to show the 300 microsecond pulse spike. Capturing this diverse set of bursts was made possible by the broad bandwidth that can be processed by the Breakthrough Listen backend at the Green Bank Telescope.
If the energy density was in a range from 24 to 144 Jy us, or Jansky,
http://www.astronomerstelegram.org/?rea ... %20article.
which is too hairy for me to work with, what was the original energy from a source 3 billion lightyears distant?
Rob Lister
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Re: The aliens are silent because they're dead

Post by Rob Lister »

So now Bitcoin (et al) is spoiling our chances to meet ET.
Cryptocurrency Miners Are 'Limiting' the Search for Alien Life Now
Berkely's SETI project can't get its hands on the latest graphics cards, which are popular with cryptocurrency miners.

The UC Berkeley-based SETI project only relies on volunteers for a portion of its computing power, however, and has its own computing installations at several telescopes. But the project team ran into problems recently when it tried to expand its operations by adding the latest and most powerful computers to two observatories. The team discovered, Berkeley SETI Research Center chief scientist Dan Werthimer told the BBC, that it couldn’t find the key computer component it needed: graphics processing units (GPUs).

That’s probably thanks to cryptocurrency miners. The same cards that make PC games look amazing and can crunch alien radio signal data can also “mine” (or generate) digital coins like Ethereum and Zcash, so cryptocurrency miners are buying them in bulk and leaving few behind for anyone else.
https://motherboard.vice.com/en_us/arti ... w-gpu-seti

Too fucking bad. Perhaps SETI could use their existing CPU cycles to mine coins. At least they'd get something for their trouble.
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Re: The aliens are silent because they're dead

Post by Anaxagoras »



Stuff about the so-called "Great Filter"

Of course, there's a lot we really don't know simply because other stars are so far away. And because we don't know how typical our own solar system is. But, there may be a little we can infer from our own planet and our own solar system.

Of the 8 major planets and all the minor planets, moons and planetoids, only one appears to have any life at all. So, there is probably a filter for life arising at all, even very simple life. It only happens where conditions are favorable. And most planetary bodies don't have favorable conditions.

However on the one planet we know of that does have favorable conditions there are literally millions of species. But only a single species with the intelligence to create advanced technology. And it took billions of years for us to evolve. And there really is no reason to suppose that the evolution of an intelligent species such as ourselves was an inevitability given that it has only happened once so far in billions of years and millions of species. So that's another filter.

So we don't necessarily need to imagine another "Great Filter" looming in our future, although there are risks. What about the depletion of fossil fuels? Or the phosphates we use for fertilizer? Or many other possible dangers.
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Re: The aliens are silent because they're dead

Post by Rob Lister »

Anaxagoras wrote:So we don't necessarily need to imagine another "Great Filter" looming in our future, although there are risks. What about the depletion of fossil fuels? Or the phosphates we use for fertilizer? Or many other possible dangers.
That was a fun video but what a party pooper! There were a lot of excluded middles but its a compelling argument. AI might be the great filter but the physics of the matter pretty much excludes interstellar travel for meatbags; we ain't going nowhere.

But where are the alien robots?
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Re: The aliens are silent because they're dead

Post by gnome »

Anaxagoras wrote: However on the one planet we know of that does have favorable conditions there are literally millions of species. But only a single species with the intelligence to create advanced technology. And it took billions of years for us to evolve. And there really is no reason to suppose that the evolution of an intelligent species such as ourselves was an inevitability given that it has only happened once so far in billions of years and millions of species.
I think that's fallacious. The first species it happened to would become the dominant life and there would be little opportunity to occur again unless something caused our extinction. I wouldn't expect it to happen more than once.
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Re: The aliens are silent because they're dead

Post by Anaxagoras »

gnome wrote:
Anaxagoras wrote: However on the one planet we know of that does have favorable conditions there are literally millions of species. But only a single species with the intelligence to create advanced technology. And it took billions of years for us to evolve. And there really is no reason to suppose that the evolution of an intelligent species such as ourselves was an inevitability given that it has only happened once so far in billions of years and millions of species.
I think that's fallacious. The first species it happened to would become the dominant life and there would be little opportunity to occur again unless something caused our extinction. I wouldn't expect it to happen more than once.
Yeah I understand your point, but do you understand mine? It took billions of years and billions of reproductive cycles to happen. I'm saying that it wasn't an inevitability. It could have been that life continued until our sun killed it all in a billion years from now without a single species like ours evolving.
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Re: The aliens are silent because they're dead

Post by Doctor X »

Anaxagoras wrote:Stuff about the so-called "Great Filter"

Of course, there's a lot we really don't know simply because other stars are so far away.
That is the huge super galactic size FAIL of that video: the insurmountable distances with a number of physical barriers to crossing them:
  • 1. Time
    2. Resources
    3. Speed of Light: not just a good idea, it's the LAW!
it is not as if one needs to imagine some infinite source of energy to get to say 90% of the speed of light, you cannot get past it beyond "something . . . something . . . warp drive . . . worm holes" fantasies. So even with the resources and the ability to get close to the speed of light, we are talking time spaces greater than human civilization's age before you even "get" anywhere.

Let us pretend that a mere 100 light years away there is a planet where Intelligent Life arose the same time as we did. So if they invent/discover radio waves around the same time we did, we still have not received their signals or a few may make it in a few years.

Visiting it? Let us be even nicer and pick the closest known solar system a mere ~4 light years away. :hyper: As this Sobering Article notes:
Ionic Propulsion:
Currently, the slowest form of propulsion, and the most fuel-efficient, is the ion engine. A few decades ago, ionic propulsion was considered to be the subject of science fiction. However, in recent years, the technology to support ion engines has moved from theory to practice in a big way. The ESA’s SMART-1 mission for example successfully completed its mission to the Moon after taking a 13 month spiral path from the Earth.

Gravity Assist:
So, if Voyager 1 was traveling in the direction of the red dwarf Proxima Centauri at a constant velocity of 60,000 km/hr, it would take 76,000 years (or over 2,500 generations) to travel that distance. But if it could attain the record-breaking speed of Helios 2‘s close approach of the Sun – a constant speed of 240,000 km/hr – it would take 19,000 years (or over 600 generations) to travel 4.243 light years. Significantly better, but still not in the ream of practicality.

Nuculer: [Stop that.--Ed.]
But adjusted for a one-way journey to Proxima Centauri, a nuclear rocket would still take centuries to accelerate to the point where it was flying a fraction of the speed of light. It would then require several decades of travel time, followed by many more centuries of deceleration before reaching it destination. All told, were still talking about 1000 years before it reaches its destination. Good for interplanetary missions, not so good for interstellar ones.
crushes all hopes.

Forget imagined filters.

That video was bad and they should feel bad for making it.

Tentacles.

--J.D.
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Re: The aliens are silent because they're dead

Post by Pyrrho »

You all do realize that it was all over the first time Slim Whitman's singing was broadcast on radio.
shemp
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Re: The aliens are silent because they're dead

Post by shemp »

Doctor X wrote:
Anaxagoras wrote:Stuff about the so-called "Great Filter"

Of course, there's a lot we really don't know simply because other stars are so far away.
That is the huge super galactic size FAIL of that video: the insurmountable distances with a number of physical barriers to crossing them:
  • 1. Time
    2. Resources
    3. Speed of Light: not just a good idea, it's the LAW!
it is not as if one needs to imagine some infinite source of energy to get to say 90% of the speed of light, you cannot get past it beyond "something . . . something . . . warp drive . . . worm holes" fantasies. So even with the resources and the ability to get close to the speed of light, we are talking time spaces greater than human civilization's age before you even "get" anywhere.

Let us pretend that a mere 100 light years away there is a planet where Intelligent Life arose the same time as we did. So if they invent/discover radio waves around the same time we did, we still have not received their signals or a few may make it in a few years.

Visiting it? Let us be even nicer and pick the closest known solar system a mere ~4 light years away. :hyper: As this Sobering Article notes:
Ionic Propulsion:
Currently, the slowest form of propulsion, and the most fuel-efficient, is the ion engine. A few decades ago, ionic propulsion was considered to be the subject of science fiction. However, in recent years, the technology to support ion engines has moved from theory to practice in a big way. The ESA’s SMART-1 mission for example successfully completed its mission to the Moon after taking a 13 month spiral path from the Earth.

Gravity Assist:
So, if Voyager 1 was traveling in the direction of the red dwarf Proxima Centauri at a constant velocity of 60,000 km/hr, it would take 76,000 years (or over 2,500 generations) to travel that distance. But if it could attain the record-breaking speed of Helios 2‘s close approach of the Sun – a constant speed of 240,000 km/hr – it would take 19,000 years (or over 600 generations) to travel 4.243 light years. Significantly better, but still not in the ream of practicality.

Nuculer: [Stop that.--Ed.]
But adjusted for a one-way journey to Proxima Centauri, a nuclear rocket would still take centuries to accelerate to the point where it was flying a fraction of the speed of light. It would then require several decades of travel time, followed by many more centuries of deceleration before reaching it destination. All told, were still talking about 1000 years before it reaches its destination. Good for interplanetary missions, not so good for interstellar ones.
crushes all hopes.

Forget imagined filters.

That video was bad and they should feel bad for making it.

Tentacles.

--J.D.
Not a problem. Once we develop sentient robots that kill off all humans, they'll have plenty of time to go wherever they want.
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Re: The aliens are silent because they're dead

Post by gnome »

Someone may need to do some actual math here, but I think there's a sort of relativistic loophole for stubborn interstellar travelers.

Let's talk about a 10,000 year journey to another star. At sufficient acceleration (and my understanding is these effects occur even with reasonable acceleration rates such as 1g), the time it takes seems shorter to the people on board. So (and I'm pulling it out of my ass here) let's say it only took 10 years from the POV of the crew. You could get out there, take a week for sightseeing and alien hookers, and then return only 20 years later by your time. However, it would be 20,000 years later Earth time when you arrived.

Have I got that right?
Rob Lister
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Re: The aliens are silent because they're dead

Post by Rob Lister »

gnome wrote:Someone may need to do some actual math here, but I think there's a sort of relativistic loophole for stubborn interstellar travelers.

Let's talk about a 10,000 year journey to another star. At sufficient acceleration (and my understanding is these effects occur even with reasonable acceleration rates such as 1g), the time it takes seems shorter to the people on board. So (and I'm pulling it out of my ass here) let's say it only took 10 years from the POV of the crew. You could get out there, take a week for sightseeing and alien hookers, and then return only 20 years later by your time. However, it would be 20,000 years later Earth time when you arrived.

Have I got that right?
That's true
To achieve your 1000:1 dilation, you'll need a relative velocity 99.99% c.
Even slightly less, like 299700 km/s gets you only a 40:1 dilation. http://keisan.casio.com/exec/system/1224059993

It would [only] take you 12 months of constant acceleration at your 1 G to reach that speed. http://www.smartconversion.com/unit_cal ... lator.aspx

But ...

Somewhere around 1 month into your mission you're traveling at about 1/10th c. You're starting to notice something funny is going on. There's a funny smell. It's you! Those micrometeoroids that normally just pit the spaceship like a sandblaster at 10 k/s are now hitting you at 30,000 k/s, and of course going right through.

The moral of the story is: Meatbags ain't going nowhere. https://arxiv.org/pdf/1503.05845v1.pdf
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Re: The aliens are silent because they're dead

Post by gnome »

Well damn. Tell Amber she won't be able to quit early that night after all.

Seriously though, I just found a loophole in relativity--surely some plain Newtonian hurdle like micrometeors won't prove an insurmountable obstacle.

Thank god we invented the... whatever... that keeps those from damaging the ship. Maybe something mounted on the front that deflects them. A dish of some kind.
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Re: The aliens are silent because they're dead

Post by Anaxagoras »

Rob Lister wrote:
gnome wrote:Someone may need to do some actual math here, but I think there's a sort of relativistic loophole for stubborn interstellar travelers.

Let's talk about a 10,000 year journey to another star. At sufficient acceleration (and my understanding is these effects occur even with reasonable acceleration rates such as 1g), the time it takes seems shorter to the people on board. So (and I'm pulling it out of my ass here) let's say it only took 10 years from the POV of the crew. You could get out there, take a week for sightseeing and alien hookers, and then return only 20 years later by your time. However, it would be 20,000 years later Earth time when you arrived.

Have I got that right?
That's true
To achieve your 1000:1 dilation, you'll need a relative velocity 99.99% c.
Even slightly less, like 299700 km/s gets you only a 40:1 dilation. http://keisan.casio.com/exec/system/1224059993

It would [only] take you 12 months of constant acceleration at your 1 G to reach that speed. http://www.smartconversion.com/unit_cal ... lator.aspx

But ...

Somewhere around 1 month into your mission you're traveling at about 1/10th c. You're starting to notice something funny is going on. There's a funny smell. It's you! Those micrometeoroids that normally just pit the spaceship like a sandblaster at 10 k/s are now hitting you at 30,000 k/s, and of course going right through.

The moral of the story is: Meatbags ain't going nowhere. https://arxiv.org/pdf/1503.05845v1.pdf
I think there's also a corresponding mass increase such that if time dilation is 2:1, for example, your mass has effectively doubled, and at 40:1 your mass is 40 times heavier. (This is what I'm relying on.) Thus, the closer you approach to C, the more energy you need to get additional acceleration. I do wonder if some kind of electromagnetic field around the ship could deflect those micrometeoroids?
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Re: The aliens are silent because they're dead

Post by Witness »

To accelerate some mass to near-relativistic speed you'll also need energy, roughly as much as the mass itself (E = mc2). Then that again to brake. So the spaceship would need to start with enormous reserves of matter + antimatter, convert that with ~ 100 % efficiency, shield the crew (or computer) from the radiation, bleed the residual heat away, and a drive without propellant (the famed "photon drive"?).

No way. :(
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Re: The aliens are silent because they're dead

Post by shemp »

Abdul Alhazred wrote:Note: Within your own inertial frame of reference there is no increase in mass.
Then how come I keep gaining weight?
Rob Lister
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Re: The aliens are silent because they're dead

Post by Rob Lister »

gnome wrote:Well damn. Tell Amber she won't be able to quit early that night after all.

Seriously though, I just found a loophole in relativity--surely some plain Newtonian hurdle like micrometeors won't prove an insurmountable obstacle.

Thank god we invented the... whatever... that keeps those from damaging the ship. Maybe something mounted on the front that deflects them. A dish of some kind.
Nominally, according to lots of Sci-fi anyway, you'd want a huge electromagnetic field projecting out the front of the spaceship to "funnel in" all the Hydrogen atoms in the forward path of your ship and use that as fuel for your fusion generator.

There are between 0.1 to 1.0 atoms/cm2 in our local area (and ~1000 near the galactic core). It is a [not quite] trivial calculation to establish just how big/strong that field would have to be at any given speed to provide enough fuel to continue acceleration. https://hypertextbook.com/facts/2000/DaWeiCai.shtml

Maybe the pretend electromagnetic field that powers the pretend fusion generator on the pretend spaceship can also deflect the decidedly real spacedust.
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Re: The aliens are silent because they're dead

Post by gnome »

Well there you go then!

Musk can start selling tickets.
Rob Lister
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Re: The aliens are silent because they're dead

Post by Rob Lister »

Anaxagoras wrote: Mon Feb 19, 2018 2:15 am
Rob Lister wrote:
gnome wrote:Someone may need to do some actual math here, but I think there's a sort of relativistic loophole for stubborn interstellar travelers.

Let's talk about a 10,000 year journey to another star. At sufficient acceleration (and my understanding is these effects occur even with reasonable acceleration rates such as 1g), the time it takes seems shorter to the people on board. So (and I'm pulling it out of my ass here) let's say it only took 10 years from the POV of the crew. You could get out there, take a week for sightseeing and alien hookers, and then return only 20 years later by your time. However, it would be 20,000 years later Earth time when you arrived.

Have I got that right?
That's true
To achieve your 1000:1 dilation, you'll need a relative velocity 99.99% c.
Even slightly less, like 299700 km/s gets you only a 40:1 dilation. http://keisan.casio.com/exec/system/1224059993

It would [only] take you 12 months of constant acceleration at your 1 G to reach that speed. http://www.smartconversion.com/unit_cal ... lator.aspx

But ...

Somewhere around 1 month into your mission you're traveling at about 1/10th c. You're starting to notice something funny is going on. There's a funny smell. It's you! Those micrometeoroids that normally just pit the spaceship like a sandblaster at 10 k/s are now hitting you at 30,000 k/s, and of course going right through.

The moral of the story is: Meatbags ain't going nowhere. https://arxiv.org/pdf/1503.05845v1.pdf
I think there's also a corresponding mass increase such that if time dilation is 2:1, for example, your mass has effectively doubled, and at 40:1 your mass is 40 times heavier. (This is what I'm relying on.) Thus, the closer you approach to C, the more energy you need to get additional acceleration. I do wonder if some kind of electromagnetic field around the ship could deflect those micrometeoroids?
Maybe, but it's worth pointing out that the micrometeoroids are also 40 times more massive. Unprotected, I think you'd be little more than goo in an hour or so.

WTF, why the necro-bump, you ask?

Related topic
Scientists Have Surprisingly Specific Answer on Alien Life

Study estimates 36 alien civilizations exist in our galaxy capable of communicating with us

(Newser) – Asked the meaning of life, the supercomputer in the Hitchhiker's Guide to the Galaxy came up with a very specific answer: 42. Tasked with a different Big Question—how many intelligent alien civilizations exist in our galaxy—real-life scientists have gotten just as specific: 36. That's the estimate from a team of researchers out of the University of Nottingham in England, reports the Guardian. The estimate is based on a big assumption: that life elsewhere in the Milky Way would form in generally the same way as it did on Earth. Starting from that premise, researchers crunched data on existing stars, exoplanets, conditions, etc., and came up with a range of four to 211, with 36 being the most likely number, according to the study in the Astrophysical Journal.

"The classic method for estimating the number of intelligent civilizations relies on making guesses of values relating to life, whereby opinions about such matters vary quite substantially," says co-author Tom Westby. He's referring to the long-standing Drake equation, which results in not-so-helpful estimates ranging from zero to billions, per a news release. "Our new study simplifies these assumptions using new data, giving us a solid estimate of the number of civilizations in our galaxy." Alas, the study figures the nearest one to be 17,000 light-years away, making communication a little difficult. Researchers estimate our own civilization would have to last more than 6,000 years before any two-way communication could take place. A weak point of the study? That original assumption that Earth is a handy model, a skeptical scientist tells Live Science. (Read more discoveries stories.)
https://www.newser.com/story/292298/sci ... -life.html

I don't understand the 6000year number.
Anaxagoras
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Re: The aliens are silent because they're dead

Post by Anaxagoras »

17,000 light years is pretty damn far and obviously it means that any kind of communication would take 17,000 years. Each way. Thus 34,000 years to send a message and get a reply, minimum.

But I also doubt their model. Maybe 6,000 is if the number of civilizations is on the high end of the range.
Anaxagoras
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Re: The aliens are silent because they're dead

Post by Anaxagoras »

There's no reason to assume that another planet like earth would produce a technological civilization like our own. It took life on earth billions of years to produce a single intelligent technological species. I bet that life is fairly common but that intelligent life is rare. And certainly not an inevitable result of evolution. Cockroaches are probably better adapted than we are for long term sustainability.
Rob Lister
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Re: The aliens are silent because they're dead

Post by Rob Lister »

I bet a cockroach thinks it pretty fucking smart.

As far as communication goes, just detecting it is one form, I suppose. Being able to analyze the atmosphere will tell us if there is life, or recent intelligent life if there are fluorocarbons and the like.

The most farthest exoplanet so far discovered is SWEEPS J175902.67−291153.5, at 27,710 light years.(wiki)
gnome
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Re: The aliens are silent because they're dead

Post by gnome »

Unfortunately being able to fill in more of the variables in Drake's Equation than thirty years ago doesn't make us any more confident of the major unknowns still present. For anything involving the development of life, we still have a sample size of one.
Anaxagoras
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Re: The aliens are silent because they're dead

Post by Anaxagoras »

Intead of approaching the question in such an abstract way, what if we look for nearby stars that look similar to our own sun?

What's the closest one? How far away are the closest 10, the closest 100?

Stars within say .85-1.1 solar masses not in binary system?
gnome
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Re: The aliens are silent because they're dead

Post by gnome »

To meet in ritual combat, so as to decide whether the Path of Now and Forever, or the Eternal Doctrine, is supreme.

Wait, that's Star Control universe.
Fid
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Re: The aliens are silent because they're dead

Post by Fid »

I always assumed that any signal received would need to be aimed at us and at a huge power level.

Fid looks out window just to make sure the Overlords haven't arrived thus rendering 2020 truly sucks.
Anaxagoras
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Re: The aliens are silent because they're dead

Post by Anaxagoras »

Not surprised. It's like Fid says, even if they were there somewhere among the 10 million stars surveyed, I don't think it's likely that even an array of powerful radio telescopes would actually be able to pick up any signals from them.
robinson
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Re: The aliens are silent because they're dead

Post by robinson »

Considering the time factor, the signal may be 40,000 tears away still
Anaxagoras
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Re: The aliens are silent because they're dead

Post by Anaxagoras »

funny typo