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.
http://news.berkeley.edu/2017/08/30/dis ... io-bursts/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.
If the energy density was in a range from 24 to 144 Jy us, or Jansky,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.
https://motherboard.vice.com/en_us/arti ... w-gpu-setiCryptocurrency 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.
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.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.
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.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.
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.gnome wrote: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.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.
That is the huge super galactic size FAIL of that video: the insurmountable distances with a number of physical barriers to crossing them: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.
crushes all hopes.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.
Not a problem. Once we develop sentient robots that kill off all humans, they'll have plenty of time to go wherever they want.Doctor X wrote:That is the huge super galactic size FAIL of that video: the insurmountable distances with a number of physical barriers to crossing them: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.
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.
- 1. Time
2. Resources
3. Speed of Light: not just a good idea, it's the LAW!
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.As this Sobering Article notes:
crushes all hopes.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.
Forget imagined filters.
That video was bad and they should feel bad for making it.
Tentacles.
--J.D.
That's truegnome 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?
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?Rob Lister wrote:That's truegnome 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?
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
Then how come I keep gaining weight?Abdul Alhazred wrote:Note: Within your own inertial frame of reference there is no increase in mass.
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.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.
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.Anaxagoras wrote: ↑Mon Feb 19, 2018 2:15 amI 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?Rob Lister wrote:That's truegnome 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?
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
https://www.newser.com/story/292298/sci ... -life.htmlScientists 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.)
Funny enough to leave it in
Something I never got to asking about related to this--Anax points to increasing energy requirements to keep up with the increased mass of the ship. If the whole ship is increasing in mass, then the fuel is too. Do you get more output from it as a result? Is the propellant also gaining mass, and thus more effective at pushing the ship? The laws of thermodynamics being the buzzkill that they are, maintaining some kind of parity between thrust and mass gain is probably wishful thinking. But has someone worked out that aspect of it before?Anaxagoras wrote: ↑Mon Feb 19, 2018 2:15 am
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?
From the outside? I assume you mean a stationary observer.
That part I get--more the question of, which frame of reference most directly feels the problem of increasing mass requiring more force for acceleration?Anaxagoras wrote: ↑Mon Oct 12, 2020 12:46 pmFrom the outside? I assume you mean a stationary observer.
Rulers get shorter (and of course, everything else too, including the spaceship) in the direction of travel. And clocks run slower.
That would be the one that isn't moving. The mass doesn't really change from the perspective of people on the spaceship.gnome wrote: ↑Mon Oct 12, 2020 2:11 pmThat part I get--more the question of, which frame of reference most directly feels the problem of increasing mass requiring more force for acceleration?Anaxagoras wrote: ↑Mon Oct 12, 2020 12:46 pmFrom the outside? I assume you mean a stationary observer.
Rulers get shorter (and of course, everything else too, including the spaceship) in the direction of travel. And clocks run slower.
Right so my point being, is that an obstacle to my scheme of maintaining 1G and traveling so far from my own point of view, even if it's taking millenia from a stationary frame of reference?Anaxagoras wrote: ↑Mon Oct 12, 2020 2:20 pmThat would be the one that isn't moving. The mass doesn't really change from the perspective of people on the spaceship.gnome wrote: ↑Mon Oct 12, 2020 2:11 pmThat part I get--more the question of, which frame of reference most directly feels the problem of increasing mass requiring more force for acceleration?Anaxagoras wrote: ↑Mon Oct 12, 2020 12:46 pmFrom the outside? I assume you mean a stationary observer.
Rulers get shorter (and of course, everything else too, including the spaceship) in the direction of travel. And clocks run slower.