| ▲ | jimbokun 2 hours ago |
| 48 light years is in our back yard. Close enough that we could probably develop a probe to get there in the next few centuries and check it out. What are the current popular candidates for propulsion systems capable of accelerating to near the speed of light? |
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| ▲ | andy_ppp an hour ago | parent | next [-] |
| Probably more likely that we work out how to fold spacetime than we get there in anything like a high enough percentage of the speed of light - the fastest object we ever made travelled at something like ~0.064% * C so we are looking at ~750 years with current technology and presumably we'd need to switch on the probe in 3/4 of a millennium and figure out how to slow it down and get it into some sort of orbit around the planet. 750 years is hard for me to get excited about even as a vampire. |
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| ▲ | fellowmartian a few seconds ago | parent | next [-] | | It’s highly unlikely we’re ever getting FTL. We should become comfortable with that and let go our fantasies. Let theoretical physicists chug away at this, we should get underway with projects that are possible with known science. | |
| ▲ | wongarsu 32 minutes ago | parent | prev | next [-] | | With variations on nuclear propulsion we could plausibly get to up to around 12% the speed of light. At least that's the number quoted for Project Daedalus [1], which is using nuclear fusion for the first stage and nuclear-powered ion engines for the second stage. With the cruder but more realistically achievable right now Project Orion design (riding the shockwaves of nuclear bombs) you could still get to ~3% the speed of light But even at 0.12c, we are looking at 400 years to get there. And we'd be zooming by at 12% the speed of light. If we want to slow down a bit that'd add hundreds of billions to the cost. It might be worth waiting another century to see if we can come up with a faster design in that time. Not like closer targets like Alpha Centauri, where the thing stopping us is mostly just the absurd cost | |
| ▲ | myrmidon 32 minutes ago | parent | prev | next [-] | | Adding to this: Those 190km/s of the Parker solar probe were, crucially, periapsis speed. This is a bit like bouncing a rubber ball from a building, measuring its speed at ground level and then going: "Given our fastest achieved speed, we expect to hit the cloud level in <10s". ~200km/s sustained speed is already insanely optimistic for anything we could realistically build in the next half century, so your position is even more ironclad than it looks at first glance. | |
| ▲ | buildbot an hour ago | parent | prev [-] | | Honestly a near millennia long expedition would be very cool, and doesn’t seem too long on the scale of space stuff. | | |
| ▲ | detritus an hour ago | parent [-] | | Perhaps, but it is horrifically long in terms of human stuff. | | |
| ▲ | andrewflnr 35 minutes ago | parent [-] | | Yep. We haven't really figured out how to do a good government that lasts more than 200 years. Maybe unless you think monarchy is good, in which case I still don't want to share a spaceship with you. | | |
| ▲ | detritus 26 minutes ago | parent | next [-] | | I have no doubt that even the most republican of cultures launched from Earth would end up thoroughly monarchistic by the time the generation ships arrived at their destination. At best monarchistic - who knows what savage new forms of society could evolve in that sort of context? | |
| ▲ | dingaling 28 minutes ago | parent | prev [-] | | Tynwald, the Isle of Man's parliament, has operated continuously for over 1000 years | | |
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| ▲ | small_model 16 minutes ago | parent | prev | next [-] |
| We have as much chance as a human stepping inside a bacteria (i.e. physics makes it near impossible) |
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| ▲ | quaintdev an hour ago | parent | prev | next [-] |
| If we design a probe that travels at speed of light it would reach there in 48 years and it would send back what it's seen after another 48 years. It would take multiple generations of scientists to work on this project. The longest we have worked on, are Voyager projects. Can we expect that level of commitments from our governments or corporations? Voyager became successful because people could see distant futures. We can barely plan few years ahead. |
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| ▲ | ryandrake 44 minutes ago | parent | next [-] | | If you could solve propulsion enough to accelerate and decelerate a spaceship at just 1G, you could forget the probe and just send people there. While it would take ~50 years of earth time, it would only take ~7.5 years for the astronauts. They could reach the planet with most of their lives free to go to work studying or even colonizing it. | | |
| ▲ | myrmidon 27 minutes ago | parent | next [-] | | This is indeed an interesting perspective, but "constant 1g rocket acceleration" is not even an engineering pipedream, it's strictly fantasy territory. | |
| ▲ | JMKH42 11 minutes ago | parent | prev [-] | | I had this realization in high school. At the time I did not appreciate how impossible it is to accelerate at 1G for that long. Absent some entirely new physics becoming available. All signs point to it not being possible, so not even likely new physics could exist. |
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| ▲ | functionmouse an hour ago | parent | prev | next [-] | | We cannot design a probe that travels at the speed of light. | | |
| ▲ | dhosek 19 minutes ago | parent [-] | | This is where English’s defective subjunctive makes life harder: The point wasn’t about the practicality of the probe from a scientific position, but rather pointing out that even in a best-case scientific scenario, the political-economic-cultural forces are against us. |
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| ▲ | slfnflctd an hour ago | parent | prev [-] | | > Can we expect that level of commitments from our governments or corporations? Clearly, right now we cannot. This is one of the worst obstacles to progress in these areas that I see, and I don't see any obvious way to fix it. The situation we're currently in would've been utterly unfathomable to me 30 years ago. I have lost a great deal of the hope and optimism I held in the past. Interstellar exploration is but one of many fields where we are suffering due to short term thinking. | | |
| ▲ | JMKH42 10 minutes ago | parent | next [-] | | Short term thinking isn't why we are suffering. We are suffering because there are no promising avenues to pursue. If you think of one, bring it up. | |
| ▲ | SoftTalker 31 minutes ago | parent | prev [-] | | Find a way to sell ads on it. |
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| ▲ | 1970-01-01 an hour ago | parent | prev | next [-] |
| Back yard meaning we can see it but never touch it. If the ship to get there was ready today, it would get there in the year one-million? Back yard is Mars, Venus, moon. And I'm being generous with Mars and Venus. |
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| ▲ | detritus an hour ago | parent [-] | | Yeah, if your username is any indication of your age, you've possibly taken much the same trajectory of pessimism that I have. As a youth, I assumed we'd be hitting multiple Cs or bending space time when I was an adult; As an adult I thought we might get a percentage of C and conquer the solar system; Now I realise Just How Much Effort it would be to accomplish much of any value on our own Moon, never mind Mars. I still hold on to the idea that very long term we might make strides in our own solar system, but it is a depressingly-longer timescale than I always used to believe. Unless we have some magic-level shift in our understanding of physics, we're never getting anything beyond Von Neumann probes to other stars, and even then we're talking thousands of years. |
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| ▲ | dijksterhuis an hour ago | parent | prev | next [-] |
| > in the next few centuries assuming we can make it another few centuries, which seems increasingly unlikely. |
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| ▲ | jonathaneunice an hour ago | parent | prev | next [-] |
| Astrophage |
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| ▲ | JMKH42 an hour ago | parent | prev | next [-] |
| laser propelled solar sails are the only plausible solution at the moment and it is not a given that even that is possible. Lots of engineering challenges there that may not have solutions. other ideas:
1. be way more patient
2. anti matter based propulsion (more out there than solar sails)
3. nuclear bomb based propulsion One issue is as you get to these speed little bits of dust will anhillate the probe, so you need some kind of shielding, raising the mass budget, making it all the harder. A solar sail has to be able to survive holes getting poked it in it and still working, etc. |
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| ▲ | baron816 an hour ago | parent | next [-] | | Interstellar travel is probably not ever going to happen. Even if we have antimatter propulsion (which is still probably not practical even under ideal circumstances), we’re still talking hundreds of years of travel time to get to somewhere like this star. This also goes for aliens visiting Earth. Interstellar travel is just so impractical that I don’t think anyone has come on safari to Earth. | |
| ▲ | Jeff_Brown an hour ago | parent | prev | next [-] | | One of the Voyager probes measured the density of the interstellar vacuum at 80,000 protons (and the same number of electrons) per cubic meter. A proton going through a piece of aluminum foil delivers a roughly constant amount of energy regardless of speed; a relativistic proton will pinch through and carry most of its energy with it. (No punchline; I just think that's cool. I understand that the real problem is the rare dust grain, not the ubiquitous gas.) | |
| ▲ | stevenwoo an hour ago | parent | prev | next [-] | | The political challenge of funding a laser program just for research for centuries seems just as daunting - lacking the capability for some self repairing, self healing devices, the automated or (lobster-ai) probe going to stars is just as far away as when Charles Stross first wrote about it in Accelerando some twenty years ago. Given the collapse of political norms, looking back, the decades long research projects of the US space program appear to be soon relics of the past. | |
| ▲ | 0x59 an hour ago | parent | prev | next [-] | | I wouldn't bet on and as I understand theory allows a shorter routes. Major caveat is weve never observed them and their existence doesn't guarantee they're traversible. What's exciting to me is that the existence of such a planet provides fuel for more research into the field. | |
| ▲ | WarmWash an hour ago | parent | prev [-] | | If humans can't make the trip, what's the point besides maybe satiating curiosity in a few hundred years from now? | | |
| ▲ | sebastianconcpt an hour ago | parent [-] | | Claude: give me all the schematics and operations manual of a production grade starship that can travel faster than light. Make no mistekaes. |
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| ▲ | DaveZale an hour ago | parent | prev [-] |
| need to get small fusion reactors online, then many options blossom. And work out safe systems for hibernation, maybe rotate the crew in shifts Oh yeah this is the stuff of science fiction coming to life |
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| ▲ | JMKH42 8 minutes ago | parent | next [-] | | Small fusion reactors don't really solve any of the key challenges. You need reaction mass to accelerate, you run out of reaction mass way too quickly even with a magical energy source on board to throw it out the back of the ship really fast. | |
| ▲ | criddell an hour ago | parent | prev [-] | | If we had a probe in orbit around this planet, do we have a way to stream data across 48 light years with any kind of reliability? | | |
| ▲ | gibybo an hour ago | parent | next [-] | | Send a lot of them and have them act as relays | |
| ▲ | DaveZale 43 minutes ago | parent | prev [-] | | why, so they can watch corporate news from earth to get depressed? /s Actually, it's a great question. Even if we have single photon sensitivity detectors, just what kind of power would a laser need? Or would it be some other area of the emf spectrum? Or some other kind of communication? Sci fi ventures into gravitational waves sometimes |
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