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Another point for anyone considering whether we should send a space-probe there... The current fastest man-man object is the Helios 2 space-probe, reaching som

by NeoTar 5y ago

Another point for anyone considering whether we should send a space-probe there... The current fastest man-man object is the Helios 2 space-probe, reaching something like 25 000 kilometres per hour. Proxima Centauri is 1.3020 parsecs away from Earth. So, just diving one by the other, we'd looking at something like 18 000 years as a rough order of magnitude for sending something from Earth to Proxima Centauri. You'd be much better off waiting, well, even a thousand years for technology to improve rather than sending something now. Note: this is a very dodgy line of reasoning. The Helios probe got a massive speed boost from a close encounter with the sun. But even if the speed is wrong by a factor of ten, we're still looking at somewhere between a thousand and a hundred-thousand years.

Udo 5y ago
I find it enjoyable to think about the technologies that might just be in the cards further into the future. If we ever figure out light-weight fusion drives, we could build light hugger space ships that accelerate to a decent fraction of the speed of light. At 1g acceleration it takes about one year to get to 0.9c, which would make the Proxima system accessible with a travel time of about 6 years. Or 8 years at 0.5g. Or 9 years if we 'only' get to 0.5c. The same goes for laser-driven light sails if we just wanted to send a probe, although deceleration would be an issue. (There is currently an aspirational research project for this called Breakthrough Starshot) The exciting thing about these technologies is that they don't require new physics in principle, just a lot of engineering. Of course, uploaded minds would probably always be better suited for space travel, but it's neat to know that even biological people could in theory make these trips.
- michaelerule 5y ago
  Is the 6 years measured in the time-frame of a passenger on the spacecraft, or as observed from Earth?
  - Udo 5y ago
    At 0.9c the relativistic time dilation is such that 2.3 days on Earth pass for every day shipboard time, meaning the crew would experience less than 4 years of travel in total: https://www.fourmilab.ch/cship/timedial.html https://www.fourmilab.ch/cship/timedial.html
  - raxxorrax 5y ago
    Since we aren't too fast yet, it would basically be the same.
- 74B5 5y ago
  Thank you for your optimism, now let me balance that out a little. Propulsion maybe the easier part of engineering. Afaik we are nowhere near to life support and environment control that could be considered stable for a time period of maybe 10 years or more. The biggest biological advantage, adaptation is meaningless for large organism on such a timescale and maybe dangerous on a microbial level.
  - Udo 5y ago
    You are correct that we are nowhere near that in life support technology, however, there don't seem to be an fundamental hurdles there. If we end up opting for a biological life support system, adaptation would not even enter the equation - it'd be a matter of genetic engineering. An obvious danger would always be onboard ecosystem collapse, of course.
- withinboredom 5y ago
  IIRC, the limit with humans on-board is like .3c due to the red/blue shifting of the background radiation of the universe. At about .3c, it turns into microwaves/radar/x-rays and such, becoming quite bad for humans. There’s so much background radiation, there may be no way to adequately shield from it and/or travel may be limited only in the direction of less background radiation. Maybe someone has a link to more information, that’s just what I remember from years ago.
  - Udo 5y ago
    That's a good point. I have no idea actually where the practical limits would be, especially considering options that arise if the ship has access to a lot of electrical power to generate a protective magnetic field. But even at 0.3c, the trip to Proxima could still be worthwhile for an unmodified human.
    - anders_p 5y ago
      You still have the deceleration issue. You need to use the same amount of energy and time to decelerate, as you did to accelerate. So you'd only be able to sustain constant acceleration for half the distance. Then deceleration for the second half of the journey. That would make the travel time much, much longer than your calculations, since you'd be traveling at relatively slow speed for both the first & last 20-25% of the distance.
      - deleted 5y ago
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  - IHLayman 5y ago
    Here’s a link to a Gizmodo article talking about the study… unfortunately I can’t get the original study to load: https://gizmodo.com/this-is-what-it-would-really-look-like-to-travel-at-nea-5976041 https://gizmodo.com/this-is-what-it-would-really-look-like-t...
  - ffhhj 5y ago
    Right, also the hull must resist the impact against hidrogen atoms at near the speed of light, which would apply tremendous forces. Dust will be like exploding nukes.
- rmbyrro 5y ago
  This is exciting stuff indeed. Imagine a year-4,000 spaceship reaching Centauri before another spaceship dispatched 1,000 years before it? For the cynical or pessimists: I'm not optimistic about humanity reaching year-4,000, I'm just possibilistic about it (as in the philosophical meaning [1]). [1] https://en.wikipedia.org/wiki/Actualism#:~:text=possibilism,%20the%20thesis%20that%20there%20are%20some%20entities%20that%20are%20merely%20possible https://en.wikipedia.org/wiki/Actualism#:~:text=possibilism,...
  - rbanffy 5y ago
    This is more or less the plot of a story by Brazilian science fiction writer Roberto Luiz Calife.
    - natechols 5y ago
      And the story "Far Centaurus" by A.E. Van Vogt.
      - rbanffy 5y ago
        Will have to look that one up.
  - Andrew_nenakhov 5y ago
    This is literally the plot of a very old computer game Alien Legacy. [0] [0]: https://en.m.wikipedia.org/wiki/Alien_Legacy https://en.m.wikipedia.org/wiki/Alien_Legacy
  - s1artibartfast 5y ago
    I can't imagine humanity not making it to 4000. There are very few true existential threats.
- messe 5y ago
  > If we ever figure out light-weight fusion drives, we could build light hugger space ships that accelerate to a decent fraction of the speed of light. At 1g acceleration it takes about one year to get to 0.9c, which would make the Proxima system accessible with a travel time of about 6 years. Or 8 years at 0.5g. Or 9 years if we 'only' get to 0.5c. No, we couldn't. The energy density of fusion isn't anywhere near close enough to make a lighthugger, you'd need insane mass ratios[1] and ramjets are probably unfeasible (as in, even-if-your-a-Kardeshev-II-civilization-unfeasible[2]). [1]: http://www.projectrho.com/public_html/rocket/slowerlight3.php#id--Go_Fast--Relativity--Mass_Ratio http://www.projectrho.com/public_html/rocket/slowerlight3.ph... [2]: https://www.sciencedirect.com/science/article/pii/S0094576521005804 https://www.sciencedirect.com/science/article/pii/S009457652...
  - thereddaikon 5y ago
    Another atomic rockets enjoyer. I've killed so much time on that site. I don't agree with every one of Winchell's conclusions. But they are small things. And I don't know of a more comprehensive and grounded take on future spaceflight technologies.
    - messe 5y ago
      I was saddened to hear about Winchell's cancer diagnosis last year[1]. I've wasted a ton of time there too, it's an oddity compared to the rest of the modern internet. I know very few other useful sites like it, and I love it all the more for its strange aesthetic. I don't agree with everything there either, but usually it's only very minor gripes. In this case though, it's hard to argue with the reality of the rocket equation. [1]: https://twitter.com/nyrath/status/1436010987086286853?s=20 https://twitter.com/nyrath/status/1436010987086286853?s=20
      - thereddaikon 5y ago
        Oh man, I hadn't heard about that. Best of luck to him but he's right prostate cancer is a pretty bad one. What are the other few sites you do know of? And you are absolutely right about the rocket equation. You can't really get around it.
- treeman79 5y ago
  Bits of dust or a pebble hitting ship at 0.5c would make for a bad day.
- iam-TJ 5y ago
  Whenever I read discussions about space travel and trying to approach the speed of light for human travel I have the feeling there's a lot of tunnel vision (excuse the pun). It always seems to assume travelling along a linear path through space. In my mind, using the admittedly poor analogy of space-time as a membrane that is distorted by gravity, my thinking is we'll find some way to effectively bring two points in space-time adjacent to each other and 'step' between them. Wormholes, Warp, or whatever you want to call it. Think of a flexible membrane 10 meters long and we are going to travel from one end to the other. We can either travel in a linear fashion over its surface for 10 meters or we can wrap the membrane so both ends are next to each other and travel 0.01m across the gap between them. Yes, I know there are all sorts of obstacles and arguments against this simplistic visualisation but this is how I've always imagined the physics of any science fiction faster-than-light travel - worm-holes, warp drives, etc. If you want an actual, real, possible-right-now analogy, think of our current situation where the fastest way to travel from London, UK to Sydney, Australia (1/2 way around the world) is through the atmosphere in an aeroplane travelling ~17000 kilometers and taking at best 19.5 hours. SpaceX (Musk) Virgin Galactic (Branson), other companies [0], and space agencies [1] have talked about, and are actively working toward, stepping outside the atmosphere into space to reduce the time element to around an hour. So just like with supposedly faster-than-light travel, by 'stepping outside' the linear/conventional thinking/physics we reduce the time of travel element dramatically. The start and end points don't move but the distance travelled by the transport vehicle itself changes in order to enable the reduction in time. [0] https://www.telegraph.co.uk/travel/news/new-flights-space-london-new-york-half-hour/ https://www.telegraph.co.uk/travel/news/new-flights-space-lo... [1] https://edition.cnn.com/travel/article/hypersonic-flight-air-breathing-rocket-scli-intl-gbr-scn/index.html https://edition.cnn.com/travel/article/hypersonic-flight-air...
  - deleted 5y ago
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  - at_a_remove 5y ago
    I've never bought it. It will still involve being able to transfer information FTL, and then you're on to the Grandfather Paradox. On top of it, let's handwave all of this away, poof. Any aliens anywhere in the Universe would also be using it once their technology got to that level. Just from the lack of visitors, we have three possibilities that are immediately evident: 1) Humans are among the first intelligent species to get to this technology in the entire Universe. 2) Other species have it, but all of them, every last far-flung one of them, even the renegade civilizations or the mad scientists at the individual level, abide by not using it around humans. Despite all of their numerous reasoning capacities and utterly inhuman motivations, every last sophont with access to the tech has agreed upon this, and has for thousands of years. 3) That tech can't exist. The first and second are unlikely, statistically.
deleted 5y ago
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uwuemu 5y ago
A probe based on nuclear pulse propulsion could do it in around 50 years, with today's technology. It's not that we can't do it fast (within one average human lifespan), it's that the project would be very expensive and something like Nasa has a relatively tight budget. I mean we, as humanity, have to have an eccentric billionaire start a Martian fire (SpaceX Starship) under our lazy asses to even start to think about getting to Mars in a reasonable timeframe and in reasonable numbers (to start a colony). We are not funding making our species multiplanetary for the last few decades because we were too lazy, how can anyone expect us sending anything to the closest star (other than the sun)... You can't.
- semi-extrinsic 5y ago
  Maybe an unpopular opinion, but Musk is just plain wrong when he thinks there is any urgency to Mars exploration (or it's just vicarious arguments because rockets are cool). Basically, the tech you need to make a Mars colony truly self sufficient is something like a compact fusion powerplant. Before we have that, no point in worrying about using Mars as a "backup plan", because if Earth was screwed, Mars would have a couple of years to live at most. And obviously it would be vastly better for humanity if Musk spent money on zero-emission large scale energy production, than on rockets.
  - mavhc 5y ago
    He should really thing about making a company to do solar, and maybe an Electric Car company that outsells every other USA EV company 10:1
  - politician 5y ago
    This is hopeful negativism. - They don't need fusion. A StarShip can deposit hundreds of solar panels and put them on the ground. No, dust isn't an issue because they'll bring a roomba. No, this isn't a joke, NASA martian probes' solar panels were cleaned by a light Martian breeze. - They will be able to become self-sufficient rapidly. They're not going to send 1M tons of cargo to Mars without a deployment plan. SpaceX and Tesla have already demonstrated effective vertically integrated supply chains and manufacturing. They have the institutional knowledge to mine raw materials and build factories that build complex parts. - There are plenty of other Earth-bound governments and billionaires that could devote funds to zero-emission large scale energy production projects. Musk, his companies and assets amount to a very small fraction of the global economy. Your ire is misdirected: your anger about the situation is properly directed at the rule of corrupt imbeciles and their questionable resource allocation decisions (Netflix, coal, etc.) here on Earth rather than one team of folks who seem extraordinarily mission driven and effective.
5350-uiop-1130 5y ago
>something like 18 000 years this is why we don't see any signs of life out there. there really isn't any point in trying to venture beyond your home. universe is just too big even at the speed of light when you start venturing beyond your local group.
- yitchelle 5y ago
  I guess the assumption is their life span is similar to that on our planet. If the life span measured in thousand of years, it will be a different story.
  - rbanffy 5y ago
    Lifespan is one thing, but also the "cadence" of life. For a mammal, spending a year in a spaceship is hard. For a brick, spending a thousand years as part of a wall is the natural order of things.
- rbanffy 5y ago
  > even at the speed of light If you get really close to the speed of light (which is not really practical from a materials engineering standpoint) your time of transit is significantly shorter. Once these (extremely hard) engineering problems are solved, a trip to the next star can be a week-long affair from your point of view, but your friends back on Earth won't see you for about a decade.
  - anders_p 5y ago
    You'd have to get very close to the speed of light, before you'd see any really significant relativistic effects. That just isn't practically doable with any technology within humanity's reach, probably for centuries. If it ever will be at all. The amount of energy needed to propel anything at that speed is enormous.
    - rbanffy 5y ago
      Unless my math is very wrong, at 0.9c the passenger perceived time is more or less half the perceived time from the departure point. That's already quite significant, although not something I could do over a vacation ;-) In order to spend a leisurely "cruise-ship" week to Proxima you'd need to go very close to c. At that speed, even friction with a non-ideal vacuum is a problem :-D.
_blu 5y ago
we need to send out a probe now before it's too late
- deleted 5y ago
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gameswithgo 5y ago
with how small you can make a probe today there isn’t any barrier to making something 100x faster or more. throw up a small camera and transmitter with a huge ion thruster thank on top of a saturn v sized rocket of your choice and you will get going very fast
narag 5y ago
Another point for anyone considering whether we should send a space-probe there... We should and do send probes anywhere that's practical. The question is more like when it will be practical to build star probes. The current fastest man-man object is the... The current fastest man-made object wasn't intended to reach the stars. On the other hand, there are many challenges that make more sense to undertake as previous steps to develop the needed technology.
dmarchuk 5y ago
Isn't Parker Solar Probe much faster than that? It's supposed to be going hundreds of thousands of km/h. [1] [1] https://en.wikipedia.org/wiki/Parker_Solar_Probe https://en.wikipedia.org/wiki/Parker_Solar_Probe
- Fatnino 5y ago
  Yes, Parker breaks the 40+ year old record set by Helios. OP is using stale data. The fastest crewed spaceship was Apollo 10 at 39,705km/h before reentry. After orbiting the moon they had lots of fuel left over so they just floored the engine on the way home. Not just falling back towards the planet but actively flying towards the ground for longer than any other Apollo mission. This record can be broken with current technology, we just have to go back to the moon.
- galacticaactual 5y ago
  It achieved those speeds by falling into a gravity well. Reaching Alpha Centauri requires escaping one.
  - netcraft 5y ago
    I very well may be wrong about this, but I believe thats not exactly true. Parker required the fasted launch as of its time because it had to shed the momentum of the earth that it started with to be able to fall into that gravity well. quoting from reddit: > You may be thinking of the Sun as a big gravity well and how you can just drop things in a well. But orbits don't work anything like that at all. Sure if you are stationary relative to the Sun then you'll fall right into it. But anything that leaves Earth is very far from stationary. You're going at 30 km/s 90 degrees off your target. Possibly the first idea many people think of if they want to hit the Sun is to cancel that 30 km/s of speed, and sure it'll work. But you need 30 km/s of delta-v. On the other hand, to escape the solar system from Earth you only need a velocity of 42 km/s relative to the Sun, of which you already have 30 km/s. So you only need to increase your speed by about 12 km/s. (And for both cases add one or two km/s to counter Earth's gravity.) https://www.reddit.com/r/askscience/comments/wjv87/comment/c5e1h1f/?utm_source=share&utm_medium=web2x&context=3 https://www.reddit.com/r/askscience/comments/wjv87/comment/c... https://www.forbes.com/sites/startswithabang/2019/09/20/this-is-why-we-dont-shoot-earths-garbage-into-the-sun/?sh=798045e5d63e https://www.forbes.com/sites/startswithabang/2019/09/20/this...
xdennis 5y ago
> 25 000 kilometres per hour 252 792 km/h
netcraft 5y ago
The formal name for this is the https://en.wikipedia.org/wiki/Interstellar_travel#Wait_calculation https://en.wikipedia.org/wiki/Interstellar_travel#Wait_calcu...
throw1234651234 5y ago
The other problem with sending a space probe is that the devs will have to actually deliver the Proxima Centauri mod on time and on budget, which, let's be honest, probably isn't going to happen for another few years. Think about it, you have to skin the whole planet, make sure the AI isn't weird, make sure it doesn't conflict with the existing storyline or retcon all the earth NPC memories. It's a HUGE project. Right now we just literally return a light curve from the function when someone looks at it. And even if we could get the adversial networks to model all this garbage, etc it needs to line up with the plan of the rest of the Universe from the franchise and the managers can't even decide whether the photon is going to be a wave or a particle. Jeez. Vaporware like HL2.

by NeoTar 5y ago

Udo 5y ago

I find it enjoyable to think about the technologies that might just be in the cards further into the future. If we ever figure out light-weight fusion drives, we could build light hugger space ships that accelerate to a decent fraction of the speed of light. At 1g acceleration it takes about one year to get to 0.9c, which would make the Proxima system accessible with a travel time of about 6 years. Or 8 years at 0.5g. Or 9 years if we 'only' get to 0.5c. The same goes for laser-driven light sails if we just wanted to send a probe, although deceleration would be an issue. (There is currently an aspirational research project for this called Breakthrough Starshot) The exciting thing about these technologies is that they don't require new physics in principle, just a lot of engineering. Of course, uploaded minds would probably always be better suited for space travel, but it's neat to know that even biological people could in theory make these trips.

michaelerule 5y ago
Is the 6 years measured in the time-frame of a passenger on the spacecraft, or as observed from Earth?
- Udo 5y ago
  At 0.9c the relativistic time dilation is such that 2.3 days on Earth pass for every day shipboard time, meaning the crew would experience less than 4 years of travel in total: https://www.fourmilab.ch/cship/timedial.html https://www.fourmilab.ch/cship/timedial.html
- raxxorrax 5y ago
  Since we aren't too fast yet, it would basically be the same.
74B5 5y ago
Thank you for your optimism, now let me balance that out a little. Propulsion maybe the easier part of engineering. Afaik we are nowhere near to life support and environment control that could be considered stable for a time period of maybe 10 years or more. The biggest biological advantage, adaptation is meaningless for large organism on such a timescale and maybe dangerous on a microbial level.
- Udo 5y ago
  You are correct that we are nowhere near that in life support technology, however, there don't seem to be an fundamental hurdles there. If we end up opting for a biological life support system, adaptation would not even enter the equation - it'd be a matter of genetic engineering. An obvious danger would always be onboard ecosystem collapse, of course.
withinboredom 5y ago
IIRC, the limit with humans on-board is like .3c due to the red/blue shifting of the background radiation of the universe. At about .3c, it turns into microwaves/radar/x-rays and such, becoming quite bad for humans. There’s so much background radiation, there may be no way to adequately shield from it and/or travel may be limited only in the direction of less background radiation. Maybe someone has a link to more information, that’s just what I remember from years ago.
- Udo 5y ago
  That's a good point. I have no idea actually where the practical limits would be, especially considering options that arise if the ship has access to a lot of electrical power to generate a protective magnetic field. But even at 0.3c, the trip to Proxima could still be worthwhile for an unmodified human.
  - anders_p 5y ago
    You still have the deceleration issue. You need to use the same amount of energy and time to decelerate, as you did to accelerate. So you'd only be able to sustain constant acceleration for half the distance. Then deceleration for the second half of the journey. That would make the travel time much, much longer than your calculations, since you'd be traveling at relatively slow speed for both the first & last 20-25% of the distance.
    - deleted 5y ago
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- IHLayman 5y ago
  Here’s a link to a Gizmodo article talking about the study… unfortunately I can’t get the original study to load: https://gizmodo.com/this-is-what-it-would-really-look-like-to-travel-at-nea-5976041 https://gizmodo.com/this-is-what-it-would-really-look-like-t...
- ffhhj 5y ago
  Right, also the hull must resist the impact against hidrogen atoms at near the speed of light, which would apply tremendous forces. Dust will be like exploding nukes.
rmbyrro 5y ago
This is exciting stuff indeed. Imagine a year-4,000 spaceship reaching Centauri before another spaceship dispatched 1,000 years before it? For the cynical or pessimists: I'm not optimistic about humanity reaching year-4,000, I'm just possibilistic about it (as in the philosophical meaning [1]). [1] https://en.wikipedia.org/wiki/Actualism#:~:text=possibilism,%20the%20thesis%20that%20there%20are%20some%20entities%20that%20are%20merely%20possible https://en.wikipedia.org/wiki/Actualism#:~:text=possibilism,...
- rbanffy 5y ago
  This is more or less the plot of a story by Brazilian science fiction writer Roberto Luiz Calife.
  - natechols 5y ago
    And the story "Far Centaurus" by A.E. Van Vogt.
    - rbanffy 5y ago
      Will have to look that one up.
- Andrew_nenakhov 5y ago
  This is literally the plot of a very old computer game Alien Legacy. [0] [0]: https://en.m.wikipedia.org/wiki/Alien_Legacy https://en.m.wikipedia.org/wiki/Alien_Legacy
- s1artibartfast 5y ago
  I can't imagine humanity not making it to 4000. There are very few true existential threats.
messe 5y ago
> If we ever figure out light-weight fusion drives, we could build light hugger space ships that accelerate to a decent fraction of the speed of light. At 1g acceleration it takes about one year to get to 0.9c, which would make the Proxima system accessible with a travel time of about 6 years. Or 8 years at 0.5g. Or 9 years if we 'only' get to 0.5c. No, we couldn't. The energy density of fusion isn't anywhere near close enough to make a lighthugger, you'd need insane mass ratios[1] and ramjets are probably unfeasible (as in, even-if-your-a-Kardeshev-II-civilization-unfeasible[2]). [1]: http://www.projectrho.com/public_html/rocket/slowerlight3.php#id--Go_Fast--Relativity--Mass_Ratio http://www.projectrho.com/public_html/rocket/slowerlight3.ph... [2]: https://www.sciencedirect.com/science/article/pii/S0094576521005804 https://www.sciencedirect.com/science/article/pii/S009457652...
- thereddaikon 5y ago
  Another atomic rockets enjoyer. I've killed so much time on that site. I don't agree with every one of Winchell's conclusions. But they are small things. And I don't know of a more comprehensive and grounded take on future spaceflight technologies.
  - messe 5y ago
    I was saddened to hear about Winchell's cancer diagnosis last year[1]. I've wasted a ton of time there too, it's an oddity compared to the rest of the modern internet. I know very few other useful sites like it, and I love it all the more for its strange aesthetic. I don't agree with everything there either, but usually it's only very minor gripes. In this case though, it's hard to argue with the reality of the rocket equation. [1]: https://twitter.com/nyrath/status/1436010987086286853?s=20 https://twitter.com/nyrath/status/1436010987086286853?s=20
    - thereddaikon 5y ago
      Oh man, I hadn't heard about that. Best of luck to him but he's right prostate cancer is a pretty bad one. What are the other few sites you do know of? And you are absolutely right about the rocket equation. You can't really get around it.
treeman79 5y ago
Bits of dust or a pebble hitting ship at 0.5c would make for a bad day.
iam-TJ 5y ago
Whenever I read discussions about space travel and trying to approach the speed of light for human travel I have the feeling there's a lot of tunnel vision (excuse the pun). It always seems to assume travelling along a linear path through space. In my mind, using the admittedly poor analogy of space-time as a membrane that is distorted by gravity, my thinking is we'll find some way to effectively bring two points in space-time adjacent to each other and 'step' between them. Wormholes, Warp, or whatever you want to call it. Think of a flexible membrane 10 meters long and we are going to travel from one end to the other. We can either travel in a linear fashion over its surface for 10 meters or we can wrap the membrane so both ends are next to each other and travel 0.01m across the gap between them. Yes, I know there are all sorts of obstacles and arguments against this simplistic visualisation but this is how I've always imagined the physics of any science fiction faster-than-light travel - worm-holes, warp drives, etc. If you want an actual, real, possible-right-now analogy, think of our current situation where the fastest way to travel from London, UK to Sydney, Australia (1/2 way around the world) is through the atmosphere in an aeroplane travelling ~17000 kilometers and taking at best 19.5 hours. SpaceX (Musk) Virgin Galactic (Branson), other companies [0], and space agencies [1] have talked about, and are actively working toward, stepping outside the atmosphere into space to reduce the time element to around an hour. So just like with supposedly faster-than-light travel, by 'stepping outside' the linear/conventional thinking/physics we reduce the time of travel element dramatically. The start and end points don't move but the distance travelled by the transport vehicle itself changes in order to enable the reduction in time. [0] https://www.telegraph.co.uk/travel/news/new-flights-space-london-new-york-half-hour/ https://www.telegraph.co.uk/travel/news/new-flights-space-lo... [1] https://edition.cnn.com/travel/article/hypersonic-flight-air-breathing-rocket-scli-intl-gbr-scn/index.html https://edition.cnn.com/travel/article/hypersonic-flight-air...
- deleted 5y ago
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- at_a_remove 5y ago
  I've never bought it. It will still involve being able to transfer information FTL, and then you're on to the Grandfather Paradox. On top of it, let's handwave all of this away, poof. Any aliens anywhere in the Universe would also be using it once their technology got to that level. Just from the lack of visitors, we have three possibilities that are immediately evident: 1) Humans are among the first intelligent species to get to this technology in the entire Universe. 2) Other species have it, but all of them, every last far-flung one of them, even the renegade civilizations or the mad scientists at the individual level, abide by not using it around humans. Despite all of their numerous reasoning capacities and utterly inhuman motivations, every last sophont with access to the tech has agreed upon this, and has for thousands of years. 3) That tech can't exist. The first and second are unlikely, statistically.

deleted 5y ago

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uwuemu 5y ago

A probe based on nuclear pulse propulsion could do it in around 50 years, with today's technology. It's not that we can't do it fast (within one average human lifespan), it's that the project would be very expensive and something like Nasa has a relatively tight budget. I mean we, as humanity, have to have an eccentric billionaire start a Martian fire (SpaceX Starship) under our lazy asses to even start to think about getting to Mars in a reasonable timeframe and in reasonable numbers (to start a colony). We are not funding making our species multiplanetary for the last few decades because we were too lazy, how can anyone expect us sending anything to the closest star (other than the sun)... You can't.

semi-extrinsic 5y ago
Maybe an unpopular opinion, but Musk is just plain wrong when he thinks there is any urgency to Mars exploration (or it's just vicarious arguments because rockets are cool). Basically, the tech you need to make a Mars colony truly self sufficient is something like a compact fusion powerplant. Before we have that, no point in worrying about using Mars as a "backup plan", because if Earth was screwed, Mars would have a couple of years to live at most. And obviously it would be vastly better for humanity if Musk spent money on zero-emission large scale energy production, than on rockets.
- mavhc 5y ago
  He should really thing about making a company to do solar, and maybe an Electric Car company that outsells every other USA EV company 10:1
- politician 5y ago
  This is hopeful negativism. - They don't need fusion. A StarShip can deposit hundreds of solar panels and put them on the ground. No, dust isn't an issue because they'll bring a roomba. No, this isn't a joke, NASA martian probes' solar panels were cleaned by a light Martian breeze. - They will be able to become self-sufficient rapidly. They're not going to send 1M tons of cargo to Mars without a deployment plan. SpaceX and Tesla have already demonstrated effective vertically integrated supply chains and manufacturing. They have the institutional knowledge to mine raw materials and build factories that build complex parts. - There are plenty of other Earth-bound governments and billionaires that could devote funds to zero-emission large scale energy production projects. Musk, his companies and assets amount to a very small fraction of the global economy. Your ire is misdirected: your anger about the situation is properly directed at the rule of corrupt imbeciles and their questionable resource allocation decisions (Netflix, coal, etc.) here on Earth rather than one team of folks who seem extraordinarily mission driven and effective.

5350-uiop-1130 5y ago

>something like 18 000 years this is why we don't see any signs of life out there. there really isn't any point in trying to venture beyond your home. universe is just too big even at the speed of light when you start venturing beyond your local group.

yitchelle 5y ago
I guess the assumption is their life span is similar to that on our planet. If the life span measured in thousand of years, it will be a different story.
- rbanffy 5y ago
  Lifespan is one thing, but also the "cadence" of life. For a mammal, spending a year in a spaceship is hard. For a brick, spending a thousand years as part of a wall is the natural order of things.
rbanffy 5y ago
> even at the speed of light If you get really close to the speed of light (which is not really practical from a materials engineering standpoint) your time of transit is significantly shorter. Once these (extremely hard) engineering problems are solved, a trip to the next star can be a week-long affair from your point of view, but your friends back on Earth won't see you for about a decade.
- anders_p 5y ago
  You'd have to get very close to the speed of light, before you'd see any really significant relativistic effects. That just isn't practically doable with any technology within humanity's reach, probably for centuries. If it ever will be at all. The amount of energy needed to propel anything at that speed is enormous.
  - rbanffy 5y ago
    Unless my math is very wrong, at 0.9c the passenger perceived time is more or less half the perceived time from the departure point. That's already quite significant, although not something I could do over a vacation ;-) In order to spend a leisurely "cruise-ship" week to Proxima you'd need to go very close to c. At that speed, even friction with a non-ideal vacuum is a problem :-D.

_blu 5y ago

we need to send out a probe now before it's too late

deleted 5y ago
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gameswithgo 5y ago

with how small you can make a probe today there isn’t any barrier to making something 100x faster or more. throw up a small camera and transmitter with a huge ion thruster thank on top of a saturn v sized rocket of your choice and you will get going very fast

narag 5y ago

Another point for anyone considering whether we should send a space-probe there... We should and do send probes anywhere that's practical. The question is more like when it will be practical to build star probes. The current fastest man-man object is the... The current fastest man-made object wasn't intended to reach the stars. On the other hand, there are many challenges that make more sense to undertake as previous steps to develop the needed technology.

dmarchuk 5y ago

Isn't Parker Solar Probe much faster than that? It's supposed to be going hundreds of thousands of km/h. [1] [1] https://en.wikipedia.org/wiki/Parker_Solar_Probe https://en.wikipedia.org/wiki/Parker_Solar_Probe

Fatnino 5y ago
Yes, Parker breaks the 40+ year old record set by Helios. OP is using stale data. The fastest crewed spaceship was Apollo 10 at 39,705km/h before reentry. After orbiting the moon they had lots of fuel left over so they just floored the engine on the way home. Not just falling back towards the planet but actively flying towards the ground for longer than any other Apollo mission. This record can be broken with current technology, we just have to go back to the moon.
galacticaactual 5y ago
It achieved those speeds by falling into a gravity well. Reaching Alpha Centauri requires escaping one.
- netcraft 5y ago
  I very well may be wrong about this, but I believe thats not exactly true. Parker required the fasted launch as of its time because it had to shed the momentum of the earth that it started with to be able to fall into that gravity well. quoting from reddit: > You may be thinking of the Sun as a big gravity well and how you can just drop things in a well. But orbits don't work anything like that at all. Sure if you are stationary relative to the Sun then you'll fall right into it. But anything that leaves Earth is very far from stationary. You're going at 30 km/s 90 degrees off your target. Possibly the first idea many people think of if they want to hit the Sun is to cancel that 30 km/s of speed, and sure it'll work. But you need 30 km/s of delta-v. On the other hand, to escape the solar system from Earth you only need a velocity of 42 km/s relative to the Sun, of which you already have 30 km/s. So you only need to increase your speed by about 12 km/s. (And for both cases add one or two km/s to counter Earth's gravity.) https://www.reddit.com/r/askscience/comments/wjv87/comment/c5e1h1f/?utm_source=share&utm_medium=web2x&context=3 https://www.reddit.com/r/askscience/comments/wjv87/comment/c... https://www.forbes.com/sites/startswithabang/2019/09/20/this-is-why-we-dont-shoot-earths-garbage-into-the-sun/?sh=798045e5d63e https://www.forbes.com/sites/startswithabang/2019/09/20/this...

xdennis 5y ago

> 25 000 kilometres per hour 252 792 km/h

netcraft 5y ago

The formal name for this is the https://en.wikipedia.org/wiki/Interstellar_travel#Wait_calculation https://en.wikipedia.org/wiki/Interstellar_travel#Wait_calcu...

throw1234651234 5y ago

The other problem with sending a space probe is that the devs will have to actually deliver the Proxima Centauri mod on time and on budget, which, let's be honest, probably isn't going to happen for another few years. Think about it, you have to skin the whole planet, make sure the AI isn't weird, make sure it doesn't conflict with the existing storyline or retcon all the earth NPC memories. It's a HUGE project. Right now we just literally return a light curve from the function when someone looks at it. And even if we could get the adversial networks to model all this garbage, etc it needs to line up with the plan of the rest of the Universe from the franchise and the managers can't even decide whether the photon is going to be a wave or a particle. Jeez. Vaporware like HL2.