Centauri Dreams

Check out https://www.centauri-dreams.org/, it's a blog dedicated to interstellar travel. It's on hiatus at the moment, but there are plenty of back articles to read! However, I recommend you figure out how to reduce your anxiety, because after reading it for a while it will become clear that interstellar travel isn't happening any time in the foreseeable future. Fortunately, I don't think that a species that flourishes from the hot tropics to the freezing arctic is likely to be in much existential danger from climate change, and even less from the volatile vagaries of politics. (Climate change might bring very substantial changes, but escaping off-planet isn't going to be less change)

I submitted a site as a joke and now I feel bad because there are a lots of interesting sites submitted. So let me contribute with 2 other sites, maybe not the "coolest" but I think they will be of interest to some fraction of the people here (for those who dont know them) - http://www.astronautix.com/ A labor of love of just 1 person, almost of 80000 pages! on humanity space programs,you can spend hours and hours reading about obscure soviet prototypes, NASA suits, the Chinese space probes, etc - https://www.centauri-dreams.org/ A very active (and long) blog about interstellar travel. Despite the fact the subject is now more fiction than science the articles discussed and reviewed are about actual science done by actual scientists (many good guest posts too)

Arthur C. Clarke: A Life Remembered is a good read for those who want to learn more about Arthur Clarke's life. It features lots of photos and stories about Clarke from his brother and other associates. Here's a review of it [1] [1] [ http://www.centauri-dreams.org/?p=29276 ]

Great article on Centauri Dreams speculating about what a civilisation living on a planet orbiting such a star might experience: http://www.centauri-dreams.org/?p=12671

Judging from the last two space operas i have read, the fashion is sending transhumans on single generation ships ( and playing with internal clocks to manage the subjective boredom). And there are certainly a few people looking at interstellar travel. A great blog about this is http://www.centauri-dreams.org/

I'd recommend one of my favorite web sites: http://www.centauri-dreams.org/ It has serious discussions about e.g. http://en.wikipedia.org/wiki/Project_Daedalus Edit: Recent discussion about Project Icarus from a conference: http://www.centauri-dreams.org/?p=14513

Published where on the internet? If it had a given domain name then you need to manage that. If it's on a specific site, then you need to know that it's there. For 10 years it's easy - pay a few dozen people to make sure it happens. 100 years is harder, but doable with the same fashion. For a movie example, consider the Western Union message that Doc Brown sent in 1885 to Marty McFly in 1955, in Back to the Future II. Brown had the advantage of knowing that Western Union would exist, but I can imagine similar systems working. After all, there are long-running experiments which take more than a lifetime, like Beal's germination experiment which started in 1879 and is expected to end in 2100. With enough money you can set up a fund, with a requirement that the information be published at set times in the future. For 1,000 years? Forget about it. There are few human systems which have worked for that long, and your best bet is to write a document that's interesting enough so as to inspire someone in the future to transmit that document for you. For example, read http://www.theatlantic.com/past/docs/issues/97nov/teller.htm and see how someone in 1916 convinced someone in 1997 to do something. For an entertaining fable, read http://www.centauri-dreams.org/?p=11894 regarding a tale of New College, Oxford needing new oak beams.

Here's on which is a composite of the ALMA (millimetre wave telescope) superimposed with Hubble (in blue) https://www.centauri-dreams.org/2017/05/22/best-images-yet-of-fomalhau… Here's just that ALMA pic https://commons.wikimedia.org/wiki/File:ALMA_Explores_Fomalhaut’s_Debr…

On top of antimatter generation, we can also collect it in space, as it gets trapped in planetary magnetosphere. Antimatter harvesting works best in places with strong magnetic fields, which makes Jupiter and Saturn much better candidates ([0] claims Saturn is the best). Not sure how much we could capture in terms of mass/energy; the impression I get is that it may be worthwhile for space missions, but I'm not sure if it's enough to power a civilization. -- [0] - https://www.centauri-dreams.org/2016/08/03/antimatter-production-harve…

Reminder that there's a fantastic analysis of the film over at Centauri Dreams : https://www.centauri-dreams.org/2019/02/01/in-wildness-is-the-preserva…

Not quite true based on current roadmaps. If BFR pans out in the next 5 years, it could pretty easily launch a significantly faster probe that would pass the Voyager probes in about a decade (with a gravity assist from Jupiter and/or the sun). This was discussed in conjunction with catching Oumuamua [1]. However, if we're stuck with the launch capability of Falcon Heavy, it would take multiple launches with in-orbit docking/refueling to do it. Still possible in a 10ish year horizon, but too expensive to be worth it. [1] https://www.centauri-dreams.org/2017/11/10/project-lyra-sending-a-spac…

Very interesting, but this assumes life evolves to Type II civ. I mean, looking at our own planet, it seems this might be extremely unlikely. To the best of my knowledge, another Planet Earth could possibly be within a few hundred ly of us(0.000000001 of known universe), and we'd have no idea(1)..? 1-https://www.centauri-dreams.org/2012/05/31/is-our-civilization-detecta…

Using the sun as a gravitational lens is our current best option for interstellar communications, presuming we settled a planet within a hundred light years: https://www.centauri-dreams.org/2009/11/06/the-gravitational-lens-and-…

There's some very interesting work on using the Sun itself as a gravitational lense for sending signals back and forth to the craft, using surprisingly small amounts of power. More writeup here: http://www.centauri-dreams.org/?p=35486

If you put a radio at ~10X the distance of Pluto, you can use the sun as a gravitational lens, and communicate with another star using milliwatts of power: http://www.centauri-dreams.org/?p=10123 You're still bound by the speed of light, unfortunately.

Here's a non-sensationalized article about the observation, posted two days prior to this article by The Observer: http://www.centauri-dreams.org/?p=36248

There are ideas for slowing them down and even returning them back to Earth, at least in principle: http://www.centauri-dreams.org/?p=31913 Nothing that could be implemented in any foreseeable future though.

heh, as you say; apparently there was a previous signal; reading the article about the find at centauri dreams, http://www.centauri-dreams.org/?p=36210 - and it does mention a pre-2016 Doppler signal with a period of 11.2 days around specifically Proxima, that was unconfirmed, and that this mission was to investigate that more closely. "The HARPS Pale Red Dot campaign was created to confirm or refute this 11.2-day signal" I'm just not sure if that's what the speaker in your video was talking about, of if the embarrasing mistake that was actually announced was the Alpha Centauri Bb planet (or maybe there were other candidates I didn't hear about); I'm gonna watch the lecture you linked and see. Thx for an interesting link, btw!

The goto site for discussions about interplanetary and interstellar anything is Centauri Dreams: http://www.centauri-dreams.org/

This post on Centauri Dreams discusses another possible way to use the Sun's gravity lens, as a way to effectively communicate with an interstellar probe: http://www.centauri-dreams.org/?p=10123.

Centauri Dreams covered this point well: > Working with Alak Ray (Tata Institute of Fundamental Research, Mumbai), Di Stefano points out that we have found low-metallicity stars known to have planets elsewhere in the galaxy. And while we can couple the occurrence of Jupiter-class planets with stars that have higher metallicity, there seems to be no such correlation when we’re dealing with smaller, rocky worlds like the Earth. Perhaps, then, we shouldn’t dismiss planets in globular clusters. http://www.centauri-dreams.org/?p=34775

There's also solar electric propulsion, which when combined with water as propellant, leads to dramatic (10-100x) cost reductions due to increased propellant efficiency plus the synergies created by using water as reaction mass (it can be used for everything from radiation shielding to crew consumables prior to being sent to the engines, which effectively turns most of your consumables mass into propellant). This approach also benefits from ongoing improvements in component technologies (thin film PV, electric propulsion, and inflatable structures), so a reusable spacecraft based on this design pattern could be upgraded as things improve. (Release early, release often, versus the 30 year Gantt chart methodology favored by space agencies). http://www.centauri-dreams.org/?p=33078

Medusa seems like a better approach, since it doesn't require detonating as close to the spacecraft and can forgo the big heavy pusher plate: http://www.centauri-dreams.org/?p=23754

Related- The 1 kg Starship, with a lively discussion in the comments, from cstross among others. http://www.centauri-dreams.org/?p=30313

Speaking of gravitational lenses, our very own sun can be used as one: http://www.centauri-dreams.org/?p=22321 Key facts: can work with existing technology $5bn cost long travel time, a century or so to the primary observation point (500-750au) but can visit several distant icy bodies before that point 100x magnification for infrared and visible-light (50-80x for radio and microwave) (only for object directly opposite the sun though) a good precursor for an interstellar mission and good study platform for the interstellar medium

Unfortunately those who have worked out the physics for Bussard ramjets in detail find that they don't really work as an energy source or a propulsion mechanism while cruising. Indeed - more useful as a brake. See http://www.centauri-dreams.org/?p=22115 for some pointers.

From a technical point of view I know that there are two teams searching for exoplanets around Alpha Centauri [1]. Hopefully this means that the other team will be able to provide evidence that correlates this find. From a human point of view, I'm in the southern hemisphere and we will have clear skies. Alpha Centauri is still high above the horizon at this time of year. Tonight, I'm going to take my two kids outside and point out Alpha Centauri to them. I'll be able to tell them about it. Tell them, that now we know, part of what’s there. Tell them, that there is likely other worlds. Worlds more like ours orbiting that tiny, almost insignificant spark of light. [1] http://www.centauri-dreams.org/?p=22603

Actually, the British Royal Navy used oaks that had been planted some 200 years earlier specifically for the navy. From http://www.centauri-dreams.org/?p=11894 which talks about long term thinking for interstellar flight: The British oak used in the ships that fought the Napoleonic wars was planted during the reign of the Stuarts some 200 years earlier and allocated for future use in the Royal Navy. Knowing this, Collingwood went on to encourage the planting of oaks that would be made ready for future Royal Navy ships, oaks that matured long after the heyday of sailing ships.

https://www.centauri-dreams.org/2020/12/10/developing-focal-mission-co… (and its critical analysis) https://arxiv.org/pdf/1604.06351 I believe that work on such a project would be interesting, even if it isn't ever done. It is something that if you worked on it as a grad student, and then became a professor and your grad students worked on it ... and they became professors and their grad students worked on it - they'd be the ones seeing the results. Not so much a "this is a way to do things..." but rather a "thinking about research that spans generations and the problems that they solve in the process of doing that great project has useful spinoffs." A mission out to 550 AU at New Horizons speed of 2.9 AU / year (it still boggles the mind of talking about those speeds and distances) is nearly 200 years from launch to primary science objective. It's "only" been 45 years since Mariner 2 to New Horizons.

A very different mode of Statite system operation is possible that would allow the Statite to be placed at any point around the Earth, at all times of the year, even over the sunlit side, at the expense of slightly greater operating distance. Instead of the Statite being balanced by sunlight in the gravitational field of the Earth, the Statite would be placed in orbit around the Sun, at such a distance from the earth that the gravitational field of the Earth plus the moon is only a perturbation on the gravitational field of the Sun. [1] But in practice, I think you're right. Forward wrote a short story about such a "pole sitter" ("Race to the Pole"), and had one of the characters say this: The control problem of keeping the [statite] balanced over the pole is very tricky, especially during the summer season of that hemisphere when the polar axis is over on the sunlit side of the Earth. That’s why ‘pole-sitters’ have to be placed so far away from the Earth. If they get any closer than 250 Earth radii, they become unstable during the summer. [2] [1] https://patents.google.com/patent/US5183225A/en [2] https://www.centauri-dreams.org/2010/07/29/statites-hovering-over-the-…