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0

Maybe life at this other planet had another chirality of nature? If life was homo-chiral on the other planet, the yeast would be adapted to homo chiral sugar, and only receiving right-handed sugar. Thus it would ferment slowly and not fully. The wine would be weak and sweet, and the measurements a wine maker rely on (gravity, diffraction) would not give off ...


4

@Thorne provides the obvious solution, but let's go a bit more in detail. Temperature This works in both directions. Too cold and the fermentation does not proceed as the yeast hibernates or dies from shock. Too hot and the yeast starts dying from shock as well as producing substances toxic to other yeast (organic processes are generally quite temperature ...


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@Thorne is absolutely correct. If you lower the temperature of the must (grape juice) to the minimum viable temperature for the selected yeast, you can extend the fermentation out greatly. This has the added benefit of improving the clarity and quality of the resulting wine, especially white wine varieties. If your selected yeast has a lower minimum ...


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Temperature It's all you need to slow it down. The whole point of refrigeration is to slow microbial growth by cooling the item.


0

You need more than dead. You need deadly. I submit that the planets that form your "dead worlds barrier" are all highly radioactive, or poisonous in some way. You brought up Halo, so maybe something like the Flood is on every one of those planets. I don't know what could irradiate so many worlds over so large an area, but maybe that could be part of your ...


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I think the nature of their FTL drive makes a big difference. How far can they go between stops? And now much choice do they have about where to go? With decent range and a drive that lets you go basically anywhere it would be pretty hard to have a viable barrier. However, some SF drives are only fixed point-to-point, your fuel cost is based mostly on ...


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The above answers, particularly Stephen's first one which sets out the total power of the object and shows that it can be achieved while maintaining a habitable planetary system, cover most of what you ask, but you do need to consider the location of the object with regard to latitude and relative position of continents. Atmospheres and oceans will convect ...


4

Freeways (almost) never follow the course of old highways Because... Very little of the old highway can be reused: Freeways are much wider that local highways, and thus all works of art (bridges, tunnels, cuttings, fillings) need to be rebuilt; Freeways need much stronger foundations, and thus the old highways would need to be dug up anyway; Freeways need ...


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It depends. Building a good road is more than just laying down a layer of blacktop. You need proper foundations, drainage, etc. This all costs money so the first step would be to consider where upgrading the roads is the most important. Then how the upgrade should happen. Is there a strip of land that the new road can be built on? Can part of the road be ...


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I think what you're asking is, would the new freeways follow the course of the old freeways. I think we can answer that "NO" - here's why... The US went through a phase where it had "basic" roads and then indeed it upgraded to "modern freeways". In fact, during that process, they did NOT especially follow the old roads - they improved the lines and took ...


8

I think that many Latin American or South American countries are a lot more developed and have more paved highways than you imagine. The Pan-American Highway1 is a network of roads stretching across the American continents and measuring about 30,000 kilometres (19,000 mi)1 in total length. Except for a rainforest break of approximately 160 km (100 mi), ...


0

A third civilisation occupies the space between these empires. This empire prevented any travel across the area of galactic space which was sandwiched between the two civilisations in question. Due to their xenophobic attitude leading to one or both their neighbours wiping them out, or some internal strife that has changed their attitude. The end result ...


0

Desert doesn't stop humans, and never has. If there are no refueling stations, one side or the other or both will build them. If there is anything at all someone will figure out how to turn it into fuel or some other raw material. At the very least you have these convenient fusion reactors aka suns. A large dead zone won't stop anyone, because it simply won'...


2

Precursor Sub-Space Gray Goo accident If the worlds are just "dead" that's not going to be enough to stop FTL travel, you need something in subspace/hyperspace/slipspace that is a serious threat. Enter the first Type III alien species. Their empire literally spanned the galaxy, yet for cultural reasons they stuck to a narrow (galacticly speaking) band ...


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Is there any particular reason why you need both civilizations to be part of the same galaxy? Because if not, then by far the simplest solution is to put them in different galaxies at opposite ends of the universe, and then have someone discover a wormhole if you ever need them to interact. No need to introduce weird regions within a galaxy so expansive that ...


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Yes; Taking the book '2321' as inspiration: We do not know that small isolated biospheres/technospheres are possible. Physics-minded people imagine that it's possible to construct mechanical system with <0.001% of the mass of Earth that can support a human for 100 years, but that might not be true. Life is messy in ways that we don't really understand. ...


0

Yes, but.... A barrier of dead worlds would only work if there are better prospects in another direction. Also, the worlds need to be both dead and useless. Why try to build a town in a desert when there is a river nearby? If there's nothing useful in the barrier then curiosity will only take people so far. Remember that they can make habitats where ...


4

What if the fuel had the following properties? It's possible all of these together would be too large of a contrivance, though. The fuel must be created/refined on an industrialized planet, preventing the fuel from being gathered in-situ by general-purpose craft. This could be explained by: needing access to a planetary core; requiring a natural gravity ...


1

Space ship plague. It's extremely contagious and slowly destroys space ships or vital space ship parts. There's some microscopic life form LF capable of surviving in space which makes a meal of space ship materials. Once a space ship has been infected, the LF steadily eats away at it, but slowly enough that you might not even realize you're infected until ...


5

The fundamental problem is that there won't be an ocean left. And evaporating the ocean will destroy the biosphere from the heat. The bottom of the ocean is 1000 bar of pressure. To stop the ocean from flowing in, you need 1000 bar of steam, which requires near star-core scale temperatures (400,000 K). And then you have a star on your planet, which means ...


2

Hm... It does sound to me like you will just keep on putting Energy into your planet, which will make the whole system gradually heat up indefinitely even if it is a small ( < 10km) Ball of 600-2500°C. I don't have that much knowledge about the details as some of the others have, but how about this: Try to have it as cool as possible (600-800°C is deep ...


0

Yes, if they regularly need resources for travel and those “dead worlds” (or simply empty space) don’t provide them. Maybe their faster-than-light drives have to be refueled regularly and it’s impossible to carry more than a certain amount of fuel (because it goes critical or something like that). The dead worlds were harvested by an ancient civilization ...


57

Let's say your magical sphere has radius $r$ of 10km (so just poking up into the outer atmosphere) and is at a temperature $T$ of 1,250K (so glowing a nice warm yellow). The total radiative heat flux from the sphere is given by: $$ Q = \sigma T^{4}. 4\pi r^2 \approx 1.7 \times 10^{14} \mathrm{W} $$ Where $\sigma$ is the Steffan-Boltzman constant. A ...


44

This is basically a variant of Willk's answer (it needs to be "dead and weird"). You specifically mention Star Wars technology, and I happen to know Star Wars uses "hyperspace" for its faster-than-light drives. A quick Google search confirms that Halo uses "slipspace", which is basically the same thing. In both cases, they rely on jumping from normal space ...


5

No Refueling stations for spaceships will be in space. Too much fuel is lost going up and down a gravity well. A dead world is perfectly fine and might be a good source of fuel making material. Even empty space is fine as long as fuel haulers keep it restocked. An asteroid belt could also work. A refueling station can be anywhere but preferably near fuel ...


8

There is no scenario in which the biosphere survives long. You have, at best, a few centuries. Say the fireball is as cool as possible while still being a fireball; 100 degrees celsius. All the oceans will continually drain towards the fireball and will boil on contact, as you said. This is bad news for your biosphere, because that's a huge amount of ...


1

Yes, potentially. If all we require is two civilizations separated by distance within the same galaxy, then we can say they evolved separately in opposite spiral arms. The planets in the middle of the galaxy aren't just dead, they're contaminated. This could be because of a terrible ancient galactic war, or some natural phenomenon (like colliding ...


6

Black Hole Drives If you have an interstellar civilization, presumably travel between stars is somewhat fast (i.e., weeks to months, rather than decades to centuries). None of the technologies we have today are remotely suitable for such interstellar travel. Nor have you stated how hard-science you want your drive technology to be. But if you want ...


7

You are basically cooking your planet on a stove. This magic fireball is an infinite source of heat, so it will sit there continually pouring heat into the planet's system. Water near it will be heated into steam, but the coolness of the water will not cool the fireball at all. This will cause the overall temperature to rise and rise until everything on the ...


79

You need more than dead. You need dead and weird. Interstellar spaces are huge. Ships need to be able to traverse these distances. The fact that there are clumps of matter - "dead worlds" - in between that are not useful to these ships should make no difference. It is like the fact that there are some empty office buildings on my route home. Who cares?...


10

Yes, but it will depend heavily on the values of each civilization. A pragmatic society will only visit solar systems they expect to be worth the return on investment based on what they already know. They will do years of analysis for hazardous solar activity, scan for signs of existing civilizations, search for promising exoworlds, and send unmanned ...


2

Probably not. Galactic civilizations require a lot of time to develop. If you have a growing civilization that grows in the span of 100.000 years then the light of their activity has also reached 100.000 lightyears of space. A quick google search of the first 3 Galaxies show them anywhere between 30.000 to 100.000 lightyears in size. So at the very least ...


7

Yes this is a realistic possibility. If Earth ever develops a probe that can travel long distances. You can bet we will pick a target where we think life exists, probably the direction that involves passing the most candidates as possible. If we find life, that will probably be where we focus all our efforts. So for your galactic civilizations, you just ...


1

as far as i read and grasp of the list, most non native Eyjagard animal wont screw up the native species, base of my observation from my own country (majority of it is livestock anyway, they are everywhere including tropical country al though some generate different trait or adaptation). except cat which as far as i know has extinct/endangered several bird ...


4

Flame cloud deflagrations. The surface of your world is mostly reduced gases: hydrogen, water, maybe some ammonia, methane. On the surface the humidity and fog shields life from most solar radiation. In the higher atmosphere, energetic rays from your sun cause photodissociation of molecules. The main effect of this is to strip oxygen out of water, ...


5

[Handwavium explanation] Without Oxygen, you will have a hard time burning the hydrogen to create a fire. Since you do not mention the composition of atmosphere, one possible way you can achieve the Firestorm could be via a sudden outburst of oxygen in the atmosphere leading to the right conditions, which are otherwise absent. This could be due to ...


2

If you're trying to penetrate fog, best go with something specifically designed to penetrate fog: Foghorns (Image by the Cardiff Council Flat Holm Project, via TR001 at Wikimedia Commons.) A foghorn uses high-pressure steam or compressed air to produce extremely loud, low-pitched notes; low-frequency sounds travel farther and penetrate bad weather much ...


2

For slower, high-bandwidth communications, simply floating barges down a river loaded with pieces of paper that have been written on is hard to beat for cost/effectiveness. The societal conditions that require instant communication don't arise in preindustrial societies.


2

To prevent eavesdropping and concentrate your sound over long distances maybe your Victorian scientists could develop a version of hypersonic sound -- which essentially makes sound act as a laser-- keeping it concentrated in a tight beam.


3

You could also use a bullroarer: The bullroarer, rhombus, or turndun, is an ancient ritual musical instrument and a device historically used for communicating over great distances. It dates to the Paleolithic period, being found in Ukraine dating from 18,000 BC.


7

Hydraulic Telegraph The use of hydraulics offers a few means of communication that would not be impacted by poor weather for the most part. And they can be build of relatively inexpensive wooden piping. How to actually send communications down a pipe can be done in several ways. If you can build your stations relatively level with one another [Such as ...


4

Whether you use light or sound, weather is going to get in your way. While sound is able to bypass a fog, it's easier to put a visual system on a hill to have line of sight above low lying fog. Visual communication is far more reliable over distance, visual recognition is more efficient than listening out for audio signals - at least when we are not trying ...


3

Soundhouse A house intended for long-distance communication with the use of musical instruments. This is a building equipped with different kinds of musical instruments that generate strong sound vibrations. This is not something new. People in old ages used musical instruments for long-distance communications. "2. Drums are used for communicating over ...


5

Silbo Gomero This is the whistling language used in the Canary Islands to communicate complex messages for distances of up to 5 km. The language requires skills, but no equipment. It should get through fog pretty well. Another answer mentioned whislting in Andorra, but the Canary Islands are more widely known for this. https://en.wikipedia.org/wiki/...


8

I found a nice history of warning signals from the US Lighthouse Society. The problem seems to be that the things, such as fog, that interfere with light also interfere with sound propagation. One of the possibilities that you should consider is that there will exist times with communication blackouts. In such times, a pony express type service for ...


12

You do realise you've just reinvented Terry Pratchett's "Clacks" system, don't you? Anyway, solutions... Put the towers closer together Over long distances, sure, weather is a problem. Over shorter distances though, bright lights will still be visible even though rain and fog, and the operators can drop their data rates to improve reliability. Of course ...


4

Signal Flares A little basic knowledge of gunpowder is all you need to make a signal flare that can be visible from a great distance even in the daytime. There are even chemicals you can mix in to make a number of different colors of flares. You'd have limited bandwidth for what kinds of messages you could send, but you could elaborate by sending multiple ...


1

According to the USGS it would look like this: Source: https://water.usgs.gov/edu/gallery/global-water-volume.html The larger sphere represents all of Earth's water, while the smaller sphere represents Earth's fresh water. The larger sphere has a diameter of 1384 km, quite large but only 0.13% of the total volume of the Earth. Ice has a density 92% that ...


2

Ok, here is a funny one: communication by smell. I don't know if that was ever tested, but in theory this form of communication could be especially useful under foggy conditions, for not-too-long distances, for the more subtle communication (let's say you don't want to let the neighbours hear the bells). Fog can smell. Usually gases and dust constantly ...


33

I'm kind of surprised that no one has mantioned the obvious time tested method of long range communication: Drums Lots of people have brought up using sound, and even the very clever use of acoustic reflectors, but Drums avoid many problems associated with things like guns (ammo ain't cheap, and how much bandwidth could you get out it). They are lighter ...


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