# The Emperor's New Palace

The Galactic Emperor is making a new palace. He has one problem: he can't think of an expensive enough material to make it out of!

At first he considered gold or silver, but those are common materials. There would probably exist enough naturally occurring gold on one planet to build the palace. He can't stand the thought of someone thinking he's cheap! He wants something no presumptuous planetary governor could afford to replicate. What's the most opulent material he can make his new palace out of?

Some ground rules:

• All suggestions must be a real material.
• The substance must be safe enough that people can enter the palace for bragging-tours. (See allowances.)
• The substance must be stable enough to leave for long periods of time as part of the building.
• Being a building material, it must be a solid at room temperature.

For practicality, the Emperor will make a few allowances:

• It's okay if he must put a layer of clear durable plastic over everything, preventing direct human touch with this substance. (But bonus if that isn't needed.) The plastic doesn't block radiation or explosions or such, though.
• He'll allow structural beams to reinforce the material if it's too weak.

This is a sci-fi setting with many thousands of systems under the Emperor's control. They can use extensive fleets and industrial centers to gather and prepare the material.

What is the most costly material he can make his palace out of?

• If the emperor is a truely galactic emperor, he is likely to rule countless millions of systems, not a mere "many thousands of systems". – M. A. Golding Sep 29 '20 at 17:04
• The title made me expect some unscrupulous architect to sell the emperor a magical material that only smart people can see... – Kevin Sep 29 '20 at 19:53
• @M.A.Golding He may CALL himself a Galactic Emperor, but that doesn't necessarily mean he actually IS. There's probably thousands of "All Powerful Supreme Ruler Of The Galaxy"s around the place – Whelkaholism Sep 30 '20 at 11:57
• @ Whelkaholism That's why the need to be pretentious. If you are the only one, there is no one to brag to, to out-do. – Justin Thyme the Second Sep 30 '20 at 14:10
• @Nuclear03020704 Of course it's plausible. Do it at night! – NomadMaker Oct 1 '20 at 2:15

## Curium-247

Curium 247 is by far one of the most stable man-made elements with a half-life of 15.6 million years. It emits very small amounts of alpha radiation, but alpha radiation is mostly harmless since it lacks the penetration power to bypass human skin. A porous transparent coating as allowed by the OP may be recommended in commonly used areas just to be on the safe side though since it would be quite toxic if accidentally ingested and to minimize any long term exposure risks for the people who actually live there.

The thing that makes it so priceless is that it has no known natural form. It is only produced as a byproduct of the radioactive decay of Californium-251. In today's market, it is literally priceless because Californium-251 costs 27 million USD/gram (12.25 billion USD/lb) and has a half life of 898 years; so, the mass production of Curium-247 requires the mass production of Californium-251.

Let's say your emperor wants to have enough Curium-247 to make a single brick 10 years from now, he will first need to synthesize about 90 bricks of Californium-251... So if we had to put a price tag on it, Curium-247 would probably go for about 2.43 billion USD/gram (1.10 trillion USD/lb) in today's market. This is about 10x cheaper than antimatter by weight, but it is so dense that it is going to be much more expensive per volume than any anti-matter that we can produce and store today; so, holding the annual GPD of Japan in Curium-247 would look something like this:

Now, your average home weights about 1342 kg/m² (275 lb/ft²), but again Curium-247 is VERY dense so a palace made out of the stuff would weigh a lot more. I've got to make some assumptions here but for the sake of argument, let's say that such a pallice would probably be closer to 4880 kg/m² (1000 lb/ft²) of floor space. Now let's assume your size is about the same as history's largest palace, Weiyang, and give it a floor area of about 10,817,819 m² (116,442,045 ft²). That gives you a palace that is made out of roughly 52.8 billion kg (116.4 billion lb) of Curium for a total material cost of about: 128 Sextillion dollars, or in other words, the entire annual GDP of about 3.5 million Earth like worlds

... since your poor emperor only rules in the thousands of worlds, this will probably actually be way out of his price range. He may in fact be forced to settle for Curium plating, or a Curium facade. Not only would this help keep the palace in his price range, but also fix any possible radiation issues since all the inner walls could be made of things that block all of the alpha-radiation from getting in.

• 327 million kg of Curium would create a significant radiation hazard. – Alexander Sep 29 '20 at 19:02
• @Alexander That is why you use Curium-247 isotope specifically. It has such a long half-life it emits fairly minimal radiation, and what radiation it does emit is α-radiation which has VERY little penetration compared to β- or γ-radiation. A simple layer of paint or wallpaper on your interior walls should be enough to keep the people inside more or less safe. – Nosajimiki Sep 29 '20 at 19:24
• @M.A.Golding I scaled up to use Weiyang as the example... that said, even this is a bit arbitrary since you could argue that a galactic emperor might go WAY bigger than any historical palace. For example in warhammer 40k, the Emperor's palace covered an area of over 200,000 square miles and was many times taller than any mountain range – Nosajimiki Sep 29 '20 at 19:35
• A building that uses its own inherent radiation to power everything? Now THAT is audacious. – Justin Thyme the Second Sep 30 '20 at 14:08
• A porous layer of paint is better than a plastic seal: Alpha radiation is helium nuclei. If they are stopped in a gas tight barrier, the produced Helium will destroy the seal's structure over time. Porous paint, on the other hand, would stop the alpha particles, and then allow the Helium to gas out without problem. – cmaster - reinstate monica Oct 1 '20 at 7:35

A piece of history

The problem is that any material could devalue or increase in value. That makes the building susceptible to become less valuable over time.

What you need is something that is expensive not just for its value as a resource. Make it valuable for its history. There's two ways to look at this.

One is using relics and old buildings with history to build your palace. These have historic value and likely will increase in value over time. The cost of moving whole buildings like the Eiffel tower, Pyramids and the Acropolis for example, together with maintaining them, will both be more expensive and more impressive than making your palace from one expensive material. Of course if the roof of a temple is missing you'll fix it with an expensive and impressive material to make it liveable if needed, while keeping the temple intact. Another advantage of using historical buildings is that it's also hard to copy. Even the very idea might become impossible if the emperor puts down laws after he did it (or ignored it for himself).

The second is making history. Somehow extract resources directly from the sun, or the furthest comet ever found, or drill deep into the core of the Earth and extract from there. Dangerous and difficult to obtain resources will have that extra bit of history. That is what makes it expensive. Iron isn't impressive, but when it's iron gotten from the strata of Neptune it'll speak more to your imagination. The value is then not the value of the simple resource, but of the perceived value. Alternatively you make history by using the latest expensive technology to build your palace, making history there as well. The latest screen technology to furnish a whole room. Build a wellness centre where supercomputers are used for the structure and their heat for the saunas. Meanwhile you're contributing valuable calculations for science.

Finally you can also make it expensive as it's close to impossible to make. There have been real suggestions to make a mountain in the Netherlands. It would be impressive, unique and is already terribly expensive to create. If it was done, it would raise its value just by existing and being the only one. So make something on the edge of possibility and imagination.

• +1 'perceived value' that is the key to anything expensive in the real world too. – Mixxiphoid Sep 29 '20 at 14:27
• quality wooden panel 30x21 in: \$100; set of oil colors: \$50; worker salary (1000md): \$30 000; license fees: \$85 000 000 – John Dvorak Sep 29 '20 at 15:03
• It's not what you build it out of, it's what you put in it. You could probably duplicate the building of the Louvre for a few hundred million (excluding the cost of land), less than 1% of cost of the artwork inside. – jamesqf Sep 29 '20 at 17:00
• @jamesqf Well besides that I do mention other relics, it's about what we make the palace out of. Not on what we hang on the walls. Some artwork might be able to be used as construction material, but most I would guess is not suitable for such materials. Unless we take the question very far and encase all in the plastic with support beams, which is still an option in the above answer. – Trioxidane Oct 2 '20 at 8:44

Materials are irrelevant

## What matters is craftsmanship.

On a galactic scale, all materials that exist are common. Theoretically all skills are also common, but getting the craftsman for hand carved oak beams is still expensive. As are hand embroidered tapestries on the walls, hand made stained glass windows (these are always expensive regardless), elaborately carved pillars and friezes, and painted ceilings. Merely coating everything in expensive materials to impress the masses will barely be noticed, but elaborate hand crafting will always do the trick.

We make passing reference to some guy who gold plated his boat or ferrari, and then he's forgotten, but the ceiling of the Sistine Chapel remains unmatched 500 years later.

• I don't think it's the cost of the craftsmanship that matters so much as the prestige. In a science-fiction future of artificial superintelligences infinitely more creative than people and precision nanoscale engineering, you'll have to appeal to peoples' sense of "classical" good old fashioned modosophont talent. – parasoup Sep 29 '20 at 21:09
• @parasoup, you can make anything irrelevant with the right SciFi scenario, I suggest always keeping true creativity slightly out of reach for the AI. – Separatrix Sep 30 '20 at 8:01
• If AI can create anything amazing easily, then the value in having it crafted by actual people is probably even rarer and more expensive. "Yes, it's not detailed down to the nanoscale, but there is only ONE GLORBNAK in the ENTIRE GALAXY who is capable of this level of work using their own biology" – Whelkaholism Sep 30 '20 at 11:59
• In the Star Wars universe (non-canon now), the Emperor did this in the Shadows of the Empire novel. It describes that he hired the galaxy's most renown botanical gardener to architect the best garden of his career, and then he killed the gardener out of fear that he might design a better garden later. – gregsdennis Oct 1 '20 at 8:59
• @gregsdennis, that's a standard trope dating back to Greek mythology, also imprisoning, cutting off hands, cutting hamstrings, putting out eyes etc. – Separatrix Oct 1 '20 at 9:27

### MicroSD cards filled with legitimately purchased Music, Software, Movies, etc from your entire empire's history

Superglued together into 1 cubic meter blocks, these make a great building material! Can be cut and shaped using conventional tools.

• MicroSD cards are 1.65 × $$10^{-7}$$ cubic metres.
• Costs \$670 for a 1tb card. • A good movie compresses to about 700mb, and costs about \$20 at my local store.
• Can fit 1462 movies on a microSD card. \$29240 for the content. • \$29910 for 1.65 × $$10^{-7}$$ cubic meters
• \$181,272,727,273 per cubic meter. Using Palace of the Parliment (in Romania) as the template, you're looking at \$$$4.6224545 * 10^{17}$$ dollars for the cost of the palace. With the Value of Earth calculated at approximate \$$$1.25 * 10^{14}$$, your palace will be more valuable than 3000 Earths. This has additional cultural value, it's the collective historical works of your society. And its good for your economy - every artist has a guaranteed album sale! • How about payed winrar licenses, they are so rare, only a handfull has been confirmed in the entire universe :) – Michael Mortensen Sep 29 '20 at 8:38 • @Mixxiphoid Can always buy duplicates. – Ash Sep 29 '20 at 15:08 • By weight, Computer Chips are one of the most expensive items on Earth. Some are thousands of dollars per gram. – Justin Thyme the Second Sep 30 '20 at 0:47 • "Welcome to the pornography wing"... – user2390246 Sep 30 '20 at 10:47 • @user2390246 More like "welcome to the non-pornography wing" – Azor Ahai -him- Sep 30 '20 at 18:06 # Size Matters The palace is a planet. One entire planet. To arrive you have to dock with the Official Arrival Space Station. Landing on the surface is strictly forbidden. The Space Station is the top of a Space Elevator, meaning it is stationary over a point on the surface. The reach the Elevator, you must walk across a big room with a glass ceiling giving a perfect view of the planet above. (The Station is a counterweight to the Elevator, meaning it is higher than a stable geostationary orbit. This gives a pseudogravity away from the planet) Looking up, you see... a portrait of the Emperor. The main continent has been reshaped into the Emperors famous profile and every piece of ground has been covered with a building of the right color to make up this portrait. Taking the Elevator to the surface means travelling into this portrait. The Emperor looms bigger and bigger until they become everything. The planet was chosen mainly because it has no cloud cover. No cloud is allowed to shadow the Emperor. This also means that it has no native biosphere. Every piece of food eaten on this planet is imported. On the opposite side of the planet is a continent with all the necessary industry, and a much bigger Elevator for freight. • I like how you think. When I rule the galaxy you can stay in it. – Ruadhan Oct 1 '20 at 8:07 • The next smaller thing: A moon, turned into a much bigger space station. Meaning the original palace was erected on a moon solely reserved for this purpose, but the "forbidden city" grew so extensively, that now the structures around are much bigger than the original moon and its a huge death star type thing, with a (relatively) small moon core. A bit like the constantly growing ISS station in "Valerian". (Btw, super epic scene: youtube.com/watch?v=u0FX8sd1uVo) – Cee Mon 3 hours ago # It's not the materials It's the location. Most of the ISS is made of things readily available on Earth; Yet it was so expensive to build because of its privileged location (and harsh conditions). Having a palace in a low orbit over Sagittarius A* would be costly due to the absurd amount of ∆v required to reach it. Might have to sacrifice a few stars for a round trip from or to Earth. However it would put you close to the greatest power sources in the Milky Way, and would give you a view and a passage to the rest of the whole galaxy. The relativity effects would also mean that the Emperor would live for many human lifetimes, making him practically immortal. • Like government bureaucracy didn't slow things down enough... ;D – Nosajimiki Sep 29 '20 at 15:48 • Here's a problem... if he can live many lifetimes in there, how long will it take to build relative to him? They would have to build it off-site and then boost the entirety, Emperor and all, into orbit. The people doing that had better be tripple-checked Emperor loving fanatical scientists. – Demigan Sep 30 '20 at 8:13 Unobtanium Any material the architects can come up with can be outdone. So, the real material should be shrouded in mystery. Covering it in plastic would help to deepen this mystery. Regular people and scientists would ponder about the nature of this unobtanium, but they would never have a clue. All their guesses would be lazily dismissed by the palace staff: "Gold? You must be joking. No, it's much more costly than that." "Diamonds? No way. It's rarer than that." Anyone trying to pick off a piece of the material should be put to death to dissuade further investigation. If any thief actually succeeds in stealing a piece of palace, declare that it was a protective ploy to offer this thief some worthless junk, while the real unobtanium was safe and secure. • Are you suggesting the "Emperor's new clothes" approach to the Emperor's new palace? – BIOStheZerg Sep 29 '20 at 14:13 • @BIOStheZerg yes, exactly. In reality it's plastic all the way down. – John Dvorak Sep 29 '20 at 15:11 # How about...no materials at all? Okay, this isn't just an allusion to the namesake of this thread, hear me out: You take an entire planet, and spend years (or quicker with handwavium style tech) bleaching it of all life, completely purifying the water, and re-seeding it with specifically engineered fauna and flora making it the perfect garden world Maintain planetary temparature and atmosphere at your most pleasant choice You completely control the weather, making it perfect all the time, and then you don't need a palace. The world is your palace. No roof necessary. If you want walls, they can be hedges or stone or whatever beautiful thing you want. You can have your furniture and stuff out in the open, sleep under the stars, whatever you want Animals (if you have any) are kept at bay with sonic tech or something so they don't intrude in private places This is an almost impossible undertaking and maintaining its biosecurity will be an enormous cost...one that only an Emperor could afford • Just go for ringworld, no need for bleaching :) – PTwr Oct 1 '20 at 13:25 • Then add underground hyperloops between interesting places. Dinner at the beach, drinks at a mountaintop, then dancing in a forest clearing, all with minimal delay? No problem, just step into the hypersonic tube. – Jann Poppinga Oct 1 '20 at 13:57 It is not the material, nor the location, nor the size, that counts in the end. It is the sheer audacity to build it in the first place that makes it so memorable. There is only one Sphinx, and even though it is just made of stone, there will never be another one like it. Same with the Eiffel Tower, and the Arc de Triomphe de l'Étoile. All made of simple materials, but all with a grandeur that will never be duplicated. Once you have demonstrated the audacity to build such a monument, there will be no other copies, because, well, they will just be copies of your audacity. Why would someone build the Sphinx? It is not really that functional. It really does not serve much of a purpose. It could easily be duplicated, the materials are not rare or exotic. Once built, the engineering becomes standard practice, taught in any engineering school. Any subsequent Pharoh could build one. Yet none did. The first and only Sphynx was built because someone had the sheer audacity to spend that much money in time and materials, that much effort, that much of the country's GDP, that much engineering technology development, on some structure, such that the construct becomes defined by that audacity, not by any intrinsic wealth or value of the structure. We admire the Sphinx not because of its cost to build, or the value of the materials that went in to it, but by the fact that one person said 'Build me a Sphinx', for no real reason except that he wanted something that no one else had ever built. And once he had it, no one else wanted one because someone already had one. Any duplicate would no longer exhibit anywhere near the original audacity. They would be an unoriginal imitation of his audacity. So this Galactic Emperor is going to be more concerned with the uniqueness of his construct, the fact that it is the first one, therefore the only one, to be built. He will not just want to build a bigger, better, more expensive palace than one already built, he would want to build something that had never been built before, that wasn't just a bigger copy of someone else's audacity. So yes, he is going to fill it up with perhaps very expensive stuff, but he is also going to use this material in a way that has never been used before, in a style never used before, in an effort never been shown before. The Sphinx was made of common material, but in a unique way. The Eifel Tower was just built of steel, but in a unique way. Same with all of our world heritage man-made sites. Even the Taj Mahal could be duplicted, or someone could even build a bigger one, but it would not be the Taj Mahal. Only the first one has audacity. So whatever material, or materials, he chose, the trick would be not just their cost, but to use them in a very unique, original, and audacious manner. For instance, not just plain old platinum, but platinum fused with diamonds built on a core of curium-247 and blended with - well, if someone described it now, it would not be an original blend, it would not be unique, it would not be audacious. Sure, someone else could manufacture it afterwards, but they would not be the FIRST. It would not show the same audacity as this Emporer showed. Edit addendum An example of sheer audacity would be, for instance, making the entire palace out of plain old gold, but doing it in just one pour of molten gold into one huge form. An absolutely solid gold palace, literally. Another absolutely audacious example would be making it out of one huge artificial diamond, cut and tunneled into one solid diamond palace. • Jupiter has been theorised to have a giant diamond crystal at its core... That may or may not be true, (probably not) but the Emperor's Prospector Core found one in a similar gas-giant, star-lifted the atmosphere away and now there's a diamond the size of Mt Everest floating around waiting for someone with a big enough ego to build their palace in it... – Ruadhan Oct 1 '20 at 8:10 • They Egyptians actually made hundreds if not thousands of sphinxes, and the great sphinx was not the first one ever made; so, that is not a good example. The Romans also built many triumph arches before Arc de Triomphe de l'Étoile commemorating nearly every major military victory; so, also a bad example. The Eiffel Tower also has many small scale replicas (probably more than any other building in the world), but probably embodies your point best since it truly was the first of its kind. – Nosajimiki Oct 1 '20 at 15:09 Gold is currently sold at around 50 Euro/gram. During my university time I worked with an organic material which we paid 3000 Euro/gram, and it was only one of the many and similarly priced we had to use to build a OLED stack. That's the figure for any material which is produced ad hoc and in limited batches. And this is where you have to be careful: the very moment your emperor orders a supply big enough to make their palace, they will inevitably trigger scale economies, lowering the specific cost of any material they might think of. Therefore my suggestion would be to build a supercalifragilisticexpialidocious palace with excellent but standard materials and then cover its walls and ceiling with small batches of rare materials, like the one I mentioned above. Ordering 1 sample of 1 gram of 10k different rare materials will be much more costly than buying 10k grams of a single substance, because the order won't trigger any economy scale effect. • it might also raise the price, as it's less available/has higher demand. For the price, availability is more important than amount in existence. – Trioxidane Sep 29 '20 at 7:41 • Salt used to be extremely expensive when the only source was to desalinate ocean water. Then they found huge salt mines with almost unlimited salt deposits. – Justin Thyme the Second Sep 30 '20 at 14:14 • Each planet supplies him with a couple of tilse of their costliest stuff. – Mad Physicist Sep 30 '20 at 18:26 • @JustinThymetheSecond. Asimov's book The Currents of Space has a similar idea. – Mad Physicist Sep 30 '20 at 18:30 • @Mad Physicist A real-life scenario would be the Debeers hold on the diamond industry. I am not sure if Asimov would have been aware of their empire, since he was 32 when the series was written, but it is possible. – Justin Thyme the Second Oct 1 '20 at 1:47 Skulls of the rebels It should be a rare material, or the emperor is not doing his job very well, but if there's a shortage then he can widen the definition of rebel to include people not turning in their library books in time. The emperor controls the supply of this material by definition, so it can be as precious as he wants. Besides that, there's a significant political advantage of crushing so many dissenters that you can use their corpses as construction material. • "significant political advantage" - not really though, as the western armies have been learning over and over in the last 60 years, when fighting rebels, each killed creates two more recruited! – BIOStheZerg Sep 29 '20 at 14:18 • @BIOStheZerg True, but that doesn't stop a galactic emperor from trying. Hence the Tarkin Doctrine :) – KeizerHarm Sep 29 '20 at 15:19 • Instead of using rebels of today (antagonizing further resistance), you could dig up historical mass graves of enemies of the state who were slain in past rebellions. That way it's not someone's brother or father in your walls, but some past enemy that history books and propaganda have already dehumanized. – Nosajimiki Sep 29 '20 at 15:47 • What about, instead of skulls of dead rebels, the perfectly preserved heads or entire corpses of the rebels, placed in the floor under transparent flooring, so that people wlak over th corpses of the revels. – M. A. Golding Sep 29 '20 at 21:02 • @KeizerHarm, the Tarkin Doctrine is a fictionalised version of the Pax Britannica and the post war Pax Americana, unfortunately it turned out from Vietnam onwards that this model is ineffective against insurgency, it only works against nation states which present actual targets to use force against. – Separatrix Sep 30 '20 at 7:11 Sorry, but I can't resist to point out: Meantime, while the Galactic Emperor was struggling to find an appropriate material for his new palace, in the great city where he lived, one day came two masons. They let it be known they were builders, and they said they could craft the most magnificent construction bricks imaginable. Not only were their colors and patterns uncommonly fine, but buildings made of these materials had a wonderful way of becoming invisible to anyone who was unfit for his office, or who was unusually stupid... (based on translation by Jean Hersholt) • Things got complicated only when the Emperor decided to move to the second floor for the better view it offered. – Schmuddi Sep 30 '20 at 13:03 • @Schmuddi: That's why it's actually made of crystal glass. – Joshua Oct 1 '20 at 2:59 Solid Mercury Mercury has always been the material of choice for emperors when they have to do something mystical and grand, though the mercury itself is readily available for all but making something out of it, using it, and maintaining it is altogether a different story. There are certain examples where mercury is solidified to create a structure, especially in the Hindu culture of making solid mercury Shivlings like this. You can take this idea, and make it grand, like really grand. Antimatter. It is pretty freaking expensive to make, but the real, ongoing, terrific expense is maintaining it. Your palace of antimatter will happily explode and take half of its planet with. This must be prevented. No atom of normal matter must be allowed to touch the walls of the palace. It is good to have redundant systems for this. Perhaps on Boom Day the Emperor releases some little shreds of antimatter shaved from the palace, just so people remember. • it would probably take all the planet with it tbh – Topcode Sep 29 '20 at 15:28 • Makes the palace a tempting target for rebels. I suggest using normal matter (for safety) and the shield generators supposedly keeping it stable are actually elaborate traps. – StephenS Sep 29 '20 at 15:54 • Sounds like an emperor that doesn't have enough problems with self preservation as it is. – Mad Physicist Sep 30 '20 at 18:58 Make it out of blocks of White Rhino Poo, or some equally almost but not quite extinct creature. Sealed in clear plastic, of course. • Why almost extinct? After harvesting the poo, kill off the remaining creatures. – Stig Hemmer Sep 29 '20 at 18:54 • Because if they are extinct, there would be no poo to harvest. To make the palace even more 'valuable', then yes, after building, kill off the rest. Of course then that addition the Empress wants can't be built out of the same materiel. – CGCampbell Sep 30 '20 at 13:01 • Methinks the Galactic Grand Poohba would want to keep a few in captivity, just to replenesh any damages. – Justin Thyme the Second Sep 30 '20 at 14:20 # Force Fields The palace should be constructed out of force fields. Force fields, of course, require a constant energy input to keep in place, so if it is large enough to require a substantial portion of the energy output of all the stars under the GE's reign, payable as a periodic tribute, no mere planetary lordling will be able to aspire to that. No plating (for decorative or obscuring purposes as in some other posts) is needed. Instead, the relevant material is injected into appropriate cavities in the force field: smoke/clouds, gold vapor, plasma, nuclear reactions, even the souls of his foes... Also, makes for quick redecorating to match his many and varying moods. Of course, they can also go contentless if the mood for minimalism or naturalism strikes him. In a cruel twist of the original children's tale - have to get back to the question's title -, whenever a visitor appears that is full of doubt regarding the palace's existence or grandeur (or, come to think of it, that of the galactic emperor hisself), a crucial supporting force field can be made to temporarily cease existence (let's say a square in front of the galactic throne in the galactic audience auditorium) at the mere push of a button (or will they have thought interfaces then?) (Of course, I've done no calculations of the energy budget actually required, I'm just making things up as I go.) Human teeth of perfect quality, manually assembled into a single gigantic mosaic showing every variety of pattern, image and gradient imaginable. To show the people's love for the Emperor, they get to participate: anyone who has perfect teeth can donate as many as they can spare. Coercion in this is of course taboo, as is any kind of monetary renumeration. But it only begins there: now an army of expert craftsmen have dedicated their lives to fitting the teeth together to form bricks and walls, like the Inca did with the rocks at Machu Picchu. The important points: • as little material as possible should be lost to make the individual teeth fit, just choose the right ones instead of cutting them into standard forms. • obviously there needs to be some kind of cement or epoxy to hold it all together, but this should not be visible at all on the visible valls - no gaps, no lines. • even perfect teeth come in variety of shades, and the craftsmen are expected to use these so that every visible area is either uniformly colored, or shows abstract patterns, smooth color gradients, or detailed pictorial mosaics glorifying the emperor and his empire. Oh, and if you want something cozy to cover the floors of your palace, take a look at the insporation for this answers: https://en.wikipedia.org/wiki/The_Carpet_Makers Part One: Preventing Competititon. I note that a galactic emperor could pevent ambitious governers or kings of kings of kings or other subordinates from building more expensive or impressive palaces by regulations or laws. Or possibly by paying governors and vasal kings fixed salaries and and forbidding them from spending tax money on their palaces. Or by spending an amount of taxes fixed by law with penalties for exceeding. Or maybe the imperial government would manufacture prefabricated palaces to a regulan design for proconsuls and kings of kings and ship them out to the planets to be assembled. So you galactic empror wouldn't have to worry about his subordinates equalling or surpassing his palace if he coud prevent them from trying. Of course, independent kings of unconquered planets, and star systems, and rivals for the title of galactic empire ruling similarly large numbers of star systems could build palaces to rival your emperor's palace. Part two: Do Your Palace Research Before Writing. One thing which a witer could think about when designing the palace of a galactic emperor is reading about other fictional palaces in fantasy and science fiction. Of course some writers even of fantasy and science fiction suffer from a lack of imagination in designing impressive palaces. I remember in one of Poul Anderson's King of Ys fantasy novels the protagonist met with the real Roman Emperor Magnus Maximus (reigned 383-385) in the imperial palace at Trier. And the room was described merely as a "splendid throne room". And I had to think that either Anderson didn't do his research, or he was "damning with faint praise" the throne room in the imperial palace at Trier, by callig it merely "splendid". In The Worm Ourobos, by E. R. Eddison, Chapter One "the Castle of Lord Juss": She spoke, and the first low beams of the sun smote javelin-like through the eastern windows, and the freshness of morning breathed and shimmered in that lofty chamber, chasing the blue and dusky shades of departed night to the corners and recesses, and to the rafters of the vaulted roof. Surely no potentate of earth, not Croesus, not the great King, not Minos in his royal palace in Crete, not all the Pharaohs, not Queen Semiramis, nor all the Kings of Babylon and Nineveh had ever a throne room to compare in glory with that high presence chamber of the lords of Demonland. https://paravel.net/ob.pdf[1] And the presence chamber does have an impressive design. Though Eddison is unclear in some details of the description, such as writing about "rafters of the vaulted roof". As I said, the presence chamber is impressively designed, but the only thing about it which has never been equalled and surpassed on Earth in real history is: But a great wonder of this chamber, and a marvel to behold, was how the capital of every one of the four-and-twenty pillars was hewn from a single precious stone, carved by the hand of some sculptor of long ago into the living form of a monster: here was a harpy with screaming mouth, so wondrously cut in ochre-tinted jade it was a marvel to hear no scream from her: here in wine-yellow topaz a flying firedrake: there a cockatrice made of a single ruby: there a star sapphire the colour of moonlight, cut for a cyclops, so that the rays of the star trembled from his single eye: salamanders, mermaids, chimaeras, wild men o' the woods, leviathans, all hewn from faultless gems, thrice the bulk of a big man's body, velvet-dark sapphires, crystolite, beryl, amethyst, and the yellow zircon that is like transparent gold. And the only thing impressive about those jewel capitals is the vast size of the original gems they were carved out of, unavailable on Earth. And I for one am not impressed merely because the builders had access to larger amounts of rare minerals than on Earth. That is a feature of the location, the result of luck instead of personal effort, and not a virture of the architectural skill of the designers. The banqueting hall in the castle of Carce later in the book, by contrast, is rather sinister looking, but it achieves its strong effect through architectural design instead of rare materials. And I think that later on there is a chamber built by the gods that is even more impressive. And in a future society people should be able to make gems at least as large as the gems in the presence chamber, whenever they want to, and so it would not be expecially impressive for a galactic emperor to use gems of that size. Of course if the Emperor synthasizes germs billions of times larger than anyone else has ever synthsized in order to carve verious parts of his palace out of those vast gems, that may be impressive. And you may remember seeing the movie Excalibur, 1981, in which the castle of Camelot appears to be made of blocks of solid gold. And to me that merely shows how dumb Arthur is in this movie, using gold in solid blocks as construction material, to build a castle with an architectural design that is not nearly as beautiful in shape as some real castles on Earth, instead of using thin sheets of gold as surfaces on the walls, as gold should be used. What form of decoration can be more spendid than gold and glass mosaics, for example? So I think that the emperor would be a little silly to obsesse about using expensive materials in his palace, instead of considering the size and the architectural design of his palace as the most desirable features for those who live in it, and the most impressive to those who see it. I also note a failure of research on Eddison's part when he lists the palaces on Earth which are suprassed by the presence hall in the castle of Lord Juss: Surely no potentate of earth, not Croesus, not the great King, not Minos in his royal palace in Crete, not all the Pharaohs, not Queen Semiramis, nor all the Kings of Babylon and Nineveh had ever a throne room to compare in glory with that high presence chamber of the lords of Demonland. And I think that all the really great palaces on Earth were built after the ones he mentions, though before the ones listed at: https://en.wikipedia.org/wiki/World%27s_largest_palace[2] I am thinking of Nero's Golden House, the Flavian Palace built by Domitian, Hadrian's Villa at Tivoli, Constantine's palace at Trier, Germany, the Palace of Galerius at Thessalonika, the Great Palace at Constantinople, the Blachernae Palace at Constantinople, The White Palace at Ctesiphon, the Arch of Chosroes at Ctesiphon, The Round City of Baghdad, the Abbasid palaces at Samarra, etc. Part Three: Who'll Stop the Rain? And Why Stop the Rain? As an example of a science fiction writer's lack of imagination, in James Blish's Mission to the Heart Stars, 1965, the characters from Earth go to the capital planet of the Hegemon of Malis, ruler of the galaxy. When they enter the vast throne room, one of the characters wonders whether the throne room has it own weather and rain inside. And Blish describes it as a whimsical thought. Here is a link to a list of buildings with the largest interior volumes on Earth: https://en.wikipedia.org/wiki/NASA[3] My answer to https://worldbuilding.stackexchange.com/questions/153965/how-not-to-turn-volkshalle-into-a-rain-factory[4] indicates that some of the buildings on the list do have interior mist, clouds, and rain. So by having a character merely get carried away by their imagination and exaggeratedly wonder if the room was big enough to have internal weather, Blish was suggesting that a galactic emperor might possibly have had such a modest and humble throne hall that it was actually even tinier than the Vehicle Assembly Building and other buildings on that list! And unlike the asker of the question, I think that interior rain can be a feature, and not a bug, of the design. Maybe a galactic emperor's throne room would be large enough to have interior rain, and the interior weather would be controlled by technology so that it rained, and thundered at the right moments to emphasise the words of the galactic emperor, sort of the effect that Chosroes or Khosrow II imitated on a much smaller scale in his fabulous palace or temple building. Part Four: What is Art? And Which is the Most Impressive Art? So I think that the effect of a galactic emperor's palace should depend a lot on it's size, far vaster than anything ever built on Earth, and on the splendor and beauty of its architectural design, rather than the expense of its construction materials. Of course the materials used on the surfaces of the exteror and interior of the palace can be very expensive materials, if they are also very beautiful materials. I mentioned above gold and glass mosaics. Gold is expensive, even when used in thin sheets, and glass used to be expensive enough to be used in fine jewelry instead of costume jewels. And of course the colored glass cubes in wall and ceiling mosaics can be be repaced by cut and faceted jewels to make the mosaices even more expensive and beautiful - in fact, jewels have occassionally be used in mosaics. If your palace has countless millions of square meters of walls and ceilings covered with mosaics designed by brilliant artists and made out of gazillions of jewels, that will be expensive both in materials and artistry, and will be very impessive and beautiful. Another answer suggested that a palace could be filled with the greatest works of art from over the galaxy, and thus be a vast museum. But paintings, and rugs, and tapestries, and sculputures, are comparatively small and movable items, and are not exactly features of the building which they happen to be displayed in at the moment. And one of the greatest arts is architecture. So the Philadelphia Museaum of Art has a wing dedicated to displays of architecture, with rooms from various places and eras on display. And possibly the imperial palace could contain original or duplicate rooms designed by all the greatest architects from thousands of planets and millennia of history. Of course if the rooms in the palace are large enough, each can contain exact full scale replicas of famous works of architecture - or possibly the original buildings - from all the planets of the Empire. Or maybe even exact full scale replicas of famous cities in the empire. And possibly, if the rooms in the palace are large enough, they can also contain famous vehicles, like cars, trains, tanks, construction equipement, ships, submarines, airplanes, space vehicles, etc., from the history of thousands of planets and star systems. As I wrote above, arcitecture is often considered one of the greatest arts, and architecture often integrates painting and scupture, two of the other greatest arts, into its design. So by making each room in the palace a masterpiece of architecture and interior decoration, each room can be a gigantic and non portable work of art. And if some of that interior decoration is metal and glass mosaics, and perhaps using cut and faceted jewels for some or all mosaic parts, the interior artwork can be dazzling. And such glittering mosaics can be used on the exteriors of buildings. I used to walk past a building in Philadelphia at the right time of day for the gold colored metal in the mosaic around the door to reflect the sunlight down to me. I have read that part of the facade of the Baths of Caracalla in Rome was decorated with silver and glass mosaics. One facade of Nero's Golden House was said to be decorated with gold and gems. Part Five: Architectural Design. And here are just a few very brief suggestions about the architectural design of a galactic emperor's palace. If you Google for At The Court of King Arthur by Samuel E. Lowe, and search for images, a picture of the blue and white endpapers of one edition is like to be one of the results. On the right side is a knight on a rearing charger, and on the left there is a fairy tale palace to end all fairy tale palaces. Ever since i was a child, I have considered that to be the fairy tale palace design to strive to equal and surpass. And you should look at the floor plan of the Villa Romana del Casale: https://en.wikipedia.org/wiki/Villa_Romana_del_Casale[5] Aand the floor plan of the ruins identified as the Palace of Antiochos in Constantinople: https://en.wikipedia.org/wiki/Palace_of_Antiochos[6] Those are good examples of ways in which the floor plan of a palace could differ from those of ordinary buildings, as it should. And to me the absolute best floor plan would be one which is made of radially symmetrical elements which are combined to make radially symmetrical units which are turn are parts of larger radially symmetrical units which in turn are parts of larger radially symmetical units, and so on and so on. Part Six: Sufficiently Advanced Technology. Also the palace of a galactic emperor should use various advanced technologies. Suppose that a galactic emperor built a super expensive palace, and then some historian pointed out that it lacks a technologically advanced feature which was used by some ancient emperor on Earth, and thus the modern palace could be considered less technologically advanced than a palace built millennia earlier by a much les advanced society. I think that the Galactic Emperor would feel humiliated, and thus his architects might feel tormented - by the imperial torturers. • ...wow. Nice answer. – Salami-tsunami Sep 30 '20 at 17:17 Consider Active Support Structures Whatever material chosen, the emperor can make his palace much more grand and expensive with the use of active support engineering. This will allow much larger structures at a constant energy upkeep cost, much more than a simple governor could afford. Make a law that no structure on the planet may be taller than the Royal Palace. Enforce it by placing Space Elevator on top of the Royal Palace which will naturally extends many tens of miles into space. Will be both unique and very, very expensive. Courtesy Yuliya Latynina. • Hmm, that's not enforcing the law, that's making the law superfluous. – Paŭlo Ebermann Sep 29 '20 at 23:27 Expensive could mean difficult to work with/manufacture. Tungsten, Titanium, and Chromium fit this bill nicely - I'm sure there are others who could list exotic alloys that are even harder. A friend of mine was going to get a Titanium wedding ring. He decided against it when a friend of his (who worked in the ER at a local hospital) pointed out that if he finger was broken a hospital doesn't have the ability to cut off a wedding ring made of titanium, so they may have to amputate. (He was an MMA fighter at the time so that was a real possibility) Titanium is also very strong and very resistant to corrosion so it would stand the test of time on any planet. Detail work with Titanium is VERY difficult I'm told. # An integrated circuit That's right, the entire palace is one single computer chip. The base price of the raw materials is laughable, a kg of semiconductor-grade purified monocrystalline silicon is just ~2000$/kg, cheaper even than gold.

The real price points are

## Fabrication

ICs are hard to make. Current-generation fabs are in the price range of 18 billion USD and so hard to build that they're driving companies like Intel out of the business. And that is for 2-dimensional Wafers with a diameter of 300mm. Fabricating one wafer costs around 17,000\$.

There's Fabs today that can build chips that are several hundreds of layers high - used for high-density SSD chips - but building a kilometer-high palace in one go?

Building a fab that creates that sort of 3D chip from one monocrystalline piece of silicon would be madness - exactly the right choice for your emperor.

## Quality control

Wafers have defects, e.g. from pieces of dust in the atmosphere. This is one of the major price points for chip production; modern processes give around one defect per 10cm² of wafer area. Every chip on a wafer must be tested carefully for defects and thrown out - or have parts of it disabled - if a defect is found. In practice this means that a significant fraction of modern CPUs and GPUs are thrown away just as they're manufactured.

Naturally, the emperor's palace - manufactured in one piece from one monocrytalline piece of silicon - will need to have zero defects. Which may add a tiny bit to the manufacturing costs.

Unfortunately, a 3D chip will be really, really expensive to test since test probes can't just touch any part of the circuit...

## Development

There's a lot of awesome things that can be done directly in silicon.

Apart from CPU cores, memory and storage you can build LEDs, capacitors, sensors for all sorts of things like magnetic fields, acceleration and pictures, protection diodes etc. Your chip can be radiation-hardened, or be a solar cell. Naturally, the emperor's palace will have every feature.

Everything that can be conceived will be integrated into the palace.

The palace will not just be a chip for the sake of being a chip; it will provide functionality. There will be no need to install electric cabling, light switches or computer screens in your palace because the building is these things.

Fabricating a chip that has all kinds of different features at once won't be cheap - there's a reason they don't put RAM and CPU cores on the same chip, the required fabrication techniques are just too different.

Intel spends more than 10 billion dollars on research and development every year, and that's mostly just for incrementally improving CPU cores, nothing else. Intel CPUs are still quite cheap nevertheless because of economy of scale.

The emperor's palace, naturally, won't have any incremental improvements, or mass production. The Emperor can assign each cubic centimeter of palace wall to a different star system, and hold and pay for a great competition to see who can design the most impressive, most innovative cubic centimeter of wall, from scratch.

Every star system will assemble a team of their most brilliant scientists and engineers in an attempt to outcompete their rivals and impress the Emperor; especially if he tells them that cost is not an issue, and, in fact, he'd prefer things to be on the expensive side.

Of course, each cubic centimeter must be interconnected with the surrounding ones, and fulfill an actual purpose. Even having a few dozens of engineers working together on a complex project on Earth typically causes an immense amount of headache and management overhead, and makes your development costs explode far beyond what planned for. Luckily, that's an intended side effect.

## Conclusion

The costs are literally inconceivable to me, but it definitely won't be cheap, and the emperor can add as much complexity, and show off as much complexity, as he likes. There's even nice synergy effects, if he chooses to share some or all of the beautiful technical advancements that are made while constructing the Fab or designing the Chips, similar to what happened with all of the money that was sunk into the Apollo project on Earth.

One important thing to get right from the start is Framing. It must be made clear that the project isn't supposed to be cheap, or efficient, but that it's supposed to be prohibitively expensive and stretch the limits of engineering, science and the general economy far beyond what seems reasonable.

There will be delays, and budget increases, and if these are not framed as part of the plan, the palace will just be perceived as a failed megaproject, like the ones that we have on Earth today (as a German I'm thinking of Berlin Brandenburg Airport, which has become a running joke due to its "series of successive and embarrassing delays due to poor construction planning, execution, management, and corruption.", but I'm sure that everybody in the world, except maybe Switzerland, can think of a multitude of similar failed projects in their own country).

This answer builds on the answers "A piece of history", "What matters is craftsmanship", so credit to those.

You can make diamond from the ashes of people. Thus a palace made from people would be quite expensive.

https://www.algordanza.com/en/

Something that is costly to maintain and generally of little utility is considered a "white elephant". These were prized animals for their rarity in the wild but kept by the wealthy as indications of their wealth. As they often came to be seen as far more costly to maintain than their actual worth they were given as backhanded gifts to others. Killing a white elephant would be considered a cruelty, as would setting it free in unfamiliar terrain. It would eat plenty and live for decades, potentially bankrupting someone of lesser wealth. Elephants are used as pack animals, and done so at a profit, but this would not be something one would expect a rare white elephant to do.

It sounds like what you seek is a palace that is made of something rare, but also has a high maintenance cost. Perhaps I'm not being very helpful as I cannot think of anything specific. Just keep in mind that any large building will require considerable maintenance and that alone can make it a white elephant.

Another thing to think of is what is considered the most valued place in an empire. I'll use America as an example. For many in the world getting to America, even as a visitor, is considered something to be valued since this is seen as something approaching an "empire" of great wealth and power. Then consider that getting to a center of great power inside the "empire", which makes getting to the US capital what people aspire to. Then comes getting to the White House, a highly guarded "palace" of sorts. Then the "center" of that is the Oval Office. This is a place people want to visit and that's because that's the office of the President of the United States. Just the fact that the palace contains the emperor makes it valuable no matter what it is made of.

A similar thing can be said of a religious example. People will want to visit Rome as that's a pilgrimage to see many holy sites. Inside that is Vatican City. Inside that the Sistine Chapel. And that's valued because it's where the Pope and College of Cardinals meet, as well as being a place bearing incredible works of art going back centuries.

A place of awe doesn't have to be a white elephant, or a seat of power for someone of political and/or religious influence. It can bring awe out of it's utility, quite the opposite of a white elephant. People desire to visit places that are examples of engineering marvels. They will want to see hydroelectric dams, military fortifications, nuclear power plants, large telescopes, particle accelerators, and tall towers. Which takes me back to the examples of DC and Vatican City where people seek out information that few can know or see, contained in books or the minds of the inhabitants. The libraries and museums that contain this information is valued.

Consider the value of information. The value of the instruments of science or espionage. A place like DC, Vatican City, or other capital cities will not only contain the "palace" but also information, large engineering projects for creating and protecting this information, and the people in authority of it all.

One such engineering feat that would bring awe could be something like the one and only known stable fusion reactor in the empire. This would be of considerable value not just in the power output to keep the capital complex lit and heated but provide power for weapons, growing food, powering industry, and so forth. This would be something that few would be allowed to even see out of concern for keeping the secrets of how it works and to defend it from sabotage. If there's a rare material to be sought then perhaps it's the plasma within an artificial star that powers the center of an empire.

Having a single such reactor is likely something no empire could rely on as that one point of failure would make too much of a target. Perhaps the palace sits upon the largest of them, or the first of them.