Летен прилив

Heritage Universe #1

by Charles Sheffield, Чарлс Шефилд, Георги Стоянов

Наближаваше летният прилив — времето когато двете планети, Опал и Куейк, се движат по орбити, най-близо до тяхното слънце, действащо с огромна сила и предизвикващо приливни вълни. Ала това щеше да е най-силният летен прилив изобщо, поради най-голямото сближаване между звездите и планетите в системата, нещо, което се случва на всеки 350 000 години.

Достъпът до нестабилната Куейк е забранен, но някои много настойчиви космически пътешественици са решени да я посетят. Професор Дариа Ланг, всепризнат специалист по артефактите, оставени от отдавна изчезнали извънземни наречени Строителите, подозира, че по време на необикновен силен летен прилив може да се натъкне и на самите Строители. Луис Ненда и сикропеанецът Атвар Х’сиал имат свои интереси на Куейк и ще направят всичко, за да се доберат дотам.

А съветникът Джулиъс Грейвс издирва масови убийци. Ако те се крият на Куейк, той не се нуждае от ничие разрешение, за да ги залови.

Genres: Science Fiction, Fiction, Space Opera, Audiobook, British Literature, Space, Science Fiction Fantasy

281 pages, Paperback

First published February 1, 1990

About the author

Charles A. Sheffield (June 25, 1935 – November 2, 2002), was an English-born mathematician, physicist and science fiction author. He had been a President of the Science Fiction and Fantasy Writers of America and of the American Astronomical Society.

His novel The Web Between the Worlds, featuring the construction of a space elevator, was published almost simultaneously with Arthur C. Clarke's novel about that very same subject, The Fountains of Paradise, a coincidence that amused them both.

For some years he was the chief scientist of Earth Satellite Corporation, a company analysing remote sensing satellite data. This resulted in many technical papers and two popular non-fiction books, Earthwatch and Man on Earth, both collections of false colour and enhanced images of Earth from space.

He won the Nebula and Hugo awards for his novelette "Georgia on My Mind" and the 1992 John W. Campbell Memorial Award for his novel Brother to Dragons.

Sheffield was Toastmaster at BucConeer, the 1998 World Science Fiction Convention in Baltimore.

He had been writing a column for the Baen Books web site; his last column concerned the discovery of the brain tumour that led to his death.

He was married to writer Nancy Kress.

Reviews

[Metodi Markov · Rating 5 out of 5]

Класическа "твърда" научна фантастика, много ми хареса!

Множество сложни артефакти, пръснати на различни места из космоса озадачават от хиляди години хората и извънземните същества, опитващи се да ги разгадаят. От Строителите - загадъчна раса, господствала в тази вселена преди милиони години, са останали 1236 конструкции, повечето с гигантски размери и с неясно предназначение.

А решението на ребуса може би се крие в странна поредица от катаклизми, които се очакват на отдалечена двойка планети, неразривно свързани заедно с други небесни тела в опасен, почти непонятен космически танц.

Мистър Шефилд се е справил чудесно и със създаването на нужните му за тази интригуваща история герои.

Преводът на български е неприятен - вероятно не е виждан от редактор и коректор, а издателство "Бард" не са издали последната книга от серията…

Цитат:

"Пълната комуникация между видовете може би бе невъзможна."

[Dirk Grobbelaar · Rating 4 out of 5]

Here's one for lovers of big dumb objects. Seriously, this novel is seeded with artifacts, and with designations like Cocoon, Sentinel, Paradox, Elephant, Lens and Umbilical you know you just can't go wrong. Sheffield was both Mathematician and Physicist so the science is pretty hard. However, it is actually a remarkably accessible novel with some pretty endearing characters (especially some of the aliens).

The Builders, the mysterious alien civilization that vanished millions of years earlier and left behind their mysterious artifacts, also bear an uncanny resemblance to the Forerunners (Halo) and the Protheans (Mass Effect).

I enjoyed this quite a bit. As did my wife, and that says a lot.

[Craig · Rating 4 out of 5]

Summertide, the first book in his Heritage sequence, is perhaps Sheffield's best known and most popular novel. It's a big, sprawling set-up of unusual astronomical events, interesting characters, and tightly-woven plotting. Rather than focusing on a single plot line, he put together a tapestry incorporating crashing planets, murder mystery, ancient artifacts, and a bit of romance, all keenly put together with with an eye for scientific accuracy and authenticity. It's a very captivating tale with a lot going on and lots of unexpected twists and turns. I enjoyed it very much.

[Oscar · Rating 4 out of 5]

El brazo espiral de la Galaxia está repleto de artefactos pertenecientes a los Constructores. Se calcula que hay más de mil doscientos, la mayoría de ellos un absoluto misterio; incluso algunos han causado la muerte de los exploradores que se han acercado a investigar. Sin embargo, en el sistema planetario Dobelle formado por Sismo y Ópalo, se espera una conjunción de planetas y estrellas como no se ha visto en 350.000 años. ¿Tendrá esto algo que ver con los misteriosos Constructores?

Entre los protagonistas de la historia, se encuentra el capitán Hans Rebka, que tiene la misión de estudiar el comportamiento de Max Perry, comandante en el planeta Ópalo, y convencerle de que abandone este sistema. La profesora Darya Lang, de la Alianza, es quizá la que más sabe sobre los Constructores, y se dirige a Sismo para estudiar el Umbilical, uno de los artefactos. Julius Graves, consejero de la Alianza, tiene como misión encontrar y apresar a unas asesinas genocidas que cree se ocultan en Sismo. E igualmente, la cecropiana Atvar H’sial, y Louis Nenda, de la Comunión Zardalu, buscan descender a Sismo. El problema estriba en la proximidad de la Marea Estival, que se espera provocará catástrofes que hacen inviable la vida en Sismo.

‘Marea Estival’ (Summer Tide, 1990), del escritor Charles Sheffield, es el primer volumen de la serie Universo Heredado. Desgraciadamente, sólo se tradujo al castellano este título. Sheffield escribe bien, y sabe atrapar al lector, algo nada fácil. Esta novela recuerda, inevitablemente, a ‘Cita con Rama’, de Arthur C. Clarke, y ‘Pórtico’, de Frederik Pohl, en cuanto a artefactos alienígenas se refiere. Es un buen libro, pero deja la trama abierta a las continuaciones, que como digo no se han traducido. Entretenido e interesante; me lo he pasado muy bien leyéndolo.

[Vincent Stoessel · Rating 3 out of 5]

Slow school classic. Not a lot action but a bunch of interesting questions. A Reynolds and P Hamilton fans should probably stay clear of this one. Having said that it was still interesting enough to hold my interest throughout the novel. Plan to do the entire series once I clear some other books out of my queue.

[John Loyd · Rating 5 out of 5]

Summertide (1990) 281 pages by Charles Sheffield.

Book one of the Heritage Universe. This felt like a standalone novel so you don't have to feel cheated if you can't find the rest of the books. In this universe there are clades -- groups of planets settled under one hierarchy. There is the fourth Alliance, Cecropian space, the Zardalu communion, and between them the poor planets of Phemus Circle. Spread throughout the spiral arm of the galaxy are builder artifacts. Most of these are enigmatic, millions of years old, and the builders themselves nowhere to be found.

Hans Rebka is all set to explore Paradox when he gets orders to go to the Dobelle system and find out what has happened to Max Perry. The Dobelle system is made up of two stars Mandel and Amaranth, tidally locked planets Opal and Quake, and a gas giant, Gargantua. Summertide happens during syzygy, and the upcoming summertide will have all the bodies in line, and at nearest approach.

Rebka gets to Opal and finds four applications to visit Quake. All wanting to visit at summertide, when Quake will be uninhabitable due to the tidal forces.

There are a varied assortment of characters, Atvar H'sial, a Cecropian -- which are blind and see only by echolocation and communicate with pheromones. She has brought along the Lo'tfian J'merlia as a translator. Louis Nenda from the Zardalu communion where biological science has gone further forward than the physical sciences. He brought his pet hymenopt, Killik. Professor Darya Lang a specialist in builder artifacts from the Fourth Alliance. Councilor Julias Graves with his mission to find a pair of suspected murderers. Along with Rebka and Perry.

Sheffield tantalizes us with some tidbits about the builders' artifacts, but the story is really how these eight (ten with the Carmel twins) interact, the adventure of trying to move from place to place on the inhospitable and often dangerous planets of Quake and Opal, and what is going to happen at Summertide?

Lots of good characters, action, and he's vague enough with the orbital mechanics that we can't really question the science.

[Ted Pikul · Rating 3 out of 5]

this was essentially a setup novel for the next, which i wish i knew but i always go in blind. it also took until almost the halfway point to get a clear idea of the central BDO mystery, which i got incredibly excited for since it was a really well written description of the relativity of simultaneity problem, but i don't think it paid off really at all. mostly you spend time with a ragtag group of people and aliens almost like a rat race situation but the tone is never clearly comedic, pulpy or hard scifi, just a mix. the characters are interesting though, favorite being how the language or intelligence capabilities of some of them are explored. not sure if i wanna chance into the sequel. i guess another publisher might have delivered this story as a single book, just because of how little is resolved in this book.

i found the following quote towards the end of the book really hilarious for anyone who felt disappointed by it, spoilers below:
"Summertide. It was over. And it had been nothing like she had imagined. She glanced over at the others, still rubbing their eyes as they lay on the starship floor, and felt a terrible sense of letdown. To see everything — but to understand nothing! The whole visit to Quake at Summertide was an unsolved mystery, a waste of time and human lives."

[Rusty · Rating 3 out of 5]

You know, I can’t help but notice that per Goodreads, I failed in my reading targets for 2020. I get why Goodreads would think that, but I really didn’t fail, because I read THIS book last year, I just didn’t mark it as complete in time. So, in the spirit of winning at any price, I’m going to backdate the date read on this so it shows completed on the 31st of 2020.

Whew. Now that that’s all out of the way. This is the third book of Charles Sheffield I’ve read. Strange that I really enjoyed them all, but somehow I don’t know anything about him or his larger body of work. I’m not gonna check up on him now, that would be ridiculous, so I’ll remain ignorant, but do intend to read more of him in the future.

And this book? It was fine, like a lot of older works, it suffers a bit from pacing, it’s a survival story (man v nature) that also has bit of mystery and betrayal and SF awesomeness thrown into a blender. It has some very human-like aliens (not in their physiology, but in their behavior) which I tend not to love outside of Star Trek or Star Wars. I’m more enamored with those unknowable types, you know, a thing that doesn’t even have the capacity to understand or be understood by humans. That I’m into.

So, yeah, like it, want to read more. Didn’t think it was blow-my-doors-off-awesome, but I do want more.

[Gendou · Rating 5 out of 5]

A wonderful example of hard science fiction. Fascinating galactic artifacts left by long vanished builders. Humans and convincing aliens working side by side. I look forward to reading more Sheffield.

[David Corbet · Rating 4 out of 5]

Never disappointed in a Sheffield Novel. Good character development. Moving plot with just enough intrigue to pull you along. And a climax that is unexpected.

[York · Rating 4 out of 5]

Nice jaunt with neat ideas...and BDOs...will probably read next in series since the backstory of the builders is intriguing...

[Jonathan · Rating 3 out of 5]

Sheffield seems to have a quiet reputation as a hard sf author, publishing regularly in Analog in the late 70s and 80s. Although he doesn’t come up too much anymore in discussions of the field, that could be my own echo chamber. I was intrigued by this and spent a few weeks looking into his work, seeking out something to try. Unfortunately, Summertide didn’t work for me.

I can try to work out what was there, what I like and what I didn’t like….But I still can’t figure out why it took me a week to read a 250 page paperback. This was the first book in a series called Heritage, which is lauded as one of his lasting achievements. The central plot device was the catastrophic effects of a tidally locked planet during…summertide. This conceit is used like a hangin carrot for the reader, many characters continuously warning about it. These passing comments did not create the high stakes effect for me it was going for. Perhaps I didn’t feel for the character..There were a handful of them all with their own motives down on this planet, Quake. The final climax seemed easy dialed in.

The space opera dressing was there with distant humans on the arm of the a spiral galaxy. The alien’s sense functionality was interesting, although it still didn’t make them “alien” enough for me. I appreciate that they needed a “translator”. The whole ancient artifact thing really got my attention and I thoroughly enjoyed how this was treated in in the text. Chapters alternated with entries from a scientific catalog, each artifact from the vanished alien race. This has narrative echoes throughout the whole book. It made for some wonder and speculation and got points with me for creative textual treatment.

There is evidence that Sheffield or this particular series of books has some influence on other hard sf authors. I recall some particular things here done (better) in Alastair Reynolds. In this series, humans leaving earth and colonizing space is known as The Expansion. It is could be easily suggested that this gave a spark to the name of the James S.A Corey project.

Underneath the BDO trope, space opera scope and the treatment of science as plausible grounds for how the universe in Summertide operates, there remains a pulp-adventure core to this. I can dig that. For what that is, this book was not bad. For me, it lacked that wide wonder of Banks’ Culture or the atmosphere of Revelation Space.

Maybe I’ll continue the series. Please fight me. I am open to more suggestions of Sheffield’s work.

[Matt Shaw · Rating 4 out of 5]

This is a better-than-average space opera adventure. While the plot relies on ancient BDOs and intrigues working against each other, the strength of Summertide lies in the character development; Sheffield does a good job creating and presenting complex individuals who don't suddenly act out-of-character to suit the storyline. Even the aliens are alien enough to not be funny-looking humans but still maintain complex backstories and motivations. It's entertaining and intelligent.

[Stanley Hanks · Rating 4 out of 5]

Thank you, Wendy! Great book!

[Hannah Dixon · Rating 4 out of 5]

Pretty solid science fiction book, it kept me intrigued enough to want to read the rest in the trilogy! It really does well in making me attached to the characters enough to care about the story, which I found hard to follow at times.

[Joe · Rating 3 out of 5]

I ran across this one as an audiobook available from my local library. It was the first thing that popped up under the "sci-fi" genre so I thought I'd give it a try. The story is about a diverse group of individuals, human and alien, that are all converging on a single planet at the same time in order to unlock the secrets of an ancient race of aliens known as the Builders. No one knows much about the Builders but they have left a multitude of artifacts behind with technology that even thousands of years later the known races have no way of fathoming. Everyone believes an event of great importance will happen on the planet of Quake at Summertide, but what will it be? What answers, if any, will it give to the mystery of the Builders? This book is a slow-burner for sure. There's really no action until the final act and the climax leaves you with more questions than answers. But with three or four other books in the series, I suppose that's the point. None of the characters particularly pop off the page but the mystery of the Builders was enough to keep me turning the pages (or in this case, to keep listening). Sheffield, who was a mathematician and a physicist before becoming a writer, has some pretty powerful imagery, a whole section on the mathematical equations of the exertion of tidal forces on the planet Quake that reads like poetry, and more than a few really cool ideas. For instance, the Builder artifact designated Paradox, a giant orb that can be easily entered but upon exit all forms of memory, mechanical or biological, are completely wiped clean. Computers have their memories erased and humans are reverted to the mental state of a newborn child. I'm looking forward to the next book in the series in the hope that the mystery of the Builders will begin to unravel and I might get some questions answered.

[Thomas · Rating 4 out of 5]

Sheffield, Charles. Summertide. 1990. Heritage Universe No. 1. SF Gateway, 2013.
Charles Sheffield (1935-2002) was a physicist-mathematician, and for a while, chief scientist at Earth Satellite Corp. He only turned to science fiction writing in his forties but still amassed nine series with impressive world-building. Summertide, the first novel in the Heritage Universe series, is typical of what he could do. Our arm of the Milky Way is littered with large artifacts created by an alien race that disappeared 5 million years ago. One system has two tidally stressed planets in a multiple star system. Both have space elevators. When there is a summer conjunction, both planets suffer severe quakes that make life on one difficult and on the other impossible. A rare grand conjunction attracts a group of scientists, government officials, and adventure tourists of several species. They land on the most severely stressed planet, ominously named Quake, in hope of discovering why the ancient aliens built a space elevator on such an inhospitable world. The scientific speculation is inventive and several of the characters are intriguing. Sheffield reminds me a lot of Arthur C. Clarke. Good stuff that deserves to be better known than it is. 4 stars.

[Michael P.]

I freely admit that I do not “get” sci-fi. The hope that I would begin to appreciate it through this well received book is why I pushed myself to read the first half before giving up. Sheffield seems much more interested in describing alternate ways to be a sentient being than he is in advancing his story. The book has no sense of pace, little tension, and with a single exception (in the first half) there are no interesting characters. I think we are supposed to be interested in the long-gone “builders” who created advanced structures on a world, but Sheffield gives us little reason to be interested in them aside from the fact that they built and tells us (in the first half) so little about their creation that I simply gave up entirely bored. This book became a chore, and that is no fun.

[Michael Hall · Rating 2 out of 5]

This book would probably be more appealing to the easily impressed by science terms. Or those impressed by alien artifacts with catchy human names. Amazing and mysterious "builder" aliens that have long since disappeared, leaving humanty to figure out "just what does this do?" In this story, the "story" takes a back seat to the science -- which really isn't all that "scienc-ey". There is barely an actual plot or any other story devices, very little action despite several life-or-death situations, willful and vain characters that you just cannot find a reason to care about, and an unresolved ending that leaves you wondering "what was the point".

[Bettie · Rating 3 out of 5]

This is an unabridged version, 8h 45m in length.

Great ride for the most; some parts were superfluous, other sections yawnable, however, overall a solid 3*

[Scythan · Rating 4 out of 5]

A great book! It ended with an awful cliffhanger, though, and I don't have the next book of the series. :(

[Gilles · Rating 4 out of 5]

Les Constructeurs ! Une race d'extraterrestres, probablement disparue, qui a construit des artefacts gigantesques vieux de plusieurs millions d'années, dans la galaxie. Ces artefacts, souvent incompréhensibles, reposent sur une science et une technologie hyper avancées. Justement, Darya Lang, une autorité en la matière, a trouvé un indice qui va l'amèner dans un système où se trouve l'artefact le plus récent des Constructeurs. Le système en question, Dobelle, comprend deux planètes jumelles qui sont reliées par un cylindre flexible de 20 000 km de long, l'artefact en question. Et tout indique que quelque chose va se produire lors du rapprochement maximum des planètes jumelles avec leurs deux soleils et la planète gazeuse géante. Ce rapprochement va entraîner des effets de marée gravitationnels extrêmement dangereux, surtout sur la planète Quake. Mais, à son arrivée dans le système, Darya remarque que d'autres visiteurs sont aussi motivés par la même observation.
Et ce n'est que la mise en bouche. On a un artefact mystérieux, des chercheurs, des extraterrestres étranges, etc. et le rapprochement de l'effet de marée maximum, le moment du plus grand danger, mais aussi celui de la révélation possible sur les Constructeurs.
Et c'est parti ! Le mystère nous transporte et l'histoire se concentre en grande partie sur l'effet de marée sur la planète Quake et sur les visiteurs qui ont la malchance de s'y trouver à un mauvais moment. Ça c'est sûr ! De l'action, du mystère, pour finir par une surprise qui sera probablement analysée dans le prochain tome.
Et hop ! on enchaine sur le tome suivant.

J'ai beaucoup aimé, surtout que Charles Sheffield est un scientifique de haut niveau, qui sait attiser notre curiosité avec des idées qui paraissent plausibles.

[Jason Miller · Rating 2 out of 5]

Anyone can see from my goodreads record that I'm a fan of SFF and speculative fiction. Of the many varieties of SFF, I like a good 'hard' SF story. 'Hard' SF is the genre that leans heavily on science and mathematics to build the world or universe, color details of the characters and narrative, and, to some extent, to drive the plot. Charles Sheffield is the first author I associated with 'hard' SF, though I haven't read many of his novels, and I haven't read him for a long time. Seeing this audiobook offered to me for free by Amazon made the decision to download and read easy.

I'm more mature and experienced than I was when I read my first Sheffield novel, and times have changed since this was first published. While I read the book, I couldn't help but see aspects of Sheffield's story telling that reflect bad habits we've left behind. For example, he uses old and discarded gender norms and tropes about the goodness of authority. These haven't aged well. Together with other aspects of the narrative and plot, my critic stayed alert while listening and prevented me from suspending my disbelief and immersing myself if the story. In the end, the it all fell flat and left me with little interest in digging gin to the (many) sequels.

Reading Sheffield today is like reading Asimov or Heinlein but without any reason to try to look beyond the flaws because the stories had such impact.

[Colleen · Rating 5 out of 5]

6.5 stars out of 5. Darya Lang travels to the double planet system Opal and Quake for the 350,000 year Grand Conjunction, a line up of both suns, and all the planets, including the gas giants. This phenomena is called Summertide and because Lang is studying Builder technology she wants to see what the gravity energy will reveal about the long disappeared masters of the galaxy. The only sparse human population is on the water-world Opal so she finds she has company. Captain Hans Rebka has also been studying Builder technology but he has been sent to find out why the colony leader, Commander Max Perry, has become an ineffective Leader. The human/alien Alliance Council has sent Julius Graves to Opal to arrest teenage human twins for multiple murders. Graves has the most authority, then Rebka, then Perry. None of the authorities want visitors to go to Quake. Famous criminal Louis Nenda with his Hymenopt slave, Kallick and Cecropian alien Atval H'sial and her insectiod translator/slave J'merlia also land on Opal to see what the conjunction will reveal. With this cast of characters all traveling to Quake, mostly by the Umbilical elevator connecting Opal and Quake, all hell breaks loose. Physicist author Sheffield graduated from Cambridge and expertly depicts the horror of volcanic Quake being torn by gravity.

[Brandon Kuenzi · Rating 5 out of 5]

Great theoretical science here! Some concepts you will find in this adventure: social/political situation when man settles the stars, dealing with alien races and cultural differences, developing faster than light travel, planetary physics, interesting engineering concepts, and extinct powerful races.

Where this book REALLY shines is in its careful and meticulous explanations about how the physics would work in extreme situations.

For example, this book focuses on what life on a double planet would be like: two planets orbiting each other. The story, while fun on its own, was a great way of explaining the author's research of this theoretical situation.

A great line from this book that I am constantly remembering goes something like: "In any mechanical system sound is a sign of inefficiency."

Only criticism is the detail can sometimes be a bit much. He goes into great depth explaining fictional historical events and species. That being said, I found these details much more palatable, maybe even enjoyable, on the second read.

I give it 4.5/5

[Claire Binkley · Rating 5 out of 5]

I read this when I was a child. It was my First Science Fiction novel. I might have read it when I was six or seven, with my dictionary in hand. (It was frustrating, yes, but fruitful!)
It was the foundational book in my development at that point.

I remember more the drawing I made from it of the blue scary many-tentacled aliens that had nasty beaks than the story itself. I am confident that it was indeed this book that had these creatures since this book is on the Talking Squids in Outer Space list.

I don't remember Divergence and Transcendence as strongly as Summertide. My memory is telling me I must have read them but I don't remember them very well.
(We're talking twenty years ago now.)

This novel, I believe, is the epitome of Science Fiction.

[Paul · Rating 3 out of 5]

Had this recommended to me because I was looking for a "sensawunda" SF novel where the exploration of alien artifacts and tech took centerstage. That's not what I got with this novel. In fact, I found that most of the novel was taken up by what I found to be rather poorly drawn characters possessing motivations that were either cliched or took far too long to reveal themselves. When they did so, they were unsurprising. Towards the end, I was skipping entire paragraphs of descriptions as being completely unnecessary as anything but padding.

First in a series I will not be continuing to read.

[Mike · Rating 4 out of 5]

If you are looking for science fiction with a lot of characters to follow, this could be the series for you. The story is told chronologically tracking different groups of people. The groups shift over time and each character is slowly developed to show their personality, history and motivations. There are interesting science concepts explored but just as interesting the interactions of the people. It is a good mix to keep you wanting to read more. Do go on to the next book when this one is done. The ends may all seem tied up nicely here, but the next book point out the things you were not watching closely and how those matters.

[MH · Rating 2 out of 5]

This is apparently the first book of a trilogy, and it shows - while nominally complete (the story reaches a conclusion), it doesn't really deliver on any of its central premises. Its Big Dumb Object SF that doesn't really talk about the object, or give any answers (or even really new questions) about its Builders; one character is there to work out what is wrong with another, but the answer is literally handed to them tied up with a bow at the end, with no work involved. A couple of them disappear for half the book, before reappearing very briefly at the end, with nothing really about what they've been doing in between. Competantly written, but all a little unsatisfying.

[Florin Constantinescu · Rating 3 out of 5]

"Poor Man's Ringworld" is how I'd summarize this book in three words.

You've got your big cosmic mystery concerning an ancient race, you've got your alien characters with bizarre biology, you've got your poorly written human characters, your easy reading, your confusing back-and-forth on the surface of the alien artifact, your cliffhanger ending, pretty much all tropes are in play here.

At the end of the day, I was curious enough to continue with book #2.