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The Lighthouse: Mirrors and The Names & Numbers

The Purpose & Function of the Lighthouse

Who built the lighthouse?

6x05 The Lighthouse.jpg

Theory: The Lighthouse mechanism was built by a technologically advanced civilisation which pre-dates any of earth's currently-accepted 'first civilisations'.

Evidence: The lighthouse is the first piece of fully functioning 'advanced technology' or 'magic artifact' seen so far on the island. (Arthur C. Clarke once said that sufficiently advanced technology appears magical).

  1. Because of its size and complexity more than one person was needed to build the tower and install the mirror mechanism.


  1. Hieroglyphs in and around the tower suggest connections to an ancient civilization.
  2. The turning mechanism is crude, but metallic, which means that ore-working was required (unless it was recycled shipwreck-debris).
  3. The 'look & feel' of the machinery is reminiscent the Antikythera mechanism (c.150 BCE), and a possible link with Hellensitic machines of around 400-300 BC.
  4. The 360 divisions indicate a link with ancient Sumeria, which originated the sexagesimal (base 60) counting system. However, the use of Hindu-Arabic numerals to represent the values is certainly post medieval; these symbols only appeared in this form in the 13th & 14th C, and as late as the 16th century, Roman Numerals were used in "official" and scientific applications.

6x05 TheLighthouse.jpg

  1. The 'ziggurat'-type construction of the lighthouse is further evidence of this connection.
  2. The glass mirrors are not the product of a known ancient culture; mirrors in antiquity were made of polished metal and glass mirrors only started to be produced during the late 12th & early 13th Century C.E.. (Crude glass mirrors date from Pliny, possibly manufactured in 1st century Sidon).
  • There are at least five explanations:

6x05-Lighthouse Dial.jpg

    1. The Lighthouse and its mechanism are very ancient and are remnants of an advanced civilization which pre-dates the Sumerian cities (prior to 5000 BCE)
    2. The lighthouse is post-medieval in origin
    3. The technology is extra-terrestrial in origin, and has been re-worked and installed more recently.
    4. The mechanism is an invention from the future, which was then transported back to an earlier time, and installed in the lighthouse
    5. The glass mirrors are a later addition to an earlier structure.

Hurley lighthouse mirror.jpg

  • A post-medieval original construction date is very unlikely, and would still have required a 19C refit. Neither the Lighthouse or its mechanisms appear alien or futuristic. However unlikley it seems, the only option appears to be that an ancient civilisation appropriated, mimicked or was provided with a piece technology alien to their culture, and we are seeing the results.

Theory: Jacob

Jacob built the Lighthouse and its mechanism because he had time, he had need (to observe/fetch/communicate with candidates), he had ability. His skills are ancient and include "magical skills", he could "employ" island residents through Richard, he could work with Nemesis (perhaps a common need). All of the mechanism parts could be imported, even made to order.

The Function of the Lighthouse


  • The lighthouse is a portal which can be used to view the past, present, and future. Jacob discovered or built it and simply marked down the names of the people whose lives he could see as he turned the wheel. These people were designated as candidates because by being able to see their past, present, and future, he could manipulate them into coming to the island by interfering with their lives. They are crossed off the list when they die or they have been deemed unworthy of candidacy.

Lighthouse List

  • The "Lighthouse" in Lost is different from an ordinary lighthouse. It is not meant to guide people to the island but is rather people's paths off the island. What Jacob wanted Jack to do was get into the lighthouse and destroy the mirrors. For some reason, in these "rules" Jacob could not occupy space that was not his or destroy the mirrors, or because he is now incorporeal. The lighthouse represents something different, much like the donkey wheel, it is a portal. It is a portal to this parallel universe that we have been watching in Season 6. As we have known for the show's entirety, Jacob does not want everyone to leave the island. By having Jack destroy the mirrors he in ensuring that MIB cannot have everyone leave using this portal. This is MIB's path home and Jacob wants it destroyed. However, Jacob couldn't have destroyed the mirrors himself because he is currently incorporeal. MIB has a physical form and he could; in this form he has already manipulated the cave environment by throwing out the white rock.

The Mirrors and the Numbers on the Mirror Dial

The Lighthouse Dial

  • Although the numbers on the dial range from 1-360, the numbers are not "compass bearings" in any real sense. The Losties didn't come to the Island because the scenes and their houses happened to be in line with a "compass bearing" in the Lighthouse. The Lighthouse showed these scenes because Jacob wanted to watch each of them. For the numbers to be compass bearings, each of the candidates' homes would have to be spread out in a perimeter around the Island, 1 degree away from the next which is not the case. It's far more likely that Jacob was interested in them already and set the compass to display each one through some "magical" means.
  • The mirror shows a person and the observer then writes the name down. The suggestion that the observer could simply write a name down and see a person's familial home, and presumably see events that shape his life is unlikely as it would mean that the act of writing on the wheel would make it show the person (Though I suppose you mean that a 'being' like Jacob should be able to make it show someone specific).

Lost lighthouse2.jpg

  • The "degrees" are only displayed as such because the mirrors work via a compass (circle) and all circles are made up of 360 degrees. 1... 4, 8, 15, 16, 23, 42...360 so those numbers would have to be assigned to each candidate. Perhaps at one time the mirror showed a location at every degree, but as candidates were crossed out, their locations disappeared. The degrees must be important in the fact that if the lighthouse were a true lighthouse, then you would need a way to accurately point your light. This is "Jacob's magic."
  • The mirrors show the flash-sideways. This is actually a simulation, running on Jacob's "What If" machine, that shows the true nature of the candidates by showing how they would have lived their lives without the influence of the Island and its players. The mirrors are the monitors of the What If machine.

The Crossed-Out Names


  • Names are crossed out on the dial once the individual has achieved their purpose. The names aren't crossed out because the people are irrelevant. Every one on the wheel is (was) relevant to the final goal, and they're names are crossed out by Jacob once they have fulfilled their destiny. This is what is meant by "progress" when Jacob was talking to the MiB. The crossed out names weren't 'the ones', but he is getting closer to the right person/people.
  • They are also crossed out as each player has been evaluated as a candidate. They are crossed out as each of them fail to meet the requirements of the job that Jacob has been fulfilling for the time past.

Names Substituted on the Wheel (Darker Text, Capitals)

  • On the Lighthouse Wheel, the text for JARRAH and SHEPHARD are noticeably darker/larger than the names around them. This may be a prop decision so that they stand out to viewers, but if it is intentional, names can be erased and replaced when more space is needed and the list is not restricted to one list of 360 names and would contribute further to the notion of a "Substitute" for John Locke, who was the centric character for The Substitute, the substitute for Christian on the Aijira flight, a substitute for the nemesis, and a substitute teacher. The names KWON and FORD being written in caps may also have been substituted.
  • The images in the mirror seemed to show where the characters (Kwon and Ford, at least) met and interacted with Jacob. If the image had been the hospital where Jack worked, this would have continued this theme and still left it ambiguous as to which Shepard this referred to. However as it shows the house, we are meant to believe the the Shephard is Christian. Jack even says, "I haven't lived there since I was a kid."
  • The lighthouse may have the ability to see the Candidates at any time. Therefore explaining why Jacks' childhood home is seen. In the sideways flash, Jack visits his mother at that house. For Sun and Jin, it could be the same as it was Mr. Paiks' house. The vision of the Church for Sawyer could be his childhood. Actual Candidates were not seen in the mirror.

Who 'owns' or 'uses' the Lighthouse and the Cave?

  • The Lighthouse & Cave are meant to be interpreted as literary 'opposites', in keeping with the themes of the show. One is man-made, one is natural; one needs to be ascended, the other descended; one is light, the other dark etc. In the lighthouse, the names are written systematically, and with purpose. In the cave the names are chaotic, jumbled and purposeless. So the viewer is invited to associate these locations with Jacob (the light player) and Nemesis (the dark player) and think about their contributions towards the yet-to-be-revealed game the pair are playing. For alternative views click here to go to the discussion.

The Lighthouse Wheel and Population of the Island

  • No one comes to the island by chance. According to Dogen, everyone that comes to the island was in fact brought there.
  • The entire population of the island can never be more than 360, including Black Rock, US Military, Hanso Foundation, Dharma Initiative, Rousseau's boat, Henry Gale's balloon, Desmond's boat, Flight 815, Kahana and Flight 316. (Ok, 363 with Jacob, the Smoke monster and the boy with bloodied arms).
    • Supporting evidence for this is the Letter of Truce between the Others and the DI, where it was specified that the entire population of Dharmaville could never exceed 216. It was Richard Alpert who insisted on the following addendum to the Letter: "The maximum population of D.I. members cannot exceed 216 at any one time on the island." (emphasis added).

Breaking the Lighthouse Mirrors

The mirrors are no longer needed

  • The purpose of the lighthouse is to be able to watch the off-island activities of the candidates. There are only 5 candidates left and they are all on the island. The lighthouse is therefore useless.

Jacob wanted Jack to break the mirrors

  • The mirrors are redundant but Jacob wanted the mirrors broken to prevent MIB from viewing them and taking advantage of anyone on the wheel list.

Breaking the Mirrors Significantly Alters the Lighthouse

  • The lighthouse was used to summon the FS Losties. By smashing the mirror, Jack has locked the mechanism in place permanently. The lighthouse is synchronized across both universes, above and below the sea. The frozen donkey-wheel is connected to the lighthouse's protractor but instead of moving the island, it has moved either the exit portal from the Tunisian desert or the entrance portal from the Pacific Ocean to Christian Shephard's house (the last reflection seen in the mirrors).

Breaking the mirror is a symbolic act

  • Mirrors are an important symbol. This episode Lighthouse (Season six, episode 5) mirrors elements of White Rabbit (Season one, episode 5). The entire sixth season is mirroring the first season. By breaking the mirrors, Jack is unknowingly breaking the cycle.

Connecting the dots: The Lighthouse, The Numbers, and the Valenzetti Equation


Valenztti equation1.jpg

The story behind the numbers is a Strange Loop, and acts like the Bad Wolf motif in the Dr.Who episode: "The Parting of the Ways". The numbers arose because the user of The Lighthouse was seeking candidates. These candidates corresponded to numbers on the dial, and had no significance other than these were the lighthouse orientations needed to view them. When he began to intervene in their lives, to affect their future destinies, coincidences and correlations between these people began to echo down the timeline. In 1963 Valenzetti discovered that such correlations existed, and was able to use mathematics to determine values underpinning these correlations. By broadcasting the numbers from the island in 1972 onwards, the numbers acted as a self-replicating virus which enhanced the original intervention effects, and thus became a self-fulfilling prophecy.

Facts and Indisputable Logic:

The Lighthouse Dial

The numbers on the dial as shown in the Lighthouse, are a clear attempt at 'trial and error' in seeking out possible candidates. At the end of this process, we appear to be left with the names corresponding to the six Valenzetti numbers (plus the additional value of 51 - Kate, which had not been crossed off). This means that whoever has been using the Lighthouse to view and select candidates, has, independently arrived at the same six core values that Valenzetti did using his equations. The numbers on the dial appear to give the user views (whether of past, present or future is uncertain) of specific locations connected to the named person. This would imply two things:

  1. The lighthouse user cannot have been aware of the Valenzetti core values, otherwise he (or she) would have saved themselves a great deal of trial and error, in trying to determine which of the 360 names on the dial would be suitable as 'candidates'
  2. The lighthouse dial numbers are either 'independent discoveries' of both the lighthouse user and Valinzetti, or one "preceded" the other, and there is a causal link between the two.

The Numbers had been broadcast on the island since 1972, and were known much earlier (evidence from the Lost Experience would put their discovery around 1963). The Lighthouse user would therefore have known about the values from at least 1972 onwards, and possibly as early as 1963.

Now, here is a dilemma: Since Kate (#51) was not born until 1977, Hugo (#8), was not born until 1982, the lighthouse user must therefore have known about the existence of these Losties prior to their actual births. In other words, one of the functions of The Lighthouse is to view the (possible) futures of (possible) candidates. In addition, because of point (1) above, the use of the lighthouse to determine the candidates, must have taken place prior to 1972.

Thus we are left with two propositions, one of which MUST be true:

(Proposition A) The Lighthouse user and Valenzetti independently discovered the numbers at around the same time (between 1963 and 1972), and they result from the same underlying factor

(Proposition B) The Numbers on the Lighthouse pre-date the Valenzetti equation, and Valenzetti's equation is simply reporting "observational" values related to the end of the human race.


(B) Offers a clear explanation of what happened. The Lighthouse user was able to see the future, and intervene in the lives of those candidates indicated by the numbers on the lighthouse wheel. These interventions were across time and space, and not limited to any one time. We have distinct evidence that such interventions occurred, via the Jacob flashbacks in The Incident, Parts 1 & 2. Note that it does not matter whether or not the interventions occur before, after or at the same time as, the discovery of the Valenzetti equation, as this equation is a prediction of the future. In making these interventions, changes to lives have occured which have echoed down through time, causing "coincidences" in the lives of those affected (e.g. Locke's father being responsible for the death of Sawyer's parents). When Valenzetti worked on the equation, he simply discovered the effects of the interventions, which showed up as correlations within the equation, and was therefore reporting a 'fact', that the numbers existed and were embedded in the history of humankind. When he began to broadcast the numbers, like a virus, they then began to self-replicate, so much so that the Original Timeline became "infected" with the Valenzetti numbers which then appeared everywhere, adding to the effect and creating a causal loop.

If (B) is incorrect, then an explanation is required of why the association of names & numbers on the lighthouse would coincidentally be identical to those signalling the end of humankind. This is not impossible, but in the face of the explanation resulting from (A), it is rendered unlikely in the extreme.

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