cipher, Narnia was a fairy-tale-come-true book for and about children. Although Lewis also wrote it so that adults could enjoy them, they are predominately children's books. Also, the books started out in the 40s, they were published then and later on. The kids were contemporary at the time of writing and publishing.
If you mean by your question that it might be possible for a story of someone from now accessing Narnia, that's just up to who's talking.
If it were me, I would say no; because Lewis was pretty chronological with Narnia time and our time. It might be possible for someone from our time to go into Narnia (now destroyed) if Aslan wished it; but I don't see why. Fan fiction would be limited to those who lived in the time-range of 1900-19(60?). Anyhow, that's my opinion. I'm a big fan of having fan fiction not contradicting the author's original work.

Thank you for the answer. But who says that Aslan couldn't create Narnia once again? The whole End of Time seems more like the story from bible when God flooms (deluge) the earth and let chosen people on board the Ark (the flood = end of time, Noah's Ark = The Real Narnia). But God gave men another chance to redeem themselves, so why wouldn't Aslan? I mean he could create a new world and give men and other creatures a new chance, a new start to redeem themselves. But did it stated in any of the books that Aslan could only create the world once? Or he would never create a new world again after he destroyed the old one? If not, then I wouldn't see any contradictions if a fan fiction tells the story about how Aslan created a new world, and a new beginning.

In his 20s and from our time.

First part first. Compare "that Hideous Strength" Older characters for a book addressed to an older audience. Thats all.

It does depend on where your heart is, well, figuratively at least (nobody writes books for elves).

As to our present time. It is only slightly more messed up than it was in 1950. And by that I mean as compared to the year 1150.

But as to your other question as to whether the world is created again, and so on, we tread on speculations - (given that you posted the question here, and not in the general section). Let's stipulate that "the bible" is a book written in This World, and , whatever it's universal pretentions, it is nonetheless, written for its audience HERE. To quote my old professor from heliopolis: The bible was not written to provide a general theory of parametric reality. It has it's beginning, and fortells an end. What came before, or comes after is not something on which it dwells in "detail"

God gave man another chance you say, but who says Aslan ended Narnia for a similar reason? For that matter, who thinks this world will end as a "punishment?" Of the two opposing forces I am aware of today, neither believes this (although one of them does like to play up the disaster meme). The world is too quick to judge! I think you would enjoy "Out of the Silent Planet," Lewis dances around this very question - the fate of Mars in this case, what comes after, and what the whole purpose of it all was. (danger, Will Robinson!)

"As it was in the beginning - is now and ever shall be, worlds without end- " A thing the elves say little about, and the Valar even less, for parametric reality, (precursor engineering) and the like is not a science for mortals, few can think about it rationally, and none dabble in it without peril.

I'll tempt the uruloki at the door.

Let's dabble: way back in the old days, (before it was deemed a heresy) they used to say that the world would be reborn, "reforged". Look up "chilaism" if you want to read old dry and clueless commentaries by ignorant scholars who write about things they have never seen (likely) or cant remember (!) and then think about the wood between the worlds where it all began and how Narnia ends in the race "further up and further in".

And if I have not bored you completely, let's pause and consider also how gold is refined from ores at 5 parts per million of aureificerous oxides. First the ore is crushed, and then it is "concentrated" then put to the fire. And ONLY THEN, mes amis, does the real magic begin. At each stage, a different process, as the gold becomes MORE LIKE gold, - reaches to greater purity and greater perfection.

By analogy, I suggest that what Aslan TOOK OUT of the old Narnia in Last Battle was NOT like that which He PUT IN at its beginning. So the question is not could he create another Narnia as a replacement. Of course he could! Rather, what comes next?

I think it's a bit misleading to describe each step in this long process as "the end of time".

When we "graduate" from kindergarten, we dont go to another one - but something altogether different. This really doesn't matter while you're IN kindergarten, but, eventually

"A new start to redeem themeselves..."

Yes, Uncle Andrew probably needs that. But I hope that you and I do not. Ah yes, that last statement will definitely not pass the council of presbyters, but there it is.

I am simply guessing that the main characters are the age of the target audience. I first read the books when I was 17 and thoroughly enjoyed them.

I always assumed that Lewis chose the ages for the characters because his intention was to write a children's book.
And I agree with Aravis Narnia, I was 11 when I first read Narnia and a enjoyed it very much, turning every page with anticipation, wanting to find out what happened next! Though I think Narnia is also for the child at heart, for all ages and anyone would enjoy it the first time they read it!

I always thought that this had something to do with the fact that as Christian children grow in height and such, they also grow in Christ Jesus.

Then again, as said, it could be because it is assumed mostly children read these books, particularly young ones, but teenagers like me and young adults can enjoy them too.

Fan fiction would be limited to those who lived in the time-range of 1900-19(60?). Anyhow, that's my opinion. I'm a big fan of having fan fiction not contradicting the author's original work.

I don't agree. Lewis explains, via the Professor:

"I should not be at all surprised to find that the other world had a SEPARATE time of its own; so that however long you stay there it would never take up any of our time." (My emphasis)

Time is not a universal force to which everything, including God, is subject. Our time is a property of our universe. Narnian time is a property of the Narnian universe. Aslan created the Narnian universe and with it, Narnian time. God, through Jesus, created our universe and with it, our time. They are separate universes, and have different physical laws (the Narnian world is flat, and its stars are human-sized, human-shaped people). Connections between the two are created by Aslan, to serve his purpose. So it's perfectly possible for Aslan to link somewhere in our world at any time with somewhere in Narnia at any time; there is no law that dictates that if someone from England in 1940 visits Narnia, then anyone from 1950 visiting Narnia has to do so at a later Narnian time. It could be later, or it could be earlier, or it could be exactly the same time.

One indication of this is the pirates who became the ancestors of the Telmarines. To me, it seems silly to insist that they must have come from the 1920s because they had to come after the time of Digory and Polly. Aslan's (admittedly limited) description of them conjures up in my mind a group of swashbuckling types like in the Pirates of the Caribbean films, from the late 18th or early 19th Century. So I think it's possible for them to have come from an earlier Earth time than Digory and Polly, but landed in the Narnian world at a later Narnian time.

It only becomes a problem if there is communication between the various worlds-travelling parties, in such a way that could cause a paradox. For instance, if Digory and Polly had known about the pirates disappearing into the Narnian world a hundred years before their (Earth) time, they could have told people in Narnia who could have been waiting for the pirates when they appeared and slaughtered them, meaning the Telmarines would never have existed. But those kind of paradox situations never arose.

As it happens, I'm about a third of the way through writing my own Narnia story in which two children from our world and our time (2012) arrive in Narnia at the time of Tirian's father, Erlian.

I always thought that this had something to do with the fact that as Christian children grow in height and such, they also grow in Christ Jesus.

Interesting idea, Leah. I think that Lewis definitely chose the ages he did because the Chronicles are, first and foremost, children's stories. As such, he picked ages that corresponded with the demographic he was writing for (even today, young adult fiction tends to star young adults, teen fiction teens, and naturally children star in children's books, etc.). However, he didn't limit the characters to a specific age range. Susan (12) was younger than Peter (13) when she was told she was "too old" in PC, but in turn, she was older than Lucy--who was told she couldn't come back at age 11. So there's a certain spiritual and psychological aspect to it.

I haven't thought about this in-depth, but I think that one of the main reasons that the characters are the age they are is because that was the age group C.S. was writing primarily to (though he indicated several times that he wasn't pleased with books written about and to children being written of as "immature books for kids." but thought that books that were worthwhile for adults and children were truly worthwhile books, a category where Narnia is definitely the leader, as most would agree.)
But, yes, I think it's largely because he wrote LWW for Lucy, who was a child (but he says that he fears she's too old to like fairy tales until she grows older yet, when she would enjoy them?) and also because his intended audience was children.

For the quote "when you grow, you see me larger" (paraphrased, sorry), I believe it applies to every Christian - child or adult - who, when they grow with age, they could grow more in the Lord? Not sure. I think it alludes to the fact that older Christians are mature and have grown in the Lord more, and therefore, love and know Him more.
I don't know if the age is so much physical. Sometimes it says that their purpose in Narnia or their purpose in coming to Narnia was fulfilled, so for that case, they would return to their world where they would come to know Aslan by His other Name. So perhaps it has to do with whatever purpose Aslan had when he brought them to Narnia.

Besides the fact that the book was written for children, and so since children like to read about children, it's only natural that Lewis would write about children, I think Lewis was implying that children have an easier time believing in things than adults, so Aslan would bring children into Narnia because they would have an easier time understanding it and seeing the parallels to our world. Considering the sad experience Uncle Andrew had in Narnia, I think it's quite clear what many adults' reaction would be to entering it. So I think that may have been an point he was trying to bring out.

Good point, Archer. Sort of like Matthew 18 “Assuredly, I say to you, unless you are converted and become as little children, you will by no means enter the kingdom of heaven.”

I think it's mostly because children are more likely to believe in fantastic things. Of course, there are exceptions, Archer mentioned Uncle Andrew, and it took Eustace a long time to understand that he wasn't on Earth anymore (even at the Lone Islands he expected to find a British Consul).

Elluinas Mirion, your post was highly interesting and very detailed - I learned a lot!

To the question at hand...

Point the first: Does being older bar you from entering Narnia?

Not all of Lewis's other-worldly characters in Narnia are children. Frank and Helen come to Narnia as full-grown adults and we can assume that at least some of the Telmarines did the same. Thus, it cannot be that age bars you from entering Narnia.

Point the second: Does being older determine when you must leave Narnia?

Putting aside the example of the many Telamrines who were not "evicted" from Narnia when Aslan opened the door between the worlds, let's just focus on our series stars. What we see with Aslan telling the Pevensies two at a time that they are now too old for Narnia is not an attempt to discriminate by age, but a realization that Narnia is not their home, and that too much time spent living a dream makes us miss the value of real life. We can see this based on the fact that Peter is older than Susan (I'm not certain by how much), yet Susan is sent away at the same time as he is. We see this again with Edmund and Lucy. So it cannot be the exact age of a "visitor from another world" that petains to when they must leave and not come back.

Point the third: Do all the characters from our world who enter Narnia come from the same time period?

We cannot tell what age the Telmarine pirates came from, but we can make an educated guess. They were sailing the southern seas (think Caribbean), there were natives on the island where they landed, and they killed the native males and took the women. These are practices that went on for much of the world's history, but became rare towards the beginning of the 1900s. So the Telmarines are almost certainly from the 1800s or earlier. That breaks with the theme of the 1940s-60s. It seems that travel to Narnia is not limited to one time zone in our world.