Twice a year, either side of the summer solstice, the setting sun is perfectly aligned with the grid of New York city streets. This urban phenomenon is known as the Manhattanhenge and Don DeLillo saw it once, some decades ago, while travelling crosstown at the back of a bus. He recalls the great ball of fire framed by towering buildings; the jubilant uproar of his fellow passengers; a vision of heaven at the end of 34th Street. The Manhattanhenge has haunted DeLillo ever since, and in the final pages of his latest book he unearths the scene and plays it out afresh. One last golden flourish before the endnotes.

I meet DeLillo inside a fifth floor apartment on the Upper East Side. The room is crowded with books; spring blazes outside. He has positioned himself in the corner, in the shadows, and he shakes hands in a manner that suggests he’s picking up a hot coal. His fine-boned face is winged with bushy grey sideburns; his checked shirt and chinos seem at least two sizes too big. “I’m losing my voice,” he announces by way of introduction, although I wonder if this might be a convenient excuse. DeLillo is known as a man who dislikes giving interviews, detests explaining his work. He used to carry business cards that bore the legend, “I don’t want to talk about it”. I suspect his faltering larynx is being deployed as a defensive measure. “No, no,” he insists and then gives the ghost of a smile. “It’s an offensive measure.”

Still, it’s an alarming prospect, DeLillo losing his voice. In a writing career that has spanned 50 years and 17 novels, he has made it his business to speak the language of America; to channel its tensions and pick at its scabs. He’s tackled (and in some cases anticipated) the underside of pop stardom (in Great Jones Street, his third novel, published in 1973), the dark glamour of terrorism (Mao II, 1991), the consequences of cyber-capitalism (2003’s Cosmopolis), the impact of the A-bomb (Underworld, 1997). His prose is always taut and unsparing. His best books hum like tuning forks, gathering vibrations from the culture at large. But the author turns 80 in November, and freely admits that his work rate has slowed. Tellingly, his elegiac new book, Zero K, is a story with both eyes on the exit and its mind on the afterlife. “All plots tend to move deathwards,” DeLillo wrote in his 1985 novel, White Noise. The same of course goes for the authors who write them.

Facebook Twitter Pinterest The Manhattanhenge phenomenon in New York on 11 July 2014. Photograph: Carlo Allegri/Reuters

It transpires that the apartment is the home of his agent, and it’s taking me a moment to get my bearings. The table is heaped with copies of Zero K, together with a stack of magazines that all bear the image of a grinning Donald Trump. After a brief hesitation, I place my coffee on the mags.

“Trump,” says DeLillo. “Our national hallucination.”

Let’s begin with the book, which is supple and sad and oddly compassionate too; his most fully realised work in more than a decade. Zero K chiefly plays out at a cryogenics compound in lawless Kyrgyzstan, just south of an old Soviet nuclear testing site. This, we learn, is to be the launchpad of a billionaire businessman, Ross Lockhart, and his invalid wife Artis. Both are preparing to enter pods, to be placed in deep freeze and then reawakened as pioneers in a world yet to come. Artis makes the jump because she is already dying, but Ross’s motivation is more complex and charged. He wants to control his own destiny. More than anything, perhaps, he wants to remain with his wife. “It’s pretty romantic for this kind of situation,” DeLillo explains. “It’s pretty romantic for this kind of writer.”

On setting out to write Zero K, DeLillo had no preconceptions about cryogenics per se. He says he did some research, but was generally content to be led by the story and by a central image that he couldn’t shake off: of shaved, naked sleepers inside body pods. These people are intent on projecting themselves forward to an uncertain future, on maintaining “a phantom life within the braincase” until technology catches up. But he’s not one to judge them as either noble or foolish. He was simply drawn to the subject and to the implications it raised. “That’s the direction the narrative decided to take. I simply needed to follow it.”

I don’t see the glimmer of Don DeLillo in this book, but then I’m not the best person to ask

Still, I wonder if it’s an impulse he relates to. One might argue the act of writing a novel has something in common with cryogenics. Assuming a book stays in print, it helps preserve the character of its creator; it even extends their life span, at least after a fashion. Open the pod and there’s naked Ross Lockhart. Open a copy of Ulysses and there’s James Joyce.

“That’s true,” says DeLillo. “But I never thought of my own work in those terms. Is there a glimmer of James Joyce in Ulysses? Or F Scott Fitzgerald in Tender Is the Night? Well yeah, there must be. I don’t see the glimmer of Don DeLillo in this book, but then I’m not the best person to ask. I know that other people have seen it.” Another thin smile. “People always use the word ‘identify’. ‘Do you identify with these individuals?’ And I really don’t. I can’t talk about characters outside the frame of the fiction. I identify with the words on the page. I identify with the paragraphs.”

Besides, he adds, there was a point where he was unsure whether he would even be published, let alone conceive of a time where those books might outlive him. “When you come from my situation, there’s a limitation built in.”

DeLillo was raised in the Bronx, the eldest son of immigrants recently arrived from the Abruzzi mountains of central Italy, and weaned on a linguistic jumble of Italian and English. “The Italian I heard was not standard Italian. It was dialect, so it didn’t teach me anything beyond dirty words. I spoke Bronx English. The only Italian I spoke was slang with my friends.” He says his parents spent their lives trying to understand America, to make sense of the culture they found themselves in. He accepts he might be doing a similar thing with his books.

DeLillo once said the Kennedy assassination made him a writer. What exactly did he mean by that? “Well, in the sense that it influenced me, although it probably influenced everyone. The assassination had an enormous impact, it changed everything. And all the turmoil that followed – the riots, the race problems, the violence – I think flowed from that one moment in Dallas. It was an enormous shock to the American system. It was like a bolt from outer space. Then you had the attendant question: was this done by a single individual, this lost boy Lee Harvey Oswald, or was it part of an elaborate conspiracy? And that uncertainty became a part of the environment we slept in and swam in. The sense that we were living in troubling times.”

At the time, he was working at a Manhattan ad agency, running with the Mad Men. He quit his job the following year and started navigating his first novel, Americana, which he almost abandoned along the way and was not completed and published until 1971. After that his books grew bigger, bolder, more successful. He revisited the Kennedy assassination, framing the crime through Oswald’s eyes in Libra, and rustled up a bona fide bestseller with Underworld – a tale that throws its arms wide to include baseball, the bomb and the entire sweep of cold war history; juggling real life characters (J Edgar Hoover, Frank Sinatra, Lenny Bruce) with the sights and sounds of his own New York youth. “And actually there are parts of Underworld where I feel that I’m in there somewhere,” he admits. “All those Bronx chapters. I felt I immersed myself in that novel.”

DeLillo fled his copywriting job and reinvented himself, but he may well have carried its lessons with him. He takes the flat language of ad-speak and twists it into exciting new shapes. He produces dark, diamond-sharp prose that hooks in your ear like a slogan or jingle. One might view his books as an anti-commercial for western capitalism or – more complicatedly – as a dispassionate study of how capital’s language speaks through its consumers. How culture rewires our brains and redefines our relationships. According to the literary critic Frank Lentricchia, DeLillo’s novels are “cultural anatomies of what make us unhappy”, while Joyce Carol Oates has hailed him as “a man of frightening perception”. And yet what fans regard as eerie and insightful, others have dismissed as chilly and contrived. John Updike lamented the way his characters have a habit of “spouting smart, swift essays at one another”. Reviewing DeLillo way back in 1985, the critic Bruce Bawer was still more pointed: “If you like your novels studded with Philosophy McNuggets, you’ll love White Noise.”

Actually I do love White Noise. It is a thing of black, tender brilliance; the tale of an academic who teaches a course in Hitler studies at “the College-on-the-Hill”, and of his wife, Babette, who takes an experimental drug, Dylar, to offset her fear of dying. I ask DeLillo how he came to write it, but his recollection is hazy. The rhythms and patterns appear to be all that remain. He says, “I can remember the main character’s name, which is Jack Gladney. And there was something in that name – JA for Jack and GLA for Gladney – which felt important. I’ve done the same thing in other books. I’m always very conscious of the patterns of letters in a name. Ross Lockhart isn’t a great example, but it’s RO and then LO. So it’s a thing that I do. A character takes shape because of that confluence of letters. I’m trying to think of another example. There must be others.”

How about Bucky Wunderlick, the reclusive rock singer from Great Jones Street? DeLillo nods distractedly. “BU then WU. There you go, you’re doing better than I am.”

He accepts he’s growing old. The stories don’t pour out the way they once did. Underworld was his Moby-Dick: 800 pages, more than 100 moving pieces. But since then the books have been slimmer, more spare, and less feted. He wonders if he has another Underworld in him. “I would like to think so but the truthful answer is that I doubt it. I don’t think I’d be able to do it at that length, even if I knew I was going to live long enough. I don’t know why that is. I think you become a little more closed in on yourself. A little more physically and mentally tired.”

He sighs, clears his throat and says, “The work gets slower, that’s for sure. This latest book took me nearly four years to write and it’s not even 300 pages. It’s not a burden, it’s just day-to-day. But at some point I realised I’d been sitting there for four years. Why isn’t it a bigger book?”

I ask if the joy of writing is still the same as it was and he insists that it is. “I take the same pleasure in a sentence that seems to work. Two words that seem to be joined and have a meaning. There’s a sentence in this book, for instance: 17 words and only one of them is more than one syllable. And how did that happen? It just flowed, it just happened.”

He makes the sentence sound like a magical spell. “Well, that’s not an exaggeration,” he says. “That’s exactly what it is.”

Facebook Twitter Pinterest An outdoor market in the Bronx, New York, 1945. Photograph: Bettmann Archive

A few years back the writer John Banville described DeLillo as “the poet of entropy”, adding that “the world he sets up is a tightly wound machine gradually running down”. So it’s no surprise that the poet himself should eventually wind down, although he’s enjoyed himself in the unwinding. He’s gone from the working-class Bronx to Madison Avenue, through plaudits and glory to a comfortable upstate home he shares with Barbara Bennett, his wife of 40 years. “I’ve had a very lucky life,” he says. “I’ve been a very lucky writer.”

Apropos of almost nothing, he recalls Ernest Hemingway. He’s been thinking a lot about Hemingway; he doesn’t entirely know why. He says, “Here’s a story I don’t think I’ve told before. Back in the early 1960s I was standing on 48th Street between Fifth and Madison. And there was Hemingway walking across the street. This was roughly a year before he killed himself. He was going towards Fifth Avenue and I knew that Scribner, his publisher, was right around the corner and that this was where he was going. And it was a wonderful thing to see him walk by. But what’s astonishing now is to think of Hemingway and Fitzgerald and to find myself with those guys in one of those special editions that Scribner did recently – one for each of us. And how did that happen? It’s astonishing to me.” He smiles. “Because I’m not Hemingway. I’m just a guy whose name can’t be spelled properly.”

I think he’s being overly modest. No doubt it’s the result of his background. It makes him feel an interloper in literary society, a borderline fraud playing the role of great writer.

DeLillo chuckles. “Or am I playing the role of the Italian kid from the Bronx? Which is the role? Which is reality? And in fact, more and more I think of myself as the kid from the Bronx. I’ve reached the age when that identity becomes more accessible. Once I left the Bronx I didn’t think of it much except when I was visiting my parents. But it crept back in when I was working on Underworld and now it’s returned on a whole other level.”

The form is strong enough to endure. There will be people who find that novels are the highest form of self-realisation

Maybe most people circle back towards home in the end? DeLillo nods; he’s positively enthused. “That’s true,” he says. “But I circle back literally, in that I go back to the same neighbourhood. I have a regular meal with the guys I grew up with, who now all live elsewhere. We all meet in a restaurant on Arthur Avenue, which is in the heart of the Italian Bronx. All these guys – I didn’t see them for years, but I never forgot. And when we meet, we talk about growing up. And all of us remember absolutely everything the same way. I mean that there’s no argument, it’s very strange. It’s as though the last 50 years have been …”

A happy dream? A hallucination? “A waste of time,” he says and laughs.

The author began his career in an age before home computers. He continues to tap out his books on a manual typewriter. He tells me that he is not on email and doesn’t own a mobile phone. “Sometimes it’s a real inconvenience. But it’s what I prefer. It feels unnatural for me to have all of those things.” In this way, perhaps, the artist of the moment slips into the past, becomes a revered piece of history, like Hemingway before him. And where DeLillo leads, might the American novel follow? Just possibly the thing has already had its day: a 20th-century behemoth, outpaced by rolling news and the rise of social media.

“Well, that’s certainly a reasonable idea,” DeLillo says, doubtfully. “But it’s not going to happen. People are going to keep writing novels. The form is strong enough to endure. And there will be enough other people, particularly as they get older, who find that words on a page – or words on a screen – are the highest form of self-realisation. It’s the best form to explore the human experience.”

Time is pressing; his voice is fast fading out. Evening rush hour rattles at the window. In our final moments, DeLillo returns to the subject of the Manhattanhenge. He explains that his original intention was to plant the scene in the middle of the book but then he came to realise that it was better placed at the end. He admits that he once tried to repeat the experience of seeing it for himself. He circled the date and camped out on the street, except that there were clouds in New Jersey and the sunset was ruined. In any case, he adds, such visions work best when they catch you unawares, when they stop you in your tracks. “And it was a wonderful moment. This enormous glow, like nothing you’ve seen, a concentration of light in that narrow street.” He smiles. “And you know, like most things, there and gone in a flash.”

• Zero K is published by Picador on 19 May. To order a copy for £12.99 (RRP £16.99), go to bookshop.theguardian.com or call 0330 333 6846. Free UK p&p over £10, online orders only. Phone orders min p&p of £1.99.