Aug 23, 2021 · In October of 1943, an alleged experiment took place at the Philadelphia Naval Shipyard that opened the proverbial door to time travel (via Military.com).According to legend, the USS Eldridge (DE 173) — a Cannon-class battleship used primarily to hunt and destroy enemy submarines — left our timeline in an experiment in invisibility gone wrong, per USS Slater. ... Feb 13, 2014 · While Basiago claims there were several time travel devices at work during these experiments, the majority of his temporal adventures can be attributed to our old friend Nikola Tesla. Documents, allegedly retrieved from Tesla’s New York City apartment after his death in January 1943, revealed the schematic for a teleportation machine. ... Feb 25, 2018 · The mysterious Montauk Project and its outlandish conspiracy theories. DURING the Cold War, the US is alleged to have conducted secretive military experiments on time travel and psychological warfare. ... Sep 21, 2012 · The second rumored experiment was the teleportation and small-scale time travel (with the ship sent a few seconds in the past) of the USS Eldridge from the Philadelphia Naval Shipyard to Norfolk ... ... These center on topics including United States government/military experiments in fields such as time travel, teleportation, mind control, contact with extraterrestrial life, and staging faked Apollo Moon landings, framed as developments that followed the 1943 Philadelphia Experiment. ... May 10, 2017 · According to popular legend, in 1943, the US Navy undertook secret experiments based out of the port of Philadelphia. These experiments were designed to put Einstein’s unified field theory to practical use by making a naval ship invisible. While conspiracy theorists debate the existence of the Philadelphia Experiment, one alleged survivor of the scientific outing, […] ... Oct 9, 2014 · Time travel is real, though. In a way, the astronauts on board the International Space Station time travel every day, albeit by a few microseconds. The principles of relativity and the very nature ... ... Jan 1, 2020 · US astrophysicist Ron Mallett has spent decades trying to crack the mystery of time travel in the hope of revisiting his past. He thinks he’s figured out the science that would make it possible. ... May 29, 2024 · l €ªªªêÿn— § @œÂ\Í—ˆð 75€„ˆH€HØÀÝ 2!!!ACMÂU"UÕ4MÅÝ" |Ým}ß•ÿÅ a€a Û Ãc ç˜!.ˆ þ¯Û _ v?¿=ÁK ]Õz‰ Á¦ƒQ”êýVÁ [ŠQi¨ßŠê*h=Ù¾«–H I,œ ... ... Sep 2, 2014 · It was, he said, "a welcome reception for future time travelers," a tongue-in-cheek experiment to reinforce his 1992 conjecture that travel into the past is effectively impossible. But Hawking may ... ... ">

What We Know About The CIA's Alleged Secret Time Travel Program

the cia

In October of 1943, an alleged experiment took place at the Philadelphia Naval Shipyard that opened the proverbial door to time travel (via Military.com ). According to legend, the USS Eldridge (DE 173) — a Cannon-class battleship used primarily to hunt and destroy enemy submarines — left our timeline in an experiment in invisibility gone wrong, per USS Slater . Part of a CIA research project known as Project Rainbow , the alleged incident with the USS Eldridge at the Philadelphia Naval Yard has become unofficially known as "the Philadelphia Experiment," per  The Guardian .

In an effort to put an end to World War II, the story says that the U.S. military began experimenting with ways to end the dragging world war in the quickest, most efficient manner. One of the ideas floating around was the idea of cloaking — or making invisible to radar — battleships. Using a device called a "time zero generator," the military attempted to do just that, per  The Guardian . What allegedly happened, however, was completely unexpected.

Where did they go?

naval vessel

On October 28, 1943, the switch was allegedly thrown on the time zero generator. Eyewitness' claim to have seen the USS Eldridge suddenly begin to glow in a green-blue haze that surrounded the vessel (via Military.com ). The Eldridge began to fade, leaving just the outline of the ship remaining. And with that, the ship blinked out of existence, according to The Guardian . Time slowly ticked by. No one knew exactly what happened to the ship or where it went. After a long 20 minutes, the Eldridge reappeared, but with horrifying results. Much of the vessel was on fire, members of the crew — who allegedly left our reality along with the ship — were found insane. And those were the lucky ones. Reports swirl that many crew members of the Eldridge had "fused" with the ship upon its return to our reality; torsos, limbs, and other miscellaneous body parts were found amalgamated into the ship's steel hull.

A hoax or horrifying accident

time travel

According to the surviving members of the ship's crew, during the vessel's alleged 20-minute disappearance, the ship seemingly re-appeared 600 miles away in Newport News, located in Virginia. Of course,  The Guardian  calls the story "hokum" concocted by UFO enthusiast Carl Allen. And with no real concrete proof of the event ever taking place, the U.S. Navy outright denies the Philadelphia Experiment ever happened. 

Nevertheless, the USS Eldridge did exist — sold off to Greece in 1951 and finally decommissioned and sold for scrap in the '90s — and Project Rainbow did occur. But the Office of Naval Research (ONR) stated that force fields to make a ship invisible don't "conform to known physical laws" (via the Black Vault ).  Coupled with the fact that there are no official documents, military or otherwise about the event, it's very well likely the story of the Philadelphia Experiment is likely to remain just that ... a story.

Recommended

The Time Travel Experiments Of Project Pegasus

Illustration of a pegasus flying through a wormhole

I’ve often mentioned Project Pegasus , but we’ve never really talked about it, you know? So sit back, relax, mix yourself a cool Pan Galactic Gargle Blaster. Or don’t, because reading this will probably give you the same effect. *

In 2004, Washington-based attorney Andrew D. Basiago began telling his story of a top-secret organization called Project Pegasus. Although he was only seven years old at the time, Basiago claims he had, from 1968 to 1972, participated in a number of bizarre experiments that took him on journeys through time, space, and potentially into parallel universes.

“Project Pegasus was the classified, defense-related research and development program under the Defense Advanced Research Projects Agency (DARPA) in which the US defense-technical community achieved time travel on behalf of the US government – the real Philadelphia Experiment.” – Project Pegasus Mission Statement

The mission of Project Pegasus was to study the effects of time travel and teleportation on children, as well as to relay important information about past and future events “to the US President, intelligence community, and military.”

The project, or so the story goes, involved a total of 140 children who would go on to become “America’s first generation of chrononauts.” According to Basiago, children were recruited specifically for their ability to adapt “to the strains of moving between past, present and future.”

While Basiago claims there were several time travel devices at work during these experiments, the majority of his temporal adventures can be attributed to our old friend Nikola Tesla.

Documents, allegedly retrieved from Tesla’s New York City apartment after his death in January 1943, revealed the schematic for a teleportation machine. Using something Basiago calls “radiant energy,” the machine would form a “shimmering curtain” between two elliptical booms.

“Radiant energy is a form of energy that Tesla discovered that is latent and pervasive in the universe and has among its properties the capacity to bend time-space.” – Andrew Basiago

Passing through this curtain of energy, Basiago would enter a “vortal tunnel” that would send him to his destination. The other teleportation devices included a “plasma confinement chamber” in New Jersey and a “jump room” in El Segundo, California. There was also some kind of “holographic technology,” which allowed them to travel “both physically and virtually.”

They weren’t always safe, though. According to the Huffington Post, one of Basiago’s cohorts, Alfred Webre, recalls one instance in which a child returned from his temporal voyage before his legs . As he puts it, “He was writhing in pain with just stumps where his legs had been.” These bugs, according Webre, have been ironed out in the 40 or so years since the experiments began.

As for his own trips, Basiago described traveling through the vortal tunnels as a rough and turbulent experience.

Through Time And Space

A photo taken during the Gettysburg Address, with a boy standing at center left

So where did Basiago travel during these experiments?

Several of his voyages led him to the 1800s. On one occasion, he found himself at Gettysburg on November 19, 1863, the day President Abraham Lincoln gave his famous Gettysburg address.

As Basiago tells the story, he had been dressed up as a “Union bugle boy.” However, he felt that his over-sized shoes were drawing too much attention, so he wandered away from the crowd, only to be photographed (as you can see in the alleged photo up there, blue arrows added). I go into more detail about this peculiar photograph here .

Basiago also traveled to the Ford Theatre on the evening President Lincoln was assassinated. In fact, he did so multiple times, even running into himself twice, though he never actually witnessed the assassination.

Each trip, he says, was slightly different than the last, leading Basiago to believe that it wasn’t just time travel at work; he was being sent into “slightly different alternative realities on adjacent timelines.”

Journeys To Mars

Finally, let’s not forget Basiago’s trips to Mars .

In the 1980s, while working under Project Pegasus, he utilized the aforementioned “jump room” to teleport to the Red Planet, with the express mission of acting as an ambassador to the Martian civilization. His fellow travelers? William Stillings and President Barack Obama, among a number of others.

During his escapades to the Red Planet, Basiago claims he encountered many extraordinary things, not the least of which were towering dinosaurs and what he described as humanoid “scorpion men.” In fact, according to Basiago, the roaming Martian dinosaurs were known to devour any humans who found themselves lost on the planet’s surface.

Indeed, to hear Basiago tell it, Project Pegasus revealed Mars to be an extraordinary and dangerous place.

A Planetary Impact?

Today, the “new” Project Pegasus, with Andrew D. Basiago himself positioned as team leader, is apparently campaigning for the United States government to publicly disclose its teleportation technology. They believe this would benefit humanity as a whole, and make transportation both on Earth and throughout the cosmos instantaneous and environment-friendly. Or something like that.

At any rate, Basiago’s story is far from over. While the Web Bot’s prediction in 2009 that he would “make a [planetary impact]” as a government whistle blower never really came to pass, he’s got some new plans. Namely, he intends to run for President of the United States. He first attempted this in 2016:

“In 2016, Andrew D. Basiago will be a candidate for President of the United States under the banner Andy 2016 – A Time for Truth.”

Their promise: To “lead the American people into a bold, new era of Truth, Reform, and innovation as great as they are great.”

To be honest, at this point I’m not entirely opposed to the idea.

* The Pan Galactic Gargle Blaster is a beverage invented by ex-President of the Universe Zaphod Beeblebrox. Drinking a Pan Galactic Gargle Blaster is said to be very much “like having your brains smashed out by a slice of lemon, wrapped ’round a large gold brick.”

Photo of Rob Schwarz

Rob Schwarz

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Know Before You Go

The Incredible Story of Al Bielek, the Man Who Traveled Through Time and Space

May 10, 2017 by Justin Andress View All On 1 Page

According to popular legend, in 1943, the US Navy undertook secret experiments based out of the port of Philadelphia. These experiments were designed to put Einstein’s unified field theory to practical use by making a naval ship invisible. While conspiracy theorists debate the existence of the Philadelphia Experiment, one alleged survivor of the scientific outing, Al Bielek, maintained that the Navy’s purpose was entirely different. According to Bielek, the true purpose of the Philadelphia Experiment wasn’t invisibility, it was time travel.

In 1990, Bielek claimed that he spent time in two separate periods of the future only to return to the present and tell his story. And that was just the beginning of the fantastic revelations of this totally, completely, absolutely, one hundred percent not fake time traveler. As if someone would make that up anyway.

Bielek

1. A Peculiar Child

A peculiar child by his own words, Al Bielek was born in 1927 to an otherwise wholesome family. He says his first memory came at a Christmas party when he was just nine months old. He found he was able to fully understand the adults talking in the room around him. Growing up, he says he was known as a “walking encyclopedia,” easily distinguishing himself among his classmates.

A Brief History of Scientists Hunting for Time Travelers

Adam Clark Estes

Time travel is possible—or at least a lot of serious physicists say so . It’s probably not possible to pull it off in a souped-up Delorean, but there are wormholes, Tipler cylinders, and other Einstein-inspired theories for how it could work. Which raises the question: Why haven’t we met any visitors from another time?

It sounds like a silly question, but it’s one that many scientists actually take very seriously. Meeting someone from the future would, of course, serve as definitive proof that we can indeed travel through time, and that would be a quite a simple way to solve a huge scientific riddle. So it’s no surprise that a handful of enthusiasts and experts have staged experiments in order to attract the time travelers that could be hiding among us.

One of them is Stephen Hawking. The renowned physicist totally believes time travel is a scientific possibility , and even says he knows how to build a time machine . He also famously wondered, “If time travel is possible, where are the tourists from the future?” It’s a good question. Here’s how we’ve tried to answer it.

Why we think time travel is possible

Time travel’s been one of man’s wildest fantasies for centuries. But in the last century scientists came up with theories that suggested it was indeed plausible to take a leap into the future. Going back in time, unfortunately, is much more complicated .

According to Einstein’s theory of general relativity, a wormhole could act like a bridge through space-time by connecting two distant points with a shortcut. Certain types of wormholes, it’s theorized, could allow for time travel in either direction, but there are several major caveats of traveling back in time. Mainly, the simple fact that we’d need a method for creating wormholes, and once created, the wormhole would only allow us to travel as far back as the point in time when it was created.

Another option for time travel involves a phenomenon called time dilation , also based on Einstein’s theories of relativity. It refers to the idea that time passes more slowly for a moving clock than it does for a stationary clock. The force of gravity also effects the difference in elapsed time. Thanks to the space program, we’ve actually been dealing with this effect for many years. This is why the clocks on the International Space Station tick just a little bit more slowly than clocks on Earth do.

us time travel experiments

Once again, we don’t really know. And we won’t really know exactly how that works until we try it, and at the moment, we don’t really have the means to do that. One easy way to find out is simply to search for time travelers walking amongst us. No laboratory required! And that’s exactly what several zany scientists have done.

The party approach

One of the earliest well-publicized attempts at finding time travelers was hardly scientific. (I’ll get back to the real scientists in a second, I promise.) It happened in the early 80s, when computers and consumer electronics started merging science and science fiction in fascinating ways. It was also when the first space shuttle, Columbia, blasted off. These sorts of things got people thinking.

A group of artist types in Baltimore acted on these curiosities in 1982 with an event The New York Times described as “an epidemic of temporary lunacy.” In March of that year, all nine planets were as close together as they’d been in almost 200 years, and a group that called themselves Krononauts gathered together to welcome “visitors from the futures.” The Times reports, “The Krononauts drank, danced, and after midnight some of them took off their clothes.” No time travelers actually showed up, but it sounds like everybody had fun.

Fast forward 30 years and a similar—although simultaneously entirely different—party took place in Cambridge, England. This time the ringleader was not a wild pack of twentysomethings but Stephen Hawking himself.

Hawking’s party was wonderfully deliberate. There was champagne and snacks in a fancy room at Cambridge University, where a banner had been hung: “Welcome Time Travellers.” Hawking had always suggested that time traveling tourists could be proof that time travel was possible, so he invited only them. Nobody showed up.

It’s hard to tell how tongue-in-cheek Hawking’s futurefest was supposed to be. On one hand, Hawking believes time travel is feasible, so he wasn’t necessarily laughing at the idea. He might’ve even expected someone to come. But, in Hawking’s words, “There’s a twist.” The sneaky scientist didn’t tell anybody about the party until after it happened. Somebody in the future would have to find out about the event after the fact and hop in a time machine in order to hang out with the famous physicist.

Still, there’s a good chance that Hawking was just trying to prove a point. As his friend and contemporary Kip Thorne explains in his book Black Holes and Time Warps , one of the most feasible methods for building a time machine would involve creating and manipulating wormholes . But this would only allow people in the future to travel back as far as the invention of the time machine itself. So if this is indeed how we might build a time machine and we haven’t built it yet, it would be impossible for people from the future to travel back to Hawking’s party.

The convention approach

A few years before Hawking’s party, an ambitious MIT grad student tried a similar but nerdier approach. Instead of keeping the event a secret, Amal Dorai organized a whole convention about time travel and encouraged everybody to spread the world. Dorai wrote on his student website :

We need volunteers to publish the details of the convention in enduring forms, so that the time travelers of future millennia will be aware of the convention. This convention can never be forgotten! We need publicity in MAJOR outlets, not just Internet news. Think New York Times, Washington Post, books, that sort of thing. If you have any strings, please pull them.

Dreams do come true. The New York Times did publish a report . NPR’s All Things Considered did a segment on the convention. Wired wrote a story . Heck, even Tina Fey made fun of it on Saturday Night Live.

The exposure makes pretty good sense. MIT is a famous university that tends to attract media attention anyway. The program was also filled with famous professors talking about time travel. And the premise itself, well, it makes for a pretty fun headline!

It still didn’t work. “The convention was a mixed success,” Dodai said in an update to the event website. “Unfortunately, we had no confirmed time travelers visit us, yet many time travelers could have attended incognito to avoid endless questions about the future.” A similar sort of event happened around the same time in Perth, Australia, to the same disappointing end.

Now, one could argue that Dodai simply underestimated the power of the internet. It would’ve been hard to tell in 2005, when the convention went down, but the internet won the war against print. Dodai discouraged everyone from publicizing on the internet, because, in his words, “The World Wide Web is unlikely to remain in its present form permanently.” It’s still ticking in 2014.

There’s probably a simpler explanation. It’s the one the MIT physicists came up with, and the same one Hawking suggested: If we eventually discover a particular way to build a time machine that works, people would only be able to travel as far back as when the time machine was built.

The academic approach

You can probably already tell how this one’s going to end. Earlier this year, a pair of physicists published the results of a pretty self-explanatory study, “ Searching the Internet for evidence of time travelers .” Instead of staging some sort of event and counting on publicity to attract the people of the future, these scientists went on the hunt for evidence of where time travelers had been online. In a sense, they were searching for their digital footprints.

Robert Nemiroff and Teresa Wilson from Michigan Technological University cast their net wide . They searched Twitter. They searched Facebook. They searched Google, Google+, and even Bing. But they came up short. Between January 2006 and September 2013, they couldn’t find a single mention of two terms from the future that people would not have known during that time. None.

It was a good effort. However, given the constraints of the experiment, they ended up searching for a very specific sort of time traveler. Why would that individual be doing putting words from the future on the internet? “A time traveller might have been trying to collect historical information that did not survive into the future, or might have searched for a prescient term because they erroneously thought that a given event had already occurred, or searched to see whether a given event was yet to occur,” the paper explains.

That’s a little bit silly, then, isn’t it. It’s no less silly than throwing a party without inviting anyone or hosting a convention celebrating technology that did not yet exist. No wonder these kinds of events ended up being fodder for sketch comedy shows.

The fact of the matter

All that said, there does seem to be a pretty concrete takeaway that’s rooted in some widely accepted ideas from theoretical physics. We have not yet invented a time machine. If and when we do, we’ll enter a new era of time travel. We will not, however be able to go any further back in time than when that machine was built.

That’s all assuming that this hypothetical time machine can actually go back in time. Again, that’s really difficult.

Time travel is real, though. In a way, the astronauts on board the International Space Station time travel every day, albeit by a few microseconds . The principles of relativity and the very nature of space-time make it possible. So if you really want to meet a time traveler, look no further than your friendly neighborhood astronaut.

us time travel experiments

Physics Science Space Stephen Hawking

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Advertisement

Quantum time travel: The experiment to 'send a particle into the past'

Time loops have long been the stuff of science fiction. Now, using the rules of quantum mechanics, we have a way to effectively transport a particle back in time – here’s how

By Miriam Frankel

29 May 2024

New Scientist. Science news and long reads from expert journalists, covering developments in science, technology, health and the environment on the website and the magazine.

Ryan wills/istock/Amtitus

When Seth Lloyd first published his ideas about quantum time loops, he hadn’t considered all the consequences. For one thing, he hadn’t anticipated the countless emails he would get from would-be time travellers asking for his help. If he could have his time over again, he jokes, he “probably wouldn’t have done it”.

Sadly, Lloyd, a physicist at the Massachusetts Institute of Technology, won’t be revisiting years gone by. Spoiler alert: no one will go back in time during the course of this article. But particles? That is another matter.

Theoretical routes to the past called time loops have long been hypothesised by physicists. But because they are plagued by impracticalities and paradoxes, they have been dismissed as impossible for just as long. But now Lloyd and other physicists have begun to show that in the quantum realm, these loops to the past are not only possible, but even experimentally feasible. In other words, we will soon effectively try to send a particle back in time.

Rethinking reality: Is the entire universe a single quantum object?

If that succeeds, it raises the possibility of being able to dispatch, if not people, then at least messages in the form of quantum signals, back in time. More importantly, studying this phenomenon takes us to the heart of how cause and effect really work, what quantum theory means and perhaps even how we can create a successor theory that more fully captures the true nature of reality.

In physics, time loops are more properly known as closed time-like curves (CTCs). They first arose in Albert Einstein’s theory of general relativity…

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September 2, 2014

Time Travel Simulation Resolves “Grandfather Paradox”

What would happen to you if you went back in time and killed your grandfather? A model using photons reveals that quantum mechanics can solve the quandary—and even foil quantum cryptography

By Lee Billings

On June 28, 2009, the world-famous physicist Stephen Hawking threw a party at the University of Cambridge, complete with balloons, hors d'oeuvres and iced champagne. Everyone was invited but no one showed up. Hawking had expected as much, because he only sent out invitations after his party had concluded. It was, he said, "a welcome reception for future time travelers," a tongue-in-cheek experiment to reinforce his 1992 conjecture that travel into the past is effectively impossible.

But Hawking may be on the wrong side of history. Recent experiments offer tentative support for time travel's feasibility—at least from a mathematical perspective. The study cuts to the core of our understanding of the universe, and the resolution of the possibility of time travel, far from being a topic worthy only of science fiction, would have profound implications for fundamental physics as well as for practical applications such as quantum cryptography and computing.

Closed timelike curves The source of time travel speculation lies in the fact that our best physical theories seem to contain no prohibitions on traveling backward through time. The feat should be possible based on Einstein's theory of general relativity, which describes gravity as the warping of spacetime by energy and matter. An extremely powerful gravitational field, such as that produced by a spinning black hole, could in principle profoundly warp the fabric of existence so that spacetime bends back on itself. This would create a "closed timelike curve," or CTC, a loop that could be traversed to travel back in time.

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Hawking and many other physicists find CTCs abhorrent, because any macroscopic object traveling through one would inevitably create paradoxes where cause and effect break down. In a model proposed by the theorist David Deutsch in 1991, however, the paradoxes created by CTCs could be avoided at the quantum scale because of the behavior of fundamental particles, which follow only the fuzzy rules of probability rather than strict determinism. "It's intriguing that you've got general relativity predicting these paradoxes, but then you consider them in quantum mechanical terms and the paradoxes go away," says University of Queensland physicist Tim Ralph. "It makes you wonder whether this is important in terms of formulating a theory that unifies general relativity with quantum mechanics."

Experimenting with a curve Recently Ralph and his PhD student Martin Ringbauer led a team that experimentally simulated Deutsch's model of CTCs for the very first time, testing and confirming many aspects of the two-decades-old theory. Their findings are published in Nature Communications. Much of their simulation revolved around investigating how Deutsch's model deals with the “grandfather paradox,” a hypothetical scenario in which someone uses a CTC to travel back through time to murder her own grandfather, thus preventing her own later birth. ( Scientific American is part of Nature Publishing Group.)

Deutsch's quantum solution to the grandfather paradox works something like this:

Instead of a human being traversing a CTC to kill her ancestor, imagine that a fundamental particle goes back in time to flip a switch on the particle-generating machine that created it. If the particle flips the switch, the machine emits a particle— the particle—back into the CTC; if the switch isn't flipped, the machine emits nothing. In this scenario there is no a priori deterministic certainty to the particle's emission, only a distribution of probabilities. Deutsch's insight was to postulate self-consistency in the quantum realm, to insist that any particle entering one end of a CTC must emerge at the other end with identical properties. Therefore, a particle emitted by the machine with a probability of one half would enter the CTC and come out the other end to flip the switch with a probability of one half, imbuing itself at birth with a probability of one half of going back to flip the switch. If the particle were a person, she would be born with a one-half probability of killing her grandfather, giving her grandfather a one-half probability of escaping death at her hands—good enough in probabilistic terms to close the causative loop and escape the paradox. Strange though it may be, this solution is in keeping with the known laws of quantum mechanics.

In their new simulation Ralph, Ringbauer and their colleagues studied Deutsch's model using interactions between pairs of polarized photons within a quantum system that they argue is mathematically equivalent to a single photon traversing a CTC. "We encode their polarization so that the second one acts as kind of a past incarnation of the first,” Ringbauer says. So instead of sending a person through a time loop, they created a stunt double of the person and ran him through a time-loop simulator to see if the doppelganger emerging from a CTC exactly resembled the original person as he was in that moment in the past.

By measuring the polarization states of the second photon after its interaction with the first, across multiple trials the team successfully demonstrated Deutsch's self-consistency in action. "The state we got at our output, the second photon at the simulated exit of the CTC, was the same as that of our input, the first encoded photon at the CTC entrance," Ralph says. "Of course, we're not really sending anything back in time but [the simulation] allows us to study weird evolutions normally not allowed in quantum mechanics."

Those "weird evolutions" enabled by a CTC, Ringbauer notes, would have remarkable practical applications, such as breaking quantum-based cryptography through the cloning of the quantum states of fundamental particles. "If you can clone quantum states,” he says, “you can violate the Heisenberg uncertainty principle,” which comes in handy in quantum cryptography because the principle forbids simultaneously accurate measurements of certain kinds of paired variables, such as position and momentum. "But if you clone that system, you can measure one quantity in the first and the other quantity in the second, allowing you to decrypt an encoded message."

"In the presence of CTCs, quantum mechanics allows one to perform very powerful information-processing tasks, much more than we believe classical or even normal quantum computers could do," says Todd Brun, a physicist at the University of Southern California who was not involved with the team's experiment. "If the Deutsch model is correct, then this experiment faithfully simulates what could be done with an actual CTC. But this experiment cannot test the Deutsch model itself; that could only be done with access to an actual CTC."

Alternative reasoning Deutsch's model isn’t the only one around, however. In 2009 Seth Lloyd, a theorist at Massachusetts Institute of Technology, proposed an alternative , less radical model of CTCs that resolves the grandfather paradox using quantum teleportation and a technique called post-selection, rather than Deutsch's quantum self-consistency. With Canadian collaborators, Lloyd went on to perform successful laboratory simulations of his model in 2011. "Deutsch's theory has a weird effect of destroying correlations," Lloyd says. "That is, a time traveler who emerges from a Deutschian CTC enters a universe that has nothing to do with the one she exited in the future. By contrast, post-selected CTCs preserve correlations, so that the time traveler returns to the same universe that she remembers in the past."

This property of Lloyd's model would make CTCs much less powerful for information processing, although still far superior to what computers could achieve in typical regions of spacetime. "The classes of problems our CTCs could help solve are roughly equivalent to finding needles in haystacks," Lloyd says. "But a computer in a Deutschian CTC could solve why haystacks exist in the first place.”

Lloyd, though, readily admits the speculative nature of CTCs. “I have no idea which model is really right. Probably both of them are wrong,” he says. Of course, he adds, the other possibility is that Hawking is correct, “that CTCs simply don't and cannot exist." Time-travel party planners should save the champagne for themselves—their hoped-for future guests seem unlikely to arrive.

The Quantum Physics of Time Travel   (All-Access Subscribers Only) By David Deutsch and Michael Lockwood

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COMMENTS

  1. What We Know About The CIA's Alleged Secret Time Travel ...

    Aug 23, 2021 · In October of 1943, an alleged experiment took place at the Philadelphia Naval Shipyard that opened the proverbial door to time travel (via Military.com).According to legend, the USS Eldridge (DE 173) — a Cannon-class battleship used primarily to hunt and destroy enemy submarines — left our timeline in an experiment in invisibility gone wrong, per USS Slater.

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    Feb 13, 2014 · While Basiago claims there were several time travel devices at work during these experiments, the majority of his temporal adventures can be attributed to our old friend Nikola Tesla. Documents, allegedly retrieved from Tesla’s New York City apartment after his death in January 1943, revealed the schematic for a teleportation machine.

  3. Did the US government successfully experiment with time travel?

    Feb 25, 2018 · The mysterious Montauk Project and its outlandish conspiracy theories. DURING the Cold War, the US is alleged to have conducted secretive military experiments on time travel and psychological warfare.

  4. What really happened during the Philadelphia Experiment?

    Sep 21, 2012 · The second rumored experiment was the teleportation and small-scale time travel (with the ship sent a few seconds in the past) of the USS Eldridge from the Philadelphia Naval Shipyard to Norfolk ...

  5. Montauk Project - Wikipedia

    These center on topics including United States government/military experiments in fields such as time travel, teleportation, mind control, contact with extraterrestrial life, and staging faked Apollo Moon landings, framed as developments that followed the 1943 Philadelphia Experiment.

  6. The Incredible Story of Al Bielek, the Man Who Traveled ...

    May 10, 2017 · According to popular legend, in 1943, the US Navy undertook secret experiments based out of the port of Philadelphia. These experiments were designed to put Einstein’s unified field theory to practical use by making a naval ship invisible. While conspiracy theorists debate the existence of the Philadelphia Experiment, one alleged survivor of the scientific outing, […]

  7. A Brief History of Scientists Hunting for Time Travelers

    Oct 9, 2014 · Time travel is real, though. In a way, the astronauts on board the International Space Station time travel every day, albeit by a few microseconds. The principles of relativity and the very nature ...

  8. Meet the scientist trying to travel back in time - CNN

    Jan 1, 2020 · US astrophysicist Ron Mallett has spent decades trying to crack the mystery of time travel in the hope of revisiting his past. He thinks he’s figured out the science that would make it possible.

  9. Quantum time travel: The experiment to 'send a particle into ...

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  10. Time Travel Simulation Resolves “Grandfather Paradox”

    Sep 2, 2014 · It was, he said, "a welcome reception for future time travelers," a tongue-in-cheek experiment to reinforce his 1992 conjecture that travel into the past is effectively impossible. But Hawking may ...