Wormholes are a popular feature in science fiction, the means through which spacecraft can achieve faster-than-light (FTL) travel and instantaneously move from one point in spacetime to another.

And while the General Theory of Relativity forbids the existence of "traversable wormholes", recent research has shown that they are actually possible within the domain of quantum physics.

The only downsides are that they would actually take longer to traverse than normal space and/or likely be microscopic.

In a new study performed by a pair of Ivy League scientists, the existence of physics beyond the Standard Model could mean that there are wormholes out there that are not only large enough to be traversable, but entirely safe for human travelers looking to get from point A to point B.

The study, titled "Humanly traversable wormholes," was conducted by Juan Maldacena (the Carl P. Feinberg Professor of theoretical physics from the Institute of Advanced Study) and Alexey Milekhin, a graduate of astrophysics student at Princeton University. The pair have written extensively on the subject of wormholes in the past and how they could be a means for traveling safely through space.

The theory regarding wormholes emerged in the early 20th century in response to Einstein's General Theory of Relativity. The first to postulate their existence was Karl Schwarzschild, a German physicist and astronomer whose solutions to Einstein's field equation (the Schwarzschild metric) resulted in the first theoretical basis for the existence of black holes.

A consequence of the Schwarzschild metric was what he referred to as "eternal black holes," which were essentially connections between different points in spacetime. However, these Schwarzschild wormholes (aka. Einstein–Rosen bridges) were not stable as they would collapse too quickly for anything to cross from one end to the other.

As Maldacena and Milekhin explained to Universe Today via email, traversable wormholes require special circumstances in order to exist. This includes the existence of negative energy, which is not permissible in classic physics – but is possible within the realm of quantum physics.

A good example of this, they claim, is the Casimir Effect, where quantum fields produce negative energy while propagating along a closed circle:

"However, this effect is typically small because it is quantum. In our previous paper ["Traversable wormholes in four dimensions"] we realized that this effect can become considerable for black holes with large magnetic charge. The new idea was to use special properties of charged massless fermions (particles like the electron but with zero mass). For a magnetically charged black hole these travel along the magnetic field lines (In a way similar to how the charged particles of the solar wind create the auroras near the polar regions of the Earth)."

The fact that these particles can travel in a circle by entering one spot and emerging where they started in ambient flat space, implies that the "vacuum energy" is modified and can be negative.

The presence of this negative energy can support the existence of a stable wormhole, a bridge between points in spacetime that won't collapse before something has a chance to traverse it.

Such wormholes are possible based on matter that is part of the Standard Model of particle physics. The only problem is, these wormholes would have to be microscopic in size and would only exist over very small distances.

For human travel, the wormholes would have to be large, which requires that physics beyond the Standard Model be employed.

For Maldacena and Milekhin, this is where the Randall-Sundrum II model (aka. 5-dimensional warped geometry theory) comes into play. Named after theoretical physicists Lisa Randall and Raman Sundrum, this model describes the Universe in terms of five-dimensions and was originally proposed to solve a hierarchy problem in particle physics.

"The Randall-Sundrom II model was based on the realization that this five-dimensional spacetime could also be describing physics at lower energies than the ones we usually explore, but that it would have escaped detection because it couples with our matter only through gravity. In fact, its physics is similar to adding many strongly interacting massless fields to the known physics. And for this reason it can give rise to the required negative energy."

From the outside, Maldacena and Milekhin concluded that these wormholes would resemble intermediately-sized, charged black holes that would generate similarly-powerful tidal forces that spacecraft would need to be wary of. To do that, they claim, a potential traveler would need a very large boost factor as they pass through the center of the wormhole.

Assuming that can be done, the question remains of whether or not these wormholes could act as a shortcut between two points in spacetime? As noted, previous research by Daniel Jafferis of Harvard University (which also considered the work of Einstein and Nathan Rosen) showed that while possible, stable wormholes would actually take longer to traverse than normal space.

According to Maldacena and Milekhin's work, however, their wormholes would take almost no time to traverse from the perspective of the traveler. From the perspective of an outsider, the travel time would be much longer, which is consistent with General Relativity – where people traveling close to the speed of light will experience time dilation (i.e. time slows down). As Maldacena and Milekhin put it:

"]F]or astronauts going through the wormhole it would take only 1 second of their time to travel 10,000 light-year distance (approximately 5000 billion miles or 1/10 of Milky Way size). An observer who does not go through the wormhole and stays outside sees them taking more than 10,000 years. And all this with no use of fuel, since the gravity accelerates and decelerates the spaceship."

Artist illustration of a spacecraft passing through a wormhole to a distant galaxy. (NASA)

Another bonus is that traversing these wormholes could be done without the use of fuel since the gravitational force of the wormhole itself would accelerate and decelerates the spaceship. In a space exploration scenario, a pilot would need to navigate the tidal forces of the wormhole to position their spacecraft just right, and then let nature do the rest.

A second later, they would emerge on the other side of the galaxy!

While this might sound encouraging to those who think wormholes could be a means of space travel someday, Maldacena and Milekhin's work presents some significant drawbacks as well.

For starters, they emphasize that traversable wormholes would have to be engineered using negative mass since no plausible mechanism exists for natural formation.

While this is possible (at least in theory), the necessary spacetime configurations would need to be present beforehand. Even so, the mass and size involved are so great that the task would be beyond any practical technology we can foresee. Second, these wormholes would only be safe if space were cold and flat, which is not the case beyond the Randall Sundrum II model.

On top of all that, any object that enters the wormhole would be accelerated and even the presence of pervasive cosmic background radiation would be a significant hazard.

However, Maldacena and Milekhin emphasize that their study was conducted for the purpose of showing that traversable wormholes can exist as a result of the "subtle interplay between general relativity and quantum physics."

In short, wormholes are not likely to become a practical way to travel through space – at least, not in any way that's foreseeable. Perhaps they would not be beyond a Kardashev Type II or Type III civilization, but that's just speculation. Even so, knowing that a major element in science fiction is not beyond the realm of possibility is certainly encouraging!

**This article was originally published by Universe Today. Read the original article.**

## FAQs

### Would it be possible to go through a wormhole? ›

"The jury is not in, so we just don't know," physicist Kip Thorne, one of the world's leading authorities on relativity, black holes and wormholes, told Space.com. "But **there are very strong indications that wormholes that a human could travel through are forbidden by the laws of physics**.

**What is the wormhole theory of relativity? ›**

wormhole, solution of the field equations in German-born physicist Albert Einstein's theory of general relativity that resembles a tunnel between two black holes or other points in space-time. Such a tunnel would provide a shortcut between its end points.

**Do wormholes violate relativity? ›**

Science fiction wormhole: travel time is shorter than d. → would allow faster than light travel, or travel to the past. They would violate the principle that signals cannot propagate faster than light in the ambient space. **We would have a violation of the principle on which special relativity rests.**

**Can we theoretically create a wormhole? ›**

**To create a wormhole on Earth, we'd first need a black hole**. This is problematic: creating a black hole just a centimetre across would require crushing a mass roughly equal to that of the Earth down to this tiny size. Plus, in the 1960s theorists showed that wormholes would be incredibly unstable.

**What would happen if you go through a wormhole? ›**

This process of growth and contraction happens so fast that not even light makes it through the tunnel, and an astronaut trying to pass through would encounter a singularity. That's sudden death, as the immense gravitational forces would rip the traveler apart.

**Has a wormhole ever been opened? ›**

Wormholes are permitted by Einstein's theory of relativity, but **none have ever been found in nature**. Recently, physicists have been toying with the idea that wormholes are related to another phenomenon, known as entanglement. Entanglement is a peculiar, quantum phenomenon involving particles.

**Do black holes break the theory of relativity? ›**

General relativity says that matter warps space and time; black holes are simply very dense agglomerations of matter. But simple **it isn't**. General relativity's equations fail catastrophically at a black hole's centre, known as its singularity, where the warping of space-time simply goes off the scale.

**What is the black hole theory? ›**

The idea of an object in space so massive and dense that light could not escape it has been around for centuries. Most famously, black holes were predicted by **Einstein's theory of general relativity**, which showed that when a massive star dies, it leaves behind a small, dense remnant core.

**Is wormhole a paradox? ›**

Known as the “**wormhole growth paradox**”, it occurs because while the volume of a wormhole grows for a very long time (depending exponentially on the size of the patch), the boundary seems to settle into equilibrium much more quickly.

**Are wormholes still theoretical? ›**

Wormholes are consistent with the general theory of relativity, but **whether wormholes actually exist remains to be seen**.

### Do wormholes allow time travel to the past? ›

A wormhole can connect two very distant points in space, such as two stars, enabling quick travel between them without the limitation of the speed of light. **It can also connect two points in time, potentially enabling travellers to go back in time**. This is called a wormhole time machine.

**Is there any scientific evidence for wormholes? ›**

Researchers have no observational evidence for wormholes, but the equations of the theory of general relativity have valid solutions that contain wormholes. Because of its robust theoretical strength, a wormhole is one of the great physics metaphors for teaching general relativity.

**How many dimensions exist? ›**

The world as we know it has three dimensions of space—length, width and depth—and one dimension of time. But there's the mind-bending possibility that many more dimensions exist out there. According to string theory, one of the leading physics model of the last half century, the universe operates with **10 dimensions**.

**What is the closest wormhole to Earth? ›**

The nearest "portal"

It is about ten times the size of the Sun and is 1,566 light years from Earth. This may be a wormhole. **Gaia BH1** has a Sun-like star orbiting it.

**Why is traveling through a wormhole thought to be impossible? ›**

Traveling through a wormhole is thought to be impossible because **wormholes are believed to collapse very quickly and are unstable phenomena**. The wormholes that were theoretically described by Einstein and Rosen in 1935 were derived mathematically from the general theory of relativity.

**What is the lifespan of a wormhole? ›**

While most wormholes only last for **24 hours**, there are some variations to this rule. When a static wormhole collapses a new one with the same properties will spawn somewhere else in the same system. It will have to be scanned down. When a non-static wormhole collapses it simply disappears forever.

**What is the white hole theory? ›**

White holes are **theoretical cosmic regions that function in the opposite way to black holes**. Just as nothing can escape a black hole, nothing can enter a white hole. White holes were long thought to be a figment of general relativity born from the same equations as their collapsed star brethren, black holes.

**How much time would pass in a wormhole? ›**

"]F]or astronauts going through the wormhole it would take only **1 second** of their time to travel 10,000 light-year distance (approximately 5000 billion miles or 1/10 of Milky Way size). An observer who does not go through the wormhole and stays outside sees them taking more than 10,000 years.

**Have humans seen a wormhole? ›**

**No one has yet seen a wormhole**, but theoretically they could provide shortcuts to distant parts of the universe, or to other universes entirely, if they exist (SN: 7/27/17).

**How many wormholes have been found? ›**

While researchers have never found a wormhole in our universe, scientists often see wormholes described in the solutions to important physics equations. Most prominently, the solutions to the equations behind Einstein's theory of space-time and general relativity include wormholes.

### Are scientists trying to create a black hole? ›

In fact, **the possibility of creating a black hole in a lab is a goal that scientists are actively pursuing**—one that could allow researchers to answer many fundamental questions about quantum mechanics and the nature of gravity. A black hole typically forms when a star much more massive than our sun dies.

**What did Einstein think was in a black hole? ›**

According to Einstein's theory of general relativity, massive objects like black holes **distort space and time**, which both magnifies the light and forces it to travel on a different path than it would otherwise — this is known as gravitational lensing.

**Is Spaghettification a real thing? ›**

In astrophysics, **spaghettification is the tidal effect caused by strong gravitational fields**. When falling towards a black hole, for example, an object is stretched in the direction of the black hole (and compressed perpendicular to it as it falls).

**Does E mc2 apply to black holes? ›**

Does the E=mc^2 equation apply to a black hole? **E=mc^2 is always true**. In the case of a black hole, for instance, there has been some speculation that black holes can, through a quantum mechanical trick, radiate energy, and in the process their mass would therefore decrease.

**Does time stop in a black hole? ›**

Near a black hole, the slowing of time is extreme. **From the viewpoint of an observer outside the black hole, time stops**. For example, an object falling into the hole would appear frozen in time at the edge of the hole.

**How many black holes are in the universe? ›**

**40,000,000,000,000,000,000**. With a new computational approach, SISSA researchers have been able to make the fascinating calculation. Moreover, according to their work, around 1% of the overall ordinary (baryonic) matter is locked up in stellar mass black holes.

**Is there anything beyond a black hole? ›**

Beyond the event horizon lies a truly minuscule point called a singularity, where gravity is so intense that it infinitely curves space-time itself. This is where the laws of physics, as we know them, break down, meaning **all theories about what lies beyond are just speculation**.

**Can anything escape a wormhole? ›**

Wormholes make for good science-fiction as ways for faster-than-light-speed travel between two extremely distant points in the universe. In reality, however, Einstein's theory of general relativity shows that **it would not be possible for matter to actually cross these “tunnels through space”**.

**What is quantum hair? ›**

**As matter collapses into a black hole, they suggest, it leaves a faint imprint in its gravitational field**. This imprint is referred to as “quantum hair” and, the authors say, would provide the mechanism by which information is preserved during the collapse of a black hole.

**Could a paradox destroy the universe? ›**

Would this destroy the entire Universe? **Perhaps not**. Paradoxes tell us that our conventional way of thinking about a subject is, at best, incomplete. But it doesn't mean that the consequences will be as dire as unraveling spacetime or destroying the Universe.

### Is it possible to travel time? ›

According to NASA, **time travel is possible, just not in the way you might expect**. Albert Einstein's theory of relativity says time and motion are relative to each other, and nothing can go faster than the speed of light, which is 186,000 miles per second. Time travel happens through what's called “time dilation.”

**Is time slower in a wormhole? ›**

A wormhole is created with one opening on Earth and the other opening on a spaceship. If this spaceship then flies through the universe at speeds approaching the speed of light, Relativity states that **time will pass more slowly for the opening of the wormhole that is on the ship.**

**Is there a way to go back in time? ›**

**Time travel to the past is theoretically possible in certain general relativity spacetime geometries that permit traveling faster than the speed of light**, such as cosmic strings, traversable wormholes, and Alcubierre drives.

**Can you time travel to the past? ›**

**We can't use a time machine to travel hundreds of years into the past or future**. That kind of time travel only happens in books and movies. But the math of time travel does affect the things we use every day.

**Who created the wormhole theory? ›**

Introduction. Physicists have purportedly created the first-ever wormhole, a kind of tunnel theorized in 1935 by **Albert Einstein and Nathan Rosen** that leads from one place to another by passing into an extra dimension of space.

**Why wormholes don t exist? ›**

If they existed, most wormholes would likely be very small and would evaporate almost as soon as they formed. Anything passing through — even a single photon — disturbs the gravitational structure of the wormhole, causing it to collapse into two infinitely dense concentrations of energy known as “naked singularities”.

**How many multi universes are there? ›**

Brian Greene's **nine** types of multiverses include quilted, inflationary, brane, cyclic, landscape, quantum, holographic, simulated, and ultimate. The ideas explore various dimensions of space, physical laws, and mathematical structures to explain the existence and interactions of multiple universes.

**What dimension is heaven? ›**

So you don't necessarily have to look up but you can look out and see heaven. Heaven is a **fourth dimension** if you will," he tells Walters.

**Has a 5th dimension exist? ›**

As of now, **we can't see the fifth dimension**, but rather, it interacts on a higher plane than we do. It's because of this that we can't really study nor fully prove it's existence.

**Can we go to 4th dimension? ›**

According to this model, there are only three dimensions of linear direction: variations of up, right, and forward. In other words, height, length, and width. But even with all the practicality of Euclid's model, **the concept cannot be mathematically proven, opening the doorway to another fourth direction**.

### Is there a black hole near us? ›

**Gaia BH1 is located just 1,560 light-years away from Earth in the direction of the constellation Ophiuchus, while Gaia BH2 lies 3,800 light-years away in the constellation Centaurus**. In cosmic terms, both black holes are therefore situated in Earth's backyard.

**Is there a wormhole in our galaxy? ›**

According to these researchers, when you consider dark matter along with the regular matter in the Milky Way, **our galaxy's density appears great enough to allow for a wormhole at the galaxy's heart**. If so, these researchers say, this wormhole is: … stable and navigable.

**Is there a black hole moving towards Earth? ›**

A team of international astronomers have reclassified a galaxy after finding that **a supermassive black hole in its centre has changed direction and is now aiming towards the Earth**. The galaxy in question is found 657 million light-years away from us and goes by the name of PBC J2333.

**Would a human survive a wormhole? ›**

**Humans could survive a trip through a wormhole**, but there's a catch. There are drawbacks to this method — namely, such wormholes would be only microscopic, which means even the most hardcore exercise routine wouldn't make humans thin enough for the trip.

**How long would it take to go through a wormhole? ›**

"]F]or astronauts going through the wormhole it would take only **1 second of their time to travel 10,000 light-year distance** (approximately 5000 billion miles or 1/10 of Milky Way size). An observer who does not go through the wormhole and stays outside sees them taking more than 10,000 years.

**Why is travel through a wormhole impossible? ›**

Answer and Explanation: Traveling through a wormhole is thought to be impossible because **wormholes are believed to collapse very quickly and are unstable phenomena**. The wormholes that were theoretically described by Einstein and Rosen in 1935 were derived mathematically from the general theory of relativity.

**What is the wormhole rule? ›**

**A player can never prevent other players from using their wormholes**. A player may warp through wormholes any number of times on their turn, but must perform another action (free or movement) between each warp. Players may use their own wormholes freely, but do not earn 1 point when doing so.

**Have we seen a real wormhole? ›**

Unfortunately, **no one has ever observed a worm hole or even any physical evidence that they actually exist**. Still, because the theory for their existence is so strong, astrophysicists assume they do exist.

**Where is the nearest wormhole? ›**

The nearest "portal"

American and German scientists recently reported that they had discovered the closest known black hole, called **Gaia BH1**. It is about ten times the size of the Sun and is 1,566 light years from Earth. This may be a wormhole. Gaia BH1 has a Sun-like star orbiting it.