Scientists Already Discover A 5th Dimension
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VOICE OVER: Peter DeGiglio
WRITTEN BY: Aidan Johnson
Have we already discovered another dimension in nature? A dimension BEYOND our 4D everyday lives?
Did Scientists Already Discover A 5th Dimension?
For the whole of human history, we’ve been able to explore reality in three spatial dimensions, and one temporal. Everything we know is guided by these fundamental rules. But, for some truly outside-the-box thinking, we could ask “what if there’s more than just length, width, height and time?” In the modern day, the search for extra dimensions is certainly alive and kicking. To the point where some believe that we should already be adding another to our established bank of four.
This is Unveiled, and today we’re answering the extraordinary question; did scientists already discover a fifth dimension?
In everyday life, we navigate three familiar dimensions: length, width, and height. The physical reality surrounding us is made up of (and realised) thanks to these three fundamental points of reference. Additionally, time is considered the fourth dimension because, as it moves forward linearly, it also assumes a crucial role in how we perceive reality. We can always find a measure for all four dimensions. But we all move through time at the same rate - rather than being able to freely move through it like we can with the spatial dimensions - which is one reason why time is really quite different. Nevertheless, altogether, our four dimensions combine to define the 4D fabric of spacetime, which is ultimately the stage on which all of reality plays out.
At first it might feel that there’s really nowhere else we can go from here. If reality is four dimensional, then surely that’s just an immovable fact of life? However, scientists and theorists have long sought to break this most ingrained of systems by adding in extras; they’ve long speculated that the universe is far more complex than we ordinarily observe.
The discovery of even one new dimension would signal a true paradigm shift for our species, but finding that extra dimension isn’t easy. If it does exist, then it’s likely to be buried from view (from our perspective) or else so intricately woven into the fabric of spacetime that we might never actually locate it, even if we did come to realise that it was there. Of course, regardless of the difficulties involved, for those researching extra dimensions, the supreme dream is usually to uncover a way, any way, to break through to the fabled other side.
There’s a rich history to the field. Theodor Kaluza, a German mathematician, made arguably the first significant breakthroughs in 1921. In short, he proposed to extend the model of general relativity by adding in a fifth dimension. By doing so, he believed, the fundamental forces of gravity and electromagnetism could be unified. Kaluza is said to have written to Albert Einstein regarding his ideas, and Einstein is said to have encouraged him to publish as soon as possible. Fast forward to today, and perhaps Kaluza’s name has been lost to time… but his quest to unify gravity with the rest of physics is one that is still ongoing. The search for the famed theory of everything is really what drives today’s scientists to study the possibility of extra dimensions in the first place.
Later on in the 1920s, Oskar Klein expanded on Kaluza’s idea, suggesting that the extra dimension is compactified on such a small scale that it’s invisible to us. According to Klein, it’s as though the fifth dimension exists something akin to an incredibly tight loop within the fabric of spacetime; again, it’s a loop that’s entirely imperceptible to us, in the here and now. The work of both physicists - Theodor Kaluza and Oskar Klein - eventually became known as the Kaluza-Klein theory. It laid the groundwork for all later explorations of extra dimensions.
But the path hasn’t been easy. After just a few decades, the Kaluza-Klein theory was largely dropped. None of its predictions could be experimentally tested, which is something that still dogs similar models today. The fact is that it’s notoriously hard to even devise a way to try to prove that a fifth dimension is even slightly possible. That said, there have been other theories that have emerged in the wake of Kaluza-Klein… and by far the most notable (and famous) of all is string theory.
During the late 20th century, string theory really shook things up, dramatically expanding upon all that came before. The theory posits that the most fundamental particles in the universe are not points - as was (and is) traditionally thought - but are tiny vibrating strings. It’s then the frequency at which these strings vibrate that determines what particles they are and their fundamental properties. To a degree, it’s like how the frequency of the vibrations of a guitar string is what determines the note that gets played. Only, rather than just music, we’re applying the same thing to how the whole of reality is rendered into being. Suffice to say, it can be a tricky idea to even contemplate, let alone accept. Sit for a moment and try to recalibrate everything you see, think, feel - everything you everything - so that at its most basic level, it’s just endless wobbly strings. It’s… not easy.
The key point, though, is that for string theory to work, advocates calculate that it requires as many as ten, eleven, or even twenty-six total dimensions. These extra dimensions are all also thought to be compactified, as per the original Kaluza-Klein theory. They would need to work at an even smaller scale though. Tiny, to-us-invisible loops, inside loops, inside loops, and so on… all to say that the ever-mystical fabric of our reality becomes more and more detailed and complex, to an almost incomprehensible degree. For those who support it, string theory is a mathematically elegant idea. But the problems remain the same; testing it in reality is an enormous challenge.
As of now, there’s no experimental evidence to confirm string theory. The extra dimensions are just too unfathomably tiny to get a hold on. To measure them directly, we’d probably need to be able to track below the Planck scale - which is currently completely out of reach, even for our most advanced particle accelerators. Therefore, the race is on to detect indirect evidence, as a starting point. Some researchers are keeping their eyes peeled for general gravitational anomalies, with this in mind. It’s thought that if extra dimensions exist, they could (even should) have subtle effects on the nature of gravity. For example, one proposal is that gravity might leak into extra dimensions all the time, which potentially explains why it’s by far the weakest of all the fundamental forces in our reality. This is one interpretation of what’s called the Randall-Sundrum model, which (to a point) ponders whether gravity might become diluted across extra dimensions. Again, at our current level of technology, we can’t yet expect to just discover that this happens. Instead, the study of high-energy particle collisions, like at CERN’s Large Hadron Collider, might one day provide indirect evidence from which we can infer the truth.
Interestingly, another route toward proving extra dimensions might also come from (in many ways) the opposite to sub-Planck length study. Some are looking to the universe as a whole to provide the answers. The cosmic microwave background radiation, or CMBR, is the heat leftover from the Big Bang. It’s everywhere in the universe, and therefore acts as a lens into reality’s very earliest moments. Theoretically, distortions or unusual patterns within the CMBR could also suggest the influence of hidden dimensions. Although, nothing so far has led to this conclusion.
Elsewhere, and there are theories that another potential indicator of extra dimensions might be carried through space via gravitational waves. These are ripples in spacetime produced by massive cosmic events… but, could they also be influenced by the presence of hidden dimensions? It’s, at this stage, almost entirely speculation, but the monitoring of gravitational waves is a relatively new field, and scientists hope that some truly profound answers as to the true nature of everything… could soon be incoming.
So, did scientists already discover an extra dimension? This could very much be one of those cases when we’re just never truly sure of what it is that we’re looking at. The universe, on both its smallest and largest scales, continually throws up puzzles to solve and mysteries to decipher. We famously don’t have a theory of everything, which means that there are still huge gaps in our understanding of how things really work. For some, those gaps can only be plugged by our realization that we live in a more than 4D world. And, as we continue to test, probe, study and conceptualize the reality around us… it might be that a fifth dimension (at least) has always been there, holding the world together but in a way that our eyes simply cannot see.
For the whole of human history, we’ve been able to explore reality in three spatial dimensions, and one temporal. Everything we know is guided by these fundamental rules. But, for some truly outside-the-box thinking, we could ask “what if there’s more than just length, width, height and time?” In the modern day, the search for extra dimensions is certainly alive and kicking. To the point where some believe that we should already be adding another to our established bank of four.
This is Unveiled, and today we’re answering the extraordinary question; did scientists already discover a fifth dimension?
In everyday life, we navigate three familiar dimensions: length, width, and height. The physical reality surrounding us is made up of (and realised) thanks to these three fundamental points of reference. Additionally, time is considered the fourth dimension because, as it moves forward linearly, it also assumes a crucial role in how we perceive reality. We can always find a measure for all four dimensions. But we all move through time at the same rate - rather than being able to freely move through it like we can with the spatial dimensions - which is one reason why time is really quite different. Nevertheless, altogether, our four dimensions combine to define the 4D fabric of spacetime, which is ultimately the stage on which all of reality plays out.
At first it might feel that there’s really nowhere else we can go from here. If reality is four dimensional, then surely that’s just an immovable fact of life? However, scientists and theorists have long sought to break this most ingrained of systems by adding in extras; they’ve long speculated that the universe is far more complex than we ordinarily observe.
The discovery of even one new dimension would signal a true paradigm shift for our species, but finding that extra dimension isn’t easy. If it does exist, then it’s likely to be buried from view (from our perspective) or else so intricately woven into the fabric of spacetime that we might never actually locate it, even if we did come to realise that it was there. Of course, regardless of the difficulties involved, for those researching extra dimensions, the supreme dream is usually to uncover a way, any way, to break through to the fabled other side.
There’s a rich history to the field. Theodor Kaluza, a German mathematician, made arguably the first significant breakthroughs in 1921. In short, he proposed to extend the model of general relativity by adding in a fifth dimension. By doing so, he believed, the fundamental forces of gravity and electromagnetism could be unified. Kaluza is said to have written to Albert Einstein regarding his ideas, and Einstein is said to have encouraged him to publish as soon as possible. Fast forward to today, and perhaps Kaluza’s name has been lost to time… but his quest to unify gravity with the rest of physics is one that is still ongoing. The search for the famed theory of everything is really what drives today’s scientists to study the possibility of extra dimensions in the first place.
Later on in the 1920s, Oskar Klein expanded on Kaluza’s idea, suggesting that the extra dimension is compactified on such a small scale that it’s invisible to us. According to Klein, it’s as though the fifth dimension exists something akin to an incredibly tight loop within the fabric of spacetime; again, it’s a loop that’s entirely imperceptible to us, in the here and now. The work of both physicists - Theodor Kaluza and Oskar Klein - eventually became known as the Kaluza-Klein theory. It laid the groundwork for all later explorations of extra dimensions.
But the path hasn’t been easy. After just a few decades, the Kaluza-Klein theory was largely dropped. None of its predictions could be experimentally tested, which is something that still dogs similar models today. The fact is that it’s notoriously hard to even devise a way to try to prove that a fifth dimension is even slightly possible. That said, there have been other theories that have emerged in the wake of Kaluza-Klein… and by far the most notable (and famous) of all is string theory.
During the late 20th century, string theory really shook things up, dramatically expanding upon all that came before. The theory posits that the most fundamental particles in the universe are not points - as was (and is) traditionally thought - but are tiny vibrating strings. It’s then the frequency at which these strings vibrate that determines what particles they are and their fundamental properties. To a degree, it’s like how the frequency of the vibrations of a guitar string is what determines the note that gets played. Only, rather than just music, we’re applying the same thing to how the whole of reality is rendered into being. Suffice to say, it can be a tricky idea to even contemplate, let alone accept. Sit for a moment and try to recalibrate everything you see, think, feel - everything you everything - so that at its most basic level, it’s just endless wobbly strings. It’s… not easy.
The key point, though, is that for string theory to work, advocates calculate that it requires as many as ten, eleven, or even twenty-six total dimensions. These extra dimensions are all also thought to be compactified, as per the original Kaluza-Klein theory. They would need to work at an even smaller scale though. Tiny, to-us-invisible loops, inside loops, inside loops, and so on… all to say that the ever-mystical fabric of our reality becomes more and more detailed and complex, to an almost incomprehensible degree. For those who support it, string theory is a mathematically elegant idea. But the problems remain the same; testing it in reality is an enormous challenge.
As of now, there’s no experimental evidence to confirm string theory. The extra dimensions are just too unfathomably tiny to get a hold on. To measure them directly, we’d probably need to be able to track below the Planck scale - which is currently completely out of reach, even for our most advanced particle accelerators. Therefore, the race is on to detect indirect evidence, as a starting point. Some researchers are keeping their eyes peeled for general gravitational anomalies, with this in mind. It’s thought that if extra dimensions exist, they could (even should) have subtle effects on the nature of gravity. For example, one proposal is that gravity might leak into extra dimensions all the time, which potentially explains why it’s by far the weakest of all the fundamental forces in our reality. This is one interpretation of what’s called the Randall-Sundrum model, which (to a point) ponders whether gravity might become diluted across extra dimensions. Again, at our current level of technology, we can’t yet expect to just discover that this happens. Instead, the study of high-energy particle collisions, like at CERN’s Large Hadron Collider, might one day provide indirect evidence from which we can infer the truth.
Interestingly, another route toward proving extra dimensions might also come from (in many ways) the opposite to sub-Planck length study. Some are looking to the universe as a whole to provide the answers. The cosmic microwave background radiation, or CMBR, is the heat leftover from the Big Bang. It’s everywhere in the universe, and therefore acts as a lens into reality’s very earliest moments. Theoretically, distortions or unusual patterns within the CMBR could also suggest the influence of hidden dimensions. Although, nothing so far has led to this conclusion.
Elsewhere, and there are theories that another potential indicator of extra dimensions might be carried through space via gravitational waves. These are ripples in spacetime produced by massive cosmic events… but, could they also be influenced by the presence of hidden dimensions? It’s, at this stage, almost entirely speculation, but the monitoring of gravitational waves is a relatively new field, and scientists hope that some truly profound answers as to the true nature of everything… could soon be incoming.
So, did scientists already discover an extra dimension? This could very much be one of those cases when we’re just never truly sure of what it is that we’re looking at. The universe, on both its smallest and largest scales, continually throws up puzzles to solve and mysteries to decipher. We famously don’t have a theory of everything, which means that there are still huge gaps in our understanding of how things really work. For some, those gaps can only be plugged by our realization that we live in a more than 4D world. And, as we continue to test, probe, study and conceptualize the reality around us… it might be that a fifth dimension (at least) has always been there, holding the world together but in a way that our eyes simply cannot see.
