# Physicists Outline 10 Different Dimensions and How You’d Experience Them

Where gravity comes from has been an utter mystery. String theory offers an explanation.

Does string theory excite you? Mathematically, it holds up. Aspects about it suggest not one but several different dimensions, ones we’re not generally privy to, though we may be interacting with some of them all the time, completely unaware. Were it true, what would these dimensions look like and how might they affect us? And what is a dimension anyway?

Two dimensions is just a point. We may remember the coordinate plane from math class with the x and y-axes. Then there’s the third dimension, depth (the z-axis). Another way to look at it is latitude, longitude, and altitude, which can locate any object on Earth. These are followed by the fourth dimension, space-time. Everything has to occur somewhere and at a certain time. After that, things get weird.

Superstring theory, one of the leading theories today to explain the nature of our universe, contends that there are 10 dimensions. That’s nine of space and one of time. Throughout the 20^{th} century, physicists erected a standard model of physics. It explains pretty well how subatomic particles behave, along with the forces of the universe, such as electromagnetism, the stronger and weaker nuclear forces, and gravity. But that last one standard physics can’t account for.

Even so, this model has allowed us the startling ability to peer back to the moments just after the Big Bang took place. Before that, scientists believe that everything was condensed into a single point of infinite density and temperature, known as the singularity, which exploded, forming everything in the observable universe today. But the problem is, we can’t peer back beyond that point. That’s where string theory comes in. The innovations it provides can account for gravity and help explain what existed before the Big Bang.

*Aftermath of the Big Bang. NASA. *

So what are these other dimensions and how might we experience them? That’s a tricky question, but physicists have some idea of what it might be like. Really, other dimensions are related to other possibilities. How we interact with these is difficult to explain. At the fifth dimension other possibilities for our world open up.

You’d be able to move forward or backward in time, just as you can in space, say while walking down a corridor. You’d also be able to see the similarities and differences between the world we inhabit and other possible ones. In the sixth dimension, you’d move along not a line but a plane of possibilities and be able to compare and contrast them. In the fifth and sixth dimensions, no matter where in space you inhabit, you’d witness every possible permutation of what can occur past, present, and future.

In the seventh, eighth, and ninth dimensions, the possibility of other universes open up, ones where the very physical forces of nature change, places where gravity operates differently and the speed of light is different. Just as in the fifth and sixth dimensions, where all possible permutations in the universe are evident before you, in the seventh dimension every possibility for these other universes, operating under these new laws, becomes clear.

*In the higher dimensions, you’d witness every possible world future, past, and present, simultaneously. Flikr. *

In the eighth dimension, we reach the plane of all possible histories and futures for each universe, branching out into infinity. In the ninth dimension, all universal laws of physics and the conditions in each universe become apparent. Finally, in the tenth dimension, we reach the point where everything becomes possible and imaginable.

For string theory to work, six dimensions are required for it to operate in a manner that’s consistent with nature. Since these other dimensions are on such a small scale, we’ll need another way to find evidence of their existence. One way would be to peer into the past using powerful telescopes which can hunt for light from billions of years ago, when the universe was first born.

String theory has an answer for what came before the Big Bang. The universe was made up of nine perfectly symmetrical dimensions, the tenth being time. Meanwhile, the four fundamental forces were united at extremely high temperatures. The structure was under high pressure. It soon became unstable and broke in two. This became two different forms of time and led to the three dimensional universe we recognize today. Meanwhile, those other six dimensions shrunk way down to the subatomic level.

*Imagine seeing every possibility and permutation in all universes, all at once. Getty Images. *

As for gravity, string theory contends that the basic units of the universe are strings— infinitesimally small, vibrating filaments of energy. They’re so tiny, they’d be measured on the Planck scale—the smallest scale known to physics. Each string vibrates at a specific frequency and represents a certain force. Gravity and all the other forces are therefore a result of the vibrations of specific strings.

One problem is that this theory is hard to test, outside of advanced mathematical equations. Some experiments have been done using supercomputers, which can run simulations and make predictions. That isn’t exactly enough to prove that it’s true, but it’s helpful and lends support. Besides astronomical observations, physicists are hopeful that experiments with the Large Hadron Collider at CERN, on the Franco-Swiss border, may offer evidence of extra dimensions, lending string theory greater credence.

To learn more about String theory and other dimensions, click here:

## Why the number 137 is one of the greatest mysteries in physics

Famous physicists like Richard Feynman think 137 holds the answers to the Universe.

- The
**fine structure constant**has mystified scientists since the 1800s. - The number
**1/137**might hold the clues to the Grand Unified Theory. - Relativity, electromagnetism and quantum mechanics are unified by the number.

## Americans under 40 want major reforms, expanded Supreme Court

Younger Americans support expanding the Supreme Court and serious political reforms, says new poll.

- Americans under 40 largely favor major political reforms, finds a new survey.
- The poll revealed that most would want to expand the Supreme Court, impose terms limits, and make it easier to vote.
- Millennials are more liberal and reform-centered than Generation Z.

## Can you solve what an MIT professor once called 'the hardest logic puzzle ever'?

Logic puzzles can teach reasoning in a fun way that doesn't feel like work.

- Logician Raymond Smullyan devised tons of logic puzzles, but one was declared by another philosopher to be the hardest of all time.
- The problem, also known as the Three Gods Problem, is solvable, even if it doesn't seem to be.
- It depends on using complex questions to assure that any answer given is useful.

### The Three Gods Problem

<iframe width="730" height="430" src="https://www.youtube.com/embed/UyOGZk7WbIk" frameborder="0" allow="accelerometer; autoplay; clipboard-write; encrypted-media; gyroscope; picture-in-picture" allowfullscreen></iframe><p> One of the more popular wordings of the problem is:<br> <br> "Three gods A, B, and C are called, in no particular order, True, False, and Random. True always speaks truly, False always speaks falsely, but whether Random speaks truly or falsely is a completely random matter. Your task is to determine the identities of A, B, and C by asking three yes-no questions; each question must be put to exactly one god. The gods understand English, but will answer all questions in their own language, in which the words for <em>yes</em> and <em>no</em> are <em>da</em> and <em>ja</em>, in some order. You do not know which word means which."<br> <br> Boolos adds that you are allowed to ask a particular god more than one question and that Random switches between answering as if they are a truth-teller or a liar, not merely between answering "da" and "ja." <br> <br> Give yourself a minute to ponder this; we'll look at a few answers below. Ready? Okay. <strong><br> <br> </strong>George Boolos' <a href="https://www.pdcnet.org/8525737F00588A37/file/31B21D0580E8B125852577CA0060ABC9/$FILE/harvardreview_1996_0006_0001_0060_0063.pdf" target="_blank" rel="noopener noreferrer">solution</a> focuses on finding either True or False through complex questions. </p><p> In logic, there is a commonly used function often written as "iff," which means "if, and only if." It would be used to say something like "The sky is blue if and only if Des Moines is in Iowa." It is a powerful tool, as it gives a true statement only when both of its components are true or both are false. If one is true and the other is false, you have a false statement. </p><p> So, if you make a statement such as "the moon is made of Gorgonzola if, and only if, Rome is in Russia," then you have made a true statement, as both parts of it are false. The statement "The moon has no air if, and only if, Rome is in Italy," is also true, as both parts of it are true. However, "The moon is made of Gorgonzola if, and only if, Albany is the capitol of New York," is false, because one of the parts of that statement is true, and the other part is not (The fact that these items don't rely on each other is immaterial for now).</p><p> In this puzzle, iff can be used here to control for the unknown value of "da" and "ja." As the answers we get can be compared with what we know they would be if the parts of our question are all true, all false, or if they differ. </p><p> Boolos would have us begin by asking god A, "Does "da" mean yes if and only if you are True if and only if B is Random?" No matter what A says, the answer you get is extremely useful. As he explains: <br> </p><p> "If A is True or False and you get the answer da, then as we have seen, B is Random, and therefore C is either True or False; but if A is True or False and you get the answer ja, then B is not Random, therefore B is either True or False… if A is Random and you get the answer da, C is not Random (neither is B, but that's irrelevant), and therefore C is either True or False; and if A is Random...and you get the answer ja, B is not random (neither is C, irrelevantly), and therefore B is either True or False."<br> <br> No matter which god A is, an answer of "da" assures that C isn't Random, and a response of "ja" means the same for B. </p><p> From here, it is a simple matter of asking whichever one you know isn't Random questions to determine if they are telling the truth, and then one on who the last god is. Boolos suggests starting with "Does da mean yes if, and only if, Rome is in Italy?" Since one part of this is accurate, we know that True will say "da," and False will say "ja," if faced with this question. </p><p> After that, you can ask the same god something like, "Does da mean yes if, and only if, A is Random?" and know exactly who is who by how they answer and the process of elimination. </p><p> If you're confused about how this works, try going over it again slowly. Remember that the essential parts are knowing what the answer will be if two positives or two negatives always come out as a positive and that two of the gods can be relied on to act consistently. </p><p> Smullyan wrote several books with other logic puzzles in them. If you liked this one and would like to learn more about the philosophical issues they investigate, or perhaps if you'd like to try a few that are a little easier to solve, you should consider reading them. A few of his puzzles can be found with explanations in this <a href="https://www.nytimes.com/interactive/2017/02/11/obituaries/smullyan-logic-puzzles.html" target="_blank" rel="noopener noreferrer">interactive</a>. </p>## New tardigrade species withstands lethal UV radiation thanks to fluorescent 'shield'

Another amazing tardigrade survival skill is discovered.