Liwaiwai Liwaiwai
  • /
  • Artificial Intelligence
  • Machine Learning
  • Robotics
  • Engineering
    • Architecture
    • Design
    • Software
    • Hybrid Cloud
    • Data
  • About
Liwaiwai Liwaiwai
  • /
  • Artificial Intelligence
  • Machine Learning
  • Robotics
  • Engineering
    • Architecture
    • Design
    • Software
    • Hybrid Cloud
    • Data
  • About
  • Science

The Theory Of Parallel Universes Is Not Just Maths – It Is Science That Can Be Tested

  • May 22, 2020
  • admin

The existence of parallel universes may seem like something cooked up by science fiction writers, with little relevance to modern theoretical physics. But the idea that we live in a “multiverse” made up of an infinite number of parallel universes has long been considered a scientific possibility – although it is still a matter of vigorous debate among physicists. The race is now on to find a way to test the theory, including searching the sky for signs of collisions with other universes.

Scientists are searching for collisions between different ‘universe bubbles’ in the cosmic microwave background.It is important to keep in mind that the multiverse view is not actually a theory, it is rather a consequence of our current understanding of theoretical physics. This distinction is crucial. We have not waved our hands and said: “Let there be a multiverse”. Instead, the idea that the universe is perhaps one of infinitely many is derived from current theories like quantum mechanics and string theory.

The many-worlds interpretation

You may have heard the thought experiment of Schrödinger’s cat, a spooky animal who lives in a closed box. The act of opening the box allows us to follow one of the possible future histories of our cat, including one in which it is both dead and alive. The reason this seems so impossible is simply because our human intuition is not familiar with it.

But it is entirely possible according to the strange rules of quantum mechanics. The reason that this can happen is that the space of possibilities in quantum mechanics is huge. Mathematically, a quantum mechanical state is a sum (or superposition) of all possible states. In the case of the Schrödinger’s cat, the cat is the superposition of “dead” and “alive” states.

Read More  How Memories Are Formed And Retrieved By The Brain Revealed In A New Study

But how do we interpret this to make any practical sense at all? One popular way is to think of all these possibilities as book-keeping devices so that the only “objectively true” cat state is the one we observe. However, one can just as well choose to accept that all these possibilities are true, and that they exist in different universes of a multiverse.

Miaaaaultiverse. Robert Couse-Baker/Flickr, CC BY-SA

The string landscape

String theory is one of our most, if not the most promising avenue to be able to unify quantum mechanics and gravity. This is notoriously hard because gravitational force is so difficult to describe on small scales like those of atoms and subatomic particles – which is the science of quantum mechanics. But string theory, which states that all fundamental particles are made up of one-dimensional strings, can describe all known forces of nature at once: gravity, electromagnetism and the nuclear forces.

However, for string theory to work mathematically, it requires at least ten physical dimensions. Since we can only observe four dimensions: height, width, depth (all spatial) and time (temporal), the extra dimensions of string theory must therefore be hidden somehow if it is to be correct. To be able to use the theory to explain the physical phenomena we see, these extra dimensions have to be “compactified” by being curled up in such a way that they are too small to be seen. Perhaps for each point in our large four dimensions, there exists six extra indistinguishable directions?

A problem, or some would say, a feature, of string theory is that there are many ways of doing this compactification –10500 possibilities is one number usually touted about. Each of these compactifications will result in a universe with different physical laws – such as different masses of electrons and different constants of gravity. However there are also vigorous objections to the methodology of compactification, so the issue is not quite settled.

Read More  Satellites May Have Underestimated Warming In The Lower Atmosphere

But given this, the obvious question is: which of these landscape of possibilities do we live in? String theory itself does not provide a mechanism to predict that, which makes it useless as we can’t test it. But fortunately, an idea from our study of early universe cosmology has turned this bug into a feature.

The early universe

During the very early universe, just after the Big Bang, the universe underwent a period of accelerated expansion called inflation. Inflation was invoked originally to explain why the current observational universe is almost uniform in temperature. However, the theory also predicted a spectrum of temperature fluctuations around this equilibrium which was later confirmed by several spacecraft such as Cosmic Background Explorer, Wilkinson Microwave Anisotropy Probe and the PLANCK spacecraft.

While the exact details of the theory are still being hotly debated, inflation is widely accepted by physicists. However, a consequence of this theory is that there must be other parts of the universe that are still accelerating. However, due to the quantum fluctuations of space-time, some parts of the universe never actually reach the end state of inflation. This means that the universe is, at least according to our current understanding, eternally inflating. Some parts can therefore end up becoming other universes, which could become other universes etc. This mechanism generates a infinite number of universes.

By combining this scenario with string theory, there is a possibility that each of these universes possesses a different compactification of the extra dimensions and hence has different physical laws.

The cosmic microwave background. Scoured for gravitational waves and signs of collisions with other universes. NASA / WMAP Science Team/wikimedia

Testing the theory

The universes predicted by string theory and inflation live in the same physical space (unlike the many universes of quantum mechanics which live in a mathematical space), they can overlap or collide. Indeed, they inevitably must collide, leaving possible signatures in the cosmic sky which we can try to search for.

Read More  If Our Reality Is A Video Game, Does That Solve The Problem Of Evil?

The exact details of the signatures depends intimately on the models – ranging from cold or hot spots in the cosmic microwave background to anomalous voids in the distribution of galaxies. Nevertheless, since collisions with other universes must occur in a particular direction, a general expectation is that any signatures will break the uniformity of our observable universe.

These signatures are actively being pursued by scientists. Some are looking for it directly through imprints in the cosmic microwave background, the afterglow of the Big Bang. However, no such signatures are yet to be seen. Others are looking for indirect support such as gravitational waves, which are ripples in space-time as massive objects pass through. Such waves could directly prove the existence of inflation, which ultimately strengthens the support for the multiverse theory.

Whether we will ever be able to prove their existence is hard to predict. But given the massive implications of such a finding it should definitely be worth the search.

The Conversation

Eugene Lim, Lecturer in theoretical particle physics & cosmology, King’s College London

This article is republished from The Conversation under a Creative Commons license. Read the original article.

admin

Related Topics
  • Multiverse
  • Parallel Universe
  • Quantum mechanics
  • String Theory
You May Also Like
View Post
  • Artificial Intelligence
  • Environment
  • Science
  • Technology

9 Ways AI Can Interact With Culture

  • February 13, 2023
View Post
  • Artificial Intelligence
  • Science
  • Technology

ChatGPT Is Making The Internet More Fun And Less Confusing

  • February 9, 2023
View Post
  • Research
  • Science

CSAIL Researchers Team Up For Neurosymbolic Programming Summer School

  • July 23, 2022
View Post
  • Artificial Intelligence
  • Robotics
  • Science
  • Technology

Is AI The Key To The Metaverse?

  • March 28, 2022
View Post
  • Science
  • Technology

How IBM Quantum Is Advancing Physics With World-Leading Theory Research

  • March 14, 2022
View Post
  • Science
  • Technology

Study Finds New Biomarkers That Could Assist In Identifying Deep-Space Flight Risks

  • March 8, 2022
View Post
  • Artificial Intelligence
  • Science

Scientists Make First Detection Of Exotic “X” Particles In Quark-Gluon Plasma

  • January 25, 2022
View Post
  • Science
  • Technology

Stanford Engineers Develop Algorithm To Aid Kidney Transplant Exchanges

  • August 13, 2021

Leave a Reply

Your email address will not be published. Required fields are marked *

Stay Connected!
LATEST
  • 1
    Unlocking The Secrets Of ChatGPT: Tips And Tricks For Optimizing Your AI Prompts
    • March 29, 2023
  • 2
    Try Bard And Share Your Feedback
    • March 29, 2023
  • 3
    Google Data Cloud & AI Summit : In Less Than 12 Hours From Now
    • March 29, 2023
  • 4
    Talking Cars: The Role Of Conversational AI In Shaping The Future Of Automobiles
    • March 28, 2023
  • 5
    Document AI Introduces Powerful New Custom Document Classifier To Automate Document Processing
    • March 28, 2023
  • 6
    How AI Can Improve Digital Security
    • March 27, 2023
  • 7
    ChatGPT 4.0 Finally Gets A Joke
    • March 27, 2023
  • 8
    Mr. Cooper Is Improving The Home-buyer Experience With AI And ML
    • March 24, 2023
  • 9
    My First Pull Request At Age 14
    • March 24, 2023
  • 10
    The 5 Podcasts To Check If You Want To Get Up To Speed On AI
    • March 24, 2023

about
About
Hello World!

We are liwaiwai.com. Created by programmers for programmers.

Our site aims to provide materials, guides, programming how-tos, and resources relating to artificial intelligence, machine learning and the likes.

We would like to hear from you.

If you have any questions, enquiries or would like to sponsor content, kindly reach out to us at:

[email protected]

Live long & prosper!
Most Popular
  • 1
    GPT-4 : The Latest Milestone From OpenAI
    • March 24, 2023
  • 2
    Ditching Google: The 3 Search Engines That Use AI To Give Results That Are Meaningful
    • March 23, 2023
  • 3
    Peacock: Tackling ML Challenges By Accelerating Skills
    • March 23, 2023
  • 4
    Coop Reduces Food Waste By Forecasting With Google’s AI And Data Cloud
    • March 23, 2023
  • 5
    Gods In The Machine? The Rise Of Artificial Intelligence May Result In New Religions
    • March 23, 2023
  • /
  • Artificial Intelligence
  • Machine Learning
  • Robotics
  • Engineering
  • About

Input your search keywords and press Enter.