Is Empty Space Truly Empty or Packed with Energy?

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Discussion Overview

The discussion revolves around the nature of empty space and its potential energy, as well as concepts related to quantum gravity and string theory. Participants explore philosophical and theoretical implications of what constitutes "empty space" and how it relates to energy and fundamental physics.

Discussion Character

  • Exploratory
  • Conceptual clarification
  • Debate/contested
  • Technical explanation

Main Points Raised

  • Some participants reference the idea from "The Holographic Universe" that empty space may contain more energy than all matter in the universe, though this is viewed with skepticism.
  • One participant argues that empty space is defined as space without atoms or particles, suggesting that regions of space can be considered "almost empty" despite the presence of radiation and particles.
  • There is a discussion about the abstraction of concepts in physics, such as friction-less surfaces, and how this relates to the understanding of empty space.
  • Another participant expresses caution regarding speculative theories like the holographic universe and string theory, suggesting a focus on more established concepts like quantum mechanics and special relativity.
  • A request for clarification on the fundamental concepts of quantum gravity and string theory is made, indicating a desire for a deeper understanding of these theories.
  • One participant describes string theory as an attempt to explain gravity at the particle scale, mentioning the concept of strings vibrating to create particles, including a graviton.
  • A contrasting and humorous viewpoint is presented, claiming that elementary particles are made of "tiny Rubik's cubes," which diverges significantly from the scientific discourse.

Areas of Agreement / Disagreement

Participants express a range of views on the nature of empty space and its energy, with no consensus reached. Some participants are skeptical of speculative theories, while others seek to understand them better. The humorous claim about Rubik's cubes introduces further disagreement and a lack of seriousness in part of the discussion.

Contextual Notes

Participants acknowledge the speculative nature of certain theories and the importance of assumptions in scientific discourse. The discussion reflects varying levels of understanding and interest in advanced theoretical physics.

Who May Find This Useful

This discussion may be of interest to those exploring concepts in theoretical physics, particularly regarding the nature of space, energy, and advanced theories like quantum gravity and string theory.

CHORGENSOTRUFORX
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In a book called the Holographic UNiverse, it has been suggested that what people now consider empty space has more energy than all in the universe. This, i am guessing is an exageration, but how do we know empty space exists?
 
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We deduce that space exists from our senses. Our lifes revolve about things happening in 3-d space and evolving in time.
We consider empty space as space without atoms or other particles. Even if in practice all space has some radiation flowing through and some particles zipping by, we could say that some regions of space are almost empty, at least compared to the atmostphere. We can focus on those properties of space that don't relate to electromagnetic radiation or the few particles we might find. We can call this "empty space".
In classical physics, we talk about friction-less surfaces. You may say: how do we know that friction-less surfaces exist?. Well, we can find tricky ways to reduce friction to negligible levels, but even if we couldn't, we can always imagine a friction-less surface and then focus on all other forces except friction. Abstraction is a very important tool in physics.
Now, if you read that in empty space there are quantum fluctuations and virtual particles and then you say that in that case empty space is not empty, you may be right. But it appears people by convention have decided to call that space empty, and it would be useless to argue.
We consider space as that thing (empty or not) that separates bodies. I guess it would be a valid question to ask if space would exist if there were no bodies, no matter. Probably space only exists if there are some massive bodies floating around, but I would leave that discussion to those who have enough knowledge to give informed opinions (I don't know enough).
The holographic universe is a very speculative theory and I would stay away from it. If I were you I would also not try to understand too much about string theory and quantum gravity as these are very advanced theories that are still in evolution and that require very advanced math. I would stick to understanding quantum mechanics and also the special theory of relativity.
About you comment on what you read about empty space containing more energy than the rest of the universe, if some sicentists think that way it is because they calculated it based on certain assumptions. Scientists normally don't make wild guesses or exagerate. They may be wrong, but because they made the wrong assumptions, not because they exagerated. The assumptions are ultimatelly tested by comparing their consequences with experiment or measurements of the universe.
--Alex--
 
Please tell me the basic idea of quantum gravity. What is the fundamental concept behind the idea of quantum gravity? I would also like to know the basic idea behind string theory, but can you please at least tell me what it is that string theory is trying to account for or explain?
 
The string Theory is trying to find an explanation for gravity on the particle scale.
Strings can vibrate in certain ways to make certain particles, one of those possibly being a graviton.
 
billy_boy_999 said:
you are fools, all of you!

they are not strings, they are Rubik's cubes! all elementary particles are made of tiny Rubik's cubes!

have you ever solved a Rubik's cube? of course not, and its a good thing - an atomic blast is simply a little elf finally solving a tiny Rubik's cube...imagine what a big one would do...they should take them off the market for sure...



Where did you come from??
 

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