Understanding Spacetime: Clarifying Misconceptions and the Role of Gravity

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In summary, the conversation discusses concepts related to the speed of light, gravity, and the expanding universe. The speakers question whether it is possible to move beyond the speed of light and if gravity affects the speed of light. They also discuss the methods used to determine the increasing rate of the universe's expansion and whether the traditional understanding of atoms is accurate. The conversation ends with a recommendation to read Einstein's explanation of relativity for a better understanding of these concepts.
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Simon76
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Please clarify / correct my misunderstanding. I'm not a physics pro (just a personal interest). Also, please excuse the complete lack of technical terms!


It has been said that to move beyond the speed of light is to move backwards in time? (Though it's also stated that this isn't possible for matter?)

The speed of light isn't constant - that is to say it is affected by forces such as gravity?

Gravity appears to cause "compression" of mass ie higher density, and has a huge range, though it's effects appear to dimish sharply with range? (or vice versus depending on your perspective)



I heard a comment some time back about the rate of the universe expanding at an increasing rate.

First question: What methods were used / how do we determine the universe is growing at an increasing rate when we the observer are sat in a gravitational field and are thus subject to the same distortion of space/time?

Is the typical "schooled" approach entirely misleading, portraying atoms etc as having fixed bounds and areas they "occupy", and would it be more accurate to portray the "effect" of am atom as being those of numerous flows or fields or "folds"?

If this is the case, can they "scale" up or down? To put it in other words, can 1 cubic meter of space "on paper" represent 2 cubic meters, with the propogation of all waves ie space/time being at 1 constant unit, but 1 cubic meter on this planet "on paper" representing 2000 cubic meters of space, with waves propogating at a much higher rate?

Sorry if the last bit makes little sense - hopefully someone will understand what I'm getting at despite the bad wording.
 
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Dr Einstein wrote a plain English exposition of Relativity which I have seen posted as a .pdf file on the web. In fact I just tried the terms 'Einstein, relativity, .pdf' as seeds for a google search and can report ready availability.
I think that your questions are easier to ask than to answer, and that Einstein will set you right.
 

Related to Understanding Spacetime: Clarifying Misconceptions and the Role of Gravity

1. What is spacetime?

Spacetime is a concept in physics that combines the three dimensions of space (length, width, and height) with the dimension of time. It is often represented as a four-dimensional continuum, where an object's position and motion are described in terms of both space and time.

2. How is spacetime related to Einstein's theory of relativity?

Einstein's theory of relativity describes how gravity affects the fabric of spacetime. It states that massive objects, such as planets and stars, can bend the fabric of spacetime, causing smaller objects to follow a curved path around them. This theory also explains how time can be affected by gravity, with time passing more slowly in areas with stronger gravitational fields.

3. What evidence supports the existence of spacetime?

There are several pieces of evidence that support the existence of spacetime. One of the most well-known is the bending of light by massive objects, which was observed during a solar eclipse in 1919 and provided support for Einstein's theory of relativity. Other evidence includes the redshift of light from distant galaxies, the observation of gravitational waves, and the accuracy of GPS systems, which rely on the principles of relativity to function correctly.

4. Can we travel through spacetime?

While we are constantly traveling through spacetime, it is not currently possible for humans to travel through it in a controlled manner. The theory of relativity suggests that time travel may be possible in certain scenarios, such as near black holes, but this has not been proven and is still a topic of scientific debate.

5. How does understanding spacetime impact our understanding of the universe?

Understanding spacetime has greatly impacted our understanding of the universe. It has allowed us to develop accurate models of the universe and make predictions about the behavior of objects in space. It has also led to advancements in technology, such as GPS systems and gravitational wave detectors, that rely on our understanding of spacetime. Additionally, the concept of spacetime has challenged our traditional understanding of time and space, leading to new philosophical and scientific discussions about the nature of reality.

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