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What Is Space?

nautil.us

121–130 of 155 posts

Re: What Is Space?

#122

I'm simultaneously glad that someone's writing articles about these things and dismayed that too many people will read this and believe they understand astrophysics without having philosophized about it on their own. Analogies like "space goo" are useful but can be a double-edged sword(seems the author recognizes this) that can mislead the public in much the same way that the holographic universe theory leads the pub…

Yea, "piled higher and deeper", indeed.

Unwarranted speculation and generalizations purely for the entertainment of those who enjoy a good mind boggle. You'd be wasting your time if you expected to gain any solid insight from the article.

Space and time are what keep everything from happening at the same time in the same place. The infinitesimal bundles of energy that make up objective reality are vastly separated in spacetime. Why is that?

Re: What Is Space?

#123
post #5
post #3

Earlier quoted context omitted.

Do you mind elaborating? Or pointing me in the direction of material that explains the space goo issue. thx

The biggest issue I see with the goo metaphor, is that it seems to suggest some sort of stationary ether that we move through as we move through space. That is to say, the mathaphor suggests that it makes sense to differentiate between stationary objects and moving objects in an objective sense. However, the core insight of relativity is that there is no such distinction.

There is currently no way to differentiate between Einsteinian relativity and Lorentzian relativity. The latter proposes an absolute reference frame. The CMB frame would be a reasonable choice for a stationary structure at the Planckian level that would host the energy bundles (quarks etc) that make up objective reality, cf. loop quantum gravity.

A one-way measurement of the speed of light is needed to differentiate between the two theories, and that has not been accomplished. In fact, it may not be possible in principle to do so. Choice then becomes a matter of taste and philosophical/physical economy.

Re: What Is Space?

#124

Earlier quoted context omitted.

Could gravity be the result of space trying to deflate/return to the pre-Big Bang singularity, kind of like pulling magnets apart? i.e. is gravity the “opposite” of, or a reaction to, “space?” I may be off the mark with what you believe, but just in case: It's a common misconception that the big bang originated at a specific point. The big bang seems to have happened everywhere simultaneously, so it wouldn't be true…

Holy shit, the Big Bang happened everywhere simultaneously because the Big Bang brought quantum fields into existence. Wow. I get it now. As a non-physicist, wording it like that made a lot that I didn't understand suddenly click.

The Big Heap Allocation.

Re: What Is Space?

#125
Usually, I enjoy articles that explain difficult concepts in math and physics, and I like to think about these concepts. But this article just rubs me the wrong way. It throws out some scientific jargon in the first paragraph that could be accurate, but instead they belittle it. Then they try to describe how some people would describe "space" but then argue as if everybody thought that way. I don't and felt talked down to. Worse, they argue as if "space" could have a simple, singular meaning, when obviously it can be defined on many levels, or at least looked at from many levels.

Then I got to the part that says: This is the part where your brain goes, “Whaaaaat ... ?” No, my brain is not so easily confused that it expresses itself in slack-jawed mono-syllables. I get it that the article is trying to simplify some explanation, but I think it's trying too hard and failing. It makes too many assumptions about what the reader thinks and then bases its arguments on these wrong assumptions.

I much preferred the discussion and links here on HN.

Fwiw, I see space as the coordinate system of our universe but with no origin because it's all inertial frames of reference. It is usually thought of as a fixed 3-d Cartesian system plus time, but as I went through life and learned about relativity and Big Bang theory and universe expansion, I understand it as a much more dynamic and complex system.

Re: What Is Space?

#126

Earlier quoted context omitted.

I think it's more that you have no absolute speed...? I.e. it's an ill-defined concept. Of course we often talk about speed as if it's absolute, but as you point out it's actually always relative to some assumed background, e.g. the ground. (It's also impossible to measure speed without some sort of external reference.)

What about angular speed, though? My physics is very rusty where it comes to rotating things, and I don't recall dealing with rotation on relativity classes in school. Since you can derive momentary linear speed from angular speed and distance from centre of rotation, I assume there is no absolute angular speed either?

My physics is also very rusty, but wouldn't any momentary linear speed derived from angular speed be relative to the center of the rotation?

Or am I not understanding you correctly?

Re: What Is Space?

#127

If you are really serious about this question then you would also consider what mathematicians have to say about "space". Unfortunately, this is pretty much the whole of mathematics, but I think special attention should be given to the duality between geometry and algebra . This stuff goes back to Descarte. For example, you can consider the points equidistant from a specific point, which gives a circle. Or you can co…

Controversial, I know—but I wonder how deep that connection actually is... 'the points equidistant from a specific point' and 'X^2+Y^2=1' are both descriptions that we know how to parse and and evaluate into the same thing. Don't get me wrong, I do think it's a super interesting property of the systems of description we formulate that it's possible to talk about the same things with different abstractions (which happ…

The last bit can be said about anything. It might be relevant if the notion is intrinsically motivated by an instinctive search for closed forms. "Space" being emptiness would be isomorphic (dual) to many experiences of limits. In contrast, mystifying the unknown might inspire curiosity at best, reserving free space in the back of the mind, or philosophic arguments at infinitum at worst.

The article is somewhere in the middle with its talk around gravitational waves and einsteinian curvature of space, without directly mentioning them.

Re: What Is Space?

#128

I'm simultaneously glad that someone's writing articles about these things and dismayed that too many people will read this and believe they understand astrophysics without having philosophized about it on their own. Analogies like "space goo" are useful but can be a double-edged sword(seems the author recognizes this) that can mislead the public in much the same way that the holographic universe theory leads the pub…

Isn't the "rubber sheet" analogy better than "space goo"?

The goo analogy makes it seem like "ripples" and "bends" are something space does, where as it's (from my understanding) actually the influence of gravitational fields/aggregations of mass.

Re: What Is Space?

#129
post #32

Earlier quoted context omitted.

Nothing to add, I just love where your questions send my mind, thank you.

You may enjoy contemplating a sort of "epiphany" that I had during that usual pondering of imponderables: That the default or base state of existence may not be nothing, not "not even nothing", but rather Everything. ... Instead of viewing the origin of all reality/creation as things being added to a canvas of blackness/emptiness/voidness, rather consider that "Existence" may be a subtractive process: akin to holes b…

Parent Edit: I suppose I should've just used the convenient CMYK vs. RGB analogy instead of "holes." :)

Re: What Is Space?

#130
post #125

Usually, I enjoy articles that explain difficult concepts in math and physics, and I like to think about these concepts. But this article just rubs me the wrong way. It throws out some scientific jargon in the first paragraph that could be accurate, but instead they belittle it. Then they try to describe how some people would describe "space" but then argue as if everybody thought that way. I don't and felt talked do…

I'm trying to read through the article now, and disappointed in every paragraph. Even the illustration that are trying to be cute are blatantly inaccurate. For example the one labeled "Space Expansion" shows a grid on the floor. In the case of expansion, the number of grid lines would be the same not more, and the point is that we definitely wouldn't feel the expansion.

And then the explanation of rigid rulers and soft taffy rulers seems wrong. Both would expand because the underlying nature of matter expands along with the universe. In other words, all atoms and their distances are affected equally because the forces that determine those distances also change. It has nothing to do with soft or rigid property of an object, which is at the macro level of our perception of matter.

I really expected better of Nautilus, I thought they had a more rigorous standard.

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