They said space, not vacuum.
Why is this important?
It is important because WE LIKE to think that space is vacuum. And this mode of thinking is wrong. It is not vacuum. There are things floating there, hydrogen atoms, other stuff. They are not really close, but they are there.

And what's between the things floating out there?

 

And what's between the things floating out there?

Solar radiation, among other things.

 

Solar radiation, among other things.

Which is only possible through fields. In QFT, vacuum is not the absence of everything, it's just the lowest energy state, like static fields. In other words, the vacuum of space is just low-energy space.

 

Which is only possible through fields. In QFT, vacuum is not the absence of everything, it's just the lowest energy state, like static fields. In other words, the vacuum of space is just low-energy space.

I am not an astrophysicist and I don't play one on TV.
I note your phrasing, low-energy space, not zero energy.
I think the Hashtag One Two was using vacuum as in "there is nothing there".
You and I are agree that there is stuff there, but it is very very very sparse.

 

A vacuum has magnetic field properties? (Blinking like a frog in a hail storm.)
It's such a stretch for me to imagine ripples in a vacuum!

Ideal Vacuum or Space has electric/magnetic field properties because of the finite (why that is true is another topic) speed of light not because of STUFF (matter) being there. This delay in moving between point A and a distant point B means that energy is being stored in space just like around the coils of a inductor or between the plates of a capacitor. The first thing is to assume that fields (as defined in any theory like QFT, etc ...) have a physical existence and are not just a mathematical construct designed to solve a problem (action at a distance). The second thing to see space as an analogy to a special type of impedance mesh that's not dissipative but dispersive in 3D over time because of those electric/magnetic field properties that allow for wave propagation.

For isotropic radiation we would see this type of pattern as the wave moves into space.

http://www.radartutorial.eu/01.basics/Free-Space Path Loss.en.html

 

That is yet another big mystery that I'd like to explore later on. That is the nature of fields themselves.

Get an introductory physics text and start at the part that introduced E & M. It should start with Coulomb's Law regarding the force between two charged particles. From there it will walk you through the definition of an electric field. Piece by piece you'll be taken through magnetic fields and then how they interact. Eventually you'll have four laws that will form Maxwell's Equations and then you'll be in a position to answer the question of what is required for a changing electric field to be able to produce a changing magnetic field that can, in turn, produce the original changing electric field. What you will discover is that the requirement is that the new instance of the changing electric field must be displaced by an amount that equates to a wave traveling at the speed of light in that medium.

 

I think the Hashtag One Two was using vacuum as in "there is nothing there".

Yeah, "vacuum" seems misleading. There is obviously light all over the place, going in all different directions, and gas molecules rather far apart, I think, (What would the wind drag be on a square meter moving at c/10?) bits of rock and stuff, but nothing like Earth atmosphere where you can have a compression wave...or am I wrong?

This just seems like the magical, "aether" like there is no mass to use to transfer energy, so it must be propagating irrelevant to physical mass.

OK. I can fire a laser into space, and the light travels just fine. I think radio frequency energy would do the same. It can even be focused with a parabolic antenna. Just it isn't wiggling any mass so it must be just radiating like light??? It is, in and of itself, traveling on its own energy?

 

OK. I can fire a laser into space, and the light travels just fine. I think radio frequency energy would do the same. It can even be focused with a parabolic antenna. Just it isn't wiggling any mass so it must be just radiating like light??? It is, in and of itself, traveling on its own energy?

The inability to understand and accept this was one of the more difficult advances in physics. You can study all the facts and math until you're blue in the face, but none of that will get a person any closer to understanding it, IMHO. You come to accept it, but not understand it. Gravity is the same. Heck, even playing with magnets boggles my mind every time. I've had graduate level physics and can plow through some of the math to describe these phenomena, but I'm nowhere near what I would call understanding them.

 

This just seems like the magical, "aether" like there is no mass to use to transfer energy, so it must be propagating irrelevant to physical mass.

We know there is no magical, "aether" due to our experiments testing the theory. So that doesn't work but what does?
Special Relativity works to provide momentum for massless (rest mass) particles traveling at exactly light speed with the notion of relativistic mass as a equivalent of energy. That means we can have a momentum equation with mass-energy equivalence and velocity.

 

Yeah, "vacuum" seems misleading

Form what I've learned, the word "vacuum" itself is very misleading. According to (the way I understand it) quantum physics, space-time itself is inhabited by virtual particles. That is because the uncertainty principle says that nothing can be determined with 100% certainty. So saying that "space is a perfect vacuum" is a contradiction to that. The correct statement is rather "space averages to a perfect vacuum". Back in 1948, Hendrick Casimir predicted the existence of "virtual particles" existing in space-time that popped in and out of existence. And it wasn't until 1997 that it was experimentally proved!

 

Form what I've learned, the word "vacuum" itself is very misleading.

I disagree, except when the concept is absolute vacuum, which is very different than what most people mean when they use the word. "Vacuum" in most common usage just means "less density" than some reference, 1 atmosphere for most of us. People that work with vacuum quantitate it with pressure or even density itself to describe ever-lower pressures approaching a theoretical absence of mass in a volume. They are fully aware there is still mass floating around but still consider it a vacuum.

 

Form what I've learned, the word "vacuum" itself is very misleading. According to (the way I understand it) quantum physics, space-time itself is inhabited by virtual particles. That is because the uncertainty principle says that nothing can be determined with 100% certainty. So saying that "space is a perfect vacuum" is a contradiction to that. The correct statement is rather "space averages to a perfect vacuum". Back in 1948, Hendrick Casimir predicted the existence of "virtual particles" existing in space-time that popped in and out of existence. And it wasn't until 1997 that it was experimentally proved!

This is a big zigzag from RF modulation.

Don't get stuck on thinking that virtual particles have physical reality.

https://www.physicsforums.com/insights/vacuum-fluctuation-myth/

 

They are fully aware there is still mass floating around but still consider it a vacuum.

You've just proved one part of my point... the other part regards the impossibility of ever achieving a "real", perfect vacuum, no matter how hard you try.

 

This is a big zigzag from RF modulation.

You're right. But I had already planned on posting questions about the nature of fields in another thread. And now that I'm already getting answers here, I say what the heck, let's cover that subject too... they're both related anyway.

 

Don't get stuck on thinking that virtual particles have physical reality.
https://www.physicsforums.com/insights/vacuum-fluctuation-myth/

Excellent article, btw. Thanks!

 

You come to accept it, but not understand it. Gravity is the same.

Mr. Pragmatic accepts the demonstrated facts that radio waves travel and gravity sucks. Getting a grip on the how and why of it is a whole 'nuther matter.

I recently speculated: that we aren't walking on this planet because of gravity, but we are walking on a curve in space-time and there is no such thing as a mysterious force called "gravity". Gravity is merely a manifestation of the curvature of space-time and does not exist as a primary force. Meanwhile, electrical fields and their associated magnetic fields propagate entirely irrelevant to the presence or absence of physical matter.

I think I'll go fix a truck. It makes more sense to me.

 

Gravity is merely a manifestation of the curvature of space-time and does not exist as a primary force

That's the way I understand it too... and yet, most scientists think that is still an incomplete interpretation.

 

Mr. Pragmatic accepts the demonstrated facts that radio waves travel and gravity sucks. Getting a grip on the how and why of it is a whole 'nuther matter.

I recently speculated: that we aren't walking on this planet because of gravity, but we are walking on a curve in space-time and there is no such thing as a mysterious force called "gravity". Gravity is merely a manifestation of the curvature of space-time and does not exist as a primary force. Meanwhile, electrical fields and their associated magnetic fields propagate entirely irrelevant to the presence or absence of physical matter.

I think I'll go fix a truck. It makes more sense to me.

It's all because we live in an eleven dimensional super reality.

 

It's all because we live in an eleven dimensional super reality.

I think I'm beginning to understand why some states are fighting for the legal use of marijuana...

 

This is one of the most fun days I've had in a long time!