An Introduction to Zero-Point Energy

CalPhysics.org ^

[cinFLA]

It seemed to be the best interpretation of the point of your question. If that is not what you meant, perhaps you could clarify

Noone with a basic understanding of physics would come to that interpretation.

[cinFLA]

Just took a survey out the window, and it appears there is air out there and sometimes water. What is the problem, aside from earth should be lowercase?

I said check your "physics" not gaze out the window.

[cinFLA]

Go check your physics for "On Earth there is always air or water available to push against."

[inquest]

You might have to think about it for a second. (snicker)

[inquest]

I think cinFLA's point is that you don't push against air and water the way you push against a wall. Rather, you accelerate the air water in the opposite direction from which you wish to move, resulting in a forward momentum on your part. Still seems like "pushing" to me, but that's the best I can glean from his statement.

[RightWhale]

air being pushed rearward, but also by the partial vacuum created in front of the motor that results when the air is being pushed backwards.

There probably is some partial vacuum, especially when considering propellers and the use of lift to generate forward speed, but the idea in the article is of having a two-component medium on earth. One component is the vehicle, the other is the mobile medium being pushed out the back. Even the mechanism of a chromatograph involves a two-component medium, the stationary and the mobile phases. It takes two components to generate controlled motion.

[PatriotGames]

Where did you come up with that outrageous conclusion?

I think that what they want to hear you say is that aircraft, ships, etc do not get "pushed" through the air, they get "pulled" through the air by the vacuum created forward of the proplusion regardless of the physical location of the propulsion unit on the craft in question.

At least, that's what I was taught. :-)

[inquest]

Except that a vacuum can't "pull". All it does is refrain from pushing, therefore it fails to neutralize the push from the other direction.

[RightWhale]

you don't push against air and water the way you push against a wall.

Sure you do. It's a trivial point. Rockets act a little differently in that they carry stuff to push out the back. Cars act a little differently in that they push against solid ground. The specific mechanisms vary except that they all require two components of a medium.

[El Gato]

On Earth there is always air or water available to push against.

Ok so they should have said "push with" or "expel" or somesuch. Give 'em a break. Physicists, like engingeers don't always have the best writing skills. I'm a perfect example of that, my writing skills are pretty minimal, although I do better than many engineers, especially the youngsters.

[PatrickHenry]

QM ping.

[This ping list is for the evolution -- not creationism -- side of evolution threads, and sometimes for other science topics. To be added (or dropped), let me know via freepmail.]

[El Gato]

If I recall some high-school physics (a VERY long time ago), planes move forward by a combination of the air being pushed rearward, but also by the partial vacuum created in front of the motor that results when the air is being pushed backwards. I could be wrong, but that is what I remember from high school.

That's essentially correct. High bypass ratio turbofans, like on most airliners, but even the ones on fighters and bombers (excepting the BUFF perhaps) get much or even most of their thrust by this effect. IOW, they don't so much blow as suck their way through the air. :)

[RightWhale]

seems like "pushing" to me

When down at the municipal pool, I get around by pushing on the water. There isn't much vacuum in front pulling me along. That's the low-speed case, extremely low speed in my case.

[CobaltBlue]

OK, we'll accept that you're smarter than we are but only if you prove it by demonstrating it.

Please explain why the statement is absurd.

[inquest]

Municipal pool? I'd have thought that the open ocean would be more you're scene ;-)

[RightWhale]

It's a big pool. :)

[spunkets]

Re: push against

Push refers to the direction of the force. If the force is derived from an IC engine, the force out of the trans is applied to either the air, water, or some hard surface. The force is accurately described as a push. The surface it acts against also exerts a push in the opposite direction. If it's a jet the walls of the motor do the pushing, by directing the hot gases pushing on it.

[VadeRetro]

If the zero-point energy is real, there is the possibility that it can be tapped as a source of power or be harnassed to generate a propulsive force for space travel.

Actually, even if it's real, it's everywhere and exactly the same everywhere. It's entropic energy. It's useless unless somebody repeals the Second Law of Thermo.

[templar]

I think that what they want to hear you say is that aircraft, ships, etc do not get "pushed" through the air, they get "pulled" through the air by the vacuum created forward of the proplusion regardless of the physical location of the propulsion unit on the craft in question.

My understanding is that the propeller compresses the air behind it to a high presure while decompressing the air in front to a lower pressure. The propeller is then pushed forward bu the high pressure air behind it into the lower pressure in front of it. Same way a Wing lifts upward because of lower pressure on the top than the bottom. The way a physics teacher explained it and I've never found the need to investigat it further.

A 'Rocket', OTOH, works by having a high pressure in the chamber pressing on the front of the chamber pushing it forward (rear of chamber is open and has nothing for the combusting gasses to press against). Same way for a Jet since the front of the 'chamber' is closed by the high pressure intake air( easiest to visualize with a ramjet, pulse jets exempted). Either way, the author seems to either be trying to give an innacurate but understandable illustration of their operation to those ignorant of the operating principles or else he is basically ignorant of the principles himself and just inventing what he considers a plausible explanation. The explanation detracts from his credibility when talking about an esoteric subject like zero point.

[Brett66]

I think a scientist may have found a way to tap into something related to this to provide propulsion using a strange side-effect of Mach's principle. The physics are well understood and no new physical laws have to be rewritten to explain it.

James F. Woodward: Mach's Principle Weight Reduction = Propellantless Propulsion