NASA Finds Direct Proof of Dark Matter

NASA News ^ | 21 Aug 2006 | Erica Hupp

[Cold Heat]

We were discussing gravity really...It was i that brought up electro magnetics by bringing up motors.

yes, I am aware of the theories on motors, and also some of the arguments.

I got into a lot of that stuff when I was maintaining some electric cranes that use DC Mag Amp systems essentially based on loosely on submarine drive controls and coupled with AC motors....

The argument were over the Fields and how they were able to modify the AC waveforms to control the motor speeds and torque.

At the time, we really did not have all the answers on how the interactions worked, but they did. Fun to argue at times...

And then there is the hole theory with silicon transistors. Something we have used for 70 or more years, yet the theorists were still arguing whether the electron came out of the hole or went into it, or something to that effect.....LOL... it is just anecdotal to understanding gravity.

Anyway, my primary questions are focused on gravity and mass and all that it entails, and not electromagnetism, which we understand well as you said, yet in some areas of the physics, we still have heated arguments, or at least did about 8 years ago when I retired.

What we do know, is that we don't know a lot, and new questions are arising frequently.

[newguy357]

So, let's see... hot gasses somehow are affected by a "drag force"... in a vacuum that is almost indistinguishable from the rest of interstellar space, say 1 atom per stere(1 cubic meter) to be really generous, but the much more plentiful and gravitationally active "dark matter" does not even collide with other dark matter???? So what is this "Drag force?" Magic?

You said it yourself, later in your post: at the temperatures mentioned the luminous gas should be largely ionized. The two approaching clouds would then most definitely have significant "drag" due to the em interaction.

[newguy357]

There is a great deal of effects that we use, and don't understand, like why the electrons flow on the outside circumference of the wire?

You're absolutely correct that there are many things we do not yet understand. Not to nitpick, but the example you used (charge flowing to the outside of a conductor) is something we do understand.

[newguy357]

at the temperatures mentioned the luminous gas should be largely ionized.

I retract this statement. It's late.

[Physicist]

At the time, we really did not have all the answers on how the interactions worked, but they did. Fun to argue at times...

It's certainly no disgrace if electricians don't understand the modern theory, because it's just not relevant to what they do. The fact that circuit diagrams represent current as flowing in the opposite direction to that in which electrons actually drift makes no difference to making the motors run and the lights go on.

As for gravity, what this result shows is that Einstein's nearly 100-year-old theory of gravity still works perfectly well. Some people thought that certain discrepancies in astrophysical measurements were showing us that Einstein's theory was wrong, but it turns out that the matter isn't what (or where!) we thought it was. The theory was making the correct predictions all along.

[Cold Heat]

We did not understand it 35 years ago when I first trained as a electrician. We only knew it did. Or at least some people knew it.

This is why most wire was solid.

We eventually derated the solid wire construction and uprated the stranded, which carried more current with less copper.

The last technical class I had on that subject was in the late eighties, when the phrase, "not completely understood" was used.

Praytell, do you know why?

Specifically why electrons flow on the surface, and not so much down the middle of a conductor....?

[Cold Heat]

The fact that circuit diagrams represent current as flowing in the opposite direction to that in which electrons actually drift makes no difference to making the motors run and the lights go on.

That must be car wiring, we work with AC, and it goes both directions. Most electricians, these days, do get training in DC controls, but don't spend a lot of time with theory, or DC circuitry.

I am a bit different as electricians go, because I started in electronics, and moved to electricity.

I once repaired televisions and the like. i still like to dabble with board level stuff and amplifier design.

Most master electricians don't venture into that field, because there is no need to. There is little money in it anymore.

[Cold Heat]

As for gravity, what this result shows is that Einstein's nearly 100-year-old theory of gravity still works perfectly well. Some people thought that certain discrepancies in astrophysical measurements were showing us that Einstein's theory was wrong, but it turns out that the matter isn't what (or where!) we thought it was. The theory was making the correct predictions all along.

My questions on gravity are not related to what it is or how to measure it. It is related to how it manifests it's self.

What sort of energy is the field attraction comprised of, and how can we manipulate it and by doing so, create it artificially.

I know the theory, and I don't pretend to understand them as it is not my field, but I have never met anyone who claims to know everything about gravity. If that were the case, why are we still using rocket propulsion and making a bird that has to fall out of orbit and endure reentry heat to land like a jumbo jet.

This is what my questions are.

So are you saying we know this!

[AndrewC]

Placemarker

[ApplegateRanch]

If it isn't an ether, is it an ester? Maybe a ketone?

I don't really "get" dark matter. Having spent time in caves, I don't consider normal matter "luminous", unless excited.
Is it not just 'regular' matter that is cold, as in near or at zero K?

Can you enlighten?

[ApplegateRanch]

I should have read further through the posts.

[Steve Van Doorn]

Let me get this straight.

If I go in to a thick forest in the middle of the night and turn out all the lights and I can not see my hand the dirt on the ground is dark matter is it not?

[Physicist]

What sort of energy is the field attraction comprised of, and how can we manipulate it and by doing so, create it artificially.

Gravity is the curvature of spacetime. One of the consequences of this is that the dipole moment of the field is constrained to be zero. This poses a problem for gravitational engineering: all of our electromagnetic technology exploits the electromagnetic dipole interaction, but while there are positive and negative charges, there is only positive mass and energy. (Even anti-matter has positive mass.)

So you won't find anti-gravity, artificial gravity gravitational wave communicators, or the like. The field just doesn't work that way.

I know the theory, and I don't pretend to understand them as it is not my field, but I have never met anyone who claims to know everything about gravity. If that were the case, why are we still using rocket propulsion and making a bird that has to fall out of orbit and endure reentry heat to land like a jumbo jet.

Whatever the next theory of gravity has in store for us, it can't repeal the conservation of momentum and energy. We use rockets because, in order to accelerate, you have to have something to push against (conservation of momentum). Things heat up on reentry because the orbital energy has to go someplace (conservation of energy).

[PatrickHenry]

Me: "If our galaxy -- a rather congenial place so far -- were to encounter something like that ... I donno."

You: AFAIK, it would be the same as our galaxy encountering a galaxy of visible matter of equal mass:

[Slaps forehead] Ah, of course!

The interesting thing is that we wouldn't see it coming. Or for the most part even realize it if were in the middle of such an event.

[Cold Heat]

Whatever the next theory of gravity has in store for us, it can't repeal the conservation of momentum and energy.

When my imagination is turned on, (happens occasionally), I alway get this feeling that we are not seeing the tree clearly because the Forest is blocking the view.

I understand that conservation of energy is a given, and that the tremendous amounts of energy needed to mimic and create artificial gravity may theoretically prevent it's creation. But i cannot get over a feeling that I have always had, that tremendous amounts of literally free energy have been at our fingertips, yet we cannot realize it.

So I continue to try to find out where, and what it might be. If found, conservation of energy may well be a problem no longer.

[js1138]

Sometimes it pays to skip the first day of a science thread.

[longshadow]

What vexes me is the structure of dark matter. Does it form some type of "proton" or "electron"? Is it homogeneously distributed or is there some kind of structure behind it? Does it aggregate to form large masses the way normal matter forms planets and stars, or even simple dust grains? With all that mass, can dark matter form black holes? Are there different types of dark matter? Evidence of its existence, like this in the NASA report, is interesting, but it breeds a whole host of additional questions.

.... most of which cannot be answered until they come up with some idea of what the "dark" matter is made up of, which is probably a job for the particle physicists.

Physicist; do you have any info on lines of research trying to determine what the dark matter is? What do they know it is is NOT made out of?

[Physicist]

Physicist; do you have any info on lines of research trying to determine what the dark matter is? What do they know it is is NOT made out of?

It is not made out of any known type of particle. It can be bound gravitationally, as we see here, but it does not form clumps like stars or dust grains.

As for the black hole question, as luck would have it, I answered that before.

[newguy357]

Praytell, do you know why?

Specifically why electrons flow on the surface, and not so much down the middle of a conductor....?

Uhhh, yes. Just like anyone who has taken freshman physics in the last 100 years should. It is taught in the EM portion of freshman physics. It is quite intuitive. Visualize a spherical conductor. Remove an electron from the center. What happens? An electric field is set up from that positive charge. What happens because of that? One of the free flowing electrons in this conductor will move along that electric field into the center where the previous electron was vacated, thus negating the original electric field but creating a new one further out (radially) of the same magnitude as the original. That causes an electron from further out to repeat the above. Do that many times and pretty soon all your charge is on the surface. That is basic physics and no one has questioned it for a century.

[newguy357]

That must be car wiring, we work with AC, and it goes both directions.

Not it doesn't: not at the same time. AC goes one direction and then the other, one and then the other. You completely missed his point. Current flows one direction at any time, not both directions simultaneously. His only point is that when designating this in a circuit diagram the convention is to show which way positive current flows, even though what's providing the currents are electrons which are moving in the opposite direction.