Dark Matter Contest Enlists the Masses

Can not be detected? Bah!

I just took this snapshot. Focus is dead on, too.

Which also raises the question... In the search for Dark Matter, is being blind a hinderance?

Can you count it?

Never mind, all my computing power is being lent to Lunar Crater Counting so I wouldn't have time.

How WOULD you look for it, anyway?

Yeah, but you outta see it at gamma wavelengths. Take a trip without leaving the farm!

Scientists have launched a public competition in an attempt to better understand dark matter

Well if they were that serious they would have posted a question on CR4

"What is dark matter?"

1) They haven't yet answered the question "What is the nature of matter?" and so they're looking to non-specialists for help with dark matter?

2) They insist repeatedly that dark matter cannot be detected directly, that it interacts only via gravitation but then show us 'ghostly halos' of dark matter around large galaxy clusters.

Even though it's invisible.

WTF, over?

"2) They insist repeatedly that dark matter cannot be detected directly, that it interacts only via gravitation but then show us 'ghostly halos' of dark matter around large galaxy clusters."

But it's dark ghosts. :)

All those pics come from plotting 'false color pixels' out of data analysis software, I guess. The whole quest seems to be data analysis, in which the non-astronomers may be able to help.

Hello Jorrie,

Long time no see! Thanks for replying.

Yes, I'm quite sure it is not an image of something there but, rather, an overlay of the results of an analysis of that Something's effect on Something Else. Straight-off photos of those same clusters do not show a halo of anything. Thing is, they don't say this, but simply let the reader believe these are photos of dark matter. Even more disconcerting is that nobody seems to make a connection between "dark matter interacts only via gravitation and is undetectable by other means" and "here's a photo of the stuff" in the very same article. Go figure. (yes, this sort of thing makes me bitchy)

If there were one or more universes parallel to ours in a higher dimension, could the gravity from the matter in these universes cross over into ours, attracting matter like a hidden magnet under the table attracts objects on the table top?

I can't shake this mental picture.

http://www.quora.com/Physics/Could-dark-matter-be-a-consequence-of-gravity-from-objects-of-neighboring-parallel-universes#

It is possible and some papers have been written suggesting that "branes" parallel to ours could cause the dark matter effects. It does however remain highly speculative and various issues have not been resolved.

The reason for studying dark matter's effects so vigorously is that the more we know about it, the more speculative ideas we can eliminate and perhaps come closer to the truth.

http://en.wikipedia.org/wiki/Brane_cosmology

Yes, that is one of the postulates of String Theory. Gravity can leak from one brane to the next and it is supposed to explain why gravity appears as such a weak force.

Gravity can 'leak'? Spacetime curvature leaks? How does curvature leak? This makes no sense at all.

Maybe the n-dimensional space is curved and the imbedded 4 dimensional spacetime we live in curves with it? Or, vice-versa, the curvature of our 4 d spacetime imparts curvature on the n-dimensional substrate in which it is imbedded which in turn affects the curvature of neighboring universes. Possibly the folks that live next door are puzzling about their "dark matter" that results from the gravitation from our galaxies.

Just speculating.

String theory postulates that gravity or more precisely, gravitons, are made of strings. There are two types of strings. Loops, which are bound to the brane that they are part of; open ended strings, which can migrate from brane to brane.

If this 'leakage' has been going on then we should see evidence that gravity was stronger in the past, yes? And if these cosmic strings (there is some circumstantial evidence for them, btw, related to anomalies in the time-of-arrival of gravitationally-lensed light from distant quasars) can migrate from brane to brane, then they can migrate into our universe as well as out of our universe, which sort of contradicts the 'leakage' bit explaining weak gravity, yes? That is, unless they only migrate out of in our particular universe's case, which naturally leads to the question "What makes our universe so special in this one regard?" Special cases are always somewhat suspect.

Meanwhile, back at the Spacetime-Curvature ranch, you still haven't related curvature and the 'leakage' thereof to string theory...?

Just a clarifying comment on spacetime curvature: it is wrong to equate it to gravity. Spacetime curvature equates to tidal-gravity, which is the point-to-point differences in gravitational acceleration. A hypothetical uniform gravitational field has gravity, but zero spacetime curvature.

As for the leaking of gravity, you just need one extra dimension and anything is possible...

A hypothetical uniform gravitational field has gravity, but zero spacetime curvature.

I assume an example of that would be a LaGrangian point, like the L1 point, where there is a gravitational field but it is relatively flat, the 'pull' of the two masses being equal within a small zone around the point. Correct?

"If this 'leakage' has been going on then we should see evidence that gravity was stronger in the past"

Maybe not if the net flow is zero. Sort of like radio waves permeating multiple rooms. The field strength may be uniform, yet able to transcend through walls.

In this case: transcend branes.

I think dark matter may be made up of nothing....Possibly just holes in space so small that they are hard to detect until a vast number of them combine....A drain to another dimension.....Like say a water tank(all of space) with holes leaking, these holes can't be plugged with debris though, they only cause an accumulation of debris, in this case visible matter....Let's take our water tank for demonstration, put several pin holes in the tank, and add a quantity of neutral weighted material so shaped that they cannot seal the hole, and watch what happens.....A lot, and I guess eventually all, of the particles will eventually accumulate at the leaking sites....

You wouldn't happen to be from the Netherlands, would you?

No, but I have visited occasionally....

My own view is that dark matter is NOT part of our universe. I believe it is part of the "exoverse", which I define as "every thing that was present" when our big bang occured. Our big bang could not have occured within "nothing", so there must be plenty of "stuff" that we are expanding around and into.

Isn't that kind of like saying that if you blow up a balloon in a room, the balloon is not in the room?

Good analogy. I am saying that the balloon IS in the room. A flea inside the balloon would not be able to see anything outside of it, but it could still be affected by wind, heat, etc.

You wrote, "Our big bang could not have occured within "nothing"."

Why not?

I have "nothing" to add.

:)

What if our understanding of the electromagnetic field generated by billions of stars in each galaxy is incorrect?

The magnetic field, (and hence the attractive power) of our sun alone is enormous, as proven by the fact that the Voyager spacecrafts have not reached the limits of the helio-pause, or end of the sun's magnetic influence.

Granted, on Earth we have not been able to generate a magnetic field of sufficient strength to affect gravity, is does not follow that the nearly incalculable amount of energy generated by billions of stars is incapable of doing so.

It would definitely explain why the Milky Way, considered to rotate at too high a rate of speed, is still maintaining cohesion. The electromagnetic attraction of the stars themselves would explain the cohesive force.

"Dark Energy" could be explained in visualizing a puddle of water.

• When you remove water from a puddle on a hydrophobic surface, the puddle shrinks. If you add water to the puddle it expands. Space is the puddle, energy is the water added.
  

The energy output of billions of stars, in billions of galaxies, would cause space, (the puddle) to expand. Since there appears to be no new galaxies, (using the energy, the added water) in our vicinity of the universe, our area appears to expand, and even accelerate in expansion.

Even though I am certain most physicists will disagree with my opinion, the theory does fit the observed facts.

Just my opinion, Dragon

It does not fit the 'observed facts' at all.

Um..the Voyagers are following trajectories determined by gravitational considerations?

Voyager 1 is presently 122.993 AU from Earth (1 AU = 1 Astronomical Unit = 1 x average distance between Earth and the Sun = 149,597,871 km). That's 18.4 billion km from Earth.

Voyager 2? 100.273 AU = 15.0 billion km.

Now, if the Sun's magnetic field were of such a magnitude as to have the effect you suggest, and at these distances, don't you think it would have a profound effect on a simple Earthbound compass needle? You know, the kind you carry camping or had as a kid? Not only would the effect be profound, but you would see the effect vary throughout the day as the compass' orientation with respect to the Sun changed as the Earth turned.

But you don't. A compass needle shows no noticeable diurnal variation at all. Not only, but the Sun's magnetic field is a dipole, and dipolar magnetic fields drop off with the cube of the distance. Do you realize how powerful that magnetic field would have to be to have the influence you suggest?

I can tell you right now your computer's hard drive - yours and everyone else's - would be piece of scrap metal. Mechanical clocks and watches wouldn't work. Motors would get fried. We'd have unimaginable electrical storms on a planetary scale. Continuously. Civilization probably wouldn't stand a chance. Maybe not even life itself.

If the Sun were a magnetar?

Nah, not even then. The superheated plasma the Sun's field would drag around with it would have long since burned the Voyagers to a crisp. And Earth.

Try gravity.

V1 has already reached the heliopause. Thing is, the heliopause doesn't stay put but expands and contracts with solar activity and variations in the interstellar medium.

Other, indirect indicators of the Voyagers' proximity to the heliopause abound. One such indicator is the VLF radio emissions from the heliopause which can only be detected at short range thanks to interactions with the Solar medium (plasmas are generally opaque to VLF radio emissions although 'magnetised' plasmas [ones containing an entrained magnetic field] are known to 'duct' such emissions parallel to field lines). The heliopause' VLF emissions, which are similar to the emissions which also occur at the boundaries of Earth's, Jupiter's and Saturn's magnetospheres, were detected a few years ago as the Voyagers approached the heliopause and place it at an average distance well in agreement with theoretical considerations. The heliopause is not a light year away by any stretch; more like light-hours distant.

Which astrophysicists? You are surely confusing someone's statements about the heliopause' distance with something else, possibly something having to do with the Oort Cloud's extent? The O.C. does extend a considerable distance and on that order, and possibly as far as halfway to Proxima Centauri. The heliosphere's bow shock is also extensive to be sure, but certainly not on the order of a light year. Really, the O.C. is the only Solar System feature on that scale.

Just to be clear, your eddy-current example is familiar except that it illustrates the case where the induced current creates a field which opposes the magnet's motion rather than one which attracts the object toward the field source, as per your original post.

As far as the Earth's field's influence on a compass needle, it does not serve to shield from external fields such as the Sun's. The interaction is complex, but if the Sun's magnetic field were of such a magnitude as to materially decelerate the Voyagers at their distance, Earth's magnetic field would be negligible by comparison.

And speaking of eddy currents, consider Earth's iron molten outer- and solid inner iron core rotating in such a field coupled with Earth's orbital motion and you'd have what? Eddy currents, maybe? How big? If you said "Big enough to heat the planet to incandescense?" you'd be dead right.

Finally, concerning galactic-scale magnetic fields, what do you think the galactic interstellar medium would do in the presence of a net galactic magnetic field sufficiently powerful to reign-in the orbits of entire stars were that even possible? 1) What happens when gaseous, ionised conductors move through magnetic fields? 2a) What do moving electrons do in the presence of magnetic fields? 2b) Ions? 3) What happens when charges accelerate? 4) What aren't we seeing from the interstellar medium that would be present in abundance were your proposition true? 5) What does its absence tell you about the net galactic magnetic field? 6) What do stellar spectral emissions do in the presence of magnetic fields that is used as an accurate measure of the magnetic field strengths of stars and other ionised media? 7) What are these spectral emissions saying? 8) What does all of the foregoing tell you?

The hard part of that theory is how non-magnetic objects are attracted by a magnet. Most of the planets in our solar system have no magnetic field nor material that is magnetic.

If that were true you would have orbital anomalies between planets with iron cores (such as our own) and the gas balls in the outer solar system.

However, Newtons equations predict every orbit in the solar system with stunning precision. The exception would be Mercury, which was found to be from effects described in Einstein's theory of Relativity.

Lastly, as pointed out before, the equations of gravity fall off at the square of the distance as opposed to the equations of magnetism which fall off at the cube of the distance.

Newtons equations work with the highest of precision. Dump in any corrective constant you want, but the equations of magnetism will not explain the motions of all the planets even in a gross way.

Actually, A.H., those 'gas balls' have larger and far more electrically-conductive innards than even planets with iron cores: oceans of metallic hydrogen which is speculated by some to also be superconducting. Witness Jupiter's enormous magnetic field. Jove's magnetosphere, were it visible from Earth, would appear as large as a full Moon.

The Sun's magnetic field periodically reverses with a period related to the Sunspot Cycle. Over this time the field strength also varies, reaching a peak and then snapping through zero to assume an opposite polarity. Very handy...

Were the Voyagers'trajectories influenced by induced eddy currents as suggested, we'd see corresponding fluctuations in the crafts' velocities. Obvious fluctuations which would have been reported in the literature. Given that we can track a spacecraft's velocity to a resolution of mere mm/sec, there should be no problem seeing velocity reductions of such magnitude as to materially delay exit from the Solar System, as suggested. Not only would the velocity fluctuate with the Sunspot Cycle, but so would the Voyagers' trajectories show cyclic variations.

Dragon: Contact JPL for detailed logs of the Voyagers' trajectories and velocity profiles from launch through present. If the data 'wiggle' at a rate related to the Sunspot Cycle, you may have something there. One test of your eddy-current theory.

I shall speak to everyone concerning Dark Matter but first I will give many reasons why I won't post this answer. I had written even to the greatest of minds (such as Stephen Hawkings) which I can verily prove beyond doubt and their programs such as on the discovery channel and others has reflected my new words pertaining to various other subjects given to them and opened new doors for them yet have they forgotten me! I can verify exactly what this Dark Matters is and even its relevance even as the Wisdom from God and given to the Ancients does testify! I shall sit upon this very wisdom until they are willing to give credit where credit is due but also know what I would speak of is certain and true and would open many new doors in given understanding!

May the blessing of the LORD be upon you.

Jan R. Hershberger

One more criterion would be the importance of learning these answers as it could only be compared with ones scientific discoveries such as Einsteins discoveries!

May the blessings of the LORD be upon you,

Jan R. Hershberger