Naked Science Forum

Non Life Sciences => Physics, Astronomy & Cosmology => Topic started by: SimpleEngineer on 01/11/2013 10:02:39

Title: Could we be surrounded by dark matter?
Post by: SimpleEngineer on 01/11/2013 10:02:39
I was walking my dog lasat night thinking about the properties of much of what i see around me and the questions that we are making about a multitude of things..

A little thought came to me, all of the time we talk about light and electromagnetic waves in a 2 dimensional form (wave length and amplitude).. but we live in a 3 dimensional universe (or yada yada about the others) yet all our calculations retain these simple calculations.. Has there been any work in 3D universes to explain the motion of light and EM?

But it also started me thinking about the rubber sheet universe as described (i think) by Einstein. what if the fabric of the universe were just lots and lots and lots of n-particles (clever word i thought up for a 'nothing' particle :P) which has the smallest possible mass (smaller than photons) and abhor energy, i.e. any energy they get they pass on as quickly as they could (i.e. speed of light) Thinking deeper into this, this explanation could describe inertia (resistance to changes in motion), wave form motion ('pulses' as waves) and all the other good stuff that I am far too stupid to even think about :P (contraction and dilation). These n-particles could exists at every point of the universe and provide the 'leverage' for all energy interactions to occur. could these particles present an explanation for the dark matter that is missing from the universe?

I googled some thoughts, and found myself redirected to neutrino.. but I am far too unsure of myself to understand any of what was said about it (as it keeps talking about neutrino's with and without mass)

I wonder if there had been any thought into this?
Title: Re: Could we be surrounded by dark matter?
Post by: woolyhead on 06/11/2013 19:38:30
Electromagnetic waves have the magnetic vector perpendicular to the electric one and move perpendicular to both at a given speed. Thus we have four dimensions for such a wave, don't we? Maxwell's equations describe such waves very well. The rubber sheet analogy describes how spacetime bends in the presence of mass so it's about gravity, not electromagnetism. How does getting rid of energy explain inertia? Please explain. I think I know what you had in mind but for the idea to work the maths must work and in this case it doesn't. All energy interactions occur because of the generation of appropriate force-carriers. In the case of gravity, it's gravitons, etc. The total mass of all the neutrinos in the universe would not come anywhere near explaining the missing mass in the universe. All this is described in the Standard Theory of atomic physics.
Title: Re: Could we be surrounded by dark matter?
Post by: evan_au on 06/11/2013 20:02:35
A Neutrino is almost a "nothing" particle - the Sun produces a lot of its energy in the form of neutrinos - and even at the orbital distance of the Earth, a billion of them pass through every square centimeter, every second. They pass through the bulk of the Earth almost without being affected.

Neutrinos can be detected (http://en.wikipedia.org/wiki/Neutrino_detector), with great difficulty. One of the aspects that was resolved once neutrinos could be reliably detected was that neutrinos oscillate between 3 different types. This changing behaviour means that they must be travelling slightly slower than the speed of light, and they must have a rest mass (but incredibly small).

Astrophysicists have done calculations of the number of neutrinos in the universe, and verified this against the experimental neutrino detector results. There just aren't enough neutrinos in the universe to account for the odd way that galaxies rotate.

So physicists are now searching  (http://en.wikipedia.org/wiki/Dark_matter#Direct_detection_experiments)for particles even more ghostly than neutrinos to account for dark matter. These particles could be all around us (and continually passing through us) without us noticing.
Title: Re: Could we be surrounded by dark matter?
Post by: Bill S on 06/11/2013 20:36:21
Quote from: SE
(clever word i thought up for a 'nothing' particle :P)


How many nothing particles equal something?

Quote
which has the smallest possible mass (smaller than photons)

How small is smaller than massless?

Title: Re: Could we be surrounded by dark matter?
Post by: SimpleEngineer on 07/11/2013 09:43:01
A Neutrino is almost a "nothing" particle - the Sun produces a lot of its energy in the form of neutrinos - and even at the orbital distance of the Earth, a billion of them pass through every square centimeter, every second. They pass through the bulk of the Earth almost without being affected.

Neutrinos can be detected (http://en.wikipedia.org/wiki/Neutrino_detector), with great difficulty. One of the aspects that was resolved once neutrinos could be reliably detected was that neutrinos oscillate between 3 different types. This changing behaviour means that they must be travelling slightly slower than the speed of light, and they must have a rest mass (but incredibly small).

Astrophysicists have done calculations of the number of neutrinos in the universe, and verified this against the experimental neutrino detector results. There just aren't enough neutrinos in the universe to account for the odd way that galaxies rotate.

So physicists are now searching  (http://en.wikipedia.org/wiki/Dark_matter#Direct_detection_experiments)for particles even more ghostly than neutrinos to account for dark matter. These particles could be all around us (and continually passing through us) without us noticing.

Oh okay was I wasnt ridiculously incorrect then :P.. It was the force carriers principle I was thinking about.. and poorly phrasing :P

and thanks evan_au, this was the premise of my thinking.. if we continuously find smaller and smaller particles, surely we would get to one that is 'almost' undetectable that is the most elementary particle of them all.

Question though, what are gravitons and how do they compare to photons?