dark matter temperature

[nebel]

We can only visually detect objects above absolute 0 degrees kelvin. so,
has anybody thought of an alternative theory that proposes matter existing at zero or even negative energy level? invisible matter? matter not giving off any radiation, where not only electro magnetism acts weirdly but not "gravity" ( spacetime warp) or it's effects?

 

[Dicart]

has anybody thought of an alternative theory that proposes matter existing at zero or even negative energy level? es.

Can a negative temperature exists ? Yes. (negative energy level i dont know what this mean).
It is not speculative science, only some scientific curiosity.
https://en.wikipedia.org/wiki/Negative_temperature

invisible matter? matter not giving off any radiation, where not only electro magnetism acts weirdly but not "gravity" ( spacetime warp) or it's effects?

Why not, but how could this matter be so cold in space ?

 

[nebel]

Why not, but how could this matter be so cold in space ?

good question, with even non baryonic gravity waves delivering energy.
I think there is a cold dark matter theory.

 

[Dicart]

good question, with even non baryonic gravity waves delivering energy.
I think there is a cold dark matter theory.

Perhaps the cold matter could be some Bose-Einstein condensate.

In condensed matter physics, a Bose–Einstein condensate (BEC) is a state of matter (also called the fifth state of matter) which is typically formed when a gas of bosons at low densities is cooled to temperatures very close to absolute zero (-273.15 °C, -459.67 °F). Under such conditions, a large fraction of bosons occupy the lowest quantum state, at which point microscopic quantum mechanical phenomena, particularly wavefunction interference, become apparent macroscopically. A BEC is formed by cooling a gas of extremely low density (about one-hundred-thousandth (1/100,000) the density of normal air) to ultra-low temperatures.

This state was first predicted, generally, in 1924–1925 by Albert Einstein[1] following and crediting a pioneering paper by Satyendra Nath Bose on the new field now known as quantum statistics.[2]

https://en.wikipedia.org/wiki/Bose–Einstein_condensate

Trying to find something about this hypothesis, it seem that it could be a possibility.

Per example here :

The nature of one of the fundamental components of the Universe, dark matter, is still unknown. One interesting possibility is that dark matter could exist in the form of a self-interacting Bose–Einstein Condensate (BEC). The fundamental properties of dark matter in this model are determined by two parameters only, the mass and the scattering length of the particle. In the present study we investigate the properties of the galactic rotation curves in the BEC dark matter model, with quadratic self-interaction, by using 173 galaxies from the recently published Spitzer Photomery & Accurate Rotation Curves (SPARC) data. We fit the theoretical predictions of the rotation curves in the slowly rotating BEC models with the SPARC data by using genetic algorithms. We provide an extensive set of figures of the rotation curves, and we obtain estimates of the relevant astrophysical parameters of the BEC dark matter halos (central density, angular velocity and static radius). The density profiles of the dark matter distribution are also obtained. It turns out that the BEC model gives a good description of the SPARC data. The presence of the condensate dark matter could also provide a solution for the core–cusp problem.

https://link.springer.com/article/10.1140/epjc/s10052-020-8272-4

 

[nebel]

the constraints for zero temperature DM are narrow. It can not absorb or reflect any radiation. Would the Bose- Einstein plama fit that limitation?

 

[Dicart]

the constraints for zero temperature DM are narrow. It can not absorb or reflect any radiation. Would the Bose- Einstein plama fit that limitation?

It would be nice if i could answer this.
But i suppose i am not skilled enough and i do not have many observational facts to draw a conclusion on this eventuality.

I can only propose an alternative solution to the dark matter problem (but it has nothing to do with matter).

 

[RainbowSingularity]

We can only visually detect objects above absolute 0 degrees kelvin. so,
has anybody thought of an alternative theory that proposes matter existing at zero or even negative energy level? invisible matter? matter not giving off any radiation, where not only electro magnetism acts weirdly but not "gravity" ( spacetime warp) or it's effects?

does a black hole "give off"(active production outward) energy that is detectable ?

while i realize there may not be a simple answer to that question
my purpose is to define the nature of detectable version perception of existence by relative actions of other matter/objects etc

e.g if there was an anti-gravity particle how could we detect it ?

 

[nebel]

my purpose is to define the nature of detectable version perception of existence by relative actions of other matter/objects etc

"other matter objects" might define a sensor, camera that directly captures the original emitted radiation. or an acho glow of it;s reflection.
The OP question was, could dark matter (and I believe it might be a red herring) give off no light, because it is too cold to do so. and it is not radioactive either.

e.g if there was an anti-gravity particle how could we detect it ?

have we even detected gravitons, tons of it? or tons of the higgs boson?

does a black hole "give off"(active production outward) energy that is detectable ?

Hawking's radiation, relativity jets

 

[RainbowSingularity]

The OP question was, could dark matter (and I believe it might be a red herring) give off no light, because it is too cold to do so. and it is not radioactive either.

are all things photonic by observable conclusion ?
e.g if we are not using photonic devices, what are we using ?[point= can it be detected using something other than its heat]

does a photon exist outside a vibrational frequency range ?
particle ?
do any particles not vibrate ?

is a particle a stationary object ?(static versus non static?)

 

[Dicart]

are all things photonic by observable conclusion ?
e.g if we are not using photonic devices, what are we using ?[point= can it be detected using something other than its heat]

Curently i see at least 3 types of "particles" detectors :
Light telescop/radiotelescop, for electromagnetic radiation (so photons).
Collision detector to detect particles (neutrino detectors, Geiger counter, cloud chambers, etc).
Gravity detector to detect gravity waves.

Now, to get an image, we can use the first of three here very efficiently, and sometime we can use a little the cloud chambers to say where the particle come from (we see the trail the particles left in the "cloud").

particle ?

In physic, a "particle" is a generic term that include atom (particle is a "small part of matter").
Smaler particle are named "subatomic particles".
So neutron/proton/electron are particles and the atom composed of these three particles are particles.
The quarks are particles and they compose the particles neutron and proton.

do any particles not vibrate ?

E=h*nu
E : Enregy
nu : Frequency (vibrational rate)
h : Planck constant
So if a particle has no energy, perhaps we can say that it dont vibrate.

But this is perhaps a too simplified point of view (i am not a specialist), in quantum physic i think that nothing can be in a "resting state". There could be a virtual vibration that can appear in some circumstances (when the particle is accelerated per example).
Immobility doesent exists.

An other question is : If we vibrate at the same rate as the incoming wave, can we detect it ?

is a particle a stationary object ?(static versus non static?)

A particle is also a wave.
Perhaps a better question could be : Do any particle expand like a wave ?

 

[nebel]

are all things photonic by observable conclusion ?
e.g if we are not using photonic devices, what are we using ?[point= can it be detected using something other than its heat]
does a photon exist outside a vibrational frequency range ?
particle ?
do any particles not vibrate ?
is a particle a stationary object ?(static versus non static?)

all very pertinent questions, and in a state of matter that is devoid of any energy, not just in place vibration, but even spin. would its presence not be undetectable by any means, safe the effects of its mass on spacetime?

 

[river]

are all things photonic by observable conclusion ?
No , the source of protons is physical .

e.g if we are not using photonic devices, what are we using ?[point= can it be detected using something other than its heat]

does a photon exist outside a vibrational frequency range ?
particle ?
do any particles not vibrate ?

is a particle a stationary object ?(static versus non static?)

Highlighted

Could maybe but eventually it will break down to its fundamental constituents .

None .

 

[river]

It would be nice if i could answer this.
But i suppose i am not skilled enough and i do not have many observational facts to draw a conclusion on this eventuality.

I can only propose an alternative solution to the dark matter problem (but it has nothing to do with matter).

To your last statement , true

DE . Dark Energy , the energy of speed . Superfluids . Non Friction motion . Absolute Zero ( and greater to my thinking ) is very interesting .

And the magnetic field is extremely confined , extremely small . Because there is no heat . Heat allows expansion . Cold does not .

 

[nebel]

Think about this: DM in it's halos has to be sustained in place against gravity. We do it by orbital speed, centrifugal "force" so:
May be
DM is so cold it freezes spacetime to kind of a "solid" for itself.

 

[Dicart]

Think about this: DM in it's halos has to be sustained in place against gravity. We do it by orbital speed, centrifugal "force" so:
May be
DM is so cold it freezes spacetime to kind of a "solid" for itself.

With this hypothesis, Dark Matter could be the space itself organized in a new unknown state .
Some are doing such speculation concerning the inner space of the black holes, saying space could be in a different phase we already know.
The problem is, for black hole we can understand why space could be in an other phase, but for space between galaxys, why ?

Phase transitions are another common theme.

If space is assembled, it might be disassembled, too; then its building blocks could organize into something that looks nothing like space. “Just like you have different phases of matter, like ice, water and water vapor, the atoms of space can also reconfigure themselves in different phases,” says Thanu Padmanabhan of the Inter-University Center for Astronomy and Astrophysics in India.

In this view, black holes may be places where space melts.

Known theories break down, but a more general theory would describe what happens in the new phase. Even when space reaches its end, physics carries on.

https://www.nature.com/articles/d41586-018-05095-z

 

[sculptor]

?
Is this true for Dark Matter :
Gravity is inversely proportional to temperature?

 

[Dicart]

?
Is this true for Dark Matter :
Gravity is inversely proportional to temperature?

If you understand well, the above hypothesis is highly speculativ.
In this case i doubt we can draw a law so simple as "gravity is proportional to temperature".

On the other hand, gravity could have something to do with "temperature", but not the same as we talk about with agitation of matter. Gravity could be a thermodynamical emergent effet.

The thermodynamic description of gravity has a history that goes back at least to research on black hole thermodynamics by Bekenstein and Hawking in the mid-1970s. These studies suggest a deep connection between gravity and thermodynamics, which describes the behavior of heat. In 1995, Jacobson demonstrated that the Einstein field equations describing relativistic gravitation can be derived by combining general thermodynamic considerations with the equivalence principle.[1] Subsequently, other physicists, most notably Thanu Padmanabhan, began to explore links between gravity and entropy.[2][3]

Erik Verlinde's theory
In 2009, Erik Verlinde proposed a conceptual model that describes gravity as an entropic force.[4] He argues (similar to Jacobson's result) that gravity is a consequence of the "information associated with the positions of material bodies".[5] This model combines the thermodynamic approach to gravity with Gerard 't Hooft's holographic principle. It implies that gravity is not a fundamental interaction, but an emergent phenomenon which arises from the statistical behavior of microscopic degrees of freedom encoded on a holographic screen. The paper drew a variety of responses from the scientific community. Andrew Strominger, a string theorist at Harvard said "Some people have said it can't be right, others that it's right and we already knew it – that it’s right and profound, right and trivial."[6]

In July 2011, Verlinde presented the further development of his ideas in a contribution to the Strings 2011 conference, including an explanation for the origin of dark matter.[7]

Verlinde's article also attracted a large amount of media exposure,[8][9] and led to immediate follow-up work in cosmology,[10][11] the dark energy hypothesis,[12] cosmological acceleration,[13][14] cosmological inflation,[15] and loop quantum gravity.[16] Also, a specific microscopic model has been proposed that indeed leads to entropic gravity emerging at large scales.[17] Entropic gravity can emerge from quantum entanglement of local Rindler horizons.[18]

https://en.wikipedia.org/wiki/Entropic_gravity

 

[nebel]

?
Is this true for Dark Matter :
Gravity is inversely proportional to temperature?

In this idea that nebel through out there, , all DM is invisible because of giving off no signal, because at zero kelvin or below, it is not energetic enough to so . so:
the inverse square law appears to be unaffected by temperature. it just is.

Dark matter becoming visible by getting warmed up and shining would not change the reading on your gravity instrument

 

[river]

sculptor said: ↑
?
Is this true for Dark Matter :
Gravity is inversely proportional to temperature?

In this idea that nebel through out there, , all DM is invisible because of giving off no signal, because at zero kelvin or below, it is not energetic enough to so . so:
the inverse square law appears to be unaffected by temperature. it just is.

Dark matter becoming visible by getting warmed up and shining would not change the reading on your gravity instrument

Highlighted

Disagree

DE then DM . Then Galaxies and Quasars Because of superconductivity ( cold ) no friction , hence speed , not heat .

 

[nebel]

DE then DM . Then Galaxies and Quasars Because of superconductivity ( cold ) no friction , hence speed , not heat .

That is an interesting scenario. if I understand right,
Energy, existing before the big Bang Bang could be called "Dark" energy, because it must have been there, but we can not see it. or beyond 13.8 light years into the past. The first few years are also opaque to us, but is that because all matter was " Dark Matter" ?--- not what mainstream science found. -- Then some of the dark matter became baronic, turned into galaxies and stars? by emerging internal friction?

instead of being supercharged with DE, think of DM as deprived of all energy to the point of invisibility. and additionally not being able to absorb or reflect any energy, waves or particles at all.