Difference between neutrinos and anti-neutrinos discovered, mightlead to more types of neutrinos

Yousuf Khan wrote:

On 8/14/2010 10:11 PM, eric gisse wrote:
Yousuf Khan wrote:

Eric, your follow-up-to is still redirecting only to sci.physics. This
is on-topic in sci.astro, you need to fix your newsreader.

On 10-08-13 06:25 AM, eric gisse wrote:
Yousuf Khan wrote:

This could lead to the discovery of the "sterile" neutrino. A
hypothetical version of the neutrino which is much more massive than
regular neutrinos, and travel at sub-relativistic speeds. Thus they
could be good candidates for Dark Matter on their own, and they are
even required by some modified gravity theories to make the equations
work out.

I've suspected there's more than 3 neutrinos, purely on the basis of
analysis of WMAP data. Interesting.

Prior to the discovery of Dark Energy, the cold fluctuations in the CMB
map were explained as the contribution of neutrinos.

They still are.

Yeah, maybe 1% of it is attributed to neutrinos these days, the
remaining 99% goes to dark energy.

Stop guessing.

http://lambda.gsfc.nasa.gov/product/...er_spectra.pdf

Section 4.2.6


Actually, the discovery of a sterile neutrino would strengthen the case
for modified gravity theories, such as STV gravity, more than it would
stengthen the case for pure Dark Matter theories.

Only in bizarro world. A moderately massive sterile neutrino would
satisfy all the features of dark matter, that's why it is such a hopeful
candidate.

STV Gravity, a modified gravity theory, requires an average neutrino
(either sterile or regular) to weigh about 2 eV.

Then all are wrong, based purely on terrestrial experiments.


I was wrong previously, a sterile neutrino would *not* be a good
candidate for explaining galactic rotation curves and other galactic
astrophysical scale phenomena. The sterile neutrino would still be
traveling at relativistic speeds, just not as highly relativistic as
regular neutrinos. However, the mass of sterile neutrinos could affect
the overall shape of the universe at cosmological scales.

Relativistic speeds at formation, maybe - depending on how much mass and
how they are generated. But not now, and not for a long time.

Well, how do you expect it's going to slow down?

Expansion.

They are only talking
about slowing down from 0.99c to something like 0.95c when going to
sterile neutrinos. Still too much speed for galaxies.

Probably, but that presumes that a lot of kinetic energy is given to them.
Since we don't know how, or even if, sterile neutrinos are produced, the
production mechanism might give them subrelativistic speeds.


However, one calculation shows that if neutrinos were to weigh just 50
eV, which is still 10,000 times less massive than electrons, just the
shear number of neutrinos would added upto enough mass to slow the whole
universe down and return it to a Big Crunch scenario.

Yousuf Khan

50 eV is about a factor of 25 larger than current observation suggests, and
a factor of 100 larger than what is required for current cosmological models
to be correct.

On Aug 14, 10:57*am, Yousuf Khan wrote:
I was wrong previously, a sterile neutrino would *not* be a good
candidate for explaining galactic rotation curves and other galactic
astrophysical scale phenomena. The sterile neutrino would still be
traveling at relativistic speeds, just not as highly relativistic as
regular neutrinos. However, the mass of sterile neutrinos could affect
the overall shape of the universe at cosmological scales.


i do not know why it is so hard for modern scientist to understand
that dark matter are really depressions in spacetime.
depressions in spacetime are not always cause by matenergy
concentrating. BH are kept in check when they are eating
matenergy but when they are not, they simply spin out like a
gyro. their event horizons chance in geometry.


Plus, there is no hope of ever detecting sterile neutrinos, as they
aren't even Weakly Interacting. They have no Weak force interactions,
therefore they won't be detected even in neutrino detectors.

* * * * Yousuf Khan


there is no way of detecting them but there are many ways of
calculating
their possible mass and populations. with great analysis on what all
other neutrinos are doing and general observation.

when Dmitri Mendeleev constructed the periodic table, he didn't
have all the elements to form it but he live empty spaces
where the probable missing elements should appear later on.

it should be a similar case with neutrino science only that
the empty spaces will not be filled with direct empirical evidence.

r.y


Dark matter - Wikipedia, the free encyclopedia
"There have been no particles discovered so far that can be categorized
as warm dark matter. There is a postulated candidate for the warm dark
matter category, which is the sterile neutrino: a heavier, slower form
of neutrino which doesn't even interact through the Weak force unlike
regular neutrinos. If warm dark matter particles do exist, it would not
be enough to explain galactic formation, and cold dark matter would
still be required to fill that purpose. Interestingly, some modified
gravity theories, such as Scalar-tensor-vector gravity, also require
that a warm dark matter exist to make their equations work out."http://en..wikipedia.org/wiki/Dark_matter#Warm_dark_matter

On 16/08/2010 8:13 PM, Raymond Yohros wrote:
i do not know why it is so hard for modern scientist to understand
that dark matter are really depressions in spacetime.
depressions in spacetime are not always cause by matenergy
concentrating. BH are kept in check when they are eating
matenergy but when they are not, they simply spin out like a
gyro. their event horizons chance in geometry.

If they aren't caused by matter or energy then what would they be caused
by, do you suppose?

Next generation theories are converging on the idea that matter, energy,
and spacetime are all made of the same thing. Matter and energy are just
more concentrated versions of spacetime. That would explain why they
cause warping of spacetime.

Yousuf Khan

On Aug 17, 12:46*pm, Yousuf Khan wrote:
On 16/08/2010 8:13 PM, Raymond Yohros wrote:

i do not know why it is so hard for modern scientist to understand
that dark matter are really depressions in spacetime.
depressions in spacetime are not always cause by matenergy
concentrating. BH are kept in check when they are eating
matenergy but when they are not, they simply spin out like a
gyro. their event horizons chance in geometry.

If they aren't caused by matter or energy then what would they be caused
by, do you suppose?


lets see if i can make you answer that


Next generation theories are converging on the idea that matter, energy,
and spacetime are all made of the same thing. Matter and energy are just
more concentrated versions of spacetime. That would explain why they
cause warping of spacetime.


imagine what happens to a warped spacetime when it can no
longer sustain itself because all the matenergy causing it has
been transfer away?

r.y

On 15/08/2010 2:31 AM, eric gisse wrote:
Yousuf Khan wrote:
On 8/14/2010 10:11 PM, eric gisse wrote:
Yousuf Khan wrote:
Prior to the discovery of Dark Energy, the cold fluctuations in the CMB
map were explained as the contribution of neutrinos.

They still are.

Yeah, maybe 1% of it is attributed to neutrinos these days, the
remaining 99% goes to dark energy.

Stop guessing.

http://lambda.gsfc.nasa.gov/product/...er_spectra.pdf

Section 4.2.6

Okay, read that section over a couple of times, still don't see what it
has to say about the relative contribution of neutrinos vs. dark energy
to the cosmic background? That section just talks about how many
different species of neutrinos there can be, and what their average mass
can be.

Only in bizarro world. A moderately massive sterile neutrino would
satisfy all the features of dark matter, that's why it is such a hopeful
candidate.

STV Gravity, a modified gravity theory, requires an average neutrino
(either sterile or regular) to weigh about 2 eV.

Then all are wrong, based purely on terrestrial experiments.

What terrestrial experiments? The paper you just cited a little while
ago shows various ways to count up the mass of the neutrinos, and they
range from 1.3 eV to 1.8 eV, which is pretty close to the 2 eV that STV
Gravity needs.

Relativistic speeds at formation, maybe - depending on how much mass and
how they are generated. But not now, and not for a long time.

Well, how do you expect it's going to slow down?

Expansion.

How do you propose that works? Shouldn't expansion make neutrinos go
faster than they started at?

They are only talking
about slowing down from 0.99c to something like 0.95c when going to
sterile neutrinos. Still too much speed for galaxies.

Probably, but that presumes that a lot of kinetic energy is given to them.
Since we don't know how, or even if, sterile neutrinos are produced, the
production mechanism might give them subrelativistic speeds.

If they are trading kinetic energy for mass, then a sterile neutrino
would acquire a lot of mass to slow down to subrelativistic levels,
which would mean that they need to slow down to below 0.1c.

However, one calculation shows that if neutrinos were to weigh just 50
eV, which is still 10,000 times less massive than electrons, just the
shear number of neutrinos would added upto enough mass to slow the whole
universe down and return it to a Big Crunch scenario.

Yousuf Khan

50 eV is about a factor of 25 larger than current observation suggests, and
a factor of 100 larger than what is required for current cosmological models
to be correct.

Exactly my point. 50 eV is way, way too large for current observations,
so 50 eV would be the upper limit of possibility.

Yousuf Khan

Yousuf Khan ) writes:
On 15/08/2010 2:31 AM, eric gisse wrote:
Yousuf Khan wrote:
On 8/14/2010 10:11 PM, eric gisse wrote:
Yousuf Khan wrote:
Prior to the discovery of Dark Energy, the cold fluctuations in the CMB
map were explained as the contribution of neutrinos.

They still are.

Yeah, maybe 1% of it is attributed to neutrinos these days, the
remaining 99% goes to dark energy.
Gravity needs.

Relativistic speeds at formation, maybe - depending on how much mass and
how they are generated. But not now, and not for a long time.

Well, how do you expect it's going to slow down?

Expansion.

How do you propose that works? Shouldn't expansion make neutrinos go
faster than they started at?

As for the cosmic microwave background? (I understood that process was why
cosmic neutrinos had only energies comparable to their rest masses, not to
their birth energies.)

--John Park

On 18/08/2010 11:33 AM, John Park wrote:
Yousuf Khan ) writes:
On 15/08/2010 2:31 AM, eric gisse wrote:
Yousuf Khan wrote:
On 8/14/2010 10:11 PM, eric gisse wrote:
Relativistic speeds at formation, maybe - depending on how much mass and
how they are generated. But not now, and not for a long time.

Well, how do you expect it's going to slow down?

Expansion.

How do you propose that works? Shouldn't expansion make neutrinos go
faster than they started at?

As for the cosmic microwave background? (I understood that process was why
cosmic neutrinos had only energies comparable to their rest masses, not to
their birth energies.)

--John Park

I'm not sure what the question is that you're asking?

Yousuf Khan