Russia Defence Forum

Would you like to react to this message? Create an account in a few clicks or log in to continue.

Military Forum for Russian and Global Defence Issues


+17
Regular
magnumcromagnon
dino00
Aristide
Walther von Oldenburg
flamming_python
GarryB
GunshipDemocracy
LMFS
Viktor
nomadski
jhelb
George1
Morpheus Eberhardt
victor1985
Werewolf
kvs
21 posters

    Physics General Subjects Thread

    kvs
    kvs

    Posts : 10843
    Points : 10988
    Join date : 2014-09-11
    Location : Canuckistan

    Physics General Subjects Thread - Page 4 Empty Re: Physics General Subjects Thread

    Post  kvs Wed Nov 04, 2020 6:22 pm



    Oops we did it again!

    So Betelgeuse was actually 25% closer than assumed and thus smaller. Some years later they may correct it to 33%, who knows.
    Lots of posturing BS from astrophysicists who talk like they know more than God. But when you scratch under the surface there
    is nothing there but hot air and ad hoc nonsense.

    Recall how UY Scuti "fell from grace" as the largest star in the known universe to 7th place. And these "experts" claim to measure
    black holes down to the last solar mass. You never hear these clowns giving error bounds on their "measurements" in any of their
    public pronouncements. They don't even give real error bounds in their papers. Funny how astronomy has always been linked with
    the occult. Seems this voodoo is still with us today.



    GarryB likes this post

    kvs
    kvs

    Posts : 10843
    Points : 10988
    Join date : 2014-09-11
    Location : Canuckistan

    Physics General Subjects Thread - Page 4 Empty Re: Physics General Subjects Thread

    Post  kvs Tue Nov 24, 2020 8:57 am



    kvs
    kvs

    Posts : 10843
    Points : 10988
    Join date : 2014-09-11
    Location : Canuckistan

    Physics General Subjects Thread - Page 4 Empty Re: Physics General Subjects Thread

    Post  kvs Wed Nov 25, 2020 8:19 am



    Video where actual imaging of modern CPU die structure is made.   The juicy part is at around 13 minutes.

    They cut through the cache which has a regular structure but which reflects the transistor process tech used
    in the rest of the chip.   Cutting through other parts of the chip would give different structures and complicate
    the comparison.

    So what we see is that 7 nm and 14 nm are marketing BS.   The gate lengths are over 20 nm and there is
    not that much difference between "7" and "14" nm.   The little rant by the narrator is misleading since the
    evolution of CPUs has clearly involved actual geometric change.   It simply can't be claimed that a 130 nm
    process is the same as a 65 nm process.   The whole 3D "FinFet" technology allows marketing departments
    to claim BS size numbers.  

    It is clear from these images that no structure in these 3D transistors is smaller than 10 nm.   In the real world
    having components as small as 7 nm and the much hyped 5 nm would result in failure of the IC to be functional.  
    Around 3 nm there is a transition to the molecular cluster regime where continuum thermodynamics and material
    properties break down.   It is physically impossible to make any FinFet at 3 nm.   And 5 nm would have so
    much quantum tunneling that these transistors would not be acting deterministically in response to
    voltages.  

    Moore's law is quite dead.

    GarryB likes this post

    kvs
    kvs

    Posts : 10843
    Points : 10988
    Join date : 2014-09-11
    Location : Canuckistan

    Physics General Subjects Thread - Page 4 Empty Re: Physics General Subjects Thread

    Post  kvs Sat Nov 28, 2020 5:37 pm



    The fractal nature of reality.

    The video above is interesting but some of the analogies are hard to swallow. The water in the brain is a volume in which
    neurons and dendrites exist. It is not an energy. The dark voids between galaxies and the filaments linking them is space.
    Dark energy is not volume in the current cosmological theories, it is the attributed to the cosmological constant term in
    Einstein's GR equations which results in space-time solutions that are not static but expanding.

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

    There are attempts to attribute the cosmological constant to the quantum mechanical vacuum energy but as of now there
    are show-stopping issues. Dark energy is not volume and space, it is the change in the volume of space(-time).

    Unlike dendrites which grow away from the neurons to form a network, the large scale filaments seen in the universe linking
    galaxies are mass acting under gravity. This mass is not moving away from galaxies but towards them. These filaments
    are evidence that there were no galaxies in the past and mass was distributed more homogeneously. Over time small
    inhomogeneities grew resulting in the aggregation of mass into clumps and into sheets which collapse into filaments. So
    the filaments are slowly being mopped up by the galaxies (and galaxy clusters) but this process is much slower than the
    initial growth of matter(-energy) clumps. The amount of matter in the filaments is tiny compared to the amount in galaxies.
    As long as we are not talking about dark matter.

    Dark matter is believed to not condense into compact objects like stars and planets. It interacts basically just through
    gravity and has no or vanishingly small EM interaction. This means it does not radiate away its kinetic energy and acts
    like a perpetual gas since it cannot cool off. Dark matter could be orchestrating the regular mass filaments to some
    extent but even though it is supposed to be most of the mass in the universe (over three times more than regular
    mass that we can observe through spectroscopy) it is clearly not counteracting the aggregation of regular mass into
    galaxies. This makes sense since galaxies are potential wells for dark matter as well. So galaxy formation dynamics
    involve the gravitational contribution of dark matter. The large voids separating galaxies may be filled with dark matter
    but it is much more diffuse than in galaxy potential wells. Since there is a finite amount of dark matter it would be
    depleted from inter-galactic space by concentrating in galaxy potential wells.



    kvs
    kvs

    Posts : 10843
    Points : 10988
    Join date : 2014-09-11
    Location : Canuckistan

    Physics General Subjects Thread - Page 4 Empty Re: Physics General Subjects Thread

    Post  kvs Sat Nov 28, 2020 8:00 pm



    Never judge a book by its cover. Just because particle physicists act nice and are not total assholes all the time
    does not mean that they are holy and justified. Always look for the money motive. These people directly depend
    on the financing of bigger and bigger colliders. Because they do not really know a priori what the physical picture
    is. That is why experimentation is required. But their experiments are mostly flops so they spend a lot of time
    in pulling theories out of their rear ends.

    This does not mean that particle colliders are totally pointless. But we may require one deployed in space with length
    scaling in the thousands of kilometers. Are we going to spend tens of trillions of dollars and develop technology we
    do not have for an experiment that is not even likely to give results? I would think that letting time pass and
    doing such experiments in the future when they make economic sense is more justified.

    kvs
    kvs

    Posts : 10843
    Points : 10988
    Join date : 2014-09-11
    Location : Canuckistan

    Physics General Subjects Thread - Page 4 Empty Re: Physics General Subjects Thread

    Post  kvs Fri Dec 04, 2020 7:54 pm



    My favourite clickbaiter on YouCrap.

    Two trigger terms "free energy" and "graphene" = ad money.

    Brownian motion or molecular motion is also known as heat and is measured with temperature. This
    energy is not free by any measure. And predictability of particle trajectories is totally irrelevant and is
    not some spooky quantum mechanical effect but is purely classical and deterministic. Brownian
    motion requires a source of heat to maintain and will not just re-emerge spontaneously. Quantum
    mechanics does not override this fact.

    This is not zero point energy which is a sci-fi myth. ZPE cannot be extracted as a usable energy. It
    makes no sense to talk about the kinetic energy of particles at absolute zero. The internal energy of
    ground state atoms cannot be extracted. Molecules that are truly at absolute zero do not vibrate and
    rotate so these energy modes cannot be exploited either.

    There is no free lunch in this universe and most likely any other. All that graphene is doing is allowing
    thermal energy to be converted to electricity in a more direct fashion. Such material effects are not
    new.

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





    LMFS likes this post

    GarryB
    GarryB

    Posts : 30953
    Points : 31479
    Join date : 2010-03-30
    Location : New Zealand

    Physics General Subjects Thread - Page 4 Empty Re: Physics General Subjects Thread

    Post  GarryB Sat Dec 05, 2020 6:04 am

    Would have interesting applications for cooling though would it not?
    kvs
    kvs

    Posts : 10843
    Points : 10988
    Join date : 2014-09-11
    Location : Canuckistan

    Physics General Subjects Thread - Page 4 Empty Re: Physics General Subjects Thread

    Post  kvs Sat Dec 05, 2020 6:34 am

    GarryB wrote:Would have interesting applications for cooling though would it not?

    Yes like with Peltier coolers. I am not dismissing graphene as not useful, but methinks the hype is over the top.
    Graphene is like the miracle cure and too good to be true. We had similar unrealistic expectations when
    high temperature superconducting materials were found during the 1980s. It's been over 35 years and little
    has come from it. Maybe there will be fruits some day.

    kvs
    kvs

    Posts : 10843
    Points : 10988
    Join date : 2014-09-11
    Location : Canuckistan

    Physics General Subjects Thread - Page 4 Empty Re: Physics General Subjects Thread

    Post  kvs Fri Jan 22, 2021 12:43 am



    A bit surprising. I swallowed the gyroscopic stabilization nonsense as well. It is very easy to swallow BS and
    that is why propaganda works.

    LMFS likes this post

    The-thing-next-door
    The-thing-next-door

    Posts : 1002
    Points : 1054
    Join date : 2017-09-18
    Location : Uranus

    Physics General Subjects Thread - Page 4 Empty Re: Physics General Subjects Thread

    Post  The-thing-next-door Thu Feb 11, 2021 6:41 pm

    I was just wondering if there were any good places to read up on physics and physics based technologies? A lot of members seem to be quite familiar with this area.
    avatar
    Vann7

    Posts : 5040
    Points : 5146
    Join date : 2012-05-16

    Physics General Subjects Thread - Page 4 Empty Re: Physics General Subjects Thread

    Post  Vann7 Fri Feb 12, 2021 12:09 am

    kvs wrote:

    My favourite clickbaiter on YouCrap.

    Two trigger terms "free energy" and "graphene" = ad money.

    Brownian motion or molecular motion is also known as heat and is measured with temperature.  This
    energy is not free by any measure.  And predictability of particle trajectories is totally irrelevant and is
    not some spooky quantum mechanical effect but is purely classical and deterministic.   Brownian
    motion requires a source of heat to maintain and will not just re-emerge spontaneously.    Quantum
    mechanics does not override this fact.  

    This is not zero point energy which is a sci-fi myth.   ZPE cannot be extracted as a usable energy.   It
    makes no sense to talk about the kinetic energy of particles at absolute zero.  The internal energy of
    ground state atoms cannot be extracted.   Molecules that are truly at absolute zero do not vibrate and
    rotate so these energy modes cannot be exploited either.

    There is no free lunch in this universe and most likely any other.   All that graphene is doing is allowing
    thermal energy to be converted to electricity in a more direct fashion.   Such material effects are not
    new.

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



    I disagree with your views.. free energy is possible , is not a myth , what physics laws say is that infinite free energy is not ,but temporary free energy it is possible and in a very usefull way . you have tons of example . from solar energy ,if you want to fry an egg , you can use the sun and and cook a breakfast , it will be slow but it will work. also  fire is energy , there are some metals that when you use a knife and provoke friction ,they will throw small particles of fire ,enough to burn very dry wood or cotton. The universe is full of free lunch examples of free non unlimited energy . The sun is the most obvious example of free energy , the waves , and the wind this is free energy that can be converted to electricity .  anything object that move or produce heat or produce gravitation field ,is an object with potential energy . take magnets for example ,a powerful magnet can be used to generate and electric field or to block electricity too.  the key is to understand how to do it, but it is possible.  Wind , who will not call wind free energy ?  navigation was done in the past without electricity , just winds power.  not all energy is electric , but on the subatomic level all atoms are electric .  The international space station is falling non stop forever to to gravity of earth , no engine is moving this orbit around earth. is all gravity . any stone that fall and land on floor , had a potential energy ,this is physics 101 ,and this energy is transformed into heat ,when hit the floor , and you can build a machine that transform this heat in electricity. if something heat ,or fall or both ,it can be transformed into electrical current.

    energy is energy , and all energy is usable , it all depends in your scientific /engineering skills
    to transform any energy into any other of your need. for transportation or for cooking with fire are the easier ways to take advantage of free and limited energy. if you send a probe into a volcano infested planet like venus ,and your equipment can sustain the the super intense heat and pressure , you could build a machine that transform the heat into electricity so that the rover move ,in nearly forever way . as long there is heat , there is a potential to transform it to electricity .
    avatar
    Vann7

    Posts : 5040
    Points : 5146
    Join date : 2012-05-16

    Physics General Subjects Thread - Page 4 Empty Re: Physics General Subjects Thread

    Post  Vann7 Fri Feb 12, 2021 12:26 am

    The-thing-next-door wrote:I was just wondering if there were any good places to read up on physics and physics based technologies? A lot of members seem to be quite familiar with this area.


    google search have the answer for many questions.

    Learn Physics Fast - Raise Grades - Excel in Class  (dvd sales)
    https://www.mathtutordvd.com/public/physics-tutorial.cfm?gclid=EAIaIQobChMI7rz-8fvi7gIVArGGCh2nVw7EEAAYAiAAEgJga_D_BwE



    and the next one i think is free ,but not sure.
    Basically all classes from primary school to university ,in free videos. it seems.

    https://www.khanacademy.org

    https://www.khanacademy.org/science/physics/one-dimensional-motion

    chemistry ,biology ,physics ,computers programming ,math , economy.. the most basic things and more there by different teachers
    kvs
    kvs

    Posts : 10843
    Points : 10988
    Join date : 2014-09-11
    Location : Canuckistan

    Physics General Subjects Thread - Page 4 Empty Re: Physics General Subjects Thread

    Post  kvs Tue Feb 16, 2021 7:59 pm

    https://twitter.com/GarbyJooman3/status/1361645766436077574

    “Above average temperatures expected for the month of February”

    Can’t predict a cold snap three weeks out, but confident on climate 20 years out.

    “Listen to the experts!”

    An example of the sort of ignorant dismissal of climate science that results from partisan political abuse of the subject.

    Climate =/= weather. A fact that clearly escapes a lot of people. Climate is the manifold of weather states
    and is an energetic constraint on the realization of those states. No climate scientist claims to be forecasting
    weather states. They are using the observed and assured through further release of CO2, CH4, etc., compositional
    changes in the atmosphere to "forecast" the energy envelope of accessible weather states of the relatively near future.

    Weather forecasting beyond one week is well known to be unreliable since we are dealing with a nonlinear dynamical
    system. Small perturbations grow into dominant structures on the timescale of days. Essentially a one or two day
    forecast is sitting in the quasi-linear regime and thus makes sense. We do not have the infinite observational
    network and god-like supercomputers to be able to make forecasts for periods well beyond 4 days.

    Seasonal weather forecasting is better framed as a probability distribution than any actual forecast. So
    you takes your chances. This has nothing to do with climate since climate is not about the nonlinear dynamics.
    In the global average the dynamics averages out and the remaining element is the radiative transfer which is
    tied to the chemical composition of the atmosphere. The nonlinear dynamics is to some extent hidden in the
    compositional state, but thanks to mixing we do not have substantial heterogeneity. The nonlinearity
    also shows up as feedback effects such as water vapour in the atmosphere and the surface albedo. The uncertainty
    in climate simulations is the cloud albedo and carbon reservoir release. Industrial activity is another issue since
    we saw with the PCFCs in paint cans and other uses that warming can be put on steroids since PCFCs have
    IR absorption levels 10,000s of times higher than CO2. So PCFCs in parts per billion are more than enough
    to mess us up. Ironically, it was the concern over the ozone layer that saved us from this climate catastrophe.

    Climate simulations have real value for "forecasting" the accessible energy of the atmosphere-ocean-land system.
    They are also done as ensembles since weather is not the focus and is a derivative effect. People who piss on
    climate science typically invoke the non-argument of variability. They do not understand what variability is.
    They think that variability applies to the radiative transfer properties of CO2. No it does not. The effects of
    CO2 and the other greenhouse gases are deterministic and their effects are known through well over a
    hundred years of laboratory work. These pissers confuse the dynamical variability with physical process variability.
    The thermal effects of CO2 do not care about transport by the winds. But weather is all about such transport.

    You can thank God that water is constrained on this planet. If our climate state was purely linked to the variability
    of water loading in the atmosphere, then life would have been wiped out if it ever formed at all on this planet. A
    self-amplifying loading of H2O in the atmosphere would result in a Venus regime. H2O is more potent as a greenhouse
    gas than CO2. But the trick is that it condenses since it is a molecule with a high electric moment compared to
    CO2. H2O is what allowed the Earth to lose its 95% CO2 atmosphere even though under such conditions both
    are in the Venus hothouse regime. Venus never got out of its hothouse because it lost H2O to space. It may
    never had the amount that Earth had to start with, but the bottom line is that H2O will act to accelerate cooling
    by forming a condensing convection cycle.

    As H2O raises to the top of the hothouse atmosphere it starts to cool and condense and radiates IR very efficiently
    at altitudes where CO2 is optically thin, so the IR is lost to space. Right now on Earth this transition zone is
    at around the tropopause level. When the Earth was in the hothouse state, this zone would have been maybe
    around 70 to 100 km. CO2 does not behave this way since it is a non-condensing dry gas. Under current conditions
    H2O simply cannot induce a runaway warming without dry greenhouse gases like CO2 to help it. Suppose that
    deus ex machina H2O was increased by some fraction with the other gases kept the same. This would initially
    increase global mean temperatures, but it would also mean more precipitation at high latitudes (snow and ice albedo
    would go up) and there would not be any warming effect in the polar caps as with CO2. It would also mean that
    the convective heat pumping would increase leading to more IR energy loss to space. Convection acts as a thermal
    valve in the system. The high latitude removal of moisture would not just apply to local H2O, it would also be a
    sink for low latitude moisture through the transport by baroclinic eddies. The relative role of additional evapouration
    of H2O and its losses can be very well quantified with 3D chemical-transport models and the loss processes are
    too fast for the initial H2O injection to sustain itself or grow. High latitude surface albedo is an important part of
    this control. Under current conditions the system is not unstable to H2O increases. That is why we can have
    life on this planet.



    GarryB likes this post

    kvs
    kvs

    Posts : 10843
    Points : 10988
    Join date : 2014-09-11
    Location : Canuckistan

    Physics General Subjects Thread - Page 4 Empty Re: Physics General Subjects Thread

    Post  kvs Sun Mar 28, 2021 1:49 am



    kvs
    kvs

    Posts : 10843
    Points : 10988
    Join date : 2014-09-11
    Location : Canuckistan

    Physics General Subjects Thread - Page 4 Empty Re: Physics General Subjects Thread

    Post  kvs Mon Mar 29, 2021 7:42 am



    Oops. The data does not conform to the theory. Time to throw out the data.

    Modern science is corrupted with political type thinking. Theories are treated as dogmas. When you challenge a theory, the response
    is typical of a true believer one: deep offense and aggression. A real scientist should not have his whole world view invested in a theory
    and should be happy to accept that their precious theory is not guaranteed to be right. In fact, revising theories in the face of new
    data is exciting and makes science appealing. Science is not theology and is not sealed in a tin for perpetuity.

    nomadski likes this post

    kvs
    kvs

    Posts : 10843
    Points : 10988
    Join date : 2014-09-11
    Location : Canuckistan

    Physics General Subjects Thread - Page 4 Empty Re: Physics General Subjects Thread

    Post  kvs Mon Mar 29, 2021 9:18 am





    If the Sun was really a giant gas ball, then it would be physically impossible for it to have a surface.   A surface clearly seen in actual
    observations.   Gases do not have step function stratification transitions.   For example on Earth, the atmosphere falls off in density
    with an exponential function only modulated by local temperature variation.   The same would happen on the Sun regardless of the
    heating.   On Earth convection in the troposphere does not counteract the exponential distribution of density.   Gravitational stratification
    acts very rapidly.  

    A huge step function transition in temperature would not be possible to maintain in a gas since diffusion would destroy any such
    gradient.   So some sort of bizarre temperature transition cannot be invoked.   Instead of seeing the Rayleigh-Benard convection
    pattern that we observe, an "apparent" surface would require the gas to be super-ejected by a dramatic temperature rise over a very
    thin layer.  In other words, a gaseous star would appear to have a well defined surface if it was blasting off the gas over an effective
    surface defined by such a temperature transition.   But the current dogma accepts that the Sun has a "surface" temperature of 5700 K
    which is the lowest compared to the temperature distribution in the interior which reaches millions of degrees near the center.

    The Rayleigh-Benard convection observed clearly indicates a mild temperature gradient with radius.   There is no million degree
    detonation transition blasting off the mass at the Sun's "apparent" surface.  

    From the second video, the coronal mass ejection events are in no way pushing off a gas from a gas ball.   They have way too much
    structure that is not simply magnetic confinement.   How would magnetism confine gas to appear like fluid in every direction
    when you can see the layout of the magnetic flux lines form an specific structure.   A plasma would just follow the flux lines,
    it would not clump and produce an obvious surface to those clumps.   The claimed ultra low density assumed by the current
    dogma is clearly inconsistent with the observations.

    BTW, there are no real models of the Sun and stars as fluid dynamical systems gaseous or liquid.   So nobody has even confirmed
    the existing dogma with computer simulations.  

    https://www.nsf.gov/news/news_summ.jsp?cntn_id=114981

    The above does not constitute a model of the system.  It is mimicry of a feature.  

    https://link.springer.com/article/10.1007/s41116-020-00025-6

    This is the closest we get so far, a simplified magneto-hydrodynamic model type that does not determine whether the Sun is
    a condensed liquid or a gas.   They are for a generic fluid with tunable parameters and do not constitute a full system simulation with surface
    convection, coronal mass ejections, solar tornadoes, etc.
    kvs
    kvs

    Posts : 10843
    Points : 10988
    Join date : 2014-09-11
    Location : Canuckistan

    Physics General Subjects Thread - Page 4 Empty Re: Physics General Subjects Thread

    Post  kvs Tue Mar 30, 2021 1:23 am

    https://www.astro.caltech.edu/~george/ay1/lec_pdf/Ay1_Lec08.pdf

    The standard solar gas ball model. Note how the density basically falls off to near zero starting from
    around 0.5 solar radii. We are supposed to believe that this vacuum zone that accounts for 87.5% of
    the volume of the Sun is opaque and produces a pronounced "apparent" surface. Total, unmitigated BS.

    GarryB
    GarryB

    Posts : 30953
    Points : 31479
    Join date : 2010-03-30
    Location : New Zealand

    Physics General Subjects Thread - Page 4 Empty Re: Physics General Subjects Thread

    Post  GarryB Tue Mar 30, 2021 4:30 am

    The obvious problem of talking about a ball of gas is gravity means it can't be all gas or it would just disperse in tiny concentrations and for a much larger gas cloud as it coalesces it rapidly stops remaining all gas.

    Looking at a planet like Jupiter the core will be liquid hydrogen that is a sort of metallic liquid because of the pressure and temperature created by all the weight pressing down on it.

    AFAIK you can't have solid hydrogen, but then in a neutron star you can crush all the electrons into the protons and form a mass that consists of neutrons... but is it in liquid, gas, or solid form?

    Filming the surface of a neutron star would be interesting... does it look solid or gas or liquid like... with no free electrons jumping from atom to atom is there a magnetic field at all?

    In a sense the earths atmosphere is tiny thin and very quickly transitions to either solid or liquid depending upon where you approach the earth from, but the gravity of earth is tiny and the variety of materials on earth is much greater than most stars which start out mostly Hydrogen and some helium and other materials created in the huge furnace at its core.

    Relative to its diameter the atmosphere of the earth is easy to miss... talking about half a solar radii is enormous in comparison.

    In terms of comparing to earth it is almost like they are talking about the Van Allen belts rather than the atmosphere...


    Last edited by GarryB on Mon Apr 05, 2021 3:45 am; edited 1 time in total
    kvs
    kvs

    Posts : 10843
    Points : 10988
    Join date : 2014-09-11
    Location : Canuckistan

    Physics General Subjects Thread - Page 4 Empty Re: Physics General Subjects Thread

    Post  kvs Tue Mar 30, 2021 5:50 am

    I can see all sorts of snow jobbing being pulled to wave the hands and heat the room.   For example they can claim that
    convection in the solar interior fluffs up the mass distribution.    But the time scale of the convective mass flow is way, way
    longer than the time scale for gravity to act to compress the gas and return it to an exponential density profile.  The best
    the convection can do is to change the e-folding rate (i.e. H in exp[-z/H]).   This leaves us with the conundrum why
    there were would an "apparent" surface and not a fuzzy zone.    

    Jupiter is like a star that never ignited.   It is likely to have a liquid metallic hydrogen interior due to the massive compression
    on account of its size.    One could say, well, Jupiter looks like it has a cloudy surface and there is no fuzzy/misty zone.   But
    the outermost layer of Jupiter is not at 5700 K.   And the "apparent" surface of Jupiter is vastly denser than the vacuum.  The
    outer layer of the Sun extending at least a few thousand kilometers has to have a density near vacuum even if you include
    convection.  There is no way it would be opaque at this density.   It could have outburst of light during CMEs, but the rest of
    the time it would be a hot low density gas.   Instead we clearly see a surface in all wavelengths in essentially the same location
    with Rayleigh-Benard convective cells.

    As noted in the "crank's" videos (anyone who does not toe the party line is officially designated a crank) Rayleigh-Benard convection
    requires a surface to form.   The horizontal scale of the cells seen on observation is close to the depth of those cells.  Convection
    in a low density gas driven by heating in the solar interior would not operate in such a regime.   Some guidance on convection is
    given by what happens on Earth.   We have Rayleigh-Benard convection in the planetary boundary layer hugging the surface.
    Then we have deep convection extending to the tropopause.   Above we no longer have convection since the atmosphere is
    optically thin in the IR bands and heat is efficiently lost to space via radiation.    Suppose that on the Sun the "troposphere"
    spans the density range which optically thick to IR.   It is rather clear that a density approaching vacuum is translucent to IR
    even if the gas is radiating.   We are talking about the ability of IR photons to travel essentially unobstructed with minimal
    absorption and re-emission.   This sort of regime must apply to the outer tens of thousand kilometers of the Sun regardless of
    the spectrum of emissions since the density is so low.   It cannot be confined to less than 100 kilometers.   Convective mass
    redistribution cannot remove the exponential variation of density with radius so it is a matter of basic math.   The near surface
    tail of the exponential given the observed density (10^-7 g/cm3) must have very low values over a deep layer (the outermost
    shell of the Sun).    If the observed surface density was large then we would have an optically thick and opaque region near the
    "surface".      

    Convection on the Sun would stop well below the "apparent surface".   For sure we would not observe any Rayleigh-Benard
    convective cells at the "apparent surface".   In the PDF I link, it is quite clear that solar radius = 1.0 is the "apparent surface"
    and not, say, 0.6.  If it was supposed to be deep in the interior, then it would have some credibility.   An additional consideration
    is that the radiation pressure would be blasting the low density outermost shell of the Sun into space rather quickly so it is
    hard to see how any 10^-7 g/cm3 density could persist at 1.0 solar radii.   But we see CMEs crashing back to the surface.

    The cognitive dissonance must come from reconciling a liquid metal Hydrogen condensed matter state with the Sun's temperature.
    But in other videos that I have not linked by this same scientist (he is an MRI specialist originally and he is qualified to deal with
    black body radiation and spectroscopy) the phase diagram of hydrogen allows such a condensed matter state even well above
    10,000 K and at "low" pressure.   So it is actually realistic for the outer shell of the Sun to be condensed matter and not a gas.
    What happens in the interior as temperature goes up becomes a competition between compression and temperature.   There is
    enough mass in the Sun to produce enormous pressures near the interior.   In the thousands of Gigapascal range.   The phase
    diagram of Hydrogen thus indicates a condensed matter state through the whole volume of the Sun.   Gas forms only near the "apparent
    surface" which is an actual surface.
    kvs
    kvs

    Posts : 10843
    Points : 10988
    Join date : 2014-09-11
    Location : Canuckistan

    Physics General Subjects Thread - Page 4 Empty Re: Physics General Subjects Thread

    Post  kvs Wed Mar 31, 2021 3:12 am



    An example of what is wrong with modern science.   A single interpretation of the observations is treated as the one and only.
    Instead of invoking the expanding universe interpretation of the red shift based on a theory, GR, which is not a field theory and
    cannot be quantized, how about a theory that takes into account the interaction of gravitons and photons.   That is, suppose
    gravity is an actual field like EM and not a magical space time curvature effect without any agent process for "mass-energy
    to tell spacetime how to curve and for spacetime to tell mass-energy how to move".   If GR was a proper theory of gravity, it
    would have a process which explains the formation of spacetime curvature instead of simply pulling an equation for the metric.
    GR is a mathematical exercise and its failure to be quantized is proof.   Get a field theory or go home.

    So if we have gravity being a field theory, then there are gravitons and these gravitons interact with each other and with photons.
    Gravity is not like EM since EM photons do not couple with each other which results in the EM equations being linear.   Light curving
    in gravitational wells implies that gravitons interact with photons.   Now consider the implications.   It is dubious that photons emit
    gravitons since they have no mass.   The GR view of mass-energy gravitating is based on the fact that there is no force involved
    and only a deformation of geodesics (worldlines) which affects both photons (energy) and particles with mass.   That's a GR feature
    which in spite of all the hysterical dogma and smear of those who do not believe as "cranks", is not established absolute fact.  
    A field theory of gravity meets all of the criteria for "proof" used for GR which date back 100 years.  

    A massive particle falling and escaping a gravitational well will not behave the same way as a photon.   Since a photon is not
    emitting gravitons it sees only a one way effect and breaks the symmetry that applies for massive particles (and similarly
    for charged particles in EM).   So where a massive particle that escapes a gravity well sees no net loss in kinetic energy,
    the photon will see a loss in energy.   So you have a red-shift just because photons travel across many gravity wells on the
    way to our telescopes from distant parts of the universe.   The farther their origin, the more is their red-shift.  

    But what about the alleged "dark energy" and accelerating expansion.  Well, the farther the origin point, the farther back
    in time.   How do we assume that there is a perfect steady state in the universe?   The Big Bang believers don't assume
    a steady state, so why should anyone else?   But suppose there is a steady state; we do not know about what happens to photons
    after billions of years of travel through space.   It is possible that in addition to the primary impact of graviton "drag" there
    may be other interactions that cost photon energy.   This would give us an apparent acceleration through a deviation of
    the red-shift from a linear dependence with distance.  

    There are way too many plausible possibilities other than the single interpretation being shoved down everyone's throat.  
    And a field theory gravity is much more physical than some magic metric equation which totally lacks a physical process
    to connect mass-energy to spacetime curvature.   If mass-energy is "telling" spacetime something, then bloody bother
    to describe the language.
    kvs
    kvs

    Posts : 10843
    Points : 10988
    Join date : 2014-09-11
    Location : Canuckistan

    Physics General Subjects Thread - Page 4 Empty Re: Physics General Subjects Thread

    Post  kvs Wed Mar 31, 2021 5:01 am

    In the name objectivity I must criticize the solar model proponent above when it comes to his understanding of gravitational collapse of a
    gas and the idea of pressure.

    1) No star would ever form if gases could not "dig their own" hole via gravity.   Gravity will clearly attract gas so it will become more dense
    if something initiates this process.    This could be current convergence (yes interstellar gas does actually flow) or other plausible mechanisms.
    That gas tries to escape into the vacuum does not nullify the gas collapse leading to star formation.   We are not dealing with some low density
    clump of gas but with vast regions of gas within which star formation begins.   The key is the progressive accumulation of mass in a finite volume
    that acts to establish a gravity well.   This will trap the gas already there and pull in more gas from its neighborhood.  Given that interstellar
    gas circulates there does not have to be any sort of self-limitation effect.   And it is all down to the initial amounts of the gas in the stellar
    nursery nebula.

    2) Looking at what happens at the atomic scale for a gas in a gravity well, you have in addition to collision events generating random
    motion vectors for each atom/molecule an additional vector towards the center of mass.   Given enough mass this additional vector can
    dominate the magnitude of the collision velocity vectors or have a comparable amplitude.   There is no need for any condensed matter
    surface in the system, you simply get an exponential density and pressure stratification.   If the temperature is too low, then the gas
    will collapse into a condensed matter object.

    3) The pressure of a gas has nothing to do with any container wall.   The container wall only maintains the gas from diffusing to zero density
    and enabling thermodynamics to function.   Thermodynamics is the steady state regime of a large number of particles/atoms in any phase.
    On Earth you have the breakdown of local thermodynamic equilibrium in the upper atmosphere above 80 km due to very small density.
    As a result thermalization of molecular vibrational and rotational states is inefficient due to lack of inter-molecular collisions.  

    4) Pressure is generated by the kinetic energy of gas particles (atoms or molecules or electrons, etc.).  That is why it is directly related
    to temperature.  Temperature is a measure of the kinetic energy of the gas.   Steady state pressure requires some confinement mechanism
    such as container walls or gravitational force.    But even a diffusing gas has a pressure.   It is simply time dependent.   The force per
    unit area definition applies to all regimes.  

    In his videos Robitaille is very lost when it comes to these aspects.  He is falling into the usual scientific trap of over-investing in his
    theory.  That is not a crime and all scientists should expect some degree of skepticism.   This does not nullify his other points as they
    stand on their own feet.   Science is about evaluating the arguments and not about faith in the one making them.
    kvs
    kvs

    Posts : 10843
    Points : 10988
    Join date : 2014-09-11
    Location : Canuckistan

    Physics General Subjects Thread - Page 4 Empty Re: Physics General Subjects Thread

    Post  kvs Sun Apr 04, 2021 7:34 pm



    There is no physics like theoretical physics.
    kvs
    kvs

    Posts : 10843
    Points : 10988
    Join date : 2014-09-11
    Location : Canuckistan

    Physics General Subjects Thread - Page 4 Empty Re: Physics General Subjects Thread

    Post  kvs Tue Apr 06, 2021 6:35 am



    kvs
    kvs

    Posts : 10843
    Points : 10988
    Join date : 2014-09-11
    Location : Canuckistan

    Physics General Subjects Thread - Page 4 Empty Re: Physics General Subjects Thread

    Post  kvs Thu Apr 15, 2021 7:03 am



    At the end of the day, without actual observations all you have is speculation. Wrapping it in formalism does not make
    it profound. The post WWII period in physics has been rampant with speculation being touted as deep insight into reality.
    More similar to cult group-think than any actual science. And it has been this pseudo-science that has been extolled
    by the media, the same media that corrupted the public information space regarding atmospheric science by trotting out
    cranks and lunatic posers as "the other side of the coin". The media never once gave a platform to anyone challenging
    the rubbish that is particle physics and cosmology.



    UZB-76 likes this post

    kvs
    kvs

    Posts : 10843
    Points : 10988
    Join date : 2014-09-11
    Location : Canuckistan

    Physics General Subjects Thread - Page 4 Empty Re: Physics General Subjects Thread

    Post  kvs Thu May 06, 2021 6:32 am



    Lots of general wisdom in this lecture.

    Sponsored content

    Physics General Subjects Thread - Page 4 Empty Re: Physics General Subjects Thread

    Post  Sponsored content


      Current date/time is Tue Oct 19, 2021 11:44 pm