Physics Discussion Thread

[Bade]

No since you came to the wrong master, I just pointed to the right ones in any nearby madarassa. It may be short walk if ju are in a cave camplex already, if my spider sense is right. Take General Relativity 101 or self-seek from Amazon.com; only thing I can assure is that it is far better than djinn breathing tachniques of indic lore for self realization of the universal secrets.

[GuruPrabhu]

But, what if the so-called Masters are packees in gora djinn clothing, hain ji?

what assurance do you have that so-called gora jaadugars know their elbow from a black hole in the ground?

The wiki page clearly states that no one has any clue about the nature of dark energy. And yet, it forms 74% of the universe. If this is not an admission of defeat by phyzzyx, what is?

After you add in another 22% of dark matter, the known universe is only 4%. What kind of "mastery" of science is that?

then you take out unknown neutrinos etc and we are left with just a couple of percent of the universe where phyzzx apparently "works".

Even Jyotishi has better percentages of success

[Bade]

Options in life are many, the only certainty is that you are born and you will die one day. Everything else is djinn of one kind or another. The djinn techniques of fizziks does not require anyone else, no guru-shishya parampara, astrological gobleegook or flying carpets or floating sanyasins nudging one towards nirvana.

It is all up to you for self-discovery and if you care enough for fat sponsorship for your indulgence then will have to do beer-reviewed-publications for peer acceptance. Isn't it the same whether you are discussing grand strategy for Akhand Bharat, fundamentalism, secularism or designing next gen JSF, flying puny bombs to wipe out entire civilizations as you know it.

No one says anything works, not even with mathematical proofs 100% of the time with "certainty", try condom fizziks till it breaks your head. Do not even need to hit the cosmological constant for that epiphany.

[GuruPrabhu]

ayyyeeeeoooohh ... Kaliyug is here! The Maulana is raising questions about phyzzyxx and Phyzzyxx Master is replying with philosophical comments akin to Hadiths.

Let Jan Janardhan be the judge.

thank you Bade Saar, no more from me.

[Bade]

fake ishtudents get fake answers onlee.

[Bade]

If non-fizziks djinn tachniques can explain anything that has real tach-no-logy, applied or philosophical (most of fizziks is just that), then I have the Thrissur Pooram grounds for sale for the lowest bidder.

[GuruPrabhu]

fake ishtudents get fake answers onlee.

reminds me of dodecahedron courtyards claimed by those not skilled in dance

[Bade]

‘The universe never dies and is going from one aeon to the next’

SKC: Could you tell us about the cyclic universe model that you are proposing?

RP: I take the view that the universe does not go through a single phase (aeon) i.e., between the big-bang and big-collapse or crunch. While the universe keeps on expanding, one has to rescale the entropy (disorderliness) so that the future does not look very much different from that of the past.

It is not a big crunch that I am thinking of. Rather I am saying that parameters in the universe rescale now and then to go from one aeon to another, that is extreme orderliness to extreme disorderliness. We need to device experiments to measure the subtle signals of earlier aeons. Maybe we would also learn whether the fundamental constants were really constants or they change from aeon to aeon.

SKC: How about the second law of thermodynamics? Would each aeon have, as a whole, more entropy than the previous one?

RP: The second law of thermodynamics is never violated while going from one aeon to the next. All one has to do is to subtract a constant entropy at the end through black hole formation and the universe looks like what it was before.

SKC: Do you believe that there could always be multi-verses, i. e., other universes disconnected from ours, which are doing their things independently?

RP: It is good idea to have multiple universes. The major reason why people wanted multiple universes is because of certain crude principles of quantum mechanics. But at a higher level this principle could be violated. So multiverses are not essential. They may be essential for those who believe in the anthropic principle (the universe evolves in a way so as to produce living beings ultimately.)

[Mort Walker]

In the US Fermi Lab's Tevatron to be shut down. In effect, shutting down HEP in the US.
U.S. Particle Collider Shutting Down
Tevatron atom smasher to close in September

Fermi Lab needed $35 million per year for operation of the Tevatron, but the Obama administration thought its better to fund Djinn physics in TSP with more billions in aid.
The sooner these clowns in Washington are defeated in election, the better.

[Bade]

And with this closure, for US to keep participating in the LHC programme it will have to shell out more to become a member state of CERN. Which in the end means less DoE money available for the universities to do High Energy Physics. No more PhDs, post-docs at the Univs in HEP, as there will be less and less grant money to support them. This is the slow death with started in 1993 with the shutdown of the SSC program and now rapidly moving towards its conclusion.

[Mort Walker]

Absolutely. Now physicists will be left to study condensed matter to develop newer batteries & capacitors for electric cars and super string theory which might as well be Djinn physics. Overall, less students in physics.

Once these advanced basic science programs are shut down, then to start back up will take much time and money. Very short sighted and the US congress with fools on both sides won't say a thing since they're too ignorant to understand the significance.

[Murugan]

Listen in Swami Vivekananda's own voice something about physics

http://www.youtube.com/watch?v=WhkF8gxc0Zs&NR=1

[Bade]

Is severe winter weather related to global warming?

Weather isn't that simple, as it turns out. On average, the world is indeed getting warmer. (Even those skeptical about the human effect on Earth's climate don't dispute that fact, which is well established from year after year of upward-trending thermometer readings around the planet.) But global warming doesn't necessarily translate into warming everywhere, all the time.

To understand how warming and snowstorms may be connected, it helps to start with the epicenter of winter weather. Around the North Pole, some of the world's coldest air currents blow in what's typically a tight loop known as the polar vortex. Air masses inside the vortex tend to have not only low temperatures but also low barometric pressures compared with air outside the vortex. The surrounding high-pressure zones push in on the vortex from all sides, helping the cold air stay where it belongs, at the top of the world.

That's what happens, most of the time, at least. Occasionally, pressure inside the vortex strengthens, causing the vortex itself to become unstable, like a top that's losing its spin. When that happens, frigid polar air is more likely to escape the meteorological fence that normally confines it. The result, sometimes felt far to the south, can take the form of severe winter weather.

Over the past two years, the polar vortex has been strikingly unstable, according to meteorological data. James Overland of the National Oceanic and Atmospheric Administration cites a couple of measures in particular: One, called the Arctic oscillation, tracks air pressure and related atmospheric variables over the North Pole. The other, the North Atlantic oscillation, takes into account similar variables in the neighborhood of Iceland. Both indexes are reliable indicators of the strength of the polar vortex.

Last winter, both indexes reflected higher air pressures and therefore less vortex stability than scientists have ever recorded. This year, both were again seriously off-kilter.

[rsingh]

I broke my plasma lamp. Outer shell is broken. any use of what is left?

[Bade]

X-post

Bade Saar,

I am sure that you are aware that the geothermal heating of the earth's mantle and crust is attributed to uranium/thorium and potassium decays. Recent discovery of geo-neutrinos have confirmed this. The U/Th deposits are part of basaltic melts -- the estimate for *average* U content is something like 10^-8 - 10^-7, However, for mining purposes, much higher concentrations are needed.

Surprisingly, the U/Th content of the mantle is much higher than the core (counter-intuitive, if you think that heavier elements should sink. However, the process is chemical, not gravitational). The source of earth's heat is to a large extent due to U/Th/Pb/K decays. There was conjecture that there is a natural reactor in the earth's core, but it is being disproven by geo-neutrino data.

Here is some reading for your pleasure:

Fyfe had done the original seminal work on geochemical cycle of uranium:
http://adsabs.harvard.edu/abs/1979RSPTA.291..433F

Here is a well regarded later work on estimating U/Th content:
http://www.jstor.org/pss/54182

Here is something from WNA on the cosmic origin of uranium:
http://www.world-nuclear.org/info/inf78.html

Here are some news items and webpages on geo-neutrinos and their discovery:
http://www.physorg.com/news187946006.html
http://kamland.stanford.edu/GeoNeutrino ... rinos.html
http://www.geol.umd.edu/~mcdonoug/geoneutrinos.htm

If your interest gets more aroused, here is a good text on geodynamics:
http://www.amazon.com/Geodynamics-Donal ... 0521666244

[Amber G.]

^^ Thanks for x-posting...
For those who want to know why heavy metals like U/Th do not "sink".. check out
terms like: "Lithophile elements" (Means "rock loving elements")

Meanwhile, just for fun, few simple Physics problems..

1) If one sleeps under a tree, one will not get wet from morning dew. (or not as wet as if one sleeps under open sky)
Because the tree:
a) Absorbs star light
b) Keeps air from rising
c) Emits infrared radiation
d) Blocks the clouds
e) Tree is older than Chernobyl, hence it absorbed all radioactive Cs and produces heat
f) No, it is not true, you get almost as wet..

P2 A nuclear reactor cannot explode like a nuclear bomb because
a) It contains too much Uranium
b) It contains no uranium
c) Nuclear reactor depends on slow neutrons
d) It is carefully designed to shutdown quickly
e) None of the above, on average there is one explosion every year
f) Not e) but there were a few in Fukushima.

P3. Plutonium can explode with fewer generations than can Uranium because:
a) Plutonium fission releases more neutrons
b)Pu fission releases more energy
c)Pu does not require moderator
d)Pu turns into Uranium

P4 Wine sold in USA is legally required to be radioactive because
a) ....
b) Not true

[Bade]

Interesting part (physics wise) about U/Th content of the mantle is much higher than the core. I have heard that before, and it indeed could be a good challenging question .. (as to why heavier elements like U, Th (and Zr, W) don't sink while Pt, Os or Iron etc do...).

Wonder if the counter-intuitive situation has to do with sequence of accretion of material when the earth formed. Elements like Iron must have been more abundant than the heavier elements like U/Th and assembled first into the core. The less abundant, but heavier elements would then show up more in the upper layers like the mantle, the core having cooled down and solidified sufficiently for gravity to provide any help in further penetration as material got accreted incrementally. All heavy elements having been produced by some faraway Supernova explosion remnants and transported by shock waves.

[Amber G.]

^^Also, from wiki (http://en.wikipedia.org/wiki/Planetary_differentiation)

Note that although bulk materials differentiate outward or inward according to their density, the elements that are chemically bound in them fractionate according to their chemical affinities, "carried along" by more abundant materials that they're associated with. For instance, although the rare element uranium is very dense as a pure element, it is chemically more compatible as a trace element in the Earth's light, silicate-rich crust than in the dense metallic core....
...Materials with a high density tend to sink through lighter materials. This tendency is affected by the relative structural strengths, but such strength is reduced at temperatures where both materials are plastic or molten. Iron, the commonest element that is likely to form a very dense molten metal phase, tends to congregate towards planetary interiors. With it, many siderophile elements (i.e. materials that like to alloy with iron) also travel downward. However, not all heavy elements make this transition as some chalcophilic heavy elements bind into low- density silicate and oxide compounds, which differentiate in the opposite direction...

[madhu]

Since there is no chemistry thread I am posting it here.
I read in some website that burning ghee with cow dung during homa gives out oxygen. I could not understand it. Ghee being a fatty acid should be made of carbon, hydrogen and oxygen. Burning it should give only carbon di oxide and water. How is the webpage claiming it gives oxygen ? Am I missing something?

[ramana]

I will let AmberG answer this chemistry question.

But in future I would not post such stuff here.

[brihaspati]

Interesting part (physics wise) about U/Th content of the mantle is much higher than the core. I have heard that before, and it indeed could be a good challenging question .. (as to why heavier elements like U, Th (and Zr, W) don't sink while Pt, Os or Iron etc do...).

Wonder if the counter-intuitive situation has to do with sequence of accretion of material when the earth formed. Elements like Iron must have been more abundant than the heavier elements like U/Th and assembled first into the core. The less abundant, but heavier elements would then show up more in the upper layers like the mantle, the core having cooled down and solidified sufficiently for gravity to provide any help in further penetration as material got accreted incrementally. All heavy elements having been produced by some faraway Supernova explosion remnants and transported by shock waves.

Seems more likely! There are similar debates on distribution of gold.

One simple pointer should be that the gravitational forces should on an average tend to cancel off the closer you go to the centre of a massive ball [for all practical purposes can neglect the GR singularity problem]. So the gravity argument will not explain differential sinking if all the elements were present in current quantities right at the beginning of the process of accretion.

[Amber G.]

Since there is no chemistry thread I am posting it here.
I read in some website that burning ghee with cow dung during homa gives out oxygen. I could not understand it. Ghee being a fatty acid should be made of carbon, hydrogen and oxygen. Burning it should give only carbon di oxide and water. How is the webpage claiming it gives oxygen ? Am I missing something?

Madhuji - Simplest is to do an experiment and see if the claim by website is actually true.
(Or ask the website to do the experiment)
("burning" of any substance, ( by definition, in science, at least in this context) means chemically this substance reacts to oxygen ..IOW using-up oxygen .. not producing it)

[Amber G.]

Seems more likely! There are similar debates on distribution of gold.

Hmm.. Gold, actually sinks (Experimental result.. no debates).. unlike U or Th..

One simple pointer should be that the gravitational forces should on an average tend to cancel off the closer you go to the centre of a massive ball [for all practical purposes can neglect the GR singularity problem]. So the gravity argument will not explain differential sinking if all the elements were present in current quantities right at the beginning of the process of accretion.

Sorry, physics wise, this makes no sense..can you explain further.. after all if you drop a heavier object in ocean .. it sinks. Period. ..Crust/mantel may be much more viscus but over long time heavier elements will tend to "sink" ... (specially if they were present in current quantities right at the beginning).. By "sink" I mean, the if the matter is heavier than its surrounding it will tend to go towards center of the earth .. .. if all other things were same ...As GP said.. the reason for U, and Th is not gravity alone...

(Hint: Mn, NI, V, Fe ..Pt, Au, Pd etc ... all "sink"...
While U, Th,... Zr, and W .. do not ...)
BTW, W and Au has almost the same density.
.

[Amber G.]

So there are no comments for the simple physics problem I asked a few posts above?

[Amber G.]

[pgbhat]

[Amber G.]

Some time ago, I had a post about debunking the urban legend about Plutonium being the most poisonous substance...

So found this interesting aid to learning ..

[GuruPrabhu]

I hadn't realized that the discussion had moved here. The explanation for U/Th not sinking is as Amber said -- U/Th are lithophile rather than siderophile (metal loving). This is seen in foundries also. If you take a large vat of molten iron, the U and Th impurities migrate from the bulk and concentrate on the periphery (mostly on top!). The core of the earth has two parts, a solid one and a liquid one -- the liquid is mostly molten Fe and Ni, which has expelled the U and Th.

There is some speculation that there is a concentration of U in the solid core also. If true, this may form a natural reactor. There is no direct evidence yet -- the numbers have to add. The measured *total* heat flow from the earth is either 31 TW or 44 TW, depending on the method used. OTOH, several calculations now agree that the radiogenic component (U/Th/K decays in the mantle) contributes 19-20 TW. There are estimates that the "core reactor" may contribute as much as 6 TW. All of this can be sorted out if planned large neutrino detectors get the go ahead.

[GuruPrabhu]

And with this closure, for US to keep participating in the LHC programme it will have to shell out more to become a member state of CERN. Which in the end means less DoE money available for the universities to do High Energy Physics. No more PhDs, post-docs at the Univs in HEP, as there will be less and less grant money to support them. This is the slow death with started in 1993 with the shutdown of the SSC program and now rapidly moving towards its conclusion.

Bade-ji,

From what I understand, Fermilab is gearing up to become a neutrino lab. HEP is far from slowing down, yet. Everyone is anticipating some new result from LHC which will be a shot in the arm for HEP. As you may know, several Indian physicists have been early proponents of the ILC -- if that gets the go ahead in the next 3-5 years, I expect India to play a major role.

[GuruPrabhu]

1) If one sleeps under a tree, one will not get wet from morning dew. (or not as wet as if one sleeps under open sky)
Because the tree:
a) Absorbs star light
b) Keeps air from rising
c) Emits infrared radiation
d) Blocks the clouds
e) Tree is older than Chernobyl, hence it absorbed all radioactive Cs and produces heat
f) No, it is not true, you get almost as wet..

I don't know the answer, but c) seems plausible.

[negi]

Well school textbooks used to say not to sleep under a tree during the night as it releases Co2 (no photosynthesis in the night), I guess some sugar(glucose) is converted to energy(heat ?)

[GuruPrabhu]

^^^ did the textbooks also say not to sleep next to SHQ because she also releases CO2? Release of other gases is OT, I suppose.

[Bade]

Negi, the hint to the correct answer is within the odd post in the Indian Nuke thread on water vapor.

[negi]

^^^ did the textbooks also say not to sleep next to SHQ because she also releases CO2? Release of other gases is OT, I suppose.

Are you pulling my leg sir ? Btw I don't have a SHQ so this is a news to me .

Bade I have not been reading the nuke dhaga; I was not contributing much there.

[Bade]

From what I understand, Fermilab is gearing up to become a neutrino lab. HEP is far from slowing down, yet. Everyone is anticipating some new result from LHC which will be a shot in the arm for HEP. As you may know, several Indian physicists have been early proponents of the ILC -- if that gets the go ahead in the next 3-5 years, I expect India to play a major role.

But with the US being bankrupt with no hopes of increasing prosperity what are the odds that it will bankroll the ILC ? But you will agree that despite an uptick in neutrino physics experiments HEP funds has shrunk over the last decade.

Why HEP, there has been a 2-3% cut even for specific areas within the earth sciences too over the past year. So basic research might get cut even further.

[GuruPrabhu]

But with the US being bankrupt with no hopes of increasing prosperity what are the odds that it will bankroll the ILC ? But you will agree that despite an uptick in neutrino physics experiments HEP funds has shrunk over the last decade.

Why HEP, there has been a 2-3% cut even for specific areas within the earth sciences too over the past year. So basic research might get cut even further.

I suppose that you are talking about US budget for science. Yes, it has shrunk in constant $$ terms. But, at close to a billion $$ per year for HEP alone, it is still by far the largest program in the world. These are not the signs of a "bankrupt" economy as such -- your claims of "no hopes for increasing prosperity" is debatable, but OT here.

In any case, my point was that countries like India and China will bankroll the ILC.

[negi]

Got it the temperature under a tree is higher than the surroundings which might have reached the dew point and hence the column of air under the tree does not condense and settle down as dew; I was always bad with humidity and related concepts.

[negi]

I was trying to solve AmberG's puzzle on a positive charge sorrounded by 6 other positive charges (from outset looked like a straight forward coloumb's law related problem); so I figured that the charge will be in a state of stable equilibrium until the destabalising force is strong enough to push it outside the imaginary box formed by the 6 point charges.

However in doing so asked myself following questions; please bare with my silly questions :

1. How does the setup behave if one were to somehow simulate this in a lab experiment ? AmberG explained it is possible to replicate this in lab. To substantiate when the destabilizing force (I presume again a negative/positive charge) will be removed will the charge come back to it’s position and stop or it will enter into an oscillation which will decay gradually (due to inertia)?


2. Does concept of ‘hysteresis’ come into picture with elementary charged partciles ? I mean like you stretch a rubber band repeatedly it looses it’s elasticity after a certain amount of time or even a permanent magnet exhibits loss in magnetic field strength after being subjected to changing EM fields ? Point being will the charges in this experiment exhibit any decay in electric field after being repeatedly subjected to an external electrical field ? Again lets assume all these point charges are protons . If Yes does that mean a charged particle will continue to retain it's charge and hence the associated electric field until eternity; assuming it does not get neutralised by particle of opposite charge ?

[GuruPrabhu]

^^^ where is this problem posted?

If Yes does that mean a charged particle will continue to retain it's charge and hence the associated electric field until eternity; assuming it does not get neutralised by particle of opposite charge ?

The answer is yes, there is no "drag" in vacuum, unless you believe in Higgs field. As for "eternity", IIRC, the limit on the lifetime of the proton is >10^34 years.

To put that in perspective, the age of the universe is only about 10^10 years. So, protons live for eternity as far as the human mind can fathom eternity.

[negi]

^ Page 4

What happens to a positive charge particle (say a proton) at the origin, surrounded by 6 fixed equal positive charges which are at the same distance from the origin in north-south, east-west, up-down position? Of course, due to symmetry, the charge will be at equilibrium, but is it stable equilibrium? (that is, if you disturb the charge just a little, will it stay at the origin or will run away?)

(Hint: If you just take two charges (say east-west or x-axis) the proton in the middle will escape in y-axis (or z-axis) if it is disturbed a little in that direction)