Bharat Rakshak

Bade, Thanks for those links.
Also ... (for general background) ..

It may not be exactly what you are looking for, but for general public, let me suggest two books which I think people will enjoy.

One is from the old prof CN Yang's popular book (AFAIK his only popular book) "Elementary Particles"
(It is quite short book, less than 100 pages. Nice book to explain symmetry without too much math)

Another one is classic, very popular by Feynman
"QED: The Strange Theory of Light and Matter"

This is a popular science book, which requires only small amount of Quantum Mechanics and Math. (It is written for an educated general public audience an understanding of what's going on behind the calculations rather than teaching actual calculations)

I think the book is based on public lectures RPF gave in UCLA in 1980's (or another series of public lectures he gave in New Zealand - or both).. The book was written much later ..They say about this book:

To learn QED you have two choices: you can go through seven years of physics grad school or read this book

Amazon Links for these books:
http://www.amazon.com/QED-Strange-Theor ... 0691024170
http://www.amazon.com/Elementary-Partic ... 0691079560

can some gurus explain in layman's terms:
1. antimatter
2. interaction between antimatter and gravity
3. anti-atoms
4. anti hydrogen beam
5. charged anti-particles
6. etc..
?
tia

ref: http://www.thehindu.com/sci-tech/scienc ... 337171.ece

SaiK wrote:can some gurus explain in layman's terms:
1. antimatter
2. interaction between antimatter and gravity
3. anti-atoms
4. anti hydrogen beam
5. charged anti-particles
6. etc..
?
tia

ref: http://www.thehindu.com/sci-tech/scienc ... 337171.ece

^^^ SaiK - FWIW, I think wiki has a nice page about anti-matter ...

Basically
Antimatter is is material composed of antiparticles
Antiparticle is basically has the same mass as particles of ordinary matter but has opposite charge (and quantum spin type quantum numbers)

For example, we have positron, (e+) which has same mass as electron but opposite charge etc. (They have been observed in labs).

A positron and anti-proton can form an atom like hydrogen - (antimatter of hydrogen)

A particle and antiparticle combines and annihilate each other producing energy (gamma ray).

Anti-atom is same as antimatter, when the matter is atom. (except antimatter can also be molecule or complex material)

anti hydrogen beam is nothing but anti-proton (plus a positron).. generally if in ionic form it is just a beam of anti-protons.

Antiparticles may be charged - or not. Anti-proton is negatively charged, while anti-neutron is neutral.

As far as "interaction between antimatter and gravity" concerned, there are theories that gravity attracts for both matter and antimatter (that is a matter and antimatter will attract each other) and there are theories where they do not.. We just don't know as we have not been able to measure this experimentally. (Some may think that all one has to do is to see if the anti-proton beam (which can be produced in lab) deflects "down" or "up" due to earth but the speed of those particles are so high and path so short, no experiment yet has been able to measure this)

Hth
****

Now a question often asked in elementary particle physics..

Einstein equation (e=mc^2) says that matter can be converted into energy, yet a single electron (or any other particle , eg, neutron for that matter), and never be converted into energy... while an electron AND a positron can be converted into energy (2*mc^2).. why?

Bade wrote:Srikumar, just for completeness if you have the stomach to pursue this further, a PhD thesis like the one below, will summarize things better with a complete synopsis of the topic.

i agree, PhD theses are very good sources of gyan.

Deleted

so, in the black hole theory ( essentially what is proposed or proved?).. everything get sucked in, both matter and anti-matter, and becomes what? where does these particles go/convert into? do they have magnitude?

The recent meteorite entry over Russia was captured on video as flaming object moving through the sky at about 30,000 mph. Call it a physics experiment on a cosmic scale. The meteor was captured on video, the one below is 20 seconds. Warning- loud boom at the end.



The booming sound was attributed by many sources to the shockwave from the meteorite moving at hypersonic speeds. Other sources have attributed it to the explosion of the meteorite.


In the above video, there are about 10+ shots showing the effect of the shockwave, but only 1 (at 1:50) shows both the light and the smashing glass. Wikipedia has plenty of details but here's a few: it moved at about 15 km/sec, it exploded about 30 km above earth, moved roughly in a north-to-south trajectory at a 20 degree angle to horizontal.

all the physics gurus! any suggestions for science fair project for high schooler? Tenth graders.

^^^Well, has the said 10th grader taken physics, chemistry and biology yet? If they did, they may have some idea. I assume this is not for some competition, but rather within the school itself, and it must be physics related?

Physics gurus

How significant is this for engineering applications? Of course, Uncertainty principle is alive and well.

Getting Around the Uncertainty Principle: Physicists Make First Direct Measurements of Polarization States of Light

Mar. 3, 2013 — Researchers at the University of Rochester and the University of Ottawa have applied a recently developed technique to directly measure for the first time the polarization states of light. Their work both overcomes some important challenges of Heisenberg's famous Uncertainty Principle and also is applicable to qubits, the building blocks of quantum information theory.

They report their results in a paper published this week in Nature Photonics.

^^^This has immense engineering applications for imaging. If you can detect the amplitude of light in horizontal and vertical polarization, it tells us the composition of the source or structure of matter that the light passed through.

Other EM too?

^^^Light includes all of the EM spectrum; however, some wavelengths are harder to manipulate.

A flash animation to demonstrate the scale of things (more for secondary school students).

http://htwins.net/scale/

Mort Walker wrote:^^^Well, has the said 10th grader taken physics, chemistry and biology yet? If they did, they may have some idea. I assume this is not for some competition, but rather within the school itself, and it must be physics related?

Physics done. Chemistry going on. Biology not done. He is interested in Physics mainly. For state science fair competition

From TOI
The famous water hole shown in the movie Awara is to be used as a Neutrino Detector
The famous water hole shown in the movie Awara is to be used as a Neutrino Detector.

The location for the immortal song “dam bhar jo udhar muh phere” was a back lot water hole in RK movie studio. Now this famous water hole has found a new use after more than sixty years.

Awaara water hole - iconic scene



The Indian government has approved plans to reuse what was one of many temporary structures as an underground neutrino detector. Physicists will dismantle the water hole and rebuild it at the bottom of a salt mine near the Salumbar salt lake in Arawali hills in Rajasthan, where the 37 m pool will be filled with 1.8 million liters of ultra-pure water. Interestingly Salumbar hills is in the famous “cave” location depicted in the 1965 Bollywood blockbuster Guide. Neutrinos striking the water will, very occasionally, create charged particles that generate small bursts of Cerenkov radiation. This light will then be detected using a new type of detector that will line the inside wall of the pool.

RK Studio has always intended to reuse the water hole for good purpose once the right project is found. The water hole’s move to Salumbar is being funded by the USA’s DoD’s Leveraging Artistic Creativity with the Sciences (LACS) program. which is seeking to find scientific uses of movie studio infrastructure. LACS managing director, Kiran Mehta, a former actress and a physicist, told physicsworld.com that neutrinos and the Bollywood movies were "a perfect fit" because "like movies”, neutrinos push the limits of speed and imagination - possibly travelling faster than the speed of light for billions of light-years. Neutrinos, in the true sense of physics, are ultimate “awaara” (vagabond) “

Known as the Awara Muon Imaging Neutrino Tank (AMINT), the new facility will detect neutrinos via the muons that are produced when neutrinos interact with the ultrapure water. The international collaboration behind the project had spent several years looking for a suitable pool to hold the 1800 m3 of water needed to conduct its research, before realizing the awaara water hole was just the right size.
AMINT spokesperson Ruchita Godbole told physicsworld.com that the main focus of the research will be to study neutrinos created when ultra-high-energy cosmic rays collide with nuclei in the atmosphere. AMINT beat a competing experiment called the Low-energy Indirect Detector Orb for use of the water hole.

When the project is finished by April 2014, the water hole will be taken apart tile by tile. All 8000 tiles will then be sent to the Duke University to be coated with multiple layers of graphene. When reassembled, the tiles will become the world's fastest neutrino detector – thanks to the fact that electrons in graphene are able to move nearly as fast as light.



Nobel Laureate CV Raman.

Inspired by a 1971 photograph of Nobel laureate C. V. Raman taking a dip in the water surrounding his home made Raman effect detector in Banglore, AMINT will allow restricted swimming movie scenes filmed for special occasions in the reused water hole, provided that users shower with ultra-pure water first.

vijayk wrote:all the physics gurus! any suggestions for science fair project for high schooler? Tenth graders.

May be of interest,
http://www.sciencebuddies.org/

Has project ideas, guide and other resources..

When did Ray Davis become CV Raman. well for April 1 !

from that meteorite strike at russia, can't they track from where it came from? like from the angle, traversal path, radar signature, etc..?

Bade, one of the CV Raman's nephew emailed me and said that he had a good laugh when he saw the above.

Saik - If you mean the trajectory in the atmosphere, you can't go that far back..from the tire marks in an accident it is not easy to find home address of the driver...

If the meteorite happened to be tracked in space far from earth, and only forces are gravitational, one can go back decades or centuries.. but even there there it becomes VERY complicated as the orbits of a smaller object will change in complicated way if it passes near other planets etc..

Larger stable orbits can be tracked back more easily and accurately.

Something on dark matter.
CERN announces measurement of antimatter excess in space

The international team running the Alpha Magnetic Spectrometer (AMS) today announces the first results in its search for dark matter. The AMS paper, to be published in the journal Physical Review Letters, reports the observation of an excess of positrons in the cosmic ray flux.

The AMS results are based on some 25 billion recorded events, including 400,000 positrons with energies between 0.5 GeV and 350 GeV (gigaelectronvolts, a unit of energy equal to one billion electron volts), recorded over a year and a half. This represents the largest collection of antimatter particles recorded in space. The positron fraction increases from 10 GeV to 250 GeV, with the data showing the slope of the increase reducing by an order of magnitude over the range 20 to 250 GeV. The data also show no significant variation over time, or any preferred incoming direction. These results are consistent with the positrons originating from the annihilation of dark matter particles in space, but not yet sufficiently conclusive to rule out other explanations.

The improved accuracy in the measurement is notable and will make these measurements more interesting with a full analysis with time and more data.

The full press release below.
http://press.web.cern.ch/backgrounders/ ... experiment

^^^ I wish there were better editors/reporters for scientific articles in mainstream media....but FWIW the stories ---

CNN:
Space station detector gives first clues to 'dark matter'

In NYTimes:
Tantalizing New Clues Into the Mysteries of Dark Matter
)

I am not sure where to put this link. Since it is related to Physics (isn't everything in a reductionist world view?), I am putting it here. This book had been free for over a week.

Nikola Tesla: Imagination and the Man That Invented the 20th Century [Kindle Edition]

My colleague just sent me an interesting link regarding the wave nature of light:
http://www.indiatribune.com/index.php?o ... Itemid=457

I do not know how far this is true. Has the scientific community anything to say about this?

Here's another link to the physicist's site:
http://www.natureoflight-particleonly.com/

^^^What on earth is Prasada Rao Bayyarapu doing in India. He should have been debating with Susskind and Hawkins. I am sure he would have been sad not participating in Bohr-Einstein debates. From the above link -

From the foregoing experiments it is evident that interference and diffraction patterns can be explained on the basis of the fluid layer adhering to solid and liquid surfaces. Hence this phenomena can be explained by particle nature of light in place of wave theory of light. Similarly polarization in certain crystals has to be viewed from the particle nature of light. The polarization can be viewed as refraction of light at molecular clusters arranged in a particular pattern in the crystals.

Light has to be denoted with a different terminology instead of wavelength and frequency. Photon has to be designated by its mass(m) and velocity (v) implying that there are different photons with varied mass and velocities, contrary to the concepts of the Special Theory of Relativity.

Doppler effect cannot be applied for propagation of light in respect of frequency emitted and measured by source and observer respectively.

The quantum mechanics and wave mechanics and Big Bang model in Cosmology have to be developed differently as they are based on wave nature.

The origin of photons and the related dynamics will open up new vistas for research into sub-atomic particles.

Please do post links like these - they make my day! I learnt about Prasada Rao Bayyarapu, Newton of 21st century only disguised as a superintendent of police...wonder how many people are out there like these. Honestly, I developed a genuine admiration for these guys as much as I like Sam Anderson of tamil cinema. They truly rock!

Huge leaps of imagination with nothing to backup the ideas !

So my new job, boss seems to be a fizzicks lover .. quantum mech to string theory.. i wonder if he is in the wrong profession. smart guy...anyway good to have fizzic bosses.

SaiK wrote:So my new job, boss seems to be a fizzicks lover .. quantum mech to string theory.. i wonder if he is in the wrong profession. smart guy...anyway good to have fizzic bosses.

Physical theories can be enticing. The Unreasonable Effectiveness of Mathematics in the Natural Sciences is really stunning. Especially if one looks at QM where infinite dimensional space constructs have real physical analogues in the atomic world is nothing but of a wonder. However, Godel's theorem sums up the limitations of what we can hope to achieve with the current mathematical framework. Hawkins beautifully summarizes my view here:
Godel and the End of the Universe

Thus a physical theory is self referencing, like in Godel’s theorem. One might therefore expect it to be either inconsistent or incomplete. The theories we have so far are both inconsistent and incomplete.

I guess we can never hope to have a unified framework that is complete (in the Godel's sense). Of course, we can rejoice the consistency aspect of it.

I always think my brain is consistently incomplete.

SaiK wrote:I always think my brain is consistently incomplete.

Amber G. wrote:

vijayk wrote:all the physics gurus! any suggestions for science fair project for high schooler? Tenth graders.

May be of interest,
http://www.sciencebuddies.org/

Has project ideas, guide and other resources..

Slightly OT, but there is link for iron man3, check it out .. and (-one of my friend's-) non-profit org of science buddies get some donation for every click it gets today..

Saik,

You want to blow your mind take a look at the 100 year old double slit experiment and what it says about reality and how much we still don't understand. Maybe can never understand.

I'm pretty sure Prasada is not correct. Maybe Bade saar can comment.

theo, that would be a double split for my mind. i am going for a banana split right away. \

so, is it because of dark matter interferrence all this slit splitting happens?

Prasada seems like one of the hundreds of wannabe physicists who think they have proved Einstein or Heisenberg wrong. Crackpot theories are dime a dozen. Unless he can explain an unexplained phenomenon or make predictions that existing theories cannot - and back this all up with math and prove that his theory is consistent logically and agrees with experiments, his theories are just fantasies.

Agreed Theo: double slit is one of those simple experiments that just defy explanation. (Like Fermat's last theorem which can be explained to a middle-schooler. The proof is a different story altogether). The "why" of the results are not explainable even by quantum theory. As Feynman said, "no one understands quantum mechanics" (even though we have the tools to successfully use the theory in practical ways).

There is also a theorem or two that prove that Quantum mechanics cannot be derived from classical mechanics (i.e. as an extreme case). It talks about a fundamentally different form of reality, which even physicists dont fully comprehend

Theo, there is only so much time each one of has to indulge in chasing wild fantasies of others. That is what peer review does for science (filter out the nonsense), with all its shortcomings which practicing scientists often whine about too. If Prasada had anything intelligent to say, someone would have already picked it up. Cursory reading showed it is all word-play with no connections between the axioms and supposed explanation for why things are what they are. It is almost like the claims we see on BRF day in and day out to show how the ancients indics had got it all right and said it so precisely in a few lines. Rest of us just have to fill in the blanks. Not much of theory, isn't it then ?

Prem,

The way my professor put it is that is very well described by quantum mechanics.
So well explained that it is the most accurate theory of any kind out there.
QM has been tested again and again and again and found to be flawless.

It is what it says about the nature of reality that blows the mind.
Every week I spend an hour or two just gazing at the implications and the implications make me want to giggle. It just seems so impossible. You almost see the imprint of god.

The idea that matter is a wave function, with nothing solid, just probability function but which collapses to a solid particle only when observed. Holy smokes!
The idea that we can not talk about path of travel or even time of travel and these are inapplicable words at the QM level.
The idea that you can put a detector near a photon that has traveled a billion years through a double slit and cause it to collapse to a solid particle a billion years ago and the photon 'knows' which slit it went through...
May be a poor selection of words....

My professor would lose me at this point.... ..my mind would simply cease to function...
----------------------------------

Saik,

It is not even clear dark matter is matter.
The double slit experiment is evidence of the nature of reality, not evidence for an unknown effect.

Prem Kumar wrote: There is also a theorem or two that prove that Quantum mechanics cannot be derived from classical mechanics (i.e. as an extreme case).

Why do we expect QM to be derived from CM? Do we have any linear axiomatic basis for these things? I understand QM as an extension of CM from an intuitive perspective.

Theo_Fidel wrote: It is what it says about the nature of reality that blows the mind.

Nature of reality cannot be confined merely to a set of equations. The right word would probably be "an aspect of reality"

Ramanujan often said "An equation for me has no meaning, unless it represents a thought of God." Here you are confining God to a set of equations. This glaringly demonstrates the difference between a mathematician and a typical physicist.

kasthuri wrote:

Prem Kumar wrote: There is also a theorem or two that prove that Quantum mechanics cannot be derived from classical mechanics (i.e. as an extreme case).

Why do we expect QM to be derived from CM? Do we have any linear axiomatic basis for these things? I understand QM as an extension of CM from an intuitive perspective.

By "deriving", I mean the ability to look at one theory as a generalization of the other. The reality is that QA and CM are fundamentally different. The classical principles & assumptions completely break down in the quantum world. CM works in the larger world because the quantum effects cancel out when larger objects are concerned (IOW, the probability of quantum events occurring amongst larger objects is exceedingly low). So, the CM assumptions that objects have a fixed position, momentum, are solid & cannot pass through each other etc etc work for our day to day calculations

Well I’m neither so willing to learn.
I did not understand that quote from Ramanujam, what does it mean.
My take away is that reality at the QM level is very mysterious.

AFAIK there is only one reality. Both QM & CM are part of that reality but not separate ‘aspects’.
There is only one reality, occasionally we get to see glimpses of it, even if we do not understand all of it yet.

The double slit experiment fascinates me like no other in physics.
The idea that the observer creates reality is impossible to comprehend for me. The implications boggle the mind.