Physics Discussion Thread

ramana · Post by **ramana** » 13 Oct 2011 09:11

Bade my dad was a physicist from Uty college of London, studied under GP Thompson. Yet he became a lawyer in India. My brother is a physicist and worked for US.

Very familiar.

Amber G. · Post by **Amber G.** » 14 Oct 2011 21:39

From MIT-tech...MIT physics professors examine the neutrino speed controversy..

Not so fast neutrinos

Also some personal observation:

After the news-conference, initial paper presentation (I have put a link to it's pp slides), and pre-print (also link given before) there is some hesitation by some to publish the article (in a journal) without some more checking. (Some of the authors want to wait)

Perhaps within a few weeks in USA (where the distance between source and detector is similar - around 800 Km) or in Japan (where distance is much smaller) we will get some more data from similar experiment...another set of eyes...

The authors in CERN have been very careful.. no one is claiming that there is no error in their readings.. just that they can't find it if it is there and asking for help...

There are too many complex things in the experiment where it is hard to know that one is not missing anything .

(There have been some amusing kind of bets.)

SaiK · Post by **SaiK** » 14 Oct 2011 21:55

Can India conduct some thing like this? are our facilities good enough?

Amber G. · Post by **Amber G.** » 14 Oct 2011 23:31

For India's Neutrino observatory please see wiki, or the official site (quite good, IMO)
http://www.ino.tifr.res.in/ino/
(See FAQ - what are neutrinos, why/how detect them etc)
India does not have, big particle accelerators. India does have many scientists who study neutrinos...

Difficulty is, neutrinos are very hard to detect... (they will pass through million mile thick lead without getting slower..).. They get produced after every beta decay.. (All that Cs-137 after Fukushima

) but it is hard to see neutrinos directly..

But ICAL's (India's detectors) with RPC(Resistive Plate Chambers) will be very good. (These things consist of about 50000 TONS of magnetized iron plates arranged in stacks).. They will be able to see CERN's neutrinos (about 6870 Km away 10x the distance of Italy's detectors) or FermiLabs (10500 Km away) neutrinos..hopefully within 4-5 years..

Amber G. · Post by **Amber G.** » 15 Oct 2011 01:59

ramana · Post by **ramana** » 15 Oct 2011 02:15

So thats why physicsts are now working at their own hedge funds!

Amber G. · Post by **Amber G.** » 15 Oct 2011 03:20

^^^

BTW, I may have mentioned it here that my son's thesis adviser told us that *everyone* (except him, of course) from his PhD physics graduating (which was probably 15-20 years ago) class went into Hedge fund (and the like) ... (Of course the story is not unique .. physics/math degree is highly sought after by hedge-fund-wala's)

Actually one of the article (WSJ) we once distributed to encourage top High School students to go in Physics/Math (I am still involved in coaching math teams) was, and this may come as a surprise to many, that a physics (or math) degree from a top school is still the highest paying degree according to this study ..(higher than engineering degree) as Wall street and banks value physics/math degree a lot. ..

As Bade said.. (and I think he is quite right - though I don't have statistics of that) about 1% of the Physics people remain in academic field of pure physics.... (It is easy, relatively speaking, to go in different fields from physics)

gakakkad · Post by **gakakkad** » 15 Oct 2011 17:33

SaiK wrote:Can India conduct some thing like this? are our facilities good enough?

you need very large space to have huge cyclotrons... The problems with land acquisitions in desh are well known...

Amber G. · Post by **Amber G.** » 15 Oct 2011 19:15

For those who are curious, from what I know, well known particle accelerators in India are:
Indus in Indore
VECC in Kolkata
IUAC in Delhi

(Of course, detecting neutrinos needs neutrino detectors.... INO will be one of the world's best)

Nandu · Post by **Nandu** » 17 Oct 2011 12:11

Amber G., I am surprised you haven't posted or commented here on the news that a physicist has claimed explanation of the neutrino anomaly by careful analysis of the relativistic effects of clocks on GPS satellites.

http://www.technologyreview.com/blog/ar ... 0/?ref=rss

ramana · Post by **ramana** » 18 Oct 2011 01:31

Bade, something for you!

http://en.wikipedia.org/wiki/Econophysics

Amber G. · Post by **Amber G.** » 18 Oct 2011 02:18

Nandu - Thanks. I have not seen that article. (There have been something like 100 posts regarding possible errors in Arxiv etc..)

After reading your ref (have not seen the actual article in Arxiv) my gut reaction is that effects on timing due to GPS clocks is probably not it. (Authors have been very careful, so this is they must have known... besides they have used Cs Atomic clocks on ground to verify the GPS based clocks..

More suspicion is in the accuracy of distance measurement .. (May be this is what your story is implying by using GPS to measure distance).. It is, to put it mildly, very hard, specially underground where you can not have lasers to do direct measurement. Also the statistical nature of the whole thing is another suspect (One does not know, actual time path of an individual neutrino, just the statistical distribution)

We will know soon enough... I think the authors themselves will find it.

Bade · Post by **Bade** » 18 Oct 2011 02:35

ramana, interesting that you mention econophysics. A close family member on shq side is from that field; madarasa educated one vina saar will know for sure. So I should shut up now before I spill more.

On GPS measurements, I vaguely remember circa 2002 or so there was a nice Physics Today article about how discovery of General Relativity is important to ensure accuracy of GPS measurements. So it is a unlikely source of error. Has to be something else.

Bade · Post by **Bade** » 18 Oct 2011 21:18

http://www.ipgp.fr/~tarantola/Files/Pro ... ty_GPS.pdf

The physics today article mentioned above.

Amber G. · Post by **Amber G.** » 25 Oct 2011 01:05

This thread has been one of my favorite (apart from maths corner) thread in BRF to read and post on things where my professional interest lies.

Yet I have to be honest that it makes me sad that BRF is going in a direction where technical discussion and diverse view points are, in my opinion frowned on. Many technically good people, who used to post here have left. The reasons, as I see it, I have posted in feedback forum.

Let me post an interesting clip, where pardon my pun, but a large magnetic field will not only distort "compasses" but may have something to do with "koop maduk"- ness (narrow view point)

Here is the clip, Enjoy. ... It comes from the same person who recently wrote
This:http://arxiv.org/ftp/arxiv/papers/1110/1110.2832.pdf

*****
..... Also enjoy Neutrino

Amber G. · Post by **Amber G.** » 25 Oct 2011 03:56

Nandu - Wrt to you message...
You may be interested in seeing this NYtimes article:
Particles Faster Than the Speed of Light? Not So Fast, Some Say

What you said was mentioned..I do get MIT's technical review, where it was discussed.. looks likely gut reaction was correct ... anyway

From NY times:

That paper got wide attention. ...

....The Opera collaborators and other outside physicists now say Dr. van Elburg’s analysis is wrong and reflects confusion about how GPS systems work.

Amber G. · Post by **Amber G.** » 28 Oct 2011 09:12

Talking about Neutrino's etc.. sad news of a great son of India passing away:
In memoriam: Ramaswamy (Raju) Raghavan
(Also see:http://cnp.phys.vt.edu/cnp-bin/raju.pl here ..

Amber G. · Post by **Amber G.** » 28 Oct 2011 09:26

Some may enjoy this: (Daily show episode)
http://www.thedailyshow.com/full-episod ... sa-randall

Bade · Post by **Bade** » 01 Nov 2011 02:46

Skeptic finds he now agrees global warming is real

WASHINGTON (AP) - A prominent physicist and skeptic of global warming spent two years trying to find out if mainstream climate scientists were wrong. In the end, he determined they were right: Temperatures really are rising rapidly.

The study of the world's surface temperatures by Richard Muller was partially bankrolled by a foundation connected to global warming deniers. He pursued long-held skeptic theories in analyzing the data. He was spurred to action because of "Climategate," a British scandal involving hacked emails of scientists.

Yet he found that the land is 1.6 degrees warmer than in the 1950s. Those numbers from Muller, who works at the University of California, Berkeley and Lawrence Berkeley National Lab, match those by the National Oceanic and Atmospheric Administration and NASA.

He said he went even further back, studying readings from Benjamin Franklin and Thomas Jefferson. His ultimate finding of a warming world, to be presented at a conference Monday, is no different from what mainstream climate scientists have been saying for decades.

What's different, and why everyone from opinion columnists to "The Daily Show" is paying attention is who is behind the study.

One-quarter of the $600,000 to do the research came from the Charles Koch Foundation, whose founder is a major funder of skeptic groups and the tea party. The Koch brothers, Charles and David, run a large privately held company involved in oil and other industries, producing sizable greenhouse gas emissions.

OK some leeway left still for non-believers in the cause or source of all this !

There is no reason now to be a skeptic about steadily increasing temperatures, Muller wrote recently in The Wall Street Journal's editorial pages, a place friendly to skeptics. Muller did not address in his research the cause of global warming. The overwhelming majority of climate scientists say it's man-made from the burning of fossil fuels such as coal and oil. Nor did his study look at ocean warming, future warming and how much of a threat to mankind climate change might be.

Still, Muller said it makes sense to reduce the carbon dioxide created by fossil fuels.

"Greenhouse gases could have a disastrous impact on the world," he said. Still, he contends that threat is not as proven as the Nobel Prize-winning Intergovernmental Panel on Climate Change says it is.

For those into nitty gritty of the analysis check this out !
The Berkeley Earth Surface Temperature site:
http://www.berkeleyearth.org/index.php

Bade · Post by **Bade** » 01 Nov 2011 02:51

Amber G. wrote:Talking about Neutrino's etc.. sad news of a great son of India passing away:
In memoriam: Ramaswamy (Raju) Raghavan
(Also see:http://cnp.phys.vt.edu/cnp-bin/raju.pl here ..

I did not know him in person, though have seen his name being mentioned. INO folks will miss him for sure.

SaiK · Post by **SaiK** » 14 Nov 2011 00:03

is bade on sabatical?

http://news.yahoo.com/einsteins-laws-pr ... 07090.html
Do Einstein's Laws Prove Ghosts Exist?

saip · Post by **saip** » 14 Nov 2011 00:51

gakakkad wrote:
SaiK wrote:Can India conduct some thing like this? are our facilities good enough?

you need very large space to have huge cyclotrons... The problems with land acquisitions in desh are well known...

When US wanted to set up Superconducting Super Collider I heard tha the only state that did NOT bid for the program was Rhode Island. RI being a tiny state, they found that they could not accommodate the whole thing in their state. It was given to Waxahachie, Texas and after spending a few billions of the tax money it was abandoned! But now with the improvement in magnets its diameter may not be that big and probably will fit in RI.

Vayutuvan · Post by **Vayutuvan** » 25 Nov 2011 07:16

I came across the following quote in one of the discussion lists I subscribe to. Thought this might be of interest to Bade saar and Kasturi garu and others.

"I consider it quite possible that physics cannot be based
on the field concept, i. e., on continuous structures. In that case
_nothing_ remains of my entire castle in the air gravitation theory
included, [and of] the rest of modern physics" From _Subtle is the Lord_
by Abraham Pais. page467. (I have not read this book which is billed as a scientific biography of Einstein - supposed to require good grounding in Physics, not sure whether I still remember the prerequisites)

In other words Einstein considers the possibility that Physics can be reduced to counting (as Bade proposed) but then that would invalidate entire modern physics. If the FTL nutrinos turn out to be right, would there be a connection between the two? Of course, modern physics may be invalidated by the (improbable) verification of the FTL nuttrinos, yet there may not be discrete structure to Physics.

SaiK · Post by **SaiK** » 06 Dec 2011 08:39

was watching curiosity/sci ch. they were talking about thunder wells blasted off at 6*escape velocity to alien crafts invading earth. it was a wonderful picturization of those getting blasted off earth and hitting the invaders.

wondering if such is a possible weapon?

member_20317 · Post by **member_20317** » 11 Dec 2011 13:35

Dear Guruji, kindly explain through some real life example, the following in English. If not impossible then kindly let the real life example be something that has something to do with big dhamakas.

.

I am not trained in any of the Sciences so I would basically not mind being told to get lost. That too would actually be a valued input.

The honeycomb–lattice structure allows physicists
to observe relativistic effects at speeds that are
much below the speed of light. This behaviour is
due to the strong interaction between the electrons
in the Graphene layer. These strong interactions
ensure that the energy and momentum of electrons
in Graphene are related through the equation,
E=νP where ν is called the ‘Fermi-Dirac velocity’
and P is the momentum. In special theory of
relativity energy, E and momentum P are related
by the equation, E=√(Mc2 + P2c2) which yields E
= c P as M turns to zero. Thus the electrons in
Graphene behave as if their mass is zero. Two
things have to be remembered to fully appreciate
this effect in Graphene. Firstly, the Fermi-Dirac
velocity in graphene is about 300 times less than
the speed of light, and secondly, that electrons
moving in honeycomb-lattice only produce this
energy-momentum relationship whereas other
lattices like square or triangular always end up
having electrons with finite band mass. The
mass-less electrons are however quite different
from their particle–physics cousins neutrinos.
This is because unlike electrons neutrinos carry
no charge and therefore cannot interact strongly
with any matter. The electrons in Graphene
can however interact with matter and can also
be manipulated through externally applied
electromagnetic fields. This manipulation is what
makes graphene a very interesting candidate
trying to beyond the technology limits set by
silicon-based systems and devices.

Amber G. · Post by **Amber G.** » 13 Dec 2011 03:59

Major news conference/announcement scheduled tomorrow in CERN about Higgs Boson ("God's particle").... There will be many stories... Here is some background.
Large Hadron Collider Background

SaiK · Post by **SaiK** » 13 Dec 2011 04:26

so physics gurus, what are these bosons made of?

Bade · Post by **Bade** » 13 Dec 2011 05:52

http://www.chicagotribune.com/news/nati ... 1322.story
So here is another tease on the topic.

Amber G. · Post by **Amber G.** » 13 Dec 2011 21:02

Webcast:

http://webcast.web.cern.ch/webcast/

rsingh · Post by **rsingh** » 13 Dec 2011 21:18

Analysis please..............................for common unwashed Abdul

Amber G. · Post by **Amber G.** » 13 Dec 2011 21:24

^^^NY times story..
‘Tantalizing Hints’ but No Direct Proof in Particle Search

(Details at CERN site.. for example: here)

Bade · Post by **Bade** » 14 Dec 2011 21:49

More of the same story with some Indian physicists quoted.

http://www.telegraphindia.com/1111214/j ... 879233.jsp

vishvak · Post by **vishvak** » 14 Dec 2011 23:43

From http://www.telegraphindia.com/1111214/j ... 879099.jsp

Physicist Vivek Sharma who was born in Muzaffarpur, Bihar, and now leads an international group hunting for the Higgs boson sees the search as an attempt to seek out answers to questions posed in the Rig Veda.

Sharma, who went to a Kendriya Vidyalaya in Pune and pursued master’s in physics at the Indian Institute of Technology, Kanpur, says he was drawn to experimental particle physics after learning Rig Veda hymns from his mother, a Sanskrit scholar.
...
“Experiments will ultimately tell us what is right and what is wrong,” he said. In the coming months, Sharma and his colleagues will refine their analyses and combine the data from the two main particle detectors looking for the Higgs boson.

“Our curiosity about our origins doesn’t change anybody’s life, but there is a satisfaction from understanding such things,” Sharma said

“But when we build machines like the Large Hadron Collider (the particle accelerator at CERN where proton-proton collisions are used to search for the Higgs boson), it requires us to invent new technologies that can change people’s lives,” he said.

The World Wide Web was created at CERN to help physicists move data around between different computers in a seamless fashion. “It’s a great example of how something that is good for physicists turned out to be fantastic for the public,” Sharma said.

New technologies and ideas that are born in experimental physics laboratories may have implications in information technology and medicine. “Our goals are esoteric, but what sometimes comes out benefits the public,” he said.
...

SaiK · Post by **SaiK** » 14 Dec 2011 23:48

so, what technology is coming out now? anybody knows little bit more or this is all stealth and only the venture capitalist will know?

Bade · Post by **Bade** » 18 Dec 2011 07:17

Since there is mucho wailing going on in other threads that GoI is not investing enough on research, here is a different take on this.

Changes and challenges: Physics in India
http://dx.doi.org/10.1063/PT.3.1357
This one has not got much publicity in Indian media, at least I did not come across articles on this potential investment.

Excitement is building about the prospect of India’s hosting a leg of Advanced LIGO, the upgrade to the US-based Laser Interferometer Gravitational-Wave Observatory. After it became clear that Australia would not come up with the funds to be a LIGO site (see PHYSICS TODAY, December 2010, page 31), IndIGO, a consortium of 11 Indian institutions involved in gravitational-wave experiments and LIGO data analysis, sprang into action to bring the experiment to India. The group’s LIGO-India proposal squeaked onto the list of megaprojects under consideration for the country’s next five-year budget plan, which begins in April 2012. So far the project has gotten a good reception, according to people who presented the case for it, and they are now working on a detailed proposal. “It’s gratifying that we are being considered,” says IndIGO spokesman Tarun Souradeep of the Inter-University Centre for Astronomy and Astrophysics in Pune. “We could be entering the field in good time, not when it has already blossomed.”

Amber G. · Post by **Amber G.** » 18 Dec 2011 22:29

Bade - Thanks.

(see PHYSICS TODAY, December 2010, page 31)

Interestingly December 2010 issue of Physics today was a special issue dedicated to Chandrasekhar. (Chandrasekhar centennial issue).

It's cover, and most articles inside, have lot of interesting articles about biographical portrait, anecdotes, his role in modern scientific thinking and his physics.. lots of old photographs, memories and gem of an article about
"Beauty and quest for beauty in Science" by Chandra himself.
(I have a hard copy of the issue saved for my archive... I knew the man and the family so it is special to me)

SaiK · Post by **SaiK** » 23 Dec 2011 08:03

http://www.thehindu.com/sci-tech/scienc ... 739035.ece
bade, the Sulai particle is making sense to the CERN team, slowly...

beauty quark and the anti quark are definitely required to make the Sulai!. Not sure how many more Sulais they will find in the future. I hope the higgs is a momentary zillionth time when the beauty Sulai and the anti-sulais, joins to create.

Bade · Post by **Bade** » 23 Dec 2011 08:21

^^^ Something is not right the way the article is written and the result explained. The 'Chi' with the beauty quarks is just a heavier version of the bound state, which makes it a meson/baryon class and not the same as the Higgs.

Bade · Post by **Bade** » 23 Dec 2011 09:39

This is what the paper available in arXiv says,

The chi_b(nP) quarkonium states are produced in proton-proton collisions at the Large Hadron Collider (LHC) at sqrt(s) = 7 TeV and recorded by the ATLAS detector. Using a data sample corresponding to an integrated luminosity of 4.4 fb^-1, these states are reconstructed through their radiative decays to Upsilon(1S,2S) with Upsilon->mu+mu-. In addition to the mass peaks corresponding to the decay modes chi_b(1P,2P)->Upsilon(1S)gamma, a new structure centered at a mass of 10.539+/-0.004 (stat.)+/-0.008 (syst.) GeV is also observed, in both the Upsilon(1S)gamma and Upsilon(2S)gamma decay modes. This is interpreted as the chi_b(3P) system.

I do not know from where did the media bozos get this idea.

Scientists identify new 'force' particle

Bade · Post by **Bade** » 28 Dec 2011 02:00

Indian duo find neutrino fault

Cowsik, Sarkar, and Nussinov applied principles of conservation of energy and momentum to the neutrino production process in CERN. Their calculations, based on equations taught in masters-level physics courses, show that if the neutrinos detected in Italy had indeed travelled faster than light, they would have had much lower energies than observed. A paper pointing out this problem is published today in the journal Physical Review Letters.

"The conservation of energy and momentum laws are fundamental to physics. If we assume they apply to these neutrinos, the experiment should not be seeing the neutrino energies that it did," Cowsik, professor of physics at the Washington University, St. Louis in the US, said.

The CERN neutrinos are produced in a step-wise process. The proton-proton collisions create subatomic particles called pions which decay into neutrinos and another type of particles called muons. The energy balance calculations show that if the neutrinos that are produced through such pion decays travelled faster than light, the neutrinos would carry a smaller fraction of energy that is shared between the neutrinos and the muons.

The calculations emerged from an informal chat about the CERN results the three physicists had when Nussinov and Sarkar, a senior physicist at the Physical Research Laboratory, Ahmedabad, were visiting Cowsik's office in St Louis about a month ago.

"This is a strong paper with well-articulated arguments," said Amitava Raychaudhuri, Palit professor of theoretical physics at Calcutta University. "Their calculations show that faster-than-light neutrinos are inconsistent with the neutrino energies seen."

Cowsik and his colleagues checked their calculations by analysing the neutrino energies seen in an observatory called IceCube buried in Antarctic ice that has been tracking neutrinos created when cosmic rays strike the Earth's atmosphere. These neutrinos are also produced from the decay of pions and mimic the CERN production process. "The contradictions are exacerbated in the Antarctic experiment ' we see neutrinos with extreme high energies," Cowsik said.