Physics Discussion Thread

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Supratik
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Re: Physics Discussion Thread

Postby Supratik » 29 May 2019 00:08

Ambient temp superconductivity is one of the holy grails of physics. There have been claims in the past which have been proven to be wrong. Hence, the scepticism. It is possible that this finding is also wrong. On other hand Chandrasekhar of the Chandrasekhar limit fame was repeatedly called wrong at best and fraud at worst by a famous British astrophysicist for decades until it was proven and he got the Noble prize.

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Re: Physics Discussion Thread

Postby Rahul M » 29 May 2019 00:22

well, this doesn't look too good.

but they have claimed that they have found a way to preserve the samples and will share it with other labs.

also, I am not exactly sure how the noise means that that the data is fraudulent ?

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Re: Physics Discussion Thread

Postby Amber G. » 29 May 2019 00:45

^^^ Rahulji - for me, the disturbing part is fake e-mail and TVR saga (see SA or PR's facebook post).. some one went through lot of trouble to impersonate TVR and send fake emails..whoever did that needs to be investigated by India.
****
Meanwhile there is another update - a video giving more "proof" in support of IISc claim:
IISc team provides video evidence of superconductivity at room temperature

(This gives further evidence - as all superconductors display diamagnetic properties. But it is not a clinching proof as diamagnetism does not prove superconductivity)

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Re: Physics Discussion Thread

Postby Amber G. » 29 May 2019 02:40

I wanted to post about IISc scientists discovery in this dhaga last August but I restrained myself. I was hoping that whole controversy will be sorted out before the story became a big news item. The authors did not published the paper then (they did not retract it also) and now the news story has been reported in Hindu and various Indian news media so thought talking about this is not improper,

Now the story is making a big news. I have many close friends in IISc so obviously I want the story to be true but ignoring scientific criticism and MSM's selling it as Indian Scientists vs Foreign Criticism is not the best policy as the truth will come out. IISc should have due diligence to make sure that not only get due credit but also the experiments are done with highest integrity.

I was doing some google, and found that lot of controversy is out in the open, I posted the SA article before. Here is another one from last August.
IISc superconductivity saga: Impersonator almost succeeds in messing up

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Re: Physics Discussion Thread

Postby Amber G. » 29 May 2019 06:21

Meanwhile there is this conference in the Bay area. for IISc alumni - so may be some interesting lectures and more info. https://conf2019.iiscaana.org/

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Re: Physics Discussion Thread

Postby Kashi » 29 May 2019 08:53

This discovery promises to be a breakthrough, but as Amber G said, every bit of it needs to be solidly verified and must be beyond reasonable doubt. Given the nature of these findings, there will be scepticism and claims and counter claims (some of it may have little to do with science), the authors should be prepared to share their data and protocols with anyone who wishes to reproduce their findings.

I am curious as to which journal they actually plan to publish their findings in.

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Re: Physics Discussion Thread

Postby tandav » 29 May 2019 11:28

https://youtu.be/G-aoR8LtFzo

Above is the link to the diamagnetic repulsion of some particles. One commenter has mentioned it looks more like electrostatic repulsion due tribological charge accumulation.

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Re: Physics Discussion Thread

Postby Amber G. » 29 May 2019 11:43

Supratik wrote:Not a physicist but I can't tell the difference or repetation that you claim from that graph. That appears to be baseline. I would assume the upward curve and then plateauing is where the real meat is and that is different. I think it is OK to criticize data but this is borderline claiming fraud. A lot of western scientists do not have a good idea of Indian science and think everyone there is cooking up data. We need to be careful and not add to the noise...

...I looked at the green dots and blue dots again. The y-axis is clearly different. As I would assume that it is the baseline hence very little difference. Now if it is the opposite then one can claim that not even negligible difference is seen. Not a copy paste..


Allow me to add something here.. hope which is helpful.

To be clear, I am here, or others scientists I have mentioned, in this case are NOT interested in calling it a "fraud" or unnecessary blaming Indian Scientists. We may not understand everything but I think we are not prejudiced and
certainly do not have have bad intentions.

And the "repetition" part is not a trivial claim. For details see the arXiv paper and the public comment article (Its very short and people with minimum background can understand) which even the authors thought was serious. (Unfortunately in the new article they do not repeat or add more trial runs of that experiment - which I thought they will surely do to see if the noise is really random. Except noticing the pattern and say they do not understand why this was so they reproduced the same data in the current paper - at least that is what I see. If I am wrong I will certainly correct myself - the paper is quite long and I am not that familiar with this experimental field)

Let me explain it here for non-physics people. It is not concern about "noise" or "accusing some one of something"..
Basically what BrianS (Prof at OSU but at that time at MIT) wrote in that arXiv part was noticing exactly the same pattern of noise at two different events.

It is like seeing the exactly the same cloud pattern in the sky at tow different times in the background - indicating something is not right. Now this does not necessary mean fraud (or photoshop) but can have other explanation. (Say same imperfect camera lens used). But it does need further investigation.

As I said before, the real controversy came what took place later - fake emails etc-- completely unexpected. The mischievous party (most likely a third party - not IISc) who went a great length in faking these emails, IMO needs to be investigated. This party, I think, knows enough about physics and Indian Physicists (to fake TVR).

One thing, we can all agree on. - IISc is a top rated place and so this will be resolved in near future for sure. While we write this post here or have twitter fight elsewhere there are lot of good scientists working to resolve this.

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Re: Physics Discussion Thread

Postby Amber G. » 29 May 2019 12:09

Rahul M wrote:also, I am not exactly sure how the noise means that that the data is fraudulent ?

Rahulji - As I mentioned (and other SA article too), it is not the "noise" per se but the noise pattern is same in two different places. This is what got many concerned. (It's like, as I said, noticing two exactly the same cloud pattern in two different photographs -in the background)
Here is technical part - public comment about that " https://arxiv.org/abs/1808.02929

Fraud in physics is rare but it does happen. One of the well known case (and BIG scandal - check out wiki) is of Jan Hendrik Schon. Interestingly he also worked on superconductors. He was caught by - yes - exactly the same way - noise patterns were same in his two different papers. (He lost his PhD and many of his papers were retracted.

More here: https://en.wikipedia.org/wiki/Sch%C3%B6n_scandal

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Re: Physics Discussion Thread

Postby Supratik » 29 May 2019 18:27

Amber G, again not a physicist but what that Prof is claiming about the noise is borderline claim of fraud. In my field I wouldn't worry about noise in the baseline specially if the phenomenon doesn't tell anything other than just "noise at the baseline". Now I don't know if noise at the baseline is important in physics or superconductivity or not. But the rest of the data clear shows they are getting a signal. Whether it is superconductivity or something different is for physicists to tell. If the IISc team is confident about the data they should just get it published wherever they can, patent their technology and move onto more research and actually making devices. That is the best proof of whether they got superconductivity at ambient temperature or not.

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Re: Physics Discussion Thread

Postby sudarshan » 29 May 2019 19:10

Supratik wrote:Amber G, again not a physicist but what that Prof is claiming about the noise is borderline claim of fraud. In my field I wouldn't worry about noise in the baseline specially if the phenomenon doesn't tell anything other than just "noise at the baseline". Now I don't know if noise at the baseline is important in physics or superconductivity or not. But the rest of the data clear shows they are getting a signal. Whether it is superconductivity or something different is for physicists to tell. If the IISc team is confident about the data they should just get it published wherever they can, patent their technology and move onto more research and actually making devices. That is the best proof of whether they got superconductivity at ambient temperature or not.


I think AmberG's example of the cloud pattern is a good one.

Let's say ISRO or DRDO develops a new missile. They flight test it three times. They release videos of these flight tests. In one video, the missile takes off vertically and hits a target in the air. In another, the missile attacks a ground target. In the third, it does a complex maneuver (just examples, I know these aren't realistic).

So now we have video evidence of three separate tests of this same missile. That proves that the missile is worthy and tested, right? Now imagine, some observer comes and points out that the background cloud pattern in all the videos is exactly the same!

Is the background cloud pattern of any importance in a video of a missile test? Nope, it's just noise. But if that pattern is exactly the same in three different videos, which have supposedly been shot at three different locations, at three different times, one in winter, one in summer, one on a late monsoon evening? Would that not be suspicious, or at the very least, would it not call for some explanation on ISRO's or DRDO's part?

Same with the noise floor pattern in the plots that AmberG posted.

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Re: Physics Discussion Thread

Postby Supratik » 29 May 2019 19:45

That would be fraud. Are you claiming the IISc scientists are frauds?

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Re: Physics Discussion Thread

Postby Supratik » 29 May 2019 19:55

Looking at the data again. I can see clear differences in the baseline. The value in the y-axis is different. The region marked by Amber G is in a different position. A few points at the bottom show similar pattern. Can happen? IMO this is deliberate calumny irrespective of whether they got superconductivity or not.

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Re: Physics Discussion Thread

Postby sudarshan » 29 May 2019 19:58

Supratik wrote:That would be fraud. Are you claiming the IISc scientists are frauds?


Supratik ji, a senior poster like you should know the difference between someone trying to explain the issue at hand, and someone claiming fraud.

The noise pattern in the plots is identical on two different runs (save the baseline shift), and this is exactly like the example I gave above. I too am curious to know the reason for why the noise pattern can be the same on two different runs. There could well be a simple explanation for this (other than fraud), if so, great.

Now are you saying that you've never analyzed the pics or videos of China's latest fighters, where there is no distortion on the background due to the exhaust plume, and wondered how that can be the case?

It's good to ask questions and have a healthy dose of skepticism and scientific curiosity, just by questioning your own side and keeping them on their toes, you don't become NDTV. On the contrary, you are doing your own side a favor through healthy skepticism.

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Re: Physics Discussion Thread

Postby sudarshan » 29 May 2019 19:59

Supratik wrote:Looking at the data again. I can see clear differences in the baseline. The value in the y-axis is different. The region marked by Amber G is in a different position. A few points at the bottom show similar pattern. Can happen? IMO this is deliberate calumny irrespective of whether they got superconductivity or not.


OK, great. If you or someone else can come up with a rational explanation for this behavior of the noise pattern, that's good enough for me.

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Re: Physics Discussion Thread

Postby Supratik » 29 May 2019 21:07

The only place where it looks similar is in the bottom two plots in the baseline. The rest are fine including what Amber G is showing (I don't think it is a good idea to crop different places of a plot and say look it is the same - that is childish). A possible explanation is that the difference between the bottom two plots is miniscule and they have rounded the value up to a higher number. If the criticism along this line continues they should just post the raw data and get it done with. As for noise (that is the points are going up and down in the baseline) only physicists can tell. Also I don't like this whole business of presenting data on such websites obviously to gain publicity and then criticizing on facebook and twitter, etc. You have data you send it to a journal and get it reviewed and published. If you have concerns you send it to one or two eminent scientists before publication for feedback. The best way to criticize a publication is to send a letter to the journal. That is what all traditional scientists do but I guess the IISc scientists wanted some publicity which has landed them in a soup.

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Re: Physics Discussion Thread

Postby Amber G. » 31 May 2019 21:55

]Meanwhile - may be not making as much noise in media but I found interesting/exciting. Just a few items: (From this week)

- Really exciting news about Super Conductivity ( at -23° C - which is a huge leap towards room temperature). (The article was published in Nature and then only big news) . ( Only a few Indian Newspapers have this story)

New superconductivity record edges closer to room temperature

Article - Abourt Prof. Subir Sachdev's (A recent awardee of Dirac's medal - I wrote about him here -- student:
Superconductivity in new magnetic materials called quantum spin liquids

Another story about IISc's prof (again the article is accepted in reputable paper) in Physics/Bio_Physics. I was intrigued because I like mathematical modeling. I especially like the term "LL = Laxman Line" - aptly named after "Laxman Rekha"


Link Rivalry in Bacillus subtilis Colonies: Enemy or Family?
Image

And 100th Anniversary
of the Eclipse
which proved the validity of Einstein's GR.. Wonderful 100 years where the story has been tested and found correct. Virtually weekly events now by LIGO -- we have learning SO MUCH (virtually daily new learnings) about neutron stars and black holes.

(Just wanted to give a perspective that there is more interesting items in Physics world than the whole tamasha the media and some people have built-up around the "break-through" about a few authors of IISc's arXiv paper which has not even been published or peer reviewed).

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Re: Physics Discussion Thread

Postby tandav » 02 Jun 2019 10:17

Amber G. wrote:]Meanwhile - may be not making as much noise in media but I found interesting/exciting. Just a few items: (From this week)

- Really exciting news about Super Conductivity ( at -23° C - which is a huge leap towards room temperature). (The article was published in Nature and then only big news) . ( Only a few Indian Newspapers have this story)

New superconductivity record edges closer to room temperature

Article - Abourt Prof. Subir Sachdev's (A recent awardee of Dirac's medal - I wrote about him here -- student:
Superconductivity in new magnetic materials called quantum spin liquids

Another story about IISc's prof (again the article is accepted in reputable paper) in Physics/Bio_Physics. I was intrigued because I like mathematical modeling. I especially like the term "LL = Laxman Line" - aptly named after "Laxman Rekha"


Link Rivalry in Bacillus subtilis Colonies: Enemy or Family?
Image

And 100th Anniversary
of the Eclipse
which proved the validity of Einstein's GR.. Wonderful 100 years where the story has been tested and found correct. Virtually weekly events now by LIGO -- we have learning SO MUCH (virtually daily new learnings) about neutron stars and black holes.

(Just wanted to give a perspective that there is more interesting items in Physics world than the whole tamasha the media and some people have built-up around the "break-through" about a few authors of IISc's arXiv paper which has not even been published or peer reviewed).


Was there any computational methods used to shortlist materials to test for superconductivity before settling on LaH10? It would be quite task to test out all potential combinations physically unless a quantum mechanical computational tool is first used to create a list of high probability combinations.

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Re: Physics Discussion Thread

Postby geeth » 02 Jun 2019 22:58


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Re: Physics Discussion Thread

Postby Amber G. » 05 Jun 2019 00:59

Some interesting development: It seems like that a group at IIT Mandi has been able to replicate results of room temp superconductivity reported first by Pandey group at IISc. The paper is posted on arxiv
Link: https://arxiv.org/abs/1906.00708
Peer-reviewed publication still awaited ...I have not had a chance to look at the paper yet.

Added later: IIT Mandi group's really do not exactly replicate IISc's findings.. Interesting but different.
Pandey et al (IISc group) paper, in my opinion, is not likely to be published in a reputable journal in present form - unless they add some *more* carefully taken data.

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Re: Physics Discussion Thread

Postby Amber G. » 07 Jun 2019 10:43

Another update in arXiv --. Link: https://arxiv.org/abs/1906.02291 (submitted by Saurav Islam).

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Re: Physics Discussion Thread

Postby Amber G. » 08 Jun 2019 20:41

^^^ There is this article about the recent arXiv preprint (which I mentioned above)
IISc team submits more evidence of superconductivity - By Prasad Ravindrana on June 7, 2019

Interestingly, as I mentioned in this forum, it talks about new resistivity data in the new pre-print but Prof Gosh (one of the author) admits here that they did not repeat (or take new data and presented in the paper) about magnetic susceptibility. I wish they did (or do is soon). As I said in the following post I wished they cleared up that part - about repeated patterns in "random" noise.

Amber G. wrote:
....

And the "repetition" part is not a trivial claim. For details see the arXiv paper and the public comment article (Its very short and people with minimum background can understand) which even the authors thought was serious. (Unfortunately in the new article they do not repeat or add more trial runs of that experiment - which I thought they will surely do to see if the noise is really random. Except noticing the pattern and say they do not understand why this was so they reproduced the same data in the current paper - at least that is what I see. If I am wrong I will certainly correct myself...
L
It is like seeing the exactly the same cloud pattern in the sky at tow different times in the background - indicating something is not right. Now this does not necessary mean fraud (or photoshop) but can have other explanation. (Say same imperfect camera lens used). But it does need further investigation.

As I said before, the real controversy came what took place later - fake emails etc-- completely unexpected. The mischievous party (most likely a third party - not IISc) who went a great length in faking these emails, IMO needs to be investigated. This party, I think, knows enough about physics and Indian Physicists (to fake TVR).

One thing, we can all agree on. - IISc is a top rated place and so this will be resolved in near future for sure. While we write this post here or have twitter fight elsewhere there are lot of good scientists working to resolve this.


I have given the link of the article above. Some excerpts from that article.

.... Still, the May 21 preprint did not have data on current-voltage characteristics and the evidence of critical current.




The article posted on June 5 fills that lacuna as it deals with current-voltage characteristics in gold-silver nanostructures with regard to superconductivity.

What typically happens in current-voltage characteristics is that when the current is increased the voltage remains zero and at a critical current the voltage suddenly increases and superconductivity is destroyed.

“The current-voltage characteristics was one of the important data that was not presented in the earlier paper. This study shows the material has some signatures of critical current — the current at which the superconductor is no longer stable and becomes resistive,” Prof. Ghosh says.

.....



The IISc team observed that at a critical temperature of 160 K (-113.15 degree C) and critical current of little less than 10 milliampere the voltage suddenly shoots up and the gold-silver nanostructures no longer exhibit superconductivity as resistance increases rapidly. A superconductor is one which conducts electricity with zero resistance to the flow of electrons.
<snip>

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Re: Physics Discussion Thread

Postby Amber G. » 08 Jun 2019 22:17

^^^ Of course, In my opinion - (and many others agree) other data is not going to impress or remove doubt (as interesting as that may be) [b]WITHOUT the (additional) susceptibility data!.. The one which really needs to be straightened out / explained. It is simply strange that they have reprinted the same year old data - just changing the colors and shifting the scale in the new graphs.

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Re: Physics Discussion Thread

Postby Amber G. » 10 Jun 2019 09:43

For those who know basic physics (need not be expert) may find this youtube video about IISC team's super-conductivity claim quite interesting and educational.

This basically goes though many points I pointed out (eg magnetic succsptlilibity data not done again).. also gives some theoretical basics too.
https://youtu.be/YmZ8Wno6Xxg

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Re: Physics Discussion Thread

Postby Amber G. » 10 Jun 2019 10:16

Kashi wrote: ,,I am curious as to which journal they actually plan to publish their findings in.

I was not going to post this before but since I have seen it in other media - they (from what I know/read/heard) is Nature - very respected journal - so if the paper gets published (and IISC is respected place) it will bring authenticity. (I obviously do not know the full details but have not heard anything significant- somewhat surprising is unusually long period or peer review.

Frustrating part for me (but I am sure authors have good reasons) is the authors are quite tight-lipped - quite likely what has been posted on Arxiv is teaser and what has been submitted has more details, But at this point I will wait till paper gets published.

For aam-abdul - since Hindu and other newspapers have been quite not good here is some details - read it if interested.

Pandey and Thapa's process: - Ag nano-particle about 1 nm wide, prepared by "standard colloidal techniques" are embedded in gold matrix using chemical sintering process. The Ag-Au composite globules are about 10-20 nm in size. It was turned into thin films and pellets for measuring resistivity and susceptibility. Very little further details and sketchy description of equipments etc. .Perhaps we would have to wait for the paper.

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Re: Physics Discussion Thread

Postby sivab » 10 Jun 2019 10:20

Amber G. wrote:For those who know basic physics (need not be expert) may find this youtube video about IISC team's super-conductivity claim quite interesting and educational.

This basically goes though many points I pointed out (eg magnetic succsptlilibity data not done again).. also gives some theoretical basics too.
...


https://twitter.com/ArindamPhysics/stat ... 0377901056

Arindam Ghosh
‏@ArindamPhysics
Jun 4
More
An excellent video on an alternative scenario of zero resistance. While some concerns are certainly valid for granular films, the films that we use are highly metallic and well-connected. Hope to produce new data soon which will address these concerns.


https://twitter.com/ArindamPhysics/stat ... 1042667520

Arindam Ghosh
‏@ArindamPhysics
11h11 hours ago
More
In response to many update requests: Progress in science is not an instantaneous process, and every claim must be scrutinized and reproduced. Two groups in IIT Mandi and NICER Bhubaneswar reported similar results as us, but the results must also be replicated internationally.

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Re: Physics Discussion Thread

Postby Amber G. » 10 Jun 2019 10:33

^^^ Thanks. For people who may not know Arindam Ghosh is one of the author and him, and another person (Rekha Mahadevu) are the only one from the team who I know are on twitter.. Most of the people (except recently there are a few posts) have been tight-lipped about it.. Some of the other well-known people from IISc are silent or waiting.. some who normally tweet are also careful - which is as it should be..

Some other leading people in the field in India - obviously there is lot of competition so may be there is some bad feeling between some of other people and them so many are, quite correctly quiet. (Unlike our papers like Hindu etc..)

Of course, in this forum we are speculating in some cases but this forum is not exactly a PRL so I guess it is okay :) :)..

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Re: Physics Discussion Thread

Postby Kashi » 10 Jun 2019 11:00

I wish the authors all the very best for their submission to Nature, if that's indeed where they are planning to submit.

If validated, these findings promise to be path-breaking both for the field and for Indian science.

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Re: Physics Discussion Thread

Postby jaysimha » 21 Jun 2019 19:05

Image

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In this context, a press conference/briefing about this extraordinary event and last one-month successful journey is being organised.

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Re: Physics Discussion Thread

Postby wig » 15 Jul 2019 12:21

https://www.bbc.com/news/uk-scotland-gl ... t-48971538

First image of Einstein's 'spooky' particle entanglement

https://ichef.bbci.co.uk/news/660/cpspr ... apture.png

The photo shows a strong form of quantum entanglement, where two particles interact and share their physical states for an instant.

It occurs no matter how great the distance between the particles is.

The connection is known as Bell entanglement and underpins the field of quantum mechanics.

Paul-Antoine Moreau, of the University of Glasgow's School of Physics and Astronomy, said the image was "an elegant demonstration of a fundamental property of nature".

He added: "It's an exciting result which could be used to advance the emerging field of quantum computing and lead to new types of imaging."

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Re: Physics Discussion Thread

Postby Prem » 29 Jul 2019 02:43

http://www.astronomy.com/news/2018/05/t ... asytwitter
[b]The case against dark matter/b]

Albert Einstein’s theory of general relativity is just over 100 years old, and so far it has predicted the interaction between celestial objects and the space-time field very well. There are a few troublesome spots, however, in which the theory of general relativity doesn’t agree with quantum mechanics. These gaps have confounded researchers for decades, and have sprouted a handful of hypotheses attempting to explain the dissonance.
Dark matter and dark energy are the prevailing stand-in answers for this problem, but they are, as of yet, merely stand-ins. And there are some physicists that do not buy into these explanations. Erik Verlinde, a professor of science mathematics, and informatics at the University of Amsterdam, is one of them. He’s developing a theory that takes another look at the mechanics of gravity, and it seems to have struck a nerve in the world of physics.Emergent gravity,” as Verlinde calls it, is the idea that gravity is not a fundamental governance of our universe, but instead a reaction to the makeup of a given environment. Rather than thinking of gravity as a fundamental force, something that “just is,” is it possible that gravity is actually the result of the positions of quantum bodies, similar to the way temperature is derived from the motions of individual particles?
“Einstein’s theory can be viewed as being derived from a more microscopic picture,” Verlinde says. “In particular what we learned about black holes is that Einstein’s theory looked more like the laws of thermodynamics, and the laws of thermodynamics we know can be derived by thinking about the microscopic constituents that are describing matter.”Verlinde focuses on quantum interactions to explain the dissonance between general relativity and quantum theories. His theory has a long way to go before completion, but so far it has held up well and has made some strong arguments, particularly against the idea of dark matter.Physicists are painfully aware of the fact that spiral galaxies are spinning faster than they should be, given the amount of matter — and therefore, gravity — they contain. At the speed that some of them are spinning, current theory says that the stars, planets, dust, and other matter should be flung off into space. Because they are not, physicists have hypothesized that “dark matter” we cannot see or otherwise detect is causing the extra gravitational pull, keeping these galaxies together. This matter is said to account for about 25 percent of the universe, but Verlinde believes that there may be another answer that can account for the deviations between the expected and observed rotation curves.“What is observed is that the deviations that we see in the rotational curves of galaxies, which is just derived by looking at the matter that we see, always seems to occur at one particular acceleration,” he says. That particular acceleration happens to play an important role in the relationship between a galaxy’s distance and the speed with which it’s moving away from our own, which is governed by the expansion of the universe, known as Hubble’s Law. A 2017 paper by Alexandre Chaloum Elbeze in the Journal of Modern Physics outlines how the expansion rate of the universe, or H0, is linked through a new parameter, which he calls E0, is linked to the rotation curves of galaxies measured by astronomer

Amber G.
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Re: Physics Discussion Thread

Postby Amber G. » 29 Jul 2019 22:39

He was quintessentially scientist, brilliant, charming, charismatic, inspirational and audacious. "S" of BCS Theory.
Shardhanjali!

Superconductivity pioneer Robert Schrieffer dies at 88
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Shwetank
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Re: Physics Discussion Thread

Postby Shwetank » 10 Aug 2019 09:14

2019 J.J. Sakurai Prize for Theoretical Particle Physics Recipient

Raman Sundrum won 2019 Sakurai Prize, shared with Lisa Randall, "For creative contributions to physics beyond the Standard Model, in particular the discovery that warped extra dimensions of space can solve the hierarchy puzzle, which has had a tremendous impact on searches at the Large Hadron Collider."


Amber G.
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Re: Physics Discussion Thread

Postby Amber G. » 27 Aug 2019 00:04

Proud to share contributions from another IIT alum. I have posted about Subir Sachdev's recent honors in this dhaga some time ago.

A nice paper.

New theory draws connections between Planckian metals and black holes

Two researchers at Harvard University, Aavishkar A. Patel and Subir Sachdev, have recently presented a new theory of a Planckian metal that could shed light on previously unknown aspects of quantum physics. Their paper, published in Physical Review Letters, introduces a lattice model of fermions that describes a Planckian metal at low temperatures (T->0).

Vayutuvan
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Re: Physics Discussion Thread

Postby Vayutuvan » 30 Aug 2019 04:17

Amber G. wrote:He was quintessentially scientist, brilliant, charming, charismatic, inspirational and audacious. "S" of BCS Theory.
Shardhanjali!


Student of Bardeen (B of the BCS) at Urbana.

Amber G.
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Re: Physics Discussion Thread

Postby Amber G. » 06 Sep 2019 06:28

This event was covered in Brf dhaga. This wins this year's Breakthrough prize. Congrats!
Amber G. wrote:^^^ The image shows a bright ring formed as light bends in the intense gravity around a black hole. This the biggest known black hole ( 6.5 billion times more massive than the Sun)

( EHT looks at gas surrounding it- it is image of a shadow. Specifically, they are looking at the event horizon - the limit beyond which light can not escape . The gas in the surrounding area heats up to billions of degrees, creating a silhouette etc . The precise shape of the ring can be predicted by Einstein’s theory of relativity - including lopsidedness of the brightness of the ring. And, of course, Einstein is proven right again.

Incredibly (to me) the magnification, or angular resolution, is equivalent to reading a text on a phone in New York from a sidewalk café in Paris. WoW!

And this, wins the Breakthrough prize for these scientists who took the photo of the blackhole!
First-ever picture of a black hole scoops US$3-million prize
The Event Horizon Telescope team wins a Breakthrough Prize — one of six awards covering physics, the life sciences and mathematics.

Image

vijayk
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Re: Physics Discussion Thread

Postby vijayk » 08 Sep 2019 05:04





Did anyone read upon this?

ArjunPandit
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Re: Physics Discussion Thread

Postby ArjunPandit » 01 Oct 2019 03:47

https://phys.org/news/2019-09-planet-pr ... S6loDLxIEo
this is quite out of carton thinking...

Amber G.
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Re: Physics Discussion Thread

Postby Amber G. » 01 Oct 2019 20:08

^^^Of course it's much more likely to be a regular planet but sometimes it's worth (and certainly fun) getting really speculative .
Anyway a good article here in MIT Technical Review about this: (Don't know if requires subscription/registration) https://www.technologyreview.com/s/614441/is-planet-9-actually-a-primordial-black-hole/
The original paper at: https://arxiv.org/abs/1909.11090


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