All posts by Debjyoti Bardhan

Is a science geek, currently pursuing some sort of a degree (called a PhD) in Physics at TIFR, Mumbai. An enthusiastic but useless amateur photographer, his most favourite activity is simply lazing around. He is interested in all things interesting and scientific.

Looking at our Universe: What the Planck Results Really Mean

The Universe seems to be just as queer as we could have supposed, or maybe less queer. The results from PLANCK, which came out in their first ever press conference, 15.5 months after the probe was launched, speaks of a Universe described almost entirely by what is known to be the Standard Model of Cosmology. In other words, there is nothing that should startle us, but a lot that should be enlightening and, frankly, quite exciting.

The progress of the Universe through its ages (Courtesy: nature.com)
The progress of the Universe through its ages (Courtesy: nature.com)

For cosmology virgins, Planck is a space probe launched into an orbit around Earth designed to pick up the radio and microwave radiations from the whole Universe. By charting out the whole sky, it creates a unique map, a map of the Universe, as seen from the microwave frequency regime, and not the optical regime that we are so used to. The Universe is extremely different in these frequencies from the star-filled Universe we know and love. But these frequencies tell a different tale – one of the early universe and what imprints of that we can see today. The story of Cosmology starts right at the beginning of the Universe, or rather, more accurately 10-32 seconds after it. The Universe underwent a sudden expansion phase, called inflation, and then stabilized, while continuing to expand. The radiation from the inflationary era have got both diluted (i.e. reduced in intensity) and ‘stretched’ (i.e. their wavelengths have increased, leading to a decrease in their energy) due to the expansion of the Universe which is continuing to this very day. So ‘cold’ have these radiations become that we need specialized probes to catch them, their temperature being just 3 K (i.e. 3 Kelvin above absolute zero). The redeeming fact about these strange low-energy waves is that they are everywhere – all over the Universe. They form a kind of ‘background’ radiation and are thus called ‘Cosmic Microwave Background Radiation’ (CMBR), the name being self-explanatory.

The Universe as Planck sees it.
The Universe as Planck sees it.

The theory goes that there arose minute quantum fluctuations in the radiation soup right after the inflationary phase. As the Universe expanded, these expanded, then gravity took over and clumped matter in these pockets of disturbed equilibrium. These manifest as galaxies or clusters we see today – the tiny quantum fluctuations have grown to giant scale. The imprint of these early fluctuations will be found in the radiation seen by Planck.

The Age of the Universe

First big observation – the Universe seems to be just a bit older than we thought it to be – about 70 million years older. So the official age of the Universe become 13.82 billion years, raised from the 13.75 (or 13.77) billion it was assigned earlier.

The constituents of the Universe

It seems that the known constitution of the Universe has changed slightly from previous estimates. The matter percentage of the Universe is slightly higher than what we had known. The constitution of the Universe is mostly unknown to us and we can only put in some percentages on the amount we know and the part we are ignorant about. For example, we know that matter forms a very small percentage, followed by dark matter which forms a large chunk and that dark energy – a strange form of energy responsible for the accelerated expansion of the Universe currently – forms the largest chunk of the matter-energy pie. The earlier estimates have been bettered by Planck which quotes 4.9% ordinary matter, 26.8% dark matter and the rest 68.3% as dark energy. This is a decrease in the estimate for dark energy from previous estimates and an increase in the estimate of normal matter and dark matter. This implies that we know a bit more about the Universe (we only know about the ordinary matter part) and that the Universe is expanding at a slightly less accelerated rate than what we thought. Our ignorance about most of the Universe is only slightly abated.

The Cosmic Recipe before and after Planck results (Courtesy: ESA, Planck)
The Cosmic Recipe before and after Planck results (Courtesy: ESA, Planck)

Closely related to this is the value of the Hubble’s Constant which Planck calculates to be 67.3 +/- 1.2 km per second per megaparsec. This is a big surprise from the earlier value of the Hubble’s constant 71.0 +/- 2.5 km per second per megaparsec. The lower value of the Hubble’s constant means that the Universe is expanding slower than earlier thought.

CMB Spectrum: Cosmic Fingerprint

The whole Cosmic Microwave Spectrum as predicted by theory matches that seen by Planck to very high precision. We see the Universe at very high angular width as well as very narrow width. What Planck says is that at high multipoles, corresponding to very narrow angular width, the data matches experiment exactly. At low values of multipoles, the error bars are large, but Planck has seen as much as can be seen.

The power spectrum of the Cosmic Background Radiation and how well data fits with theory (Courtesy: Resonaances blog: http://resonaances.blogspot.in/)
The power spectrum of the Cosmic Background Radiation and how well data fits with theory (Courtesy: Resonaances blog: http://resonaances.blogspot.in/)

No probe in the future will be able to see at finer resolution, since the limit on resolution is not placed by the instrument anymore, rather by the Universe itself as a whole. Our Universe not only seems perfect, it seems good at hiding possible imperfections as well.

Asymmetry and Anisotropy

Planck gives an asymmetry in temperature over the two hemispheres of the Universe. This is a startling find, but nothing absolutely new. It’s just that Planck has confirmed – at high resolution – something that WMAP had already hinted at.

The Anomalies as seen by Planck. Notice the clear blue and red regions on opposite hemispheres. (Courtesy: ESA, Planck)
The Anomalies as seen by Planck. Notice the clear blue and red regions on opposite hemispheres. (Courtesy: ESA, Planck)

An important point to be made here: The distribution of the fluctuations are exactly random, even though we might not feel it to be so. They pass all tests of randomness. Just to emphasize, the angular distribution of the fluctuations is really exactly random. The fluctuations could have been anywhere and they just happen to be where they are! What is important is that the amplitudes of the fluctuations are not random. The amplitudes – i.e. the real temperature of the fluctuations – are not random and one hemisphere seems to be on the whole hotter than the other. This wasn’t expected! Note that a small patch of sky could’ve been warmer than the other, but this is seeing a whole trend in the temperature – one side is colder and the other hotter – and we have nothing to explain that. In fact, our cherished notions of isotropy of space (I.e. cosmological phenomena and features don’t have a preferred direction) contradict this finding. We have to wait for a verdict on this. There is also a cold spot detected in the Universe – a region of space considerably colder than the other parts. No one knows why this is the case – is it just random or is there some forces at play there?

Let’s look at a couple of more topics, both being a bit more technical.

Neutrino masses and the limit on them:

Planck puts a stern limit on the sum of the neutrino masses – a value of 0.23 eV. This is at a 95% Confidence level and this result is completely consistent with the neutrino mass being zero. However, the phenomenon of neutrino oscillation says that neutrino mass cannot be zero, no matter how small. Planck also says that the number of neutrino species is 3 and no more, well almost. This rules out those elusive sterile neutrinos, the possible fourth species of neutrinos which don’t even interact via weak interaction and their effect is felt only through the gravity that they exert.

Spectral Index and Inflationary Theories

Inflation as a theory receives a major boost from these results. The simplest inflationary models predict that knowing the two-point correlation function would be enough since the whole spectrum of the fluctuations right after inflation can be modelled by a Gaussian. Planck reinforces that. The models also say that spectrum is scale invariant (or ‘conformal’) and Planck shows slight deviation from that. A quantity called ‘spectral index’, ns, quantifies the scale invariance. If ns=1, then the scale invariance is perfect, otherwise there is deviation. Planck gives the value of ns = 0.9603 +/- 0.0073. So inflation is also nearly as simple as we can imagine and all ‘complicated’ models of inflation can be ruled out. So Planck reveals our Universe in details we have never seen before. However, even after looking at the Universe this closely, we find that the Universe is indeed plain vanilla, with a couple of chocolate chips thrown in. People are calling it the MBU or Maximally Boring Universe. Is the Universe really less queer than we thought?

[For more technical references, I refer you to the clutch of papers published by the Planck collaboration. They can be found here:
http://www.sciops.esa.int/index.php project=PLANCK&page=Planck_Published_Papers]

Neurons Caught in Action: Zebrafish Brain Filmed While Firing Signals

It’s the brain like never seen before. A group of researchers – Misha Ahrens, neurobiologist, and Phillipp Keller, microbiologist from Howard Hughes medical Institute’s Janelia Farm Research Campus, have been able to see individual neurons firing in the brain of a larval zebra-fish, recording activities across the entire fish brain.

And they’ve made a cool video of the whole thing (below).

They have mapped the exact firing pattern for 80% of the 100,000 neurons in the brain, suggesting that, should an upscaling of this mapping be done, the human brain might finally be in the imaging line.

The brain map - taken from the paper (link at the bottom)
The brain map – taken from the paper (link at the bottom)

The Imaging Technique

The imaging technique is ingenious, but theoretically simple. The researchers created genetically modified zebrafish, so that the neurons make a protein which fluoresces when there is a change in the concentration of the calcium ions. Calcium ion concentrations change when a neuron fires, meaning that there will be a small fluorescence when a neuron fires.

Now, a thin sheet of light was sent through the brain and this captures any optical activity in the brain and then records it on a screen. This imaging technique is called ‘light-sheet microscopy’ and the Janelia team was able to upgrade it count at a rate tenfold its original rate. The entire brain of the larval fish was mapped every 1.3 seconds. One whole experiment lasted for 10 hours, generating as much a few terabytes of data.

Ahrens commented on his pet method, explaining why it is so much better than conventional techniques. Available techniques allow one to image at most 2000 neurons at one go, but this one can see the entire circuitry in the brain. As Ahrens puts it:

you don’t need to guess what is happening — you can see it.

There is definitely room for improvement. One would be distinguish between one neuron firing and multiple firings in a short interval. Also, researchers would like to try it on other organisms.

Is the human brain up next? Not for quite some time, surely.

The work appeared here: http://www.nature.com/nmeth/journal/vaop/ncurrent/full/nmeth.2434.html

Google Plans To Bundle All Its Chat Services Under ‘Babble’

Forget regular chats, it might be time to babble. And soon, if Google has its way.

Google-Babble
Google Babble

At one point or the other, faithful Google users must have felt that the disparate facilities offered by Google – Google Talk, Google+ Hangout, Google Voice and Google Drive – would be much better off if merged into one giant facility. That is where Babble comes in – it’s the promised unification of all these above-mentioned facilities.

What will that give you? That will allow you to use the same chat window as Google Talk and start a Hangout, while still editing a Google Drive file. You will be able to Hangout with anyone in the contact list.

Geek.com reported this story here and it’s drawing quite a bit of attention. Google is not launching a new product in this as it is just bundling up its old services into one master service and that has a lot of users excited.

What about Skype and AIM, which are similar services but not under the Google umbrella? Unfortunately, they will continue to be out of the shade as Google will integrate only its own services under the XMPP, a message-oriented communication protocol originally launched as Jabber.

The most exciting aspect of the grand unification plan is the promised quality. Geek.com reports that Babble will have exceptional voice and video quality.

Google has however not released any comment on any of the above issues. Maybe, the initial rollout will be quiet and on an experimental basis, like Google+. The interest is quite high, and the same can be said about the imminent launch of the new Android OS ‘Key Lime Pie’.

Enough Talk-ing, let’s start Babble-ing.

Don’t Panic: Google Just Paid Tribute To Douglas Adams With An Doodle

Google has done it again. On the 61st birthday of the great Douglas Adams, Google chooses to pay tribute to the author who almost set alight a whole new genre and fired up the imagination of so many people, most of whom became his fans. The scale is massive, the ideas, all taken from his book, span the entire length and breadth of the universe and the doodle epic! Let’s just hitchhike through the whole animated doodle.

Oh that Frood!

Before that, a brief introduction to who Douglas Adams was.  Since you can read up on him on Wikipedia, I’m going to be opinionated and basically give you a fan’s eye view of the genius. Towering at 6’ 5’’, Adams was the perfect example of the gentle giant you read about in literature – the person who melts the hearts of children with his warmth and endears the adults alike with his wide depth of knowledge in so many different fields. And of course, wins over the entire galaxy with his unique sense of humor, sarcastic and dry in parts, warm and witty at other times, but never alienating. His most favorite bragging right included that fact that his initials are D.N.A. (Douglas Noel Adams is his full name).

Remembering Adams

Of course, the one-liners don’t hurt at all. The reach of his imagination spanned till the end of the universe, where he founded a restaurant in which time was just an illusion, especially lunchtime, doing all sorts of crazy things! And that spaceship, the Heart of Gold, which could zap through every point in space-time all at once but then end up in an indeterminate state! And that paranoid android Marvin who could kill a supercomputer just out of depression! And of course, who can forget the mad two-headed Zaphod Beeblebrox, the President of the Galaxy! All of this and much much more make Douglas Adams, who is no longer with us, that same smiling genius towering over all of us, literally and metaphorically, gently imploring us all to think a little bit beyond our own reach.

And of course, 42!

Google’s Doodle

Google does a splendid job with the doodle. Go the page and click once on the calculator, on which is written ‘Don’t Panic’, one of the Adams trademark lines. You’ll be greeted with an animated video accompanied by digital music. Subsequent clicks yield more such scenes. I’ll just describe a few of these – don’t treat them as spoilers, just enjoy them.

Scene: Translation

The first click gives you a small orange creature, which fellow froods (fans of the author) will recognize to be the Babel fish. When implanted into someone’s ear, it feeds off any sound frequency entering and then excretes a sound frequency which the person can understand. Translating from any known language in the Universe to a language understood by the user, this has removed all barriers of communication. Well, there will definitely be consequences of that!

Scene: Flying

Another shows the art of flying. The “knack [of flying] lies in learning how to throw yourself at the ground and miss”, says the Hitchhikers’ Guide. An animation shows a figure throwing himself on the ground and finally flying! Mission accomplished.

Scene: Infinite Improbability

There is definitely the Heart of Gold spaceship and the Infinite Improbability Drive which allows it to go through all space-time points all at once!

Scene: Intelligence

And froods also know that humans are the third most intelligent creatures on Earth preceded by mice and dolphins. An animation celebrates that as well. The trusty towel also is not to be missed.

Scene: The Ultimate Answer

The grand finale is definitely the supercomputer, which is built to compute the answer to Life, the Universe and Everything. The animation shows that when it’s asked what ‘1+1=’ is, it shows ‘2’ and when asked what “E=” is, it shows “mc2”, but then it’s asked The question on Life, the Universe and Everything and it computes for millions of years and returns the answer “42”! Of course, the question is unknown!

Google, hats off.  And from a big fan of the author, a big ‘Thank You’!

Reported: The First Known Case of a Child Being Cured of HIV

HIV might have finally met its match. We report the first documented case of a child being cured of HIV after antiretroviral therapy. Dr. Deborah Persaud of John Hopkins University presented this remarkable case yesterday at the 2013 Conference on Retroviruses and Opportunistic Infections, Atlanta, Georgia. The breakthrough was confirmed by various ultra-sensitive test on the child, all coming out negative for the presence of the HIV viral load.

Scanning Electron Micrograph of an HIV attacking a live cell.

The child was born HIV positive, since the mother was also HIV positive. At the age of 2 years, the child in Mississippi was diagnosed with the deadly virus and immediately put on antiretrovirals. This therapy continued for 18 months. After five more months, during which the child was off treatment, the child was tested and the absence of HIV was confirmed via highly sensitive tests. Dr. Persaud said that it was beyond any doubt that the child showed no signs of being HIV positive.

The treatment for HIV depends crucially on the patient’s immune system makeup. Also, an infant’s immune system differs from that of an adult. Scientists want to study the individual’s immune system, especially since the treatment of the patient happened via only very cheap antiretroviral therapy, rather than expensive treatment. No one is really sure how this cure happened.

This is only the second documented case of an HIV cure, the first one being the famous ‘Berlin Patient’, Timothy Ray Brown. He has founded his own AIDS Foundation, the Timothy Ray Brown Foundation, dedicated exclusively to finding a cure for the deadly disease.

However, the Ray Brown case is quite different from this. Even though, the Ray Brown involved a longish course of antiretrovirals, there was a diagnosis of myeloid leukemia in case of Ray Brown. His heamatologist, Dr. Gero Hutter, make a stem-cell bone-marrow transplant from a doner who had a very rare HIV immunity called the CCR5 mutation. A few months later, there was no active HIV viral load in his body.

Nothing nearly as drastic as a stem-cell bone-marrow implant was done in this present case. And that makes this case all the more special.

More info here: http://www.nytimes.com/2013/03/04/health/for-first-time-baby-cured-of-hiv-doctors-say.html

Google Celebrates Pioneer Copernicus’ Birthday With Cool Doodle

He pioneered a revolution so strong that it lasts to this day. While Galileo is considered to be the first real scientist, Nicolaus Copernicus, yes, the one of the heliocentric model of the universe, was the one who started it all off!

Copernicus was the first great proponent of the theory that the Earth goes round the Sun and the Sun is the center of the Universe. This hypothesis served to explain why we see retrograde motion of the planets (meaning, sometimes, the planets like Venus seemed to go back and then again start moving forward; today this is known as epicyclic motion). His hypothesis contained little mathematical formalism and mostly comprised logical deductions from a set of seven assumptions about the ‘firmament’, Earth and Sun.

The Copernican Google Doodle

Google celebrates the 540th birthday of the pioneer with a brilliant doodle. The doodle sketches the Copernican universe having 5 bodies and the Earth revolving around a central Sun on circular paths. The moon for the Earth has also been indicated. I hope the speeds are in proper ratio but I haven’t checked that. As is usual, clicking the doodle leads you to search results for Copernicus.

Ideas and acceptance

One might have expected a wildfire-like spread of Copernicus’ idea, since it was almost universally accepted, and also severe backlash from the Church, as the basic tenet of the theory violates the geocentric view of the religious majority. None of the two happened. The idea was slow to catch on and the fact that Copernicus was a Catholic cleric – and that too an active one – helped with the latter part of the above. Copernicus himself suspected a backlash, and thus delayed publishing his ideas in a book.

It strikes me as odd how these ideas, about a quarter of a century before Galileo was accepted largely because it hailed from a Catholic cleric, while Galileo, with no direct links to the gentry, was ostracized and threatened with torture.

Science has since made giant strides. Happy Birthday Nicolaus.

BREAKING: Did North Korea Just Conduct Its Third Nuclear Test?

The 1984 state may have just conducted a nuclear test, fears the world. An earthquake of 4.9 magnitude on the Richter Scale was detected today, at about 12 noon (Korean time) which occurred in North Korea and it bears significant resemblance to a tremor expected to accompany a nuclear test. Pyongyang hasn’t confirmed any nuclear test though.

A TV broadcast at a South Korean rail station. The writing in Korean reads: North, artificial earthquake 11:58 a.m (Photo Courtesy: AP Photo)

South Korea has raised its military alertness to high priority after the quake, and Seoul is also trying to ascertain the exact cause of the quake. Natural quakes are preceded and succeeded by tremors of smaller magnitude than the actual quake, while an earthquake due to a strong explosion occurs as a single wave of a particular magnitude. The quake detected today is such a quake.

UPDATE: We note that N.Korea has confirmed the nuclear test. The New York Times has more. 

Third time’s a charm

If confirmed, this will be the third nuclear test conducted by North Korea after 2006 and 2009 and rough position triangulation suggests that the epicenter of the quake is about the same as that of the two previous quakes. The Democratic People’s Republic of Korea (DPRK) would be violating international peace treaties and sanctions imposed upon them by the UN if this turns out to be a nuclear explosion.

Chi Heoncheol, an earthquake specialist at the Korea Institute of Geoscience and Mineral Resource says

There is a high possibility that North Korea has conducted a nuclear test

Not only was the epicentre location congruent with previous tests, the strength was also roughly the same – 3.9 and 4.5 were confirmed the last two times. This latest one is between 4.9 to 5.2, according to the South Korean weather stations monitoring seismic activity.

The US and its allies in the region have been on high alert since the quake.

Monkey Photo Embarrasses Iran, Calls Into Doubt Their Space Program

Quit monkeying around Iran, the world community seems to be saying. Very recently, Iran boasted of putting its very first primate into space and to bring him safely back to Earth. However, the image of a monkey, which Iranian officials claim is the ‘wrong picture’, has shattered Iran’s claims. People have several questions: did the landing happen? Did the monkey survive the journey? Or even, did the mission ever happen?

The monkey strapped up before being sent to space. (Photo Courtesy: AP/Getty Images)

Not the same Monkey!

Iran’s rocket Pishtam (meaning ‘pioneer’ in Parsi) was scheduled to carry a primate, a grizzly monkey, into space. The mission would last 20 minutes. The release of a picture showing a monkey which bears little resemblance to the one supposedly launched into space has now called into question the veracity of Iran’s claims. What happened to the other monkey?

The two monkeys

The new photo clearly shows a monkey with dark fur and narrower nose, while the one supposedly launched was grizzlier and had a distinctive red mole over the right eye.

The Pishtam launch vehicle. (Courtesy: AP/Getty Images)

The doubts increase further since there were no landing photos released by Iran, despite there being launch photos. Some are calling the whole mission a hoax, and it seems justified too!

The interest in Iran’s space launch is because any space launch capability directly influences the state’s ability to develop long-range ballistic missiles. Topped with a nuclear warhead and a regime not afraid to use nuclear weapons, this could be a deadly combination.

Google’s Project Glass Gets Patent

It’s reality like you’ve never seen before. Google has just acquired a patent for Project Glass which is aimed at changing people’s lives forever and how they view it. Google’s Project Glass has already received space here on this blog with my colleagues Chinmoy and Pallab writing about it here and here. Very recently, a test report described the prototype for Google’s wearable computing project was released. It described all the cool features of the Project Glass ‘smart glasses’ headset.

Sky divers tested Google Glasses while freefalling. (Courtesy: Google)

A new paradigm to hearing

Google recently sought – and obtained – patentfor their audio transmission technology titled ‘Wearable Computing Device with Indirect Bone-Conduction Speaker’. It doesn’t use earplugs, as that might interfere with the ambient sounds, but transmits sounds via the skull bones into the inner ear. This is a refined version of what Beethoven is said to have done about his own deafness – he put a rigid rod between the piano and his head, so that he could pick up vibrations from the piano. While the success of that experiment is unknown, Google has certainly impressed people with their bone-conduction technology. Reviewers however rate the quality of sound to be slightly lower than the earplug sound quality, but it is good enough for most purposes.

More things to be packed in!

The Heads-Up Display is also being modernized. Google plans to incorporate most features of the Android OS onto the display. Its concept video shows all sorts of cool additions, like Google Maps, Video chats on the go and sharing display while video chatting, but these will take a long time to incorporate.   Google showed off the glasses by having skydivers sound and video test it. A group of skydivers relayed live photos from the glasses last year as they dropped down towards the Google developers’ forum. Publicly promoting the glasses was Google’s co-founder Sergey Brin who was spotted sporting these shades!

The future?

The market seems to be ripe for picking. A lot of companies are vying for the Head-Up display eyegear, and Microsoft and Motorola have filed their respective patents in order to bite into the massive potential market pie. However, Google seems to be heads and shoulders above these companies when it comes to this market share. Only time will tell whether Google can create – and rule over – this niche in the highly competitive hardware market.

Wikipedia Takes Down Page On “Goan War” After Being Revealed As Elaborate Hoax

And this is how you create history – literally! A long standing hoax on the ‘The Bicholim Conflict’ has been taken down by Wikipedia, when none of the references cited were found to be authentic. There was a detailed entry of 4500 words about the “Bicholin Conflict” of 1640-41, marked as a ‘good article’ on Wikipedia which describes a conflict between the Maratha Empire and the colonial Portuguese forces, which turns out to be a tall tale by some mischievous user.

The article came into existence in 2007 and stood as a respectable article for five long years. Another user, identifying himself as ‘ShelfSkewed’ found that the sources are all either non-existent or fake.

The article has now been taken down and a link cannot be provided, but this is what a part of the article read:
From 1640 to 1641 the might of colonial Portugal clashed with India’s massive Maratha Empire in an undeclared war that would later be known as the Bicholim Conflict.

The article even has photos to back up its claim! Look at the following two photos – one of a building and the other a map – the descriptions of both are now lost after the page was taken down.


However, this kind of hoaxes is nothing new. They have happened before and will definitely happen again. Wikipedia maintains a list of hoaxes that have been seen on the site since 2001. There have appeared Bunaka, an island of Indonesia and Gauis Flavius Antoninus, the fictitious murderer of Julius Caesar.

Wikipedia generally bans users posting such fake content.