150 Years of the Periodic Table

Happy 150th Birthday, Periodic Table! You don't look a day over 149!



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150 Years of the Periodic Table

Hey, I'll admit it. I wouldn't have known about this 150th birthday of the periodic table if it weren't for this news article. ScienceNews has a lot more detail on the history and background of Mendeleev, who came up with the first periodic table.

Unfortunately, there might be a chance for a bit of inaccuracy here from the Miami Herald news article.

The periodic table lists the elements in order of their atomic weights, but when Mendeleev was classifying them, no one even knew what was inside these tiny things called atoms. 

While it is true that, historically, Mendeleev originally arranged the elements with respect to each atom's atomic weight (since no one knew that was inside these atoms at that time), the periodic table that we have now lists the elements in order of their atomic number, i.e. the number of protons in the element. This is because we now know that an element of a particular atomic number may have several different isotopes (atomic weights). So the atomic weight is not a unique number for an element, but atomic number is. That is why the period table is arrange in order of the element's atomic number.

In any case, Happy 150th Year, Periodic Table!

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Is QM About To Revolutionize Biochemistry?

It is an intriguing thought, and if these authors are correct, a bunch of chemical reactions, even at higher temperatures, may be explained via quantum indistinguishibility.

The worlds of chemistry and indistinguishable physics have long been thought of as entirely separate. Indistinguishability generally occurs at low temperatures while chemistry requires relatively high temperatures where objects tend to lose their quantum properties. As a result, chemists have long felt confident in ignoring the effects of quantum indistinguishability.

Today, Matthew Fisher and Leo Radzihovsky at the University of California, Santa Barbara, say that this confidence is misplaced. They show for the first time that quantum indistinguishability must play a significant role in some chemical processes even at ordinary temperatures. And they say this influence leads to an entirely new chemical phenomenon, such as isotope separation and could also explain a previously mysterious phenomenon such as the enhanced chemical activity of reactive oxygen species. 

They have uploaded their paper on arXiv.

Of course, this is still preliminary, but it provides the motivation to really explore this aspect that had not been seriously considered before. And with this latest addition, it is just another example on where physics, especially QM, are being further explored in biology and chemistry.

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The Laws Of Life

Physics Today has made the article "The Laws of Life" from the March 2017 issue available for free. In the article, astrobiologist Charles Cockell describes how the fundamental laws of physics influences the forms of life on Earth.

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Mpemba Effect Is Still Hot After All These Years

OK, maybe not hot, but it is certainly at least lukewarm.

If you don't know anything about this, I've made several posts on the Mpemba effect before (read here, here, here, and here). Briefly, this is the effect where hot water is seen to freeze faster than cold water. Even after its purported discovery many years ago, the validity of this effect, and the possible explanation for it are still being debated.

Add this report to the body of discussion. It seems that there are new papers that are using molecular bonds in water as the possible explanation for this effect.

Now researchers from the Southern Methodist University in Dallas and Nanjing University in China think they might have a solution - strange properties of bonds formed between hydrogen and oxygen atoms in water molecules could be the key to explaining the elusive Mpemba effect.

Simulations of water molecule clusters revealed that the strength of hydrogen bonds (H-bonds) in a given water molecule depends on the arrangements of neighbouring water molecules.

"As water is heated, weaker bonds break, and groups of molecules form into fragments that can realign to form the crystalline structure of ice, serving as a starting point for the freezing process," Emily Conover reports for Science News.

"For cold water to rearrange in this way, weak hydrogen bonds first have to be broken."

I'm sure this will not be the last time we hear about this.

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Is There A Fundamental Difference In The Teaching of Physics and Chemistry/Biology?

I read in utter fascination of this opinion piece by Micheal McCracken. As you read this, pay attention not only to the fact that there appears to be a difference between how he perceived physics is taught at the undergraduate level, but also how the differences between the pedagogy of physics and chemistry/biology translates itself into how science is perceived by the public.

Abstract: During recent collaboration with colleagues to revise our institution's general-education curriculum, I encountered many perceptions of what we mean by the Natural Sciences. I was surprised to find that perceptions of scientific pedagogy varied significantly among the scientific disciplines, especially concerning issues of philosophy of science and epistemology, manifested in the approaches to teaching theoretical concepts and their development. These realizations suggest that Physics occupies a singular role in college curricula, introducing students, even at the introductory level, to the acquisition of knowledge by theoretical means and the assessment of theory based on experimental evidence.

His idea that fulfilling a student's requirement on learning Natural Science without taking physics and either chemistry or biology will be a serious deprivation on how science is done.

I tend to agree.

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Chemistry Nobel Prize Goes To Physicists

The Nobel Prize in chemistry this year goes to a team that was responsible for the development of fluorescence microscopy.

This year’s Nobel Prize in Chemistry went to three scientists whose work surpassed the long-established resolution limit for optical microscopes. The award went to Eric Betzig of the Howard Hughes Medical Institute, Stefan W. Hell of the Max Planck Institute for Biophysical Chemistry, and William E. Moerner of Stanford University “for the development of super-resolved fluorescence microscopy.”

There is an important point here that should be addressed to the public, the politicians, and those who think that we can fund one part of science over another. Many of the instruments used in chemistry, biology, medicine, etc. came out of basic physics research. Before anyone else used these instruments, physicists were the first people to thought of the concept, develop the theory and instrumentation, and then used them. It is only after that that the potential applications for such a device can be envisioned in other fields.

This technique is not the first. The history of Nobel prizes is littered with many instruments that came out of physics but are now ubiquitous in other fields. STM/AFM instruments are indispensable in biology and chemistry, yet this is clearly an instrument that came out quantum mechanics and then developed by physicists once they knew that such a device can probe a sample of interest. Only after that is the possibility of applications in other areas can be seen.

So folks, when you choke the support, and the funding, of basic science/physics, please note that you are really choking off the upstream waters. You may not feel the effect right away, but eventually, your water supply will drop down to a trickle, and you don't quite now what happened. The instruments that those people funded by the NIH here in the US were all derivatives of devices invented out of physics!

Think about that next time you want to cut off your nose to spite your face.

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Starting Fire In Water

The ISS might be useful after all, in addition to having the AMS. From this video, you get to at least learn about some of the properties of supercritical water.



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First Direct Measurement of Van der Waals Force

In an amazing feat of experimental ingenuity, the first direct measurement of Van der Waals force between two atoms has been accomplished.

This latest research was done by researchers at the Laboratoire Charles Fabry (LCF) in Palaiseau and the University of Lille. "What we have done here, for the first time to our knowledge, is to measure directly the Van der Waals interaction between two single atoms that are located at a controlled distance, chosen by the experimenter," says Thierry Lahaye, who is part of the LCF team.

Controlling the distance between normal atoms – while measuring the force between them – is extremely difficult because the relevant distances are tiny. To get round this problem the team used Rydberg atoms, which are much larger than normal atoms. Such atoms have one electron in a highly excited state. This means that they have a very large instantaneous dipole moment – and therefore should have very strong Van der Waals interactions over relatively long distances. They also have unique properties that allow them to be controlled with great precision in the lab.

You can also read more review of this work at APS Physics, and, get a free copy of the paper.

Nice piece of work.

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Flames In Microgravity

This is actually an interesting video on the physics of flames, and the physics of flames in microgravity. It shows a flame experiment on the International Space Station.



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The Origins of the Elements

If you have an hour to spare, here's something you might either want to watch, or just listen in the background.



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The Chemistry Of Cleaning

Yes, cleaning! Enough with the Higgs, and the Dark Energy, and the pnictide superconductivity. Let's get dirty and learn about the physics and chemistry of cleaning!

This brief overview actually came from a janitorial service company, but it has a nice article on the chemistry of cleaning, with lots of external links if people care to read more. It's one of those things that we use and encounter each day, but for many of us, we don't give a second thought on how or why it works. So wash your hands (with soap), sit down, and learn what you just did.

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Winner of "What Is A Flame" Challenge

OK, I didn't even know that there was such a challenge. Apparently, they got quite a number of submission too! And they got a winner!

Ames, who is studying for his Ph.D. in quantum optics at the University of Innsbruck, Austria, got national recognition this month when his 71/2-minute video was selected as the best explanation of flame to a young audience. The worldwide contest, run by Stony Brook University in New York, was inspired by actor and visiting professor Alan Alda and was judged by 6,000 sixth-graders.

The award was given by the Stony Brook Center for Communicating Science, a part of its School of Journalism.

Ames’ video bested 800 entries by getting the top number of rating points from sixth-graders in 131 schools.

So I went scrambling off to YouTube to see if I can find the video, and I did!




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The Elements iPad App

{Don't miss our nomination period to nominate your most attractive physicists}

Hey, did you see NOVA's "Hunting the Elements" last week? If you enjoyed that, then there's an iPad app for you to continue with your exploration of the various elements.

The Elements iPad AppThe free app, available now on the App Store, takes the periodic table off the wall and puts it into users’ hands, bringing life to the world’s elements in colorful and dynamic ways.

NOVA Elements, featuring tech guru David Pogue, allows users to explore an interactive periodic table, build elements from their particles, construct 3D rotating molecules, and watch the two-hour NOVA program, “Hunting the Elements,” premiering tonight at 9PM/8c on PBS (check local listings).

The NOVA Elements App allows users to:

• Learn key facts about each element: its discovery, appearance, real-world application and more.

• Play in an atomic sandbox to create any or all of the 118 elements by adding the correct number of protons, neutrons and electrons.
  
• Combine the elements you’ve built into 3D rotatable molecules found in everyday objects, like a banana or a watch, in the “My Essential Elements” game.
  
• Jump to related segments in NOVA’s “Hunting the Elements” program with the tappable periodic table.
  
• Share your exploration and discoveries with tweets.

• Watch the complete two-hour NOVA program, “Hunting the Elements.” Streaming is only available in the U.S. and its territories.

The NOVA Elements App is available for free from the App Store on iPad or at here.

So here's another app to add to something that might be useful and relevant to physics.

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Three New Elements Join The Periodic Table

Please welcome the three new members of our Periodic Table Club: darmstadtium (Ds), roentgenium (Rg) and copernicium (Cn).

These elements are so large and unstable they can be made only in the lab, and they fall apart into other elements very quickly. Not much is known about these elements, since they aren't stable enough to do experiments on and are not found in nature. They are called "Super Heavy," or Transuranium, elements.

The General Assembly approved these name suggestions proposed by the Joint Working Party on the Discovery of Elements, which is a joint body of IUPAP and the International Union of Pure and Applied Chemistry (IUPAC).

Don't think most of us will be encountering these elements anytime soon.

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Let's Make Oobleck!

Ooooh.. green goo!

Those wacky people at Jefferson Lab are at it again. This time, they are making "Oobleck"!




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STM Images Molecular Orbital

Scanning tunneling microscopy has been extremely useful in condensed matter/material science. Now, it might finally be an important tool in chemistry. A new report shows a very neat experiment using a STM with a tip that has been "functionalized" with a CO molecule. So in this case the tunneling goes through the p-wave orbital of the molecule and allows for an imaging of the nodal direction.

With their new results, Gross et al. show that combining CO-functionalized tips and alkali-halide interlayers allows them to image the nodal pattern of the orbitals of flat organic molecules (Fig. 1). Here, again, the two CO 2π^* orbitals play an important role. These derive from the p orbitals of the carbon and oxygen atoms that stand perpendicular to the molecular axis. Figure 1 shows one of the 2π^* orbitals: it has four lobes (drawn in red and light blue, representing their phase or sign) separated by two nodal planes. The other 2π^* orbital, perpendicular to the one in Fig. 1, is not shown. By bringing the tip close to a sample molecule (pentacene in Fig. 1) separated by a salt layer from a metallic substrate, and tuning the voltage between tip and substrate to address a particular orbital of the pentacene molecule, the lobes of the CO 2π^* orbital and those of the pentacene orbital (shown in purple and rose) come into and out of registry, as the tip is scanned across the molecule.

Amazing work. You can get the paper for free at the link above.

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Origin Of Life At CERN

A rather fascinating and unexpected topic of a workshop held at CERN recently.

On 20 May, a small group of biologists and chemists arrived at Cern for a workshop from the institution's experts on how to organise a disparate community of research groups all over the world into a single scientific force. While much of the research at Cern is focused on the beginnings of the Universe, the delegates also held a discussion on the beginnings of life.

Much of the research in the field is currently focused on so-called "autocatalytic sets". These are groups of molecules that undergo reactions where all molecules mutually catalyse each other -- speed up the rate at which the reaction takes place. In this way, the sets are self-sustaining. It's believed that protocells emerged from such a system, but there's a significant question mark over how likely it is for these sets to occur randomly.

There's plenty of opportunities to expand the horizon of a facility and organization such as CERN. This certainly is one way that it can contribute to a field of study that needs the expertise and capability that CERN has.

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The 20th Anniversary of the Nanotubes

Carbon nanotubes was first described in 1991, so 2011 is the 20th Anniversary of this amazing structure.

This lecture, I presume, was given in conjunction with this occasion. It presents a new nanotube not made of carbon, but rather, of boron nitride nanotube. If you have an hour to spend, it might be an interesting lecture to sit through, especially in the beginning that should give you a brief history and the physics of nanotubes.



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2011 International Year of Chemistry

Did you know that 2011 is the International Year of Chemistry? No? I didn't either! And I wouldn't have had I not read Charles Day's blog.

I suppose since we've had Year of Physics, Year of Astronomy, it wouldn't hurt for Chemistry's turn to take the spotlight. So go over to the webpage and see what they have in store for the year-long celebration.

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