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Amazon Rainforest

We are sharing one wrong statistic about the Amazon fire

For the past few weeks news of the Amazon wildfire has spread across social media like wildfire itself. Social media influencers and even general users have been doing their best to bring awareness to this issue by talking about how the amazon accounts for 20% of the world’s oxygen which is not completely true.

Nearly all free oxygen present in the air is produced by plants through photosynthesis. (⅓)rd of this is produced by tropical forests of which the Amazon basin is a major contributor. But there is a twist here. All that oxygen is used up by living organisms and fires. With trees constantly shedding leaves and twigs, it adds to the nourishment of the microbes and insects which in turn consume a lot of oxygen. As a net result, the oxygen produced by forests is close to zero.

Research shows that the ocean produces almost all the oxygen we breath, and can last us millions of years. 

For oxygen to accumulate in the air, the organic matter produced during photosynthesis needs to be removed from circulation before the oxygen itself gets consumed. They need to be quickly buried in places where oxygen has been depleted for example in deep-sea mud.

This process takes place in parts of the ocean that have high levels of nutrients to fertilize algae blooms. The dead blooms float to the bottom where microbes feed off of it. The remaining matter gets buried and eventually becomes a source of coal.

The oxygen produced by the algae blooms still remains in the air due to the lack of decomposers. In this way, it adds to about 0.0001% of the oxygen in the air. While this a small number, over millions of years it has become a legitimate source of oxygen that all animal life depends on.

Although plant growth is responsible for breathable oxygen, it accounts for a very small percentage and if all of the organic matter on earth were burnt it would be worth less than 1% of the oxygen consumed.

While the amazon wildfire is a serious disaster and worrisome for several reasons such as the extremely rare species of flora and fauna that cannot be found anywhere else in the world and the indigenous tribes that see the amazon as their home, loss of oxygen production isn’t one of them.

Physicists design an experiment to pin down the origin of the elements

Physicists design an experiment to pin down the origin of the elements

Nearly all of the oxygen in our universe is forged in the bellies of massive stars like our sun. As these stars contract and burn, they set off thermonuclear reactions within their cores, where nuclei of carbon and helium can collide and fuse in a rare though essential nuclear reaction that generates much of the oxygen in the universe.

The rate of this oxygen-generating reaction has been incredibly tricky to pin down. But if researchers can get a good enough estimate of what’s known as the “radiative capture reaction rate,” they can begin to work out the answers to fundamental questions, such as the ratio of carbon to oxygen in the universe. An accurate rate might also help them determine whether an exploding star will settle into the form of a black hole or a neutron star.

Now physicists at MIT’s Laboratory for Nuclear Science (LNS) have come up with an experimental design that could help to nail down the rate of this oxygen-generating reaction. The approach requires a type of particle accelerator that is still under construction, in several locations around the world. Once up and running, such “multimegawatt” linear accelerators may provide just the right conditions to run the oxgen-generating reaction in reverse, as if turning back the clock of star formation.

The researchers say such an “inverse reaction” should give them an estimate of the reaction rate that actually occurs in stars, with higher accuracy than has previously been achieved.

“The job description of a physicist is to understand the world, and right now, we don’t quite understand where the oxygen in the universe comes from, and, how oxygen and carbon are made,” says Richard Milner, professor of physics at MIT. “If we’re right, this measurement will help us answer some of these important questions in nuclear physics regarding the origin of the elements.”

Milner is a co-author of a paper appearing today in the journal Physical Review C, along with lead author and MIT-LNS postdoc Ivica Friščić and MIT Center for Theoretical Physics Senior Research Scientist T. William Donnelly.

A precipitous drop

The radiative capture reaction rate refers to the reaction between a carbon-12 nucleus and a helium nucleus, also known as an alpha particle, that takes place within a star. When these two nuclei collide, the carbon nucleus effectively “captures” the alpha particle, and in the process, is excited and radiates energy in the form of a photon. What’s left behind is an oxygen-16 nucleus, which ultimately decays to a stable form of oxygen that exists in our atmosphere.

But the chances of this reaction occurring naturally in a star are incredibly slim, due to the fact that both an alpha particle and a carbon-12 nucleus are highly positively charged. If they do come in close contact, they are naturally inclined to repel, in what’s known as a Coulomb’s force. To fuse to form oxygen, the pair would have to collide at sufficiently high energies to overcome Coulomb’s force — a rare occurrence. Such an exceedingly low reaction rate would be impossible to detect at the energy levels that exist within stars.

For the past five decades, scientists have attempted to simulate the radiative capture reaction rate, in small yet powerful particle accelerators. They do so by colliding beams of helium and carbon in hopes of fusing nuclei from both beams to produce oxygen. They have been able to measure such reactions and calculate the associated reaction rates. However, the energies at which such accelerators collide particles are far higher than what occurs in a star, so much so that the current estimates of the oxygen-generating reaction rate are difficult to extrapolate to what actually occurs within stars.

“This reaction is rather well-known at higher energies, but it drops off precipitously as you go down in energy, toward the interesting astrophysical region,” Friščić says.

Time, in reverse

In the new study, the team decided to resurrect a previous notion, to produce the inverse of the oxygen-generating reaction. The aim, essentially, is to start from oxygen gas and split its nucleus into its starting ingredients: an alpha particle and a carbon-12 nucleus. The team reasoned that the probability of the reaction happening in reverse should be greater, and therefore more easily measured, than the same reaction run forward. The inverse reaction should also be possible at energies nearer to the energy range within actual stars.

In order to split oxygen, they would need a high-intensity beam, with a super-high concentration of electrons. (The more electrons that bombard a cloud of oxygen atoms, the more chance there is that one electron among billions will have just the right energy and momentum to collide with and split an oxygen nucleus.)

The idea originated with fellow MIT Research Scientist Genya Tsentalovich, who led a proposed experiment at the MIT-Bates South Hall electron storage ring in 2000.  Although the experiment was never carried out at the Bates accelerator, which ceased operation in 2005, Donnelly and Milner felt the idea merited to be studed in detail. With the initiation of construction of next-generation linear accelerators in Germany and at Cornell University, having the capability to produce electron beams of high enough intensity, or current, to potentially trigger the inverse reaction, and the arrival of Friščić at MIT in 2016, the study got underway.

“The possibility of these new, high-intensity electron machines, with tens of milliamps of current, reawakened our interest in this [inverse reaction] idea,” Milner says.

The team proposed an experiment to produce the inverse reaction by shooting a beam of electrons at a cold, ultradense cloud of oxygen. If an electron successfully collided with and split an oxygen atom, it should scatter away with a certain amount of energy, which physicists have previously predicted. The researchers would isolate the collisions involving electrons within this given energy range, and from these, they would isolate the alpha particles produced in the aftermath.

Alpha particles are produced when O-16 atoms split. The splitting of other oxygen isotopes can also result in alpha particles, but these would scatter away slightly faster — about 10 nanoseconds faster — than alpha particles produced from the splitting of O-16 atoms. So, the team reasoned they would isolate those alpha particles that were slightly slower, with a slightly shorter “time of flight.”

The researchers could then calculate the rate of the inverse reaction, given how often slower alpha particles — and by proxy, the splitting of O-16 atoms — occurred. They then developed a model to relate the inverse reaction to the direct, forward reaction of oxygen production that naturally occurs in stars.

“We’re essentially doing the time-reverse reaction,” Milner says. “If you measure that at the precision we’re talking about, you should be able to directly extract the reaction rate, by factors of  up to 20 beyond what anybody has done in this region.”

Currently, a multimegawatt linear accerator, MESA, is under construction in Germany.  Friščić and Milner are collaborating with physicists there to design the experiment, in hopes that, once up and running, they can put their experiment into action to truly pin down the rate at which stars churn oxygen out into the universe.

“If we’re right, and we make this measurement, it will allow us to answer how much carbon and oxygen is formed in stars, which is the largest uncertainty that we have in our understanding of how stars evolve,” Milner says.

Konstantinos Giapis Oxygen

Comet Inspires Chemistry for Making Breathable Oxygen on Mars

Science fiction stories are chock full of terraforming schemes and oxygen generators for a very good reason—we humans need molecular oxygen (O2) to breathe, and space is essentially devoid of it. Even on other planets with thick atmospheres, O2 is hard to come by.

So, when we explore space, we need to bring our own oxygen supply. That is not ideal because a lot of energy is needed to hoist things into space atop a rocket, and once the supply runs out, it is gone.

One place molecular oxygen does appear outside of Earth is in the wisps of gas streaming off comets. The source of that oxygen remained a mystery until two years ago when Konstantinos P. Giapis, a professor of chemical engineering at Caltech, and his postdoctoral fellow Yunxi Yao, proposed the existence of a new chemical process that could account for its production. Giapis, along with Tom Miller, professor of chemistry, have now demonstrated a new reaction for generating the oxygen that Giapis says could help humans explore the universe and perhaps even fight climate change at home. More fundamentally though, he says the reaction represents a new kind of chemistry discovered by studying comets.

Most chemical reactions require energy, which is typically provided as heat. Giapis’s research shows that some unusual reactions can occur by providing kinetic energy. When water molecules are shot like extremely tiny bullets onto surfaces containing oxygen, such as sand or rust, the water molecule can rip off that oxygen to produce molecular oxygen. This reaction occurs on comets when water molecules vaporize from the surface and are then accelerated by the solar wind until they crash back into the comet at high speed.

Comets, however, also emit carbon dioxide (CO2). Giapis and Yao wanted to test if CO2 could also produce molecular oxygen in collisions with the comet surface. When they found O2 in the stream of gases coming off the comet, they wanted to confirm that the reaction was similar to water’s reaction. They designed an experiment to crash CO2 onto the inert surface of gold foil, which cannot be oxidized and should not produce molecular oxygen. Nonetheless, O2 continued to be emitted from the gold surface. This meant that both atoms of oxygen come from the same CO2 molecule, effectively splitting it in an extraordinary manner.

“At the time we thought it would be impossible to combine the two oxygen atoms of a CO2molecule together because CO2 is a linear molecule, and you would have to bend the molecule severely for it to work,” Giapis says. “You’re doing something really drastic to the molecule.”

A stop-motion animation of carbon dioxide being converted to molecular oxygen.

In Giapis’s reactor, carbon dioxide is converted into molecular oxygen. Credit: Caltech

To understand the mechanism of how CO2 breaks down to molecular oxygen, Giapis approached Miller and his postdoctoral fellow Philip Shushkov, who designed computer simulations of the entire process. Understanding the reaction posed a significant challenge because of the possible formation of excited molecules. These molecules have so much energy that their constituent atoms vibrate and rotate around to an enormous degree. All that motion makes simulating the reaction in a computer more difficult because the atoms within the molecules move in complex ways.

“In general, excited molecules can lead to unusual chemistry, so we started with that,” Miller says. “But, to our surprise, the excited state did not create molecular oxygen. Instead, the molecule decomposed into other products. Ultimately, we found that a severely bent CO2 can also form without exciting the molecule, and that could produce O2.”

Tom Miller, professor of chemistry, stands in front of a rack of computers.

Tom Miller, professor of chemistry(Credit: Caltech)

The apparatus Giapis designed to perform the reaction works like a particle accelerator, turning the CO2 molecules into ions by giving them a charge and then accelerating them using an electric field, albeit at much lower energies than are found in a particle accelerator. However, he adds that such a device is not necessary for the reaction to occur.

“You could throw a stone with enough velocity at some CO2 and achieve the same thing,” he says. “It would need to be travelling about as fast as a comet or asteroid travels through space.”

That could explain the presence of small amounts of oxygen that have been observed high in the Martian atmosphere. There has been speculation that the oxygen is being generated by ultraviolet light from the sun striking CO2, but Giapis believes the oxygen is also generated by high-speed dust particles colliding with CO2 molecules.

He hopes that a variation of his reactor could be used to do the same thing at more useful scales—perhaps one day serving as a source of breathable air for astronauts on Mars or being used to combat climate change by pulling CO2, a greenhouse gas, out of Earth’s atmosphere and turning it into oxygen. He acknowledges, however, that both of those applications are a long way off because the current version of the reactor has a low yield, creating only one to two oxygen molecules for every 100 CO2 molecules shot through the accelerator.

“Is it a final device? No. Is it a device that can solve the problem with Mars? No. But it is a device that can do something that is very hard,” he says. “We are doing some crazy things with this reactor.”

The paper describing the team’s findings, titled “Direct dioxygen evolution in collisions of carbon dioxide with surfaces,” appears in the May 24 issue of Nature Communications. Caltech co-authors include Tom Miller, professor of chemistry; Philip Shushkov, a postdoctoral scholar in chemistry; and Yunxi Yao, postdoctoral researcher, formerly of Caltech. Funding for the research was provided by the National Science Foundation, the Joint Center for Artificial Photosynthesis, and the U. S. Department of Energy.

Materials provided by the California Institute of Technology

Mono Lake South Tufa August

Studies find microbes in Pacific Ocean surviving on arsenic

Oceans are a rich and biodiverse habitat on its own. We can find organisms and plants ranging from a few millimetres to a length of 12 meters which is the size of the largest whale which weights close 50 tonnes. The vastness and the richness of the oceans are a wonder to study and explore a curious mind.

Scientists for many decades have believed that arsenic is a poisonous chemical for almost all living beings but until recently researchers have found a microorganism that lives by breathing Arsenic and is found over a large area in the Pacific ocean. The study has been published in The Proceedings of the National Academy of Sciences. Scientists have believed that this species had used arsenic during the time of formation of Earth where the presence of oxygen was limited and microorganism had to survive on arsenic. In the face of global warming, there is a need to adapt which is slowly happening in the ocean ecosystem as organisms need to be able to adapt to lower levels of oxygen in the water.

Arsenic was known to be present in water for quite a long time but its use by microorganism for living was quite a new concept. These microorganisms were discovered off the coast of Mexico where there is a patch called anoxic where there is virtually no oxygen dissolved in water. Microorganisms which breath on sulphur and nitrogen were known for quite a long time but living on arsenic is still new to researchers.

Scientists have analyzed the DNA samples of these microorganisms and found two pathways which convert arsenic-based molecules to energy resource. It has opened gateways to explore the life where oxygen does not exist and also extraterrestrial life on other planets might take place. These arsenic-based microorganisms might account for around one percent of the total marine microbial community but there is scope to find and understand the complex chemical reactions which happen in oceans as a whole.

Scientists think that the best way to study these microorganisms is to artificially grow these samples in the lab and study their metabolism and how they respond to various levels of arsenic content in water.

Jaclyn Saunders, a researcher has commented that the coolest thing about these organisms is that they are expressing the genes in an environment that is very low on arsenic and that it opens up boundaries to finding other organisms that are respiring arsenic in poor arsenic conditions.

The amount of diversity one may find on the Earth may surprise anyone, there are a lot more opportunities and organisms that are waiting to be explored in the depth and the vastness of our Earth’s oceans.