MIT Archives - The Silver Ink

World’s coldest molecules are created by MIT researchers

June 16, 2015 By Doyle Buehler 1 Comment

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It is known that potassium molecules when cooled to temperatures just above absolute zero could exhibit strange behaviors.

Researchers in a new study brought the molecules down to just above the coldest possible temperature.

The molecules of sodium potassium or NaK were cooled to just 500 billionths of a degree Celsius over absolute zero. At this temperature, no more energy remains in the molecules that can be extracted as heat. The temperature was million times colder than the interstellar space.

Molecules of air generally collide into each other at speeds of several hundreds of miles per hour. Researchers suspected that if the gases were frozen down to temperatures just above absolute zero, the molecules would act together as a single unit. This strange form of matter was a theoretical idea and was never seen.

When the researchers brought the gas down to these ultracold temperatures, they found the magnetic difference in between poles of molecules became more pronounces. The molecules were also found to be come longer lived as the collision between the molecular units became less frequent. The molecules in this state traveled just inches per second, vibrating and tumbling at the lowest possible rate.

Martin Zwierlein of the Massachusetts Institute of Technology or MIT said, “We are very close to the temperature at which quantum mechanics plays a big role in the motion of molecules. So these molecules would no longer run around like billiard balls, but move as quantum mechanical matter waves.”

Sodium potassium was selected for the study because it is an example of the simplest class of molecules. The structure of the molecules is made up to just two atoms, one is potassium and the other is sodium, bound together like a dumbbell.

Molecules vibrate and tumble erratically, making it difficult for the material to freeze. Doing so with single atoms is a much easier task. Bringing the sodium potassium molecules to just above absolute zero was accomplished in a multistage process.

The first stage was evaporating cooling and lasers to slow down motions of the molecules. Later, magnets were used to coax the molecules into binding with one another, forming single large, supercold molecule. However, these bonds only bind the molecules together weakly, allowing the particles to vibrate faster than desired. A pair of lasers was then employed to bind the molecules together as a more cohesive hole.

Some of the theoretical properties of such supercold materials are bizarre when compared with the behavior of matter at room temperature.

Zwierlein said, “With ultracold molecules, you can get a huge variety of different states of matter, like superfluid crystals, which are crystalline, yet feel no friction, which is totally bizarre. This has not been observed so far, but predicted. We might not be far from seeing these effects, so we’re all excited.”

The tiny origami robot can do incredible things like fold, walk

June 2, 2015 By Dave Smith Leave a Comment

Scientists have revealed a tiny origami robot that can fold itself, walk and self destruct.

The robot has been presented at the ICRA or International Conference on Robotics and Automation, 2015 by the scientist from Massachusetts Institute of Technology or MIT along with Technische Universität München or TU Munich.

Scientists believe that his new technology can be used in medicines where it can be utilized to help doctors with critical surgery.

This invention was developed by a team led by Shuhei Miyashita from MIT’s Computer Science and Artificial Intelligence laboratory where the tiny robot measuring 1.7 cm and weighting just one third of the gram was developed.

The special feature of the robot is the neodymium magnet that is covered with polystyrene and PVS that allows the robot to take on a form that is similar to origami when heat is applied to it.

When the heat is applied at different degrees, the robot can fold into numerous processes and multi stages.

For the movement of robot, external magnetic field as opposed to a set of wires is used. This magnetic field involves four coils that serve as a guide towards its path. The magnets provide power to the robot to move which is cycling at 15 hertz.

Depending on the task, the robot can walk, roll and it can also be disintegrated when exposed to acetone.

Scientists are designing and experimenting on some material for robot so that it can also be dissolved in water.

Scientists are planning to create another robot version of this shape shifter with sensors so that it can operate autonomously.

Researchers are hoping to use this innovation for medical surgeries where it can be inserted inside a human body through blood stream where it can perform the medical task and when the job is done, dissolve away into the stomach.

This robot can also be used in space mission where it can collect small samples and specimens within small cracks on a planet’s surface.

Scientists discover Earth-sized exoplanets have circular orbits like earth

June 2, 2015 By Dave Smith 1 Comment

Scientists have discovered that Earth sized exoplanets orbit their parent star just like our planets orbit the sun, would help them to zero in on planets most likely to harbor extraterrestrial life.

It was a debate whether our solar system was a special case or it is a common norm for all the planets to orbit around that parent star and at same distance.

Scientists are from the MIT and Denmark’s Aarhus University.

Scientists for the study have examined orbits of 74 exoplanets travelling around 28 stars.

Vincent Van Eylen, a visiting graduate student in the MIT Department of Physics said, “Twenty years ago, we only knew about our solar system, and everything was circular and so everyone expected circular orbits everywhere. Then we started finding giant exoplanets, and we found suddenly a whole range of eccentricities, so there was an open question about whether this would also hold for smaller planets.”

The scientists have determined roughly equidistant circular orbits, and believe that the norm is followed in at least the systems with planets as small as the Earth.

Researchers have first created the hypothetical orbits of planets around parent star with predetermined characteristics, based on the assumption of circular orbits.

Then the researchers have used the NASA’s Kepler space telescope to determine the actual orbital periods of the planets, and they found that it matched with the predicted models, confirming that their orbits were circular and regular.

Giant exoplanets are in contrast to the Earth sized bodies, as they orbit in eccentric orbits, which bring them very close to the host star and then take them very far from it.

This discovery is going to have an effect on the search for extraterrestrial life, as Earth sized exoplanets have stable orbit around their host star which means that the conditions on those planets are likely to remain stable and steady over time.

Van Eylen says an earth sized planet compact enough to consist mostly of rock, as opposed to consisting mostly of gas, as with giant exoplanets, in regular circular orbit around its star would result in stable climate all through the planets year that could make it hospitable to life.

He added, “If eccentric orbits are common for habitable planets, that would be quite a worry for life, because they would have such a large range of climate properties, but what we find is, probably we don’t have to worry too much because circular cases are fairly common.”

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