Gallium Metal Melts in Your Hands

By Anupum Pant

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Atomic number: 31
Symbol: Ga

At first what seems like an uninteresting material, Gallium, in truth has, much more to it than meets the eye.

Gallium’s melting point

Like most other metals, Gallium is solid at room temperature (or liquid if it is too hot in your room). But, if it is held [in hands] for long enough, it melts in your hands, and doesn’t poison you like Mercury would. This is because of its unusually low melting point of (~29 degree Centigrade). It can melt by drawing heat from a human body which is normally at around 37 degrees.

Buy Gallium: This property, and the affordable price of $24 for 15 grams, probably makes it an appropriate gift for science geeks. They will love making mirrors at home by sticking it onto plain glass sheets.

Talking about a classic prank, it is advised to beware of the scientists who would offer spoons made out of Gallium to unsuspecting guests at a tea party. These spoons melt in hot tea and make it a potentially harmful concoction to ingest.

Since it isn’t poisonous like Mercury, Gallium is often mixed with Indium to further lower its melting point to -19 degrees. This makes it a safer option for us to use in thermometers instead of Mercury.

Interesting uses and compounds

  • Dilute sulphuric acid changes the surface properties of Gallium due to the formation of Gallium Sulfide on the surface. It no longer sticks that badly to glass, gets pulled up into a ball and starts beating like a heart when dichromate is added.
  • 98% of the world’s Gallium metal is used as Gallium Arsenide and Gallium Nitride, used in the electronic industry for making semiconductors, LEDs and high-speed circuits. In fact the laser in your Blu-Ray player is also made using Gallium.
  • Probably the most amount of Gallium used in a single place is at a Neutrino observatory in Russia. It houses around 57 tons of liquid Gallium.
  • With Silicon, Graphite and Molybdenum, Gallium is also used in ski wax to make skis more slippery.
  • Finally, nothing beats a metal that melts in your hands.

Tardigrades – Toughest Creatures on Earth

By Anupum Pant

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So, if you think elephants or cockroaches are tough, that could be because you probably haven’t heard about these amazing creatures called Tardigrades (picture).

What are Tardigrades?

Tardigrades, also known as moss piglets or waterbears, are oddly cute little animals that live in water and feed on moss. Their size ranges from 0.1 mm to 1.5 mm and they have eight legs (they walk like bears). The most extreme thing about these extremophiles is that they can survive almost anything (actually, they kind of die for a while with an option to come back to life later). Here is a list of things Tardigrades can survive. They can:

  • Survive without water and food for 10 years.
  • Waddle away in the vacuüm of space (for 10 days & get exposed UV radiation), come back and walk around as if nothing happened.
  • Survive 1000 times more radiation that would kill an elephant.
  • Live through extremely low temperatures (almost absolute zero) or high temperatures (~150 degree Centigrade)
  • Repair their own DNA after getting exposed to lethal amounts of radiation.
  • Survive pressures of about 300 Jumbo jets stacked on a person. (6 times more than the deepest ocean trenches)

Scientists love them

People at NASA and the European Space Agency love doing tests on them because they think, Tardigrades can help them understand the origin of life on earth (probably by supporting Panspermia). Also, scientists want to find out more about their extreme capabilities. If you ask them, if these things are aliens, they’ll tell you – “Probably not”

[Learn more about Tardigrades]

4D Printing is Here

By Anupum Pant

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We had just started getting comfortable with printing objects in 3D, and 4D printing is already here. Early this year, in the month of April, Skylar Tibbits, an architect, designer and computer scientist at MIT, gave a revolutionary demonstration explaining their advances in the field of 4D printing at a TED conference. This was an initial proposal and it got things moving at a rapid pace.

Side note: In the world of 3D printing:

What is 4D printing?

At first 4D printing sounds like a catch phrase, it isn’t really just that. 4D printing is actually 1D better than 3D printing and it aims at making objects out of a 3D printer, that can reconfigure themselves into useful shapes, on their own. For instance, think of a non-living stick changing itself into a 3D cube as time passes. In short, 4D printing will enable us to create living objects without any living cells, micro-processors, chips or batteries involved. Sounds simple enough, but the promises are nothing less than extraordinary.

In the TED talk attached below, Skylar explains how a string of plastic placed in water can turn itself into the letters MIT. But, this was something that happened back in April. Things have moved further.

A few days back, Researchers at the University of Colorado Boulder revealed a successful test of their 4D printing technology. They were able to print out flat objects using normal plastic combined with a smart material which was able to turn into a cube on its own. Cubes are just the start.

According to scientists, in the future, 4D printing will probably churn out smart car bodies that would heal automatically, smart soldier uniforms and advanced building materials. Imagine a camouflage material that changes to match the surroundings, that could be the future. Or a pipe that contracts and expands to move water without pumps. Or a building material that builds itself into a structure. 4D printing could probably best suited for building in an extremely hostile environment like space. The possibilities are endless.

But, let us not get ahead of ourselves. It is almost impossible to predict what we’ll actually see in the future. Things have just started to happen in the field of 4D printing. But, it sure looks amazing. What will you build?