science

Remembering Future?

Ever wondered that we can remember past but, are unable to do so for future. Why we perceive the time’s arrow moving only in one direction that is from past to future and not the other way round? The answer to this could be explained by entropy of a closed system. But, before we get into into the answer, we should know a little about notions of time. According to Stephen Hawking, there are three notions or arrows of time: psychological (that we perceive through brain), entropic (movement in nature from order to disorder) and cosmological (it moves forward or backward depending upon the inflationary or deflationary state of the universe). Psychological and entropic arrows of time could be considered same and here we are discussing the reason that forbids us from remembering future in the context of psychological and entropic notions of time.

In a closed system, changes take place in a direction that increases entropy. Now, what is entropy? In simple language, we can say that entropy is the degree of unpredictability of a system. In case of Universe, we are on a constant move that is increasing the entropy or disorganisation within it. It is the reason behind the flow of heat from a hot to cold object but, not vice versa. Our memory is created by the particular fashion in which neurons orient themselves within our brain, energy is required to create this orientation which in turn heats up our bodies, thus increasing the entropy. So, the reason behind our perception of uni-directional psychological notion of time is that it creates increase in entropy.


Read more on it: http://www.math.cornell.edu/~numb3rs/luthy3/thearrowoftime.html

http://physics.aps.org/articles/v7/47?referer=rss

http://preposterousuniverse.com/eternitytohere/faq.html

http://physics.aps.org/story/v24/st7

 

Explaining Missing Gravity at Hudson Bay

In 1960, when for the first time earth’s global gravity was charted then it was noted that certain regions of earth have lower gravity than others. Regions of Canada, particularly Hudson Bay area have remarkably low gravity compared to other parts of the world. Initially, it appeared to be a mystery but, now there are more than one explanation for the presence of low gravity in that region.

Hudson Bay with Canadian bordering states. by Rishabh Tatiraju

Hudson Bay with Canadian bordering states. by Rishabh Tatiraju

 

How is gravity created?

Gravity is directly promotional to mass of a body so, in other words mass creates gravity. The shape of earth is not even, it bulges out near equator and gets flatter near poles. Regions of earth with lower masses have lower gravity compared to regions having higher masses. So, do the Hudson Bay area have lower land mass compared to other parts of Earth? Yes, but why? In case of Hudson Bay area, it could be explained by two factors, which are explained below:

Convection in Earth’s mantle

The mantle of earth consists of molten rocks known as magma, magma is in constant movement creating convection currents. These convection currents pull the continental land masses toward them and there by decreases the land mass of the area that is getting pulled. Convection currents are not always same at an area and keep on shifting from place to place bringing on various geographical changes too along with its movements.

Rebound effect of ice sheet

The maximum extent of glacial ice in the north polar area during Pleistocene time. {{PD-USGov-Interior-USGS}} http://pubs.usgs.gov/gip/continents/map.jpg

The maximum extent of glacial ice in the north polar area during Pleistocene time. {{PD-USGov-Interior-USGS}} http://pubs.usgs.gov/gip/continents/map.jpg

Around two miles thick ice sheet known as Laurentide Ice Sheet existed in the area which is now Hudson Bay area. This ice sheet was extremely heavy and had weighed down the area of earth where it existed. It started melting due to rising temperature of earth and disappeared completely around 10,000 years ago but, had left an indentation in that area. The indentation has pushed land masses towards the sides and created a low land mass in the central area which has resulted in lower than usual gravity in this area.

 

Ooho: The Edible Water Bottle

Plastic water bottles, due to their non-biodegradable properties, are tough to dispose of and there by are a big source of environmental pollution. To usher a path for a solution to this problem, designers from Skipping Rocks Lab: Rodrigo Garcia Gonzalez, Pierre Pasalier and Guilaume Couche, have developed an edible blob that could be used to store water.


The blob known as “Ooho” has double gelatinous membrane, made up of brown algae and calcium chloride. Designers say that the Ooho is cheap to make costing only two cents per blob, durable, hygienic and biodegradable. It is simple to make and can be made even in the convenience of home. Water is kept frozen while packaging so that a bigger membrane could be created. Ooho has been awarded at Lexus Design awards 2014.


The only demerit of Ooho is the way one could drink water from it, that demands it to be torn which could be quite convoluted. Ooho could be very helpful in live events where organizers generally tackle with loads of wastes. Edible lunch box known as WikiPearl is already available in the market that is being used to sell yoghurt, ice creams etc. We can hope to see edible water blob, Ooho, soon in the market too.

Biodegradable Electronics

We have moved one step closer to a world free of harmful non-biodegradable electronics as a group of researchers created electronic components soluble in body and water. These components could be used in future electronic devices which could perish after a certain time of use, thereby helping to tackle the current problem of electronic wastes. Biodegradable electronic components would also be a great help in medical implants where surgical removal of implants are necessary after a certain duration of time. 

Two researchers who led this project are: John Rogers from University of Illinois at Urbana-Campaign and Fiorenzo Omenetto from Tufts University. According to them they have found solution to various types of dissolving like that of electronic or optical device.

This project was started in 2009, they conducted various researches on silk. Thin sheets of silk created by processing of proteins extracted from silkworm has been developed, these sheets can be easily attached to body tissues. Duration of degradation of silk can be controlled depending upon its processing. Researchers put silicon integrated circuits with light emitting diodes on processed silk.

Initially, researchers faced problem as all components didn’t dissolve in animal testing and silicon for long-term in body could be harmful.

Researchers used magnesium instead of stable metals like gold or silver to connect integrated circuits, wires and antennas which could be powered from outside of body. The researchers further found that by changing the thickness of silicon membranes, the duration taken by it to dissolve could be controlled, ideally a 100 nanometres thick silicon membrane can dissolve at the rate of 4.5 nanometres per day.

Thus, researchers are able to control the duration of the component’s degradation by simply controlling the properties of silk and thickness of silicon membranes used. Large scale production of silk-silicon electronic components are under process and medical implants that generally don’t require much sophistication will most probably be the first in line to get manufactured.