What Should I Know About Dark Matter?

Well lucky for you if you're reading this (unlucky if you're a theoretical physicist in CERN reading my blog{highly unlikely}) dark matter hasn't been proved to exist. Now you might ask me "why am I lucky?". Well you're lucky because if dark matter was proved to exist it would be a MASSIVE breakthrough in the field of physics. Dark matter is probably one of the most sough after discoveries in the world now and a the person who discovers it is guaranteed a Nobel Prize in Physics for sure.



Another common thing is associating dark energy with dark matter. Dark energy is also hypothetical but many discoveries have shown that it must be there too.

Now here's a reason why dark matter should exist. Our universe exists sort of like a huge carousel with the stars rotating around like a ponies. In the middle it's suspected to be a black hole. Now this carousel picture isn't fitting the mathematics. According to mathematics the stars should have been flung off from the carousel by now. Reality as we know it is different. Our universe is stable(for now and is bound to change any second) and we see no stars flying off. Scientists explanation for this is .............(drumroll) DARK MATTER.



A second observation, which dark matter is used to explain is the fact that we are existing now. Observations of  the cosmic background radiation, the "afterglow" of the big bang fireball, show that matter in the beginning was spread very evenly throughout space. Dense regions, having stronger gravity than their surroundings, dragged in matter and became ever denser. But this process is too slow to build a galaxy as big as the Milky Way. To explain our existence it is necessary to postulate a large amount of Dark matter whose extra gravity greatly speeded up galaxy formation. 

Why Should We Worry About Nukes?

Nukes or Nuclear bombs are probably the most destructive weapons man has now. Deploying five of them could wipe out the earth. Even then, nuclear bombs still pose a very pressing problem. Human life is one. Even if humans could survive the bomb, there is a potentially larger problem looming over our heads right now.



The biggest problem with nuclear warheads is a problem which is already existent on earth right now, even as we speak.That is............"Global Warming". The earth has a major problem in the form of Global Warming. Carbon dioxide is being trapped by the earth in massive amounts. Though with relation to nukes, excessive Carbon dioxide isn't the problem. Its the fact that when a nuclear bomb explodes the smoke released is enough to prevent sunlight reaching us for days. Its as though a massive rain cloud appeared, but there was no rain. The thought of even releasing even three nukes is horrifying. It would cause the earth to move into an ice age.



But that's not the only problem. Nuclear bombs on exploding release enormous amounts of highly charged rays called gamma rays. The only thing which can stop gamma rays is 2 metres of solid lead. Our body, though people sometimes call others dense, just isn't dense enough to stop the radiation.
The gamma rays caused by the explosion on Hiroshima and Nagasaki killed more people than the actual flying debris and the heat did.



Now most of you might say that there's absolutely no chance that any of the world leaders might let lose a nuclear warhead, but that's not the case. These nukes can be deployed "accidentally". North Korea as we know has a rising  nuclear stockpile and it is lead by a strong but very very touchy leader, Hon'ble Supreme Leader Kim Jong Un. Now if US just happened to try a new Unmanned Plane and just happened to fly over North Korean Air Base then US is in trouble with a capital "T". This could be very destructive as Russia would side with North Korea and pretty soon the Earth would cease to exist. Therefore just possessing nukes is incredibly risky.Spreading awareness about the way nukes can be prevented from growing is the only way to save earth.

The Beginning of Digital Storage:Compact Discs

CD discs are now on the brink of being removed from the digital world. The Macbook Pro, released by Apple,  doesn't even have a CD slot. The new pen drives and hard drives are taking the place of the Compact Discs.

Compact Discs are important from a beginners point of view as they were one of the first means of storing large amounts of digital data. Until then data was stored in an analog way. Digital data is usually represented in bits. On and off signals are generally used to relay messages. Analog data, however, is transmitted by using changes in amplitude, frequency or an other property in proportion to that of a variable.

CDs initially could store 650 Mb of data, a far cry from today's terabyte storing hard drives. Nevertheless in their time CDs were very important. A CD works with a very important concept called Optic Laser Technology. A CD is initially a flat disc. A machine in a factory uses a "write laser" to carve out certain patterns on the CD discs. The patterns are in the form of "pits" and "lands".

These "pits" and "lands" themselves do not represent "1" and "0" but rather a change from pit to land or land to pit is read as one, but no change is read as zero. The write laser as mentioned above is quite powerful and is used to write or "burn" information onto the CD's polycarbonate layer in the form of pits and burns.



Reading the CD is also a similar process. Another laser known as the "read laser" moves across the CD in a spiral fashion. The CD reader also includes a photo cell or a diode which detects light by changing its resistance based on the light received(for more information on photocells: http://www.instructables.com/id/Photocell-tutorial/). As the laser moves on the disc different readings emerge. When the laser encounters a land the light is reflected normally and the photocell receives the light and sends a signal to the microcontroller transmitting the binary digit "1". If a pit is encountered the light is scattered and no data is light is received by the photocell and hence it transmits the binary digit "0". Like this a series of  "1" and "0" are transmitted. This is later used by the computer.



CDs at first to a layman might seem as an ordinary electric component, but the brains,ingenuity, and precision must be applauded. Though CDs will cease to exist in another few years the spark they have created in the realm of storing massive digital data is worth recognising.