Big Bang Experiment(Particle accelerator)- key to understanding our universe

  Particle Accelerators – key to understanding our universe

Stephen Hawking says particle accelerators are the closest mankind got to time machine! What are these particle accelerators? How do they work? Why are they so important?

Particle accelerators as the name suggests are used to accelerate particles (such as protons, electrons), they basically increase speed of particles and collide them with desired targets under intent observation to unlock properties of universe and create states that were present moments after big bang.  The concept of accelerators were introduced in 1930s, cyclotron being the first and basic one. There are more than 30000 operating accelerators around the world.

How do they work?

Particle accelerators aka atom smashers vary in sizes, the smallest being 5 inches in diameter and largest being 27 kms in circumference. World’s largest atom smasher is the Large Hadron Collider (LHC), it is beneath the France–Switzerland border near Geneva, Switzerland, and the famous big bang experiment was done here. CERN is the European Organization for Nuclear Research which houses the LHC.

Working of LHC (an particle accelerator)

Hydrogen atoms are fed into source chamber of LHC and then stripped off their electrons, as a hydrogen atom has 1 electron and 1 proton; they are now ionized hydrogen or Protons. Protons as we know are positively charged and electric field is applied such that these protons are repelled and hence accelerate (gain speed).

In the 1^st stage these packets of protons are travelling in a linear accelerator and reaching 1/3^rd speed of light.

2^nd stage is a booster; it is a circular accelerator and is 167m in circumference. Packets of proton are divided into even smaller packets to increase intensity and are distributed among rings of circular accelerator. Powerful magnets are used to bend the beam of protons so as to circulate in the ring; protons reach 91.6% speed of light. All the divided packets are combined and flung into proton synchrotron.    

3^rd stage is proton synchrotron (it is a larger circular accelerator), it is 628m in circumference and protons reach to 99.9% speed of light here. A transition stage is reached as a proton cannot exceed speed of light as formulated by Einstein’s theory.

     E=MC² plays a vital role here- Energy supplied henceforth is converted into mass of proton, as a result they get heavier not faster, protons in synchrotron are 25 times heavier than a normal proton at rest.

4^th stage is a super proton synchrotron; it is a huge ring of 7kms in circumference. Soon injected protons will be at precisely desired velocity to launch them finally into orbit of the LHC

In LHC

It has a circumference of 27 kms and contains 2 vacuum pipes;. Packets of protons are systematically injected into these vacuum metal pipes in clockwise and anti-clockwise directions in order for them to collide at specified detector junctions. Protons finally have energy of 7000Tev (10¹²electron volt) of energy and 7000 times heavier than at rest. Magnetic fields needed to bend these high energy beams is enormous, it is however achieved by maintaining temperatures colder than outer space inside metal pipes of LHC, this cold temperature allows for superconductivity(no or least resistance). 4 detectors cabins are positioned to track the impact and elementary particles (quarks, gluons etc.) produced in these super high energy (more than 14000Tev) collisions. Detectors are connected to super computers to analyze the particle tracks and the observations made are anticipated to give us insight into birth of our universe. Particle accelerators are also used for hunt on ‘God Particle’ (Higgs boson)

Time Travel through accelerator as said by hawking:

This is a hypothetical situation and not anywhere close to reality (we are faced by many physical restrictions). Imagine injecting a human instead of particle accelerated to such high speeds. When our human is out of ring, he/she is going to look years younger than the rest of us cause of time dilation from special relativity. Similar effect on protons in accelerator and their time runs slowly than ours.   

Big Bang theory,Story of our universe!!

                                     STORY OF OUR UNIVERSE-BIG BANG

Theory rose from a basic question, where did our universe start? Did it just sprung into existence or is it a continuous timeline of existence without end or beginning?

Countless theories have been developed to explain this, big bang is most profound and it’s hence stood out. It gives an idea about the beginning of time.

Expanding Universe

Astronomer Edwin Hubble had observed movement of galaxies closer to ours over years, in 1929 conclusions drawn from these observations presented astounding results. His observations indicated red wavelength Doppler’s shift.

Doppler’s shift

 Sound produced by vehicle coming towards you is clearly heard, as it passes you and goes farther, and then the pitch drops, this is an example of Doppler Effect. As the source (being vehicle here) is moving and not stationary hence there is a change in transmitted and received wavelength. Basically when something is approaching towards observer its wavelength is shorter and has spectrum color of blue, when moves away from observer reflected wavelength has spectrum color of red. So when Hubble saw red Doppler shift it led to conclusion that galaxies are moving away from ours.

Back to expanding universe

Important thing to notice here is, galaxies on all sides of earth are moving away. If galaxies that are forward or backward of Milky Way alone are moving away, we can conclude that universe is moving in one particular direction, but here galaxies in all directions(that is all sides of milky way) are moving away from us at speed of light.

For a closer picture, consider this experiment

 Take a deflated balloon; mark 5 dots on it using marker/pen. Now, blow that balloon, you can notice that all dots  are moving away from each other, no matter which dot you take as reference and observe, you can see that other dots are moving away from it. There by concluding that the balloon is expanding uniformly in all directions. Apply same phenomena to expansion of our Universe, dots here are galaxies and balloon is the universe. Similarly it’s established that universe is expanding at the speed of light uniformly in all directions.

THE BIG BANG

Stephen Hawking thought what if we rewind this? Going back in time same way (contracting universe), universe has been expanding and now we go back in time to the point where it all existed in immensely hot (millions of degrees), extremely dense point which is a singularity (yes, the one in black holes).

Predictions say it took millionth of a millionth of a second for big bang to occur, this singularity’s density was too much to handle anymore and too hot as well, it burst out with a big “bang”, bang is from the expression used to describe sound produced in explosions, this is the biggest and most violent explosion in the history of universe.

Few seconds after big bang: 

Initially protons, electrons and neutrons were moving at such great speeds (due to very high temperatures) that they could overcome attractive forces, so no matter was formed. Within few seconds it cools down enough for nuclear forces to take over and form atoms. On cooling further over years, weak force such as gravity could also take over and lead to formation of planets, stars and galaxies.

E=MC² Energy mass conservation

It plays a vital role in explaining formation of matter from big bang theory, this blast had unimaginable amount of energy, which was converted into matter eventually as the temperature decreased.

Explosion of this magnitude sets of huge amount of radiation, and this radiation exists till today. In 1964 Arno Penzias and Robert Wilson accidentally picked unknown background radiation which is now called cosmic microwave background radiation (they won Nobel Prize for it in 1978) and it is proof of a consequence expected from big bang. We are exposed to this radiation everyday of our lives and it’s below harmful level and yet good enough for detection. This is most widely accepted story of our universe.