The Story of Physics

The Story of Physics

If you want a brief history of physics (hopefully in animated form) then you have come to the right place.

Basic of Particle Physics & Higgs Boson

Basic of Particle Physics & Higgs Boson

More than 2000 years we believe that the fundamental part of all the matter is the atom. Atom consist of Protons, Neutrons which made nucleus and electron orbiting around it.

But according to the quantum mechanics even proton and neutrons can be breakable i.e. it is not fundamental particles. QM suggests that Proton and neutrons are made up of Quarks.Electron is fundamental particles and its one type of leptons.

And according to the string theory all the point like particle i.e. quarks, leptons (see fundamental particles) are made up of tiny vibrating strings. These strings vibrates at different frequency makes different particles. Imagine playing guitar and vibrating the strings.

What is Particle?

infact all the particles is the excitation in the field i.e. when the EM field is "excited," meaning its energy is flared up in a certain spot, that flare-up is, itself, a photon.

Recently discovered Higgs Boson (named after Physicist Peter Higgs) particle is also the excitation in the Higgs Field. infact we cannot see the higgs boson we actually excite the Higgs field by colliding the two protons (fancy name Hadrons) in LHC (Large Hadron Collider) at the speed of light and which generates enough energy to excite the Higgs field.

Higgs Boson is the important discovery without it every particle moves at the speed of light so no molecules,no atom,no stars,no planets,no galaxy even the no universe exist.because of the Higgs field the particle gets its mass.the particle which interacts more with the field is heavier than that which interacts less.photon doesn't interact with the field at all so it is mass less.

top quark interact more with field that's why its is heavy particle.(see below)

Standard Model of Particle

to be continued...

Cosmic Microwave Background Radiation

Cosmic Microwave Background Radiation

Ever notice that when we tune the analog Television between the two channel we see white snow noise on the screen.it is coming from the radiation/EM Wave (1%) left over from the BIG BANG. Today, we call it Cosmic Microwave Background Radiation.

The discovery of the cosmic microwave background (CMB) in the early 1960's was powerful confirmation of the Big Bang theory.

When the CMB was initially emitted (about 300,000 years after THE BIG BANG) it was not in the form of microwaves at all, but mostly visible and ultraviolet light. Over the past few billion years, the expansion of the universe has redshifted this radiation toward longer and longer wavelengths, until today it appears in the microwave band.

Today wherever we see in all direction the temperature is extremely uniform all over the sky.The CMB is remarkable in that no matter which direction in the sky you look, it appears to be almost the same temperature.i.e. 2.7 Kelvin. This is called isotropy.

pixel in the map above corresponds to the pixel temperature. It seems to be a perfectly uniform temperature distribution in the radiation field. However, the fact that we see galaxies and stars in the sky today tells us that there must have been some "clumpiness" in the matter distribution in very early times. This uneven matter distribution should have left an imprint on the radiation distribution of the time. Thus, we should see tiny irregularities in the CMB today which represent these ancient matter inhomogeneities.

Another set of instruments on the COBE satellite were designed to look for these irregularities in the CMB; they were called the Differential Microwave Radiometers. If there were to be irregularities in the CMB, they could be seen as tiny hot and cold variations on the sky. In 1992, the COBE research team announced that it had evidence that these hot and cold spots did exist, and they released the map below.

 However, tiny temperature variations or fluctuations (at the part per million level) can offer great insight into the origin, evolution, and content of the universe. The temperature variations in the CMB are very, very small, and the CMB is uniform up to about 1 part in 100,000. So the variances in temperature have a range of 2.7K ± 0.00003. If you were to just look at the CMB, it would look entirely uniform, but scientists have enhanced these small perturbations in the CMB so that you can see them in the map

Comparision of COBE,WMAP,PLANCK Sensitivity

This CMB image is a picture of the last scattering epoch, i.e. it is an image of the moment when matter and photons decoupled, literally an image of the recombination wall. This is the last barrier to our observations about the early Universe, where the early epochs behind this barrier are not visible to us.

                                   Below is the Latest Release From Planck Satellite by European Space Agency.

The clumpness of the CMB image is due to fluctuations in temperature of the CMB photons. Changes in temperature are due to changes in density of the gas at the moment of recombination (higher densities equal higher temperatures). Since these photons are coming to us from the last scattering epoch, they represent fluctuations in density at that time.

The origin of these fluctuations are primordial quantum fluctuations from the very earliest moments that are echo'ed in the CMB at recombination. Currently, we believe that these quantum fluctuations grew to greater than galaxy-size during the inflation epoch, and are the source of structure in the Universe.

also visit below site:-
http://www.bigbangregistry.com/panojs3/exploreMap.php#navbar

Time Dilation and GPS

From Einstein’s theory of relativity Time slow down at the massive body. Clock on the earth runs slower than the one beyond the earth (in space). This is called Time Dilation.

Let’s understand this in simple way.as we know that when we throw a ball towards the sky ball continuously moves up until it lose its energy and then starts to fall because gravity slows it down .

Similarly, for example when high energy light (blue shifted-high frequency) is emitted from the earth towards the on board astronauts, the high energy photons (lights is EM wave) loses its energy when climbing up as gravity slows it down and appears to astronaut as red shifted-low frequency.

Also the same when red shifted light emitted from on board astronauts gravity pull it down and appears to people on earth blue shifted.

So, the Astronaut’s point of view they see that everything on the earth takes longer (low frequency light reaches to them) also i.e. clock runs slower on earth.

While the people on earth see that everything on board appears faster (high frequency light reaches to them) also i.e. clock run faster in space.

We also need to consider this time dilation in GPS System otherwise the users may mislead by wrong coordinates or the difference is in kilometers. That’s why engineers offset the atomic clock by some amount before launch it in space to synchronize the time i.e. suppose time dilation is of 1 sec that they set 00 on earth clock and 01 on space clock.

The same concept is also true for any biological events like two twins one on earth and other in space. The twins in space looks younger than that on earth even spending the same time.

Note :- here also think where does lost energy go ?? cause energy should be somewhere and must follow the 1st law of thermodynamics.

Hawking Paradox

Cosmic Distance Ladder

Cosmic Distance Ladder

while observing the sky last night one question come in my mind how astronomers calculates the distance to the stars,galaxies.i know that they use the technique by transmitting and receiving the pulse from a radar but for a very large distance the EM waves itself takes years to receive back the signal pulse.

so,i come across the CDL. Cosmic Distance Ladder is series of methods that astronomers use to determine the distance to celestial object.

There are different types of methods depending on location of the celestial object.(below diagram) 

for the solar system and nearby stars we can use the radar and parallax techniques.but for very large distance beyond the milkyway and above we can't use this techniques.because transmitting a pulse to a very large distance and receiving it back takes a long time i.e hours,months,years (cause speed of light is constant).

here i discuss Type Ia Supernova Technique.

To find distances in space, astronomers use objects called "standard candles." Standard candles are objects that give a certain, known amount of light. Because astronomers know how bright these objects truly are, they can measure their distance from us by analyzing how dim they appear.

say you're standing on a street evenly lined with lampposts. According to a formula known as the inverse square law, the second streetlamp will look one-fourth as bright as the first streetlamp, and the third streetlamp will look one-ninth as bright as the first streetlamp, and so on. By judging the dimness of their light, you can easily guess how far away the streetlamps are as they stretch into the distance.

so how can we put the standard candle whose luminosity is known and look it from earth to calculate the distance.well here comes supernova.

Supernovae are extremely luminous and cause a burst of radiation that often briefly outshines an entire galaxy, before fading from view over several weeks or months. During this short interval a supernova can radiate as much energy as the Sun is expected to emit over its entire life span. The explosion expels much or all of a star's material.

below pictures shows the sn2011fe supernova explosion in The Pinwheel Galaxy (also known as Messier 101, M101 or NGC 5457)

The luminosity differs by the type of supernova but the typical visual Absolute Magnitude of Type Ia supernovae is Mv = −19.3 (about 5 billion times brighter than the Sun).

so we know the absolute luminosity (standard candle like street lights in our analogy) and by using the inverse square law we can find out the distance of the galaxies in which Type Ia supernova occurred.

also watch this for parallax technique.

sources :- Wikipedia,Hubblesite,Skynet University Channel youtube