Higgs Field

 When you step on a scale and look down at the number that shows up, what that number is telling you is how much force the mass of your body exerts on the ground. It's simple Newtonian mechanics. Force equals mass times acceleration. Gravity exerts the acceleration on the mass of your body, which creates a force. That's your weight. So weight is probably easy enough to understand, but mass is a little more nebulous. If you were floating in space, far away from Earth, you would essentially have no weight. But you would still have the same mass as you did standing on that scale. Where does the mass of your body come from? Well, the mass comes from all the atoms in your body that individually have a mass. Where does an atom's mass come from? Well, this is interesting because the mass of atoms at its core is really energy. In fact, all mass is energy. This is exemplified in Einstein's famous mass energy equivalence equation E equals mc squared.

 Massis interchangeable with energy, andthe constant c squared, or speed of light squared, is the conversion factor. So where is the energy of the atom coming from? Well, 99 % of the mass of an atom is contained in the binding energy within the nucleus. This energy is a result of one of the four fundamental forces of nature, called the strong force, which keeps the protons and neutrons glued together in the nucleus of atoms. That's where most of your body's so -called mass resides.

But it turns out that some of your mass, about 1%, is contained in the mass of the subatomic particles that make up the atoms. These are the electrons that form a cloud around the nucleus, as well as the quarks that make up the protons and neutrons. So now the question is, how did these subatomic particles have an intrinsic mass? If mass is energy, then what is the mechanism that confers this energy to these fundamental particles? This is where the Higgs field comes into the picture.

 This field is everywhere in space -time, but most explanations of how this field confers mass can't avoid getting highly technical, talking about symmetry breaking and other advanced mathematical concepts. In this video, I'm going to attempt to explain how the Higgs field confers mass in an intuitive way. So whether you're a math geek or not, you will hopefully get a very good intuitive understanding of what's really going on. That's coming up, right now. I've been wanting to make this video for a while, and I think you're going to find it really interesting. Before we get into it though, I want to thank our sponsor Blinkist that helped make this video possible. This is the one app that saves me more time than any other. Now, as you might suspect, I'm a voracious reader. Blinkist gives me access to over 5 ,500 non -fiction books and podcasts that I can read or listen to in only about 15 minutes. Now, it's not a replacement for reading the whole book, but it allows me to understand the most important things from them.

For example, I just finished listening to a book called The Latte Factor. It's about how making small changes in your life can result in huge outcomes over time, like drinking less latte. What I learned is how life is really a series of baby steps that may not have an immediate payoff, but over time can help you achieve big goals. And my goal this year is to improve my mental and physical health. Blinkist will help me reach that goal, and it can do the same for you. Whatever you want to achieve for yourself is available to you at Blinkist. Right now, Arvin Ash viewers get a whopping 30 % off your subscription, and you can enjoy two memberships for the price of one in a new feature called Blinkist Connect. This allows you to recommend and share your favorite titles with a friend or loved one. Your first 7 days is absolutely free. When you sign up, I highly recommend you click the link in the description. I think you'll be very impressed. Now, where were we? To understand how the Higgs field works, we have to first understand what our best theory describing all the matter in the universe, the standard model of particle physics, is trying to tell us.

 This theory describes all fundamental particles in the universe as excitations in quantum fields. So for example, an excitation of the electromagnetic field would be a photon. An excitation of the electron field is an electron. And an excitation of the quark field would be a quark, etc. These are waves, but when they are well localized as in a measurement, they appear to us as particles. These fields span all of space -time in all directions. The animation you're seeing here is a 2D representation for visualization, but the fields would be in three dimensions. Every type of matter and force particle has its own field. So all the fundamental particles of the standard model would be represented by different fields. All these fields, when they are in their ground state, that is their lowest energy state, even when no excitations or particles are present, always have some vibration. Due to the Heisenberg uncertainty principle, particles are constantly being created and annihilated.

These are virtual particles that exist for such short periods of time that they cannot be measured. They borrow energy from the vacuum when they are created and give it right back very quickly when they are annihilated. But this flurry of energetic activity for each field collectively adds up to zero net real particles. Real particles are created only when enough energy is transferred to these fields from some other field to cause an excitation.

 These excitations are the real particles. And since these are quantized fields, any excitation occurs only in set quantities. So for example, an excitation of the electron field would have to occur in integer multiples of 0 .511 MeV, which is the mass of one electron. So the field can have energy of 1 .022 MeV, which would be the energy of two electrons, or any other multiple of 0 .511, but not for example 0 .7 MeV, which would not be an integer multiple of 0 .511. But the electron only has this intrinsic mass of 0 .511 MeV because of its interaction with the Higgs field. Without this interaction, an electron would be massless. It would have energy, but only in the form of momentum, just like photons. This massless electron would be like a charged photon and move at the speed of light.

 In fact, without the Higgs field, all the other fundamental particles of the standard model would also be massless, with the possible exception of neutrinos. So the question is, how does this mass come about? To answer this, we have to understand the concept of vacuum expectation value of the various fields. What does this mean? Let's imagine for a minute, as if there were no Higgs field. If we then took any of the fields and put them inside an empty box, like the electron field, and if we then weighed that box, we would find that box would have no weight. In other words, the field would have no mass, even though the virtual electrons would be present throughout it. Similarly, all the other fields of the standard model would also have no mass inside the empty box, just quantum fluctuations. But here's the big kicker. There's an exception to this rule. The Higgs field. It's unique because the Higgs field in empty space, unlike every other field, has a net positive mass. Its mass is not zero in empty space. If we were to weigh the box with the Higgs field inside, it would have a weight. The Higgs field in empty space has a mass. This is called the vacuum energy. A more technical term for this is the vacuum expectation value, VEV, of the Higgs field. It is non -zero. It is in fact 246 Giga electron volts, or GeV. This is just the value that we would expect the Higgs field to have when it is in its vacuum state, or in its lowest energy state. Now, as I stated earlier, quantum fields can interact with each other. What this basically means is that anything that interacts with the Higgs field now effectively interacts with this new vacuum expectation value. And that interaction means energy.

And since energy and mass are equivalent, the form this interaction energy takes is indistinguishable from the form of energy associated with a rest mass. So when a fundamental particle interacts with the Higgs field, it gains an energy, or intrinsic mass. Without the Higgs field, forexample, the electron would be massless, like photons, and travel at the speed of light. However, since the electron is coupled to a field with positive value everywhere in the universe, individual electrons are constantly interacting with this Higgs field. This constant interaction effectively slows the electron down. So if you apply a force to an electron, youcan imagine a sort of pushback from the Higgs field that causes the electron to resist acceleration. This property is what we call inertial mass. The electron's behavior in the vacuum is that of a particle with a well -defined rest mass of 0 .511 MeV.

 This rest mass is determined by the strength of the coupling, or interaction, between the electron and the Higgs vacuum expectation value. It's like the mass of the Higgs field is shared with any other field that interacts with it. How much mass an excitation or particle in any given field has depends on its coupling constant. The fields of all massive particles are coupled to the Higgs to some degree.

 The larger this coupling is, the more mass its particles will have. Without the Higgs field, none of the other particles would have an intrinsic mass. The Higgs field is like a thick gravy, and if you try to run a spoon through it, it feels heavy, compared to moving the spoon through the air. So every elementary particle with mass interacts with this gravy in some way. The particles of the Standard Model that have mass such as electrons, quarks, and W and Z bosons are coupled to the Higgs field. While the fields of massless particles, like photons and gluons, are not. So why are some particles coupled, meaning why do some particles interact with the Higgs field, while others do not? We're not sure. This just appears to be the way the universe works. The photon happens to be one of the particles that does not interact with the Higgs field, and so it remains massless and moves at the speed of light.

 The mechanism of the Higgs field giving out mass to other particles is called symmetry breaking. This is a complex subject, but if you want to know more about symmetry breaking, I made a video about it right up here. Now I should add a note about neutrinos. The Standard Model predicts that they should be massless, but measurements seem to indicate that they do have a very tiny mass. We don't know the origin of this mass. It could be that they also interact with the Higgs, but no one really knows for sure.

 Now I want to reiterate what I said at the beginning. The Higgs field is only responsible for about 1 % of the mass of all the matter in the universe that we can see. The vast majority of this mass is due to the energy of the strong force, which keeps the nuclei of atoms tightly glued together. Yet, this 1 % is essential to have the kind of universe we have. In a simple hydrogen atom, for example, the radius of the electron's orbit is inversely proportional to its mass. In a universe with no Higgs field, a massless electron would have an infinite radius, meaning no atoms would form at all. In addition, differences in particle mass are also responsible for the decay of free neutrons to protons. This is called beta decay. Without the Higgs field, the universe may not have any protons at all. So this tiny 1 % mass contribution turns out to be responsible for 100 % of the universe we happen to have.

9th Class || Short Questions/Answers of chapter 8

Why metallic handle of a door is colder than the wood of the same door when touched?

Because, the transfer of heat from our hand to the metallic handle is faster, as compared to wood, thus loosing more thermal energy resulting in our hand feeling colder.

Which type of the clothes do the people of desert wear and why?

The people of the desert wear loose-fitting, long, heavy robes, and head wrappings. 

The loose-fitting cloth prevents sweat from evaporating quickly and allows the air to circulate, hence help the body to retain fluids. These clothes also protect people living in deserts from hot winds and dust storms.

Why does temperature of sea shore cities remain moderate during most of the year?does temperature of land areas vary more during winters and summers? Why

Water has a higher heat capacity than soil and rock, so the ocean takes much longer to heat and to cool than the land. Coastal areas will generally have more moderate temperatures than in land areas because of the heat capacity of the ocean. 

Warm ocean currents tend to raise winter temperatures, while cool currents can lower summer temperatures. Prevailing winds also affect world temperatures. The difference in temperature between the land and the sea in different seasons determines the temperature of the prevailing wind.

During the process of sweating (perspiration), we feel cooling during a hot day. Why? 

That's because cooling your body via sweating relies on a principle of physics called "heat of vaporization." It takes energy to evaporate sweat off of your skin, and that energy is heat. As your excess body heat is used to convert beads of sweat into vapor, you start to cool down.

How a bimetallic strip, made up of copper and iron is used as automatic switch in different devices? Give one example.

Thermal expansion of bimetallic strips used as a heat operated switch in the circuit of automatic equipment's like iron box, fire alarms, electric heater etc. Some thermometers work on the principle of expansion of liquids In automobile engines useful work is done by the expansion of gases. 

How is anomaly in the expansion of water help marine life to survive in extremely cold areas?

The anomalous expansion of water helps preserve aquatic life during very cold weather. When temperature falls, the top layer of water in a pond contracts, becomes denser and sinks to the bottom. A circulation is thus set up until the entire water in the pond reaches its maximum density at 4°C.

Examples of anomalous expansion of water

Bottle Burst: If you put a fully-filled water bottle in the refrigerator and its temperature is below 4 degrees Celsius, then according to the anomalous behavior of water, the water inside the bottle will expand. Therefore, due to no space in the bottle for the expansion of water molecules, water will exert force on the walls of the bottle and it will burst.

Breaking of Rocks: Rocks break during winter because as the temperature decreases below, water inside the rocks starts expanding and hence exert a large amount of force on the rocks and results in the breaking of rocks. 

Aquatic Life: This unique property of water helps aquatic life to survive. With a further drop in temperature, water on top forms ice and becomes a bad conductor of heat. This stops the heat from escaping the water body and helps aquatic life to survive. Hence, aquatic life can survive even when the temperature reaches or falls below. 

Why rollers are used at the ends of steel bridges?

One end of girder is fixed in concrete, but the other end is not fixed into concrete. It is supported on rollers. This is because when temperature increases in summer, the steel girder in a bridge expands and the rollers slide to allow the expansion otherwise the bridge may break. 

MCQs QUESTIONS Chapter 8

1. Temperature is equal to of substance.

A. Average K.E. of molecules

B. Individual K.E. of each molecule

C. Average P.E of molecules

D. Individual P.E. of each molecule

2. Boiling point of water is.

A. 212 °C

B. 212 °F

C. 100 K

D.373 °C

3. J/kg K is the unit of:

A. Specific Heat Capacity

B. Heat Capacity

C. Latent Heat of Fusion

D. Heat Energy

4. At temperature, water has maximum density?

A. 0 °C

B. -4 °C

C. -273 K

D. 4°C

5. Evaporation takes place from of liquid.

A. Surface

B. Bottom

C. center

D. any location

6. Number of divisions on Fahrenheit scale between its reference points are:

A. 100

B. 173

C. 212

D. 180

7. By adding heat at melting point, the temperature of substance does not change. Heat added to substance is used to of substance.

A. increase K.E. of particles

B. decrease K.E. of particles

C. increase the attraction between particles

D. decrease the attraction between particles

8. 336 J/g is latent heat of fusion of a material. How much heat is required to melt 10 g of material at its melting point?

A. 336J

B. 3360 J

C. 33600 J

D. 3.36× 1051

9. Substances with their specific heats are given below. Which of the following substances will cool down quickly if heated for same temperature?

A. Water (4200 J/kg K)

B. Wood (1700)/kg K)

C. Copper (400 J/kg K)

D. Silver (250)/kg K)

MULTIPLE CHOICE QUESTIONS || Thermal Properties of Matter

1. All the bodies expand on heating:

a) Variable

b) Constantly

c) Uniformly

d) All of them:

2. Temperature is the:

a) Mass contained by the body

b) Force of the molecules of body

c) Degree of hotness or coldness of the body 

d) none of above

3. The SI unit of temperature is:

a) °C

b) °F

c) K

d) °K

4. Temperature of 30 °C in Fahrenheit is:

a) 86 °F

b) 80 °F

c) 30 °F

d) 90 °F

5. Human normal body temperature of 37 °C in Fahrenheit is:

a) 98. 6 °F

b) 98 °F

c) 100 °F

d) None of above

6. Boiling point of water in Fahrenheit is:

a) 100 °F

b) 273 °F

c) 212 °F

d) 373 °F

7. Celsius equivalent of O K is:

a) -273 °C

b) -459.4 °C

c) 0 °C

d) 100 °C

8. Fahrenheit equivalent of OK is: 

a) -273 "F 

b) -459.4 °F

c) 0 °F

d) 100 °F

9. Heat is a type of energy: 

a) Kinetic

b) Potential 

c) Mechanical 

d) None of above

10. Linear expansion of a rod occur along- dimension(s):

a) One

b) Two

c) Three

d) All

11. The acteristic of unequal expansion of different metals is employed in a device known as:

a) Thermometer

b) Burner

c) Calorimeter

d) Thermostat

12. Linear expansion depends on:

a) Length of rod

b) Change in temperature 

c) Nature of material of rod

d) All of above

13. Thermostat works on the principle of: 

a) Unequal expansion of solids

c) Anomalous expansion of water

b) Pascal's law

d) Vaporization

Change of State

 Matter can be changed from one state to another. For such a change to occur, thermal energy is added to or removed from a substance.

Take a beaker and place it over a stand. Put small pieces of ice in the beaker and suspend a thermometer in the beaker to measure the temperature of ice. 

Now place a burner under the beaker. The ice will start melting. The temperature of the mixture containing ice and water will not increase above 0°C until all the ice melts and we get water at 0°C. If this water at 0°C is further heated, its temperature will begin to increase above 0 °C as shown by the graph in figure.

Part AB: On this portion of the curve, the temperature of ice increases from -30 °C to 0 °C.

Part BC: When the temperature of ice reaches 0 °C, the ice water mixture remains at this temperature until all the ice melts.

Part CD: The temperature of the substance gradually increases from 0 °C to 100 °C. The amount of energy so added is used up in increasing the temperature of water.

Part DE: At 100 °C water begins to boil and changes into steam. The temperature remains 100 °C till all the water changes into steam.

MDCAT Preparatory questions of Chapter 4 Work and Energy

A truck and a car are moving with equal velocity. On applying brakes, both will stop after a certain distance, then?

A. Truck will cover less distance before stopping 

B. Car will cover less distance before stopping

C. Both will cover equal distance

D. None of the mentioned 

What sort of energy does flying bird possess?

A. Potential energy

B. Kinetic energy

C. Both potential and kinetic energy 

D. Both potential and kinetic energy

When the velocity of an aero plane is doubled, the momentum

A. Remains unchanged 

B. Is conserved

C. Becomes zero

D. Increases uniformly

A machine gun fires 60 bullets per minute, with a velocity of 700m/s. If each bullet has a mass of 50g, find the power developed by the gun.

A. 1225W 

B. 12250W

C. 122.5W

D. 122W

A bullet fired from a gun can pierce a target due to its

A. Mechanical energy 

B. Heat energy

C. Kinetic energy

D. Acceleration

Kinetic energy with any reference must be

A. Zero

B. Positive

C. Negative

D. Either negative or positive 

At what angle work done will be maximum?

A. 0°

B. 45°

C. 90°

D. 30°

Which one of the following is a greater work? 

A. +100 J

B. -1000 J

C. -100 J

D. +200 J

Work done will be zero if angle between Force and displacement is:

A. 0°

B. 270°

C. 60°

D. 360°

A force 2i+j has moved its point of application from (2,3) to (6,5). What is work done?

A.-10

B.-18

C. +10

D. +18

At what angle the work done will be half of its maximum value

A. 0°

B. 300°

C. 45°

D. 60°

A man pushes a wall with 50 (N) and it displaces it zero (m), his work is

A. Negative

B. No work

C. Positive

D. May all possible

If a mass of 5 Kg is lifted upto 5m height, what will be the work done against the gravitational field

A. 245 J

B. 25 J

C. 49 J

D. 98 J

A person walks 2 m with an acceleration of 5 ms^-2, holding an object of mass 2 kg. The net work done on the object is

A. 20 J

B. 10 J

C. 5 J

D. 0 J

A force of 3i+2j+4k N gives displacement of 10j m. The work done is 

A. 20 J

B. 26 J

C. 32 J

D. Zero

A body travels displacement of 10 m by force of 5 N If work done is 25 J then angle between F and d is

A. 0°

B. 450°

C. 30°

D. 60°

A person holds a bucket of weight 60 N. He walks 7 m along the horizontal path and then climbs up a vertical distance of 5 m. The work done by the gravity is:

A. 300 N-m

B. 720 N-m

C. 420 N-m

D. None of these

If force and displacement of particle in direction of force are doubled. Work would be 

A. Double  

B. 1/4 times 

C. Half

D. 4 times

A person is holding a bucket by applying a force of 10N. He moves a horizontal distance of 5m and then climbs up a vertical distance of 10m. Find the total work done by him? 

A. 50J  

B. 100J 

C. 150J

D. 2003

A gardener pushes a lawn roller through a distance of 20m. If he applies a force of 20kg weight in a direction inclined at 60° to the ground, find the work done by him. (g = 9.8m/s²)

A. 400J

B. 250J

C. 1960J

D. 2514J

If velocity is double, then

A. Momentum increase 4 times and K.E increases 2 times

B. Momentum increases 2 times and K.E increase constant

C. Momentum and K.E remain same 

D. Momentum increases 2 times and K.E increases 4 times

What will be the ratio of kinetic energies of alpha particle and proton if their linear momentum will be same?

A. 18:1

B. 4:1

C. 1:4 

D. 104: 1

The Bodies of one kg and four kg have same kinetic energy. The ratio in their momenta will be

A. 1:2

B. 1:4

C. 1:16

D. 1:1

The velocity and momentum of a moving body are 10,000 cm-s^-1 and 10,000 g cm-s^-1 respectively. The K.E will be

A. 5 × 10s⁷ J

B. 5×10 J

C. 5 x 10s² J

D. 5X10° J

If momentum of a moving object is doubled then its kinetic energy will be

A. Doubled

B. Four times 

C. Halved

D. Same

The momentum and kinetic energy of a ball is numerically equal. The numerical value of velocity is

A. 1 m/s

B. 3 m/s

C. 2 m/s

D. 4 m/s

Kinetic energy of a body moving with speed of 10 ms^-1 is 30 J. If its speed becomes 30 m/s its K.E will be

A. 10 J

B. 90 J

C. 180 J

D. 270 J

Car X is traveling at half the speed of car Y. Car X has twice mass of car Y. Which statement is correct?

A. Car X has half the kinetic energy of car Y 

B. Car X has twice the kinetic energy of car Y

C. Car X has one quarter of the kinetic energy of car Y 

D. The two cars have the same kinetic energy

A ball of mass 2 kg and another of mass 4 kg are dropped together from a 60 feet tall building. After a fall of 30 feet each towards earth, their respective kinetic energies will be in the ratio of:

A. √2:1

B. 1:2

C. 1:4

D. 1:√2

A bomb of mass 30 kg at rest explodes into two pieces of masses 18 kg and 12 kg. The velocity of 18 kg mass is 6 m s'. The K.E of other mass is

A. 324 J 

B. 256 J 

C. 486 J

D. 524 J

The kinetic energy acquired by a body of mass m is travelling some distance s, starting from rest under the actions of a constant force, is directly proportional to

A. m⁰ 

B. m

C. m²

D. m^1/2

When force and displacement are in the same direction, the kinetic energy of the body 

A. Increases

B. Remains constant

C. Decreases

D. Becomes zero

A truck and a car are moving with equal velocity. On applying brakes, both will stop after a certain distance, then?

A. Truck will cover less distance before stopping 

B. Both will cover equal distance

C. Car will cover less distance before stopping

D. None of the mentioned

Potential energy per unit volume is given by

A. mgh 

B. gh

C. mgh/ρ

D. ρgh 

A body is falling from a height h. After it has fallen a height h/2, it will possess

A. Only potential energy 

B. Half potential and half kinetic energy 

C. Only kinetic energy

D. More kinetic and less potential energy

Energy stored in the spring of watch is

A. Electrical energy

B. potential energy

C. Kinetic energy

D. Elastic potential energy

A stone is thrown up from the surface of earth when it reaches at maximum height. Its total energy is equal to

A. mgh

B. 1/2mv²

C. Zero

D. 2 mgh

Energy consumed by 60-watt bulb in 2 minutes is equal to

A. 7.2 kilo joules

B. 120 joules

C. 720

 D. 72000 joules

The consumption of energy by 60-watt bulb in 2 seconds is:

A. 201

C. 120 J

B. 30J

D. 0.02 J