What are wormholes?

Wormholes

             A wormhole is a special solution to the equations describing Einstein's theory of general relativity. that connects two distant points in space or time via a tunnel. Ideally, the length of this tunnel is shorter than the distance between those two points, making the wormhole a kind of shortcut. 

            Though they are a staple of science fiction and have captured the popular imagination, wormholes are, as far as we know, only hypothetical. They are legitimate solutions to general relativity, but scientists have never figured out a way to maintain a stable wormhole in the real universe.

The Millimeter

The Millimeter

The millimeter or millimeter is a unit of length in the metric system, equal to one thousandth of a meter, which is the SI base unit of length. Therefore, there are one thousand millimeters in a meter. There are ten millimeters in a centimeter. One millimeter is equal to 1000 micrometers or 1000000 nanometers.

Electromagnetic Waves

 

Definition :

Electromagnetic waves or EM waves are waves that are created as a result of vibrations between an electric field and a magnetic field. In other words, EM waves are composed of oscillating magnetic and electric fields.

Properties of Wave Function

Properties of Wave Function

• All measurable information about the particle is available.
• 𝚿 should be continuous and single-valued.
• Using the Schrodinger equation, energy calculations becomes easy.
• Probability distribution in three dimensions is established using the wave function.
• The probability of finding a particle if it exists is 1.          Graphic image example    Wave Function 

Positron

 

Positron, also called positive electron, positively charged subatomic particle having the same mass and magnitude of charge as the electron and constituting the antiparticle of a negative electron

PIEZOELECTRIC EFFECT

PIEZOELECTRIC EFFECT

           If one pair of opposite faces of a quartz crystal is subjected to pressure, the other pair of opposite faces develop equal and opposite electric charges on them (Fig.). The Sign of the charges is reversed when the faces are subjected to tension instead of pressure. The electric charge developed is proportional to the amount of pressure or tension. This phenomenon is called Piezoelectric effect

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          The effect is reversible i.e., if an electric field is applied across one pair of faces of the crystal, contraction or expansion occurs across the other pair.

          When the two opposite faces of a quartz crystal, their faces being cut perpendicular to the optic axis, are subjected to alternating voltage, the other pair of opposite faces experiences stresses and strains. The quartz crystal will continuously contract and expand Elastic vibrations are set Up in the crystal.

          When the frequency of the alternating voltage 18 equal to the natural frequency of vibration of the crystal or its simple higher multiples, the crystal is thrown into resonant vibrations The amplitude' is large. These vibrations are longitudinal in nature.
         

         Consider a X-cut crystal plate of thickness t. The fundamental frequency of vibration is given by n=1/2t √E/P

E is the Young’s modulus and p is the density of the material of the crystal plate.

ULTRASONIC WAVES

DETECTION OF ULTRASONIC WAVES

Quartz crystal method :

This method is based on the principle of Piezoelectric effect. When one pair of opposite faces of a quartz crystal is exposed to the ultrasonic waves, the other pair of opposite faces develop opposite charges. These charges are amplified and detected using an electronic circuit.

Thermal detectors :

A platinum wire is placed in the region to be tested for ultrasonic waves. At nodes, due to alternate compressions and rarefactions, alternate heating and cooling is produced. Change in temperature at the node brings about changes in the electrical resistance of the platinum wire. This is detected by means of a Wheatstone’s bridge. No change in temperature occurs at the antinode.

Kundt’s tube method : 

If the wavelength of the ultrasonic waves is greater than a few millimeters, a Kundt’s tube can be used to form a stationary wave pattern with well defined nodes and antinodes. In the air or gas medium, lycopodium powder collects in the form of heaps at the nodes. In liquid medium, powdered coke is used to detect the position of nodes.

PROPERTIES OF ULTRASONIC WAVES

PROPERTIES OF ULTRASONIC WAVES

1. They have a high energy content.

2. lust like ordinary sound waves, ultrasonic waves get reflected, refracted and absorbed.

3. They show negligible diffraction due to their small wavelength. Hence they can be transmitted over long distances without any appreciable loss of energy.

4. They produce intense heating effect when passed through a substance.

5. If an arrangement is made to form stationary waves of ultrasounds in a liquid, it serves as a diffraction grating. It is called an acoustic grating.

Spontaneous Fission

Spontaneous Fission 

   Another type of radioactive decay is spontaneous fission. In this decay process, the nucleus will split into two nearly equal fragments and several free neutrons. A large amount of energy is also released. Most elements do not decay in this manner unless their mass number is greater than 230. 

                                                                                                                                                                                            
                                                     

                                                          Spontaneous Fission 

    The stray neutrons released by a spontaneous fission can prematurely initiate a chain reaction. This means that the assembly time to reach a critical mass has to be less than the rate of spontaneous fission. Scientists have to consider the spontaneous fission rate of each material when designing nuclear weapons.

 
   For example, the spontaneous fission rate of plutonium 239 is about 300 times larger than that of uranium 235. This forced scientists working on the Manhattan Project to abandon work on a gun-type design that used plutonium. 

Gamma Rays

Gamma Rays 

    Gamma rays are a type of electromagnetic radiation that results from a redistribution of electric charge within a nucleus. Gamma rays are essentially very energetic X rays ; the distinction between the two is not based on their intrinsic nature but rather on their origins. X rays areemitted during atomic processes involving energetic electrons. Gamma radiation is emitted by excited nuclei or other processes involving subatomic particles; it often accompanies alpha or beta radiation, as a nucleus emitting those particles may be left in an excited (higher-energy) state.

      Gamma rays are more penetrating than either alpha or beta radiation, but less ionizing. Gamma rays from nuclear fallout would probably cause the largest number of casualties in the event of the use of nuclear weapons in a nuclear war. They produce damage similar to that caused by X-rays such as burns, cancer, and genetic mutations.