Energy-Mass Equivalence
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Transcript of Energy-Mass Equivalence
Energy-Mass Equivalence
Niels Bohr Max Planck Albert Einstein Modern Physics 20th &
21st century Louis de Broglie Werner Heisenberg Relativity
Energy-Mass Equivalence Uncertainty Quantum Mechanics E=mc2 In
nuclear reactions, energy can be converted into mass and mass into
energy. Fission: splitting an atom (WWII Bomb) Fusion: joining
atoms (how the sun makes energy) The Lorentz Factor Distances
(space) contracts by this factor as you approach the speed of
light. Graphing shows that doesnt grow much beyond 1 until you
reach about ___% of the speed of light Einstein applied the Lorentz
factor to time
Einstein applied the Lorentz factor to time. Thus, time _______s at
high speed and mass So if you try to get something up to light
speed, it just keeps getting heavier and harder to move. increases
Length Contraction Equation
Length contraction takes place only along the direction of motion.
Section 26.4 Another Verification of General Relativity
General Relativity predicts that a light ray passing near the Sun
should be deflected by the curved spacetime created by the Suns
mass. The prediction was confirmed by astronomers during a total
solar eclipse. Section 26.8 Black Holes * were theorized from
Einstein's theory of gravitation.
* General relativity says gravity bends light andwarps space and
time. * Black holes are old,very dense, dead starsthat attract like
so strongly that nothing can escape their pull, not even light. *
We think black holes may be at the center of many spinning
galaxies, sucking stars in. * Time itself is radically altered near
and in black holes. Thought Experiment Werner Heisenbergs
Uncertainty Principle
A thought experiment for viewing an electron with a powerful
microscope In order to see the electron, at least one photon must
bounce off it. During this interaction, momentum is transferred
from the photon to the electron. Therefore, the light that allows
you to accurately locate the electron changes the momentum of the
electron. Section 27.8 The Uncertainty Principle
Mathematically, It is physically impossible to measure
simultaneously the exact position and the exact linear momentum of
a particle. Physics admits there are some things we simply cannot
ever know, no matter what! Section 27.8 The Compton Effect Compton
saw that X-rayphotons collided with team particles in a cloud
chamber, knocked electrons off the water molecules. Photons acted
like particles in collisions. Energy and momentum were conserved.
Section 27.5 Louis de Broglie 1987 Found a way to describe
electrons as waves in 1924. postulated that because photonsalso
have wave and particle characteristics, perhaps all forms of matter
have both properties. Section 27.6 de Broglie Wavelength and
Frequency
The de Broglie wavelength of a particle is The frequency of matter
waves is Section 27.6 Electrons Orbit The circumference of the
electrons orbit must contain an integral number of de Broglie
wavelengths. 2 r = n N = 1, 2, 3, Section 28.3 Particle
accelerators have revealed that there are a LOT more particles
inside the atom than protons, neutrons and electrons The Standard
Model of Matter
Particle accelerators have revealed that there are a LOT more
particles inside the atom than protons, neutrons and electrons The
Large Hadron Collider (LHC) in Switzerlandis the most powerful
accelerator in the world.It went online in Smashing particles
together forces ousub-atomic particles we have never seen before.
The Standard Model of Matter