SPACETIME
VISHWAS SHUKLA
DAYALBAGH EDUCATIONAL INSTITUTE
JAN, 29 2016
OVERVIEW OF PRESENTATION:
MAXWELLS’S EQUATIONS
LORENTZ
TRANSFORMATIONS
MINKOWSKI SPACETIME
DIAGRAM
VISUALIZATION OF SPACE
TIME
APPLICATIONS
“
When you are courting a nice girl an hour seems like a second.When you sit on a
red-hot cinder a second seems like an hour. That’s relativity. -Albert Einstein
Relativity challenges your basic intutions that you’ve built up from everyday
experience.It says your experience of time is not what you think it is, that time is
malleable.Your experience of space is not what you think it is: it can stretch and
shrink. -Brian Greene
Einstein,in the special theory of relativity, proved that different obsevers, in
different states of motion, see different realities. -Leonard Susskind
No person can escape Einsteinian relativity, and no soldier or veteran can
escape the trauma of war’s discolation. -Thomas Cochrane
QUOTATIONS
MAXWELL’S EQUATIONS:A CONTRADICTION
Old Galilean view of space and time work to explain this?
WAVE EQUATION
• Light is an electromagnetic wave and
travels with speed c=3*10^8m/s
Any such beam of any kind of particles generated at the speed of light by a moving
observer would be received by a stationary observer at that same speed – regardless of
how fast the two observers were moving relative to one another.
▹ MAXWELLS’
S
EQUATIONS
▹ LORENTZ
TRANSFOR
MATIONS
▹ MINKOWSKI
SPACETIME
DIAGRAM
▹ VISUALISATI
ON OF
SPACE TIME
▹ APPLICATIO
NS
RESEARCH PAPER ON SPECIAL RELATIVITY BY EINSTEIN
)(
)(
2
x
c
v
tt
zz
yy
vtxx






tt
zz
yy
vtxx




In Galilean relativity In Special relativity
Lorentz
transformations
LORENTZ TRANSFORMATIONS : A SOLUTION
Assumptions:
• Speed of light in vacuum remains same to every inertial observer regardless of the
motion of the source .
• Laws of physics hold in all inertial frames.
▹ MAXWELLS’
S
EQUATIONS
▹ LORENTZ
TRANSFOR
MATIONS
▹ MINKOWSKI
SPACETIME
DIAGRAM
▹ VISUALISATI
ON OF
SPACE TIME
▹ APPLICATIO
NS
LORENTZ TRANSFORMATIONS : CONCLUSIONS
1.TIME DILATION
The faster you move ,the slower you would get.
▹ MAXWELLS’
S
EQUATIONS
▹ LORENTZ
TRANSFOR
MATIONS
▹ MINKOWSKI
SPACETIME
DIAGRAM
▹ VISUALISATI
ON OF
SPACE TIME
▹ APPLICATIO
NS
LORENTZ TRANSFORMATIONS : CONCLUSIONS
2.LENGTH CONTRACTION
PROPER LENGTH
v = 10% c
v = 80% c
v = 99% c
WARNING : No contraction among perpendicular directions
▹ MAXWELLS’
S
EQUATIONS
▹ LORENTZ
TRANSFOR
MATIONS
▹ MINKOWSKI
SPACETIME
DIAGRAM
▹ VISUALISATI
ON OF
SPACE TIME
▹ APPLICATIO
NS
SPACETIME: MINKOWSKI DIAGRAMS
Spacetime diagrams were first used by H. Minkowski in 1908 and are
often called Minkowski diagrams. Paths in Minkowski spacetime are
called worldlines.
If we consider two events, we can determine the quantity Δs2 between the two
events, and we find that it is invariant in any inertial frame. The quantity Δs is
known as the spacetime interval between two events.
Considering space and time together and taking into account that the speed of light must be
constant in any frame, we find that the new line element to satisfy such conditions is
ds2
= −𝑐2
d𝑡2
+ dx2
+ dy2
+ dz2
▹ MAXWELLS’
S
EQUATIONS
▹ LORENTZ
TRANSFOR
MATIONS
▹ MINKOWSKI
SPACETIME
DIAGRAM
▹ VISUALISATI
ON OF
SPACE TIME
▹ APPLICATIO
NS
SPACETIME: MINKOWSKI DIAGRAMS
There are three possibilities for the invariant quantity Δs2:
1. Δs2 = 0: Δx2 = c2 Δt2, and the two events can be connected only
by a light signal. The events are said to have a lightlike separation.
2. Δs2 > 0: Δx2 > c2 Δt2, and no signal can travel fast enough to
connect the two events. The events are not causally connected and
are said to have a spacelike separation.
3. Δs2 < 0: Δx2 < c2 Δt2, and the two events can be causally
connected. The interval is said to be timelike.
▹ MAXWELLS’
S
EQUATIONS
▹ LORENTZ
TRANSFOR
MATIONS
▹ MINKOWSKI
SPACETIME
DIAGRAM
▹ VISUALISATI
ON OF
SPACE TIME
▹ APPLICATIO
NS
SPACETIME: MINKOWSKI DIAGRAMS
To illustrate observer situated in an inertial frame, it is convenient to overlay spacetime
diagrams as seen by an observer.
x
t
T axis:
when we are not moving, then our path corresponds to the
t axis. Or in general, the t axis is the trajectory of the
observer which perceives himself as stationary.
X axis:
This axis basically shows all events that happen at the same
time
▹ MAXWELLS’
S
EQUATIONS
▹ LORENTZ
TRANSFOR
MATIONS
▹ MINKOWSKI
SPACETIME
DIAGRAM
▹ VISUALIZATI
ON OF
SPACE TIME
▹ APPLICATIO
NS
SPACETIME: MINKOWSKI DIAGRAMS
The Sun right now.
It’s 8 light minutes away, what happen
over there right now is not going to
affect us till 8 minutes later.
We are here
right now.
Assume that we
don’t move
about.
The Sun’s future
light cone.
Our trajectory in
spacetime.
Our trajectory intersects with the Sun’s future
light cone – we see the light from the Sun that is
emitted ‘now’ 8 minutes ‘later.’
Trajectory of a spaceship
moving away from Earth in
direction opposite from the Sun.
The light from the Sun
finally catches up with
the spaceship.
SPACETIME: MINKOWSKI DIAGRAMS:GEOMETRY
▹ MAXWELLS’
S
EQUATIONS
▹ LORENTZ
TRANSFOR
MATIONS
▹ MINKOWSKI
SPACETIME
DIAGRAM
▹ VISUALIZATI
ON OF
SPACE TIME
▹ APPLICATIO
NS
SPACETIME: MINKOWSKI DIAGRAMS:GEOMETRY
▹ MAXWELLS’
S
EQUATIONS
▹ LORENTZ
TRANSFOR
MATIONS
▹ MINKOWSKI
SPACETIME
DIAGRAM
▹ VISUALIZATI
ON OF
SPACE TIME
▹ APPLICATIO
NS
SPACETIME: MINKOWSKI DIAGRAMS:GEOMETRY
▹ MAXWELLS’
S
EQUATIONS
▹ LORENTZ
TRANSFOR
MATIONS
▹ MINKOWSKI
SPACETIME
DIAGRAM
▹ VISUALIZATI
ON OF
SPACE TIME
▹ APPLICATIO
NS
VISUALIZATION OF SPECIAL RELATIVITY
▹ MAXWELLS’
S
EQUATIONS
▹ LORENTZ
TRANSFOR
MATIONS
▹ MINKOWSKI
SPACETIME
DIAGRAM
▹ VISUALIZATI
ON OF
SPACE TIME
▹ APPLICATIO
NS
SPACETIME MAKES SENSE
The views of space and time which I wish to lay before
you have sprung from the soil of experimental physics,
and therein lies their strength. They are radical.
Henceforth space by itself, and time by itself, are
doomed to fade away into mere shadows, and only a
kind of union of the two will preserve an independent
reality. – Hermann Minkowski ,1908
(22 June 1864 – 12 January 1909)
APPLICATIONS:
1. Even light is bent by gravity!
The position of a star observed during
an eclipse confirmed Einstein’s theory
2.Black holes
Dying stars can become black holes - gravity to an
extreme! At some point, even light cannot escape!
So named as “black holes” because you cannot see
them … but you can see stuff around them
▹ MAXWELLS’
S
EQUATIONS
▹ LORENTZ
TRANSFOR
MATIONS
▹ MINKOWSKI
SPACETIME
DIAGRAM
▹ VISUALIZATI
ON OF
SPACE TIME
▹ APPLICATIO
NS
(Object moving away)
3.Relative motion in the Universe
Red shift
(Object approaching)
Blue shift
APPLICATIONS:
▹ MAXWELLS’
S
EQUATIONS
▹ LORENTZ
TRANSFOR
MATIONS
▹ MINKOWSKI
SPACETIME
DIAGRAM
▹ VISUALIZATI
ON OF
SPACE TIME
▹ APPLICATIO
NS
THANK YOU!!!
ANY
QUESTIONS??
REFERENCES:
1. NEIL TUROK TALK AT PERIMETER INSTITUTE “ASTONISHING SIMPLICITY OF EVERYTHING”.
2. “A FIRST COURSE IN GENERAL RELATIVITY”-BERNARD SCHUTZ.
3. GOOGLE IMAGES
4. JUAN MALCADENA TALK AT PERIMRTER INSTITUTE
5. BRAINY QUOTES

Spacetime

  • 1.
  • 2.
    OVERVIEW OF PRESENTATION: MAXWELLS’SEQUATIONS LORENTZ TRANSFORMATIONS MINKOWSKI SPACETIME DIAGRAM VISUALIZATION OF SPACE TIME APPLICATIONS
  • 3.
    “ When you arecourting a nice girl an hour seems like a second.When you sit on a red-hot cinder a second seems like an hour. That’s relativity. -Albert Einstein Relativity challenges your basic intutions that you’ve built up from everyday experience.It says your experience of time is not what you think it is, that time is malleable.Your experience of space is not what you think it is: it can stretch and shrink. -Brian Greene Einstein,in the special theory of relativity, proved that different obsevers, in different states of motion, see different realities. -Leonard Susskind No person can escape Einsteinian relativity, and no soldier or veteran can escape the trauma of war’s discolation. -Thomas Cochrane QUOTATIONS
  • 4.
    MAXWELL’S EQUATIONS:A CONTRADICTION OldGalilean view of space and time work to explain this? WAVE EQUATION • Light is an electromagnetic wave and travels with speed c=3*10^8m/s Any such beam of any kind of particles generated at the speed of light by a moving observer would be received by a stationary observer at that same speed – regardless of how fast the two observers were moving relative to one another. ▹ MAXWELLS’ S EQUATIONS ▹ LORENTZ TRANSFOR MATIONS ▹ MINKOWSKI SPACETIME DIAGRAM ▹ VISUALISATI ON OF SPACE TIME ▹ APPLICATIO NS
  • 5.
    RESEARCH PAPER ONSPECIAL RELATIVITY BY EINSTEIN
  • 6.
    )( )( 2 x c v tt zz yy vtxx       tt zz yy vtxx     In Galilean relativityIn Special relativity Lorentz transformations LORENTZ TRANSFORMATIONS : A SOLUTION Assumptions: • Speed of light in vacuum remains same to every inertial observer regardless of the motion of the source . • Laws of physics hold in all inertial frames. ▹ MAXWELLS’ S EQUATIONS ▹ LORENTZ TRANSFOR MATIONS ▹ MINKOWSKI SPACETIME DIAGRAM ▹ VISUALISATI ON OF SPACE TIME ▹ APPLICATIO NS
  • 7.
    LORENTZ TRANSFORMATIONS :CONCLUSIONS 1.TIME DILATION The faster you move ,the slower you would get. ▹ MAXWELLS’ S EQUATIONS ▹ LORENTZ TRANSFOR MATIONS ▹ MINKOWSKI SPACETIME DIAGRAM ▹ VISUALISATI ON OF SPACE TIME ▹ APPLICATIO NS
  • 8.
    LORENTZ TRANSFORMATIONS :CONCLUSIONS 2.LENGTH CONTRACTION PROPER LENGTH v = 10% c v = 80% c v = 99% c WARNING : No contraction among perpendicular directions ▹ MAXWELLS’ S EQUATIONS ▹ LORENTZ TRANSFOR MATIONS ▹ MINKOWSKI SPACETIME DIAGRAM ▹ VISUALISATI ON OF SPACE TIME ▹ APPLICATIO NS
  • 9.
    SPACETIME: MINKOWSKI DIAGRAMS Spacetimediagrams were first used by H. Minkowski in 1908 and are often called Minkowski diagrams. Paths in Minkowski spacetime are called worldlines. If we consider two events, we can determine the quantity Δs2 between the two events, and we find that it is invariant in any inertial frame. The quantity Δs is known as the spacetime interval between two events. Considering space and time together and taking into account that the speed of light must be constant in any frame, we find that the new line element to satisfy such conditions is ds2 = −𝑐2 d𝑡2 + dx2 + dy2 + dz2 ▹ MAXWELLS’ S EQUATIONS ▹ LORENTZ TRANSFOR MATIONS ▹ MINKOWSKI SPACETIME DIAGRAM ▹ VISUALISATI ON OF SPACE TIME ▹ APPLICATIO NS
  • 10.
    SPACETIME: MINKOWSKI DIAGRAMS Thereare three possibilities for the invariant quantity Δs2: 1. Δs2 = 0: Δx2 = c2 Δt2, and the two events can be connected only by a light signal. The events are said to have a lightlike separation. 2. Δs2 > 0: Δx2 > c2 Δt2, and no signal can travel fast enough to connect the two events. The events are not causally connected and are said to have a spacelike separation. 3. Δs2 < 0: Δx2 < c2 Δt2, and the two events can be causally connected. The interval is said to be timelike. ▹ MAXWELLS’ S EQUATIONS ▹ LORENTZ TRANSFOR MATIONS ▹ MINKOWSKI SPACETIME DIAGRAM ▹ VISUALISATI ON OF SPACE TIME ▹ APPLICATIO NS
  • 11.
    SPACETIME: MINKOWSKI DIAGRAMS Toillustrate observer situated in an inertial frame, it is convenient to overlay spacetime diagrams as seen by an observer. x t T axis: when we are not moving, then our path corresponds to the t axis. Or in general, the t axis is the trajectory of the observer which perceives himself as stationary. X axis: This axis basically shows all events that happen at the same time ▹ MAXWELLS’ S EQUATIONS ▹ LORENTZ TRANSFOR MATIONS ▹ MINKOWSKI SPACETIME DIAGRAM ▹ VISUALIZATI ON OF SPACE TIME ▹ APPLICATIO NS
  • 12.
    SPACETIME: MINKOWSKI DIAGRAMS TheSun right now. It’s 8 light minutes away, what happen over there right now is not going to affect us till 8 minutes later. We are here right now. Assume that we don’t move about. The Sun’s future light cone. Our trajectory in spacetime. Our trajectory intersects with the Sun’s future light cone – we see the light from the Sun that is emitted ‘now’ 8 minutes ‘later.’ Trajectory of a spaceship moving away from Earth in direction opposite from the Sun. The light from the Sun finally catches up with the spaceship.
  • 13.
    SPACETIME: MINKOWSKI DIAGRAMS:GEOMETRY ▹MAXWELLS’ S EQUATIONS ▹ LORENTZ TRANSFOR MATIONS ▹ MINKOWSKI SPACETIME DIAGRAM ▹ VISUALIZATI ON OF SPACE TIME ▹ APPLICATIO NS
  • 14.
    SPACETIME: MINKOWSKI DIAGRAMS:GEOMETRY ▹MAXWELLS’ S EQUATIONS ▹ LORENTZ TRANSFOR MATIONS ▹ MINKOWSKI SPACETIME DIAGRAM ▹ VISUALIZATI ON OF SPACE TIME ▹ APPLICATIO NS
  • 15.
    SPACETIME: MINKOWSKI DIAGRAMS:GEOMETRY ▹MAXWELLS’ S EQUATIONS ▹ LORENTZ TRANSFOR MATIONS ▹ MINKOWSKI SPACETIME DIAGRAM ▹ VISUALIZATI ON OF SPACE TIME ▹ APPLICATIO NS
  • 16.
    VISUALIZATION OF SPECIALRELATIVITY ▹ MAXWELLS’ S EQUATIONS ▹ LORENTZ TRANSFOR MATIONS ▹ MINKOWSKI SPACETIME DIAGRAM ▹ VISUALIZATI ON OF SPACE TIME ▹ APPLICATIO NS
  • 17.
    SPACETIME MAKES SENSE Theviews of space and time which I wish to lay before you have sprung from the soil of experimental physics, and therein lies their strength. They are radical. Henceforth space by itself, and time by itself, are doomed to fade away into mere shadows, and only a kind of union of the two will preserve an independent reality. – Hermann Minkowski ,1908 (22 June 1864 – 12 January 1909)
  • 18.
    APPLICATIONS: 1. Even lightis bent by gravity! The position of a star observed during an eclipse confirmed Einstein’s theory 2.Black holes Dying stars can become black holes - gravity to an extreme! At some point, even light cannot escape! So named as “black holes” because you cannot see them … but you can see stuff around them ▹ MAXWELLS’ S EQUATIONS ▹ LORENTZ TRANSFOR MATIONS ▹ MINKOWSKI SPACETIME DIAGRAM ▹ VISUALIZATI ON OF SPACE TIME ▹ APPLICATIO NS
  • 19.
    (Object moving away) 3.Relativemotion in the Universe Red shift (Object approaching) Blue shift APPLICATIONS: ▹ MAXWELLS’ S EQUATIONS ▹ LORENTZ TRANSFOR MATIONS ▹ MINKOWSKI SPACETIME DIAGRAM ▹ VISUALIZATI ON OF SPACE TIME ▹ APPLICATIO NS
  • 20.
  • 21.
    REFERENCES: 1. NEIL TUROKTALK AT PERIMETER INSTITUTE “ASTONISHING SIMPLICITY OF EVERYTHING”. 2. “A FIRST COURSE IN GENERAL RELATIVITY”-BERNARD SCHUTZ. 3. GOOGLE IMAGES 4. JUAN MALCADENA TALK AT PERIMRTER INSTITUTE 5. BRAINY QUOTES