Lorentz transformation And Einstein's Laws.

In summary, the formulas for time dilation, known as "the law of Einstein" and "the Lorentz law," are derived from the Lorentz transformation and are used to determine the relationship between time intervals for stationary and moving objects. The difference between the two formulas can be understood by considering two special cases where events take place at the same location in different frames. The "law of Einstein" formula is used when the events are at the same location in one frame, while the "Lorentz law" formula is used when the events are at the same location in the other frame. Both formulas are correct and are necessary for understanding time dilation.
  • #1
Hepic
118
0
To=(time of moving object.)
T=(Time of standing object.)
^=power of number.
sqrt=square of number.(x^1/2)Law of einstein say: T= To / ( sqrt( 1 - u^2/c^2 ) )
Lorentz law say: T= (To + u*Xo/c^2) / ( sqrt( 1 - u^2/c^2 ) )Why there is difference??
Is for other things?? I thought is for the same reasons...
 
Last edited:
Physics news on Phys.org
  • #2
The time dilation formula that you're calling "the law of Einstein" is derived from the Lorentz transformation.

There's only one way to understand the different meaning of the two formulas, and that's to do the derivation yourself. Start with the Lorentz transforms, and use them to answer the questions:

When my clock advances from time ##t## to ##t+\Delta{t}##, how much does the moving clock advance? What does the moving clock read when my clock reads ##t##? What does the moving clock read when my clock reads ##t+\Delta{t}##? What is the difference between those values?
 
  • #3
So,for example we have two humans. One in Earth and one in spaceship.
To count the difference of time that they count,which law is the correct?

Both,counts the time of standing,relative to the time of moving person.
 
  • #4
Hepic said:
So,for example we have two humans. One in Earth and one in spaceship.
To count the difference of time that they count,which law is the correct?

Both,counts the time of standing,relative to the time of moving person.

Clock on Earth advances from ##t## to ##t+\Delta{t}##. What did the spaceship clock read when the Earth clock read ##t##? What did the spaceship clock read when the Earth clock read ##t+\Delta{t}##? Use the Lorentz transform to answer these questions.

The difference between these values will give you the amount of time that passed on the spaceship while an interval ##\Delta{t}## passed on earth. What does that formula look like?
 
  • #5
The einstein law,will not give me correct answers??
 
  • #6
What you call the Einstein law is determining the relation between time intervals for stationary and moving objects. What you call the Lorentz law is just the time component of the Lorentz transformation, which relates space-time coordinates of different inertial frames.

If you start out with both objects at x = 0 at t = 0 (which according to the standard setup Lorentz transformation is also t' = 0 and x' = 0) and the moving object moves with velocity v, then at time t = T the moving object will be at x = vT. The t' coordinate (i.e., the time that a clock moving with the moving object will show) is then (according to the Lorentz transformation)

t' = T0 = (t - vx/c^2)/sqrt(1-v^2/c^2) = (T - v^2 T/c^2)/sqrt(1-v^2/c^2) = T sqrt(1 - v^2/c^2)

resulting in the time dilation

T = T0/sqrt(1-v^2/c^2)
 
  • #7
Hepic said:
To=(time of moving object.)
T=(Time of standing object.)
^=power of number.
sqrt=square of number.(x^1/2)


Law of einstein say: T= To / ( sqrt( 1 - u^2/c^2 ) )
Lorentz law say: T= (To + u*Xo/c^2) / ( sqrt( 1 - u^2/c^2 ) )


Why there is difference??
Is for other things?? I thought is for the same reasons...

If you have two events [itex]e_1[/itex] and [itex]e_2[/itex] that take place at different times and locations, and you let [itex]\delta t[/itex] be the time between the events in one frame, frame [itex]F[/itex], and [itex]\delta x[/itex] be the distance between them in that frame, then in the other frame, frame [itex]F'[/itex], you have:

[itex]\delta t' = \dfrac{1}{\sqrt{1-u^2/c^2}} (\delta t - u\ \delta x/c^2)[/itex]
[itex]\delta x' = \dfrac{1}{\sqrt{1-u^2/c^2}} (\delta x - u\ \delta t)[/itex]

Now, let's look at two special cases:

Case 1: the two events take place at the same location, according to frame [itex]F[/itex].

In this case, [itex]\delta x = 0[/itex]. So the formula for [itex]\delta t'[/itex] becomes:

[itex]\delta t' = \dfrac{1}{\sqrt{1-u^2/c^2}} \delta t[/itex]

Case 2: the two events take place at the same location, according to frame [itex]F'[/itex].

In this case, [itex]\delta x' = 0[/itex]. This means that [itex]\delta x = u\ \delta t[/itex].

In this case, the formula for [itex]\delta t'[/itex] becomes:

[itex]\delta t' = \dfrac{1}{\sqrt{1-u^2/c^2}} (\delta t - u\ (u\ \delta t)/c^2)[/itex]

which simplifies to:

[itex]\delta t' = \sqrt{1-u^2/c^2} \delta t[/itex]
 
  • #8
stevendaryl said:
If you have two events [itex]e_1[/itex] and [itex]e_2[/itex] that take place at different times and locations, and you let [itex]\delta t[/itex] be the time between the events in one frame, frame [itex]F[/itex], and [itex]\delta x[/itex] be the distance between them in that frame, then in the other frame, frame [itex]F'[/itex], you have:

[itex]\delta t' = \dfrac{1}{\sqrt{1-u^2/c^2}} (\delta t - u\ \delta x/c^2)[/itex]
[itex]\delta x' = \dfrac{1}{\sqrt{1-u^2/c^2}} (\delta x - u\ \delta t)[/itex]

Now, let's look at two special cases:

Case 1: the two events take place at the same location, according to frame [itex]F[/itex].

In this case, [itex]\delta x = 0[/itex]. So the formula for [itex]\delta t'[/itex] becomes:

[itex]\delta t' = \dfrac{1}{\sqrt{1-u^2/c^2}} \delta t[/itex]

Case 2: the two events take place at the same location, according to frame [itex]F'[/itex].

In this case, [itex]\delta x' = 0[/itex]. This means that [itex]\delta x = u\ \delta t[/itex].

In this case, the formula for [itex]\delta t'[/itex] becomes:

[itex]\delta t' = \dfrac{1}{\sqrt{1-u^2/c^2}} (\delta t - u\ (u\ \delta t)/c^2)[/itex]

which simplifies to:

[itex]\delta t' = \sqrt{1-u^2/c^2} \delta t[/itex]


So,that what I call eistein's law,is when two phenomena,are located at the same location(dx=0) ??

Thank you by the way!
 

1. What is the Lorentz transformation?

The Lorentz transformation is a mathematical equation that describes how measurements of space and time are affected by the relative motion between two inertial reference frames. It was first introduced by Dutch physicist Hendrik Lorentz in 1904 and later incorporated into Einstein's theory of special relativity.

2. How do the Lorentz transformation and Einstein's laws relate to each other?

The Lorentz transformation is a fundamental concept in Einstein's theory of special relativity. It is used to reconcile the principle of relativity, which states that the laws of physics are the same for all observers in uniform motion, with the constancy of the speed of light. This led to the development of Einstein's famous equations E=mc² and the theory of time dilation and length contraction.

3. Can you explain time dilation and length contraction in the context of the Lorentz transformation?

Time dilation and length contraction are both consequences of the Lorentz transformation. Time dilation refers to the slowing down of time for an object in motion relative to an observer, while length contraction refers to the shortening of an object in motion relative to an observer. Both of these phenomena occur due to the constant speed of light and the relativity of simultaneity in different reference frames.

4. What are some practical applications of the Lorentz transformation and Einstein's laws?

The Lorentz transformation and Einstein's laws have numerous practical applications, including GPS technology, particle accelerators, and nuclear energy. These principles are also crucial in the field of astrophysics and help us understand the behavior of objects moving at high speeds, such as stars and galaxies.

5. Are there any limitations or exceptions to the Lorentz transformation and Einstein's laws?

While the Lorentz transformation and Einstein's laws have been extensively tested and proven to be accurate in many scenarios, they do have limitations and exceptions. For example, they do not apply to objects moving at speeds close to the speed of light or in the presence of extremely strong gravitational fields. Additionally, these laws may not hold in the realm of quantum mechanics, where the effects of gravity are negligible.

Similar threads

  • Special and General Relativity
Replies
22
Views
1K
  • Special and General Relativity
2
Replies
54
Views
1K
  • Special and General Relativity
3
Replies
101
Views
3K
  • Special and General Relativity
Replies
10
Views
603
  • Special and General Relativity
4
Replies
120
Views
6K
  • Special and General Relativity
Replies
6
Views
1K
  • Special and General Relativity
Replies
32
Views
3K
  • Special and General Relativity
Replies
1
Views
1K
  • Special and General Relativity
Replies
27
Views
1K
  • Special and General Relativity
Replies
9
Views
2K
Back
Top