Physics is the belief that a simple and consistent description of nature is possible.
—Niels Bohr
There are innumerable doors in physics. All these doors are very special and mysterious because once you enter, it leads to another door.
Some doors have been unlatched and many more are yet to be unlatched. Today I will take you to two doors that have been unlatched.
1) What is Time Dilation?
According to classical mechanics, time is absolute. On the contrary, Albert Einstein showed time is “relative” not “absolute”. “Speed and gravity affects time.”
Time slows down and speeds up depending on the value of “gravity” and “speed .”
Speed affects time:
Suppose you are travelling very fast in a rocket and your friend standing on the Earth. Time slows down for you, compared to your friend who is standing on the Earth.
Time dilation formula:
Gravity affects time:
Jupiter’s gravity is much stronger than Earth’s gravity. Therefore, time passes slower in Jupiter than on Earth.
Time dilation formula:
What is the twin paradox?
Let’s explore “time dilation”, a little more and understand “twin paradox.
- Suppose two identical twins “Tom” and “Jerry”, whose age is 10 years. One of them is sent in a rocket, travelling at the speed of light and the other remains on the Earth.
- When Tom comes back to Earth after 10 years. He will find out that, he is 20 years old and his twin brother has grown old now.
- This difference in age is due to, when Tom was inside the rocket, the reference frame of time was much slower, resulting in slowing down of time.
2) Are electricity and magnetism related?
Could we ever have imagined that there would be a relation between “moving charges” and “magnets”.
Oersted’s Experiment:
In 1820, danish physicist “Hans Christian Oersted,” observed, when the magnetic needle is placed near a current carrying wire, the magnetic needle deflects and aligns in a particular direction. As the current in the wire changes, the direction of the magnetic needle changes.
He concluded, the current carrying wire produces a magnetic field. The magnetic field produces around the current carrying wire is in the form of concentric circle, which exerts a force on the needle. Thus, needle deflects.
A brief summary of the entire discussion is given below:
- The magnetic field lines lie in a plane perpendicular to the wire.
- If the direction of the current is reversed, the direction of magnetic field will also be reversed.
- The strength of the magnetic field is directly proportional to the magnitude of the current.
- The magnetic field lines produced by a current carrying wire are in the form of concentric circles around the wire.
What did Oersted’s experiment show us?
Oersted’s discovery of the connection between electricity and magnetism was a foundational step toward the field of electromagnetism. Because this was the first experimental evidence that electric current creates a magnetic field.
This was really incredible, because for the first time someone was saying that electricity and magnetism were not two separate phenomena but were interconnected. This discovery was a turning point in physics, leading to the development of electromagnetism and showing the way for future technologies.
If you want to know more about electromagnetism please let me know in the comment box below.
“Stay connected, keep smiling!”
