What Does Relative Really Mean and How Is It Used?

  • Context: High School 
  • Thread starter Thread starter Jadaav
  • Start date Start date
  • Tags Tags
    Relative
Click For Summary

Discussion Overview

The discussion centers around the concept of "relative" in physics, exploring its meaning, applications, and implications in various contexts, including time and motion. Participants seek to clarify how relativity is understood and used in both everyday language and scientific contexts.

Discussion Character

  • Exploratory
  • Conceptual clarification
  • Debate/contested

Main Points Raised

  • Some participants suggest that "relative" contrasts with "absolute," indicating that measurements depend on a chosen reference point.
  • One participant explains that observers may disagree on elapsed time and lengths due to their relative motion, using the example of two people on a fast-moving train.
  • Another participant references Galileian relativity, noting that speed is perceived differently depending on the observer's frame of reference.
  • Einstein's extension of relativity is mentioned, highlighting that not only speed but also time, distance, and simultaneity are relative properties.
  • There is a discussion about the phrase "He is relatively wealthy," questioning how relativity applies in everyday language.
  • Some participants express confusion about the term "relative" and seek clarification on its usage in physics and everyday contexts.
  • One participant emphasizes that when discussing relative motion, it is important to specify the property being measured.
  • There are repeated inquiries about the reasons for using the term "relative" and its implications in nature.
  • One participant asks how to explain the concept of relative motion without using the term "relative," indicating a desire for further clarification.

Areas of Agreement / Disagreement

Participants generally agree that "relative" involves a comparison to a reference point, but there is no consensus on the broader implications or the best way to explain the concept. Confusion and differing interpretations persist regarding its application in both physics and everyday language.

Contextual Notes

Some participants express uncertainty about the specific properties that are relative and the contexts in which the term is appropriately used. There are unresolved questions about the implications of relativity in various scenarios.

Who May Find This Useful

This discussion may be useful for individuals interested in understanding the concept of relativity in physics, as well as those seeking to clarify its application in everyday language and various contexts.

Jadaav
Messages
175
Reaction score
1
I heard many people telling this is relative to something, it moves relatively... and so on

I wanted to know what is relative?

What does it mean?

How is it used?

They tell that time is relative?

What does that mean?
 
Physics news on Phys.org


it means that two observers will not not agree upon how long time has elapsed between to events, and on lengths.

you sit on a train that goes very fast according to me, but according to you - it is ME who travels fast! If you and I would measure motion on this train, such as a ball being thrown, we will not agree upon the dynamics of the ball.
 


In physics, there are a few distinct uses for the word "relative".

Essentially, relative is used to contrast with absolute. If something is relative, you need to pick a reference point to measure it. Two people measuring the same thing at the same time will get different values unless they are using the same reference point.

The most common example has been known since Galileo. We call it Galileian relativity. The idea is speed is relative. When you're standing still on a sidewalk, a car zooms past you at 50 miles per hour. However, if you are traveling in that car, the car appears to be still and a man on the sidewalk is the one flying at 50 miles per hour.

Similarly, if you are traveling in a car, and you accidently rear-end the car in front of you, the amount of damage isn't determined by your speed relative to the road (~50 mph). Instead, it's determined by your speed relative to the other car (~2 or 3mph).

Einstein extended Galileian relativity in the early 20th Century, accounting for a strange property of light (that it always moves at the same speed regardless of your reference point). Some other consequences of Einstein's theory of special relativity are that not only velocity, but also distances, time spans, and simultaneous-ness are "relative" properties.
 


Jadaav said:
How is it used?

"He is relatively wealthy"

Jadaav said:
They tell that time is relative?

What does that mean?

If a clock measures time by moving parts and the collection of parts are moving relative to you the clock is going to register a different time than a clock that is not moving relative to you. All clocks measure time by moving parts, including sundial/solar system clocks. So time is relative.

Since a human is made of moving parts if they moved fast enough relative to Earth they could out live all other humans on earth.
 
Last edited:


In what types of situations can it be used?

if I'm relative to something what will it mean?
 


Jadaav said:
In what types of situations can it be used?

if I'm relative to something what will it mean?

in physics, we use "relative motion"

you can not just say "I am relative him" etc... it has no meaning, one must specify what PROPERTY is relative, not just WHOM
 


ok

but for what reason is relative used?

Why?
 


Jadaav said:
ok

but for what reason is relative used?

Why?


relative WHAT?

relative motion is "used" since that is what happens in nature, things move relative each other all the time!
 


"things move relative each other all the time! "

I don't understand the word 'relative'

if you wouldn't used the word relative how would you explain that phrase to me?
 

Similar threads

High School Rotating disc: tidal relativity across surface of disc
  • · Replies 14 ·
Replies
14
Views
1K
High School Simplest symmetrical time dilation question
  • · Replies 16 ·
Replies
16
Views
2K
Undergrad Why does general relativity break down at high energies?
  • · Replies 8 ·
Replies
8
Views
1K
High School Meaningfulness of the speed of light
  • · Replies 25 ·
Replies
25
Views
2K
Undergrad Does the metric in general relativity depend only on position because of the equivalence principle?
  • · Replies 16 ·
Replies
16
Views
2K
High School What does symmetry of time dilation really mean?
  • · Replies 16 ·
Replies
16
Views
2K
Graduate What does G mean in general relativity?
  • · Replies 55 ·
2
Replies
55
Views
5K
High School Relativistic simultaneity and effects on time
  • · Replies 9 ·
Replies
9
Views
863
High School Special relativity thought: Traveling to the future relative to a particle
  • · Replies 29 ·
Replies
29
Views
3K
High School Very simple exercises in General Relativity
  • · Replies 57 ·
2
Replies
57
Views
5K