- #1
runner
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How would you explain the Theory of Relativity to someone in non-mathematical, everyday language?
Can You Explain the Theory of Relativity in Simple Terms?
- Thread starter runner
- Start date
In summary: It's like when you're standing on a moving sidewalk, and you throw a ball forward at 5 mph, the person watching from the side sees the ball moving at 5 mph, and the person on the sidewalk sees the ball moving at 10 mph, right?But then something weird happens when we try to apply this to light. When we throw a light beam forward at c miles an hour, the person watching from the side still sees the light moving at c miles an hour, but the person on the sidewalk also sees the light moving at c miles an hour. It's like the light is moving at 2c miles an hour!But that can't be right - nothing can move faster than the speed of
- #2
ice109
- 1,714
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going in circles is the same as being on a spaceship that´s speeding up
- #3
magpies
- 177
- 2
First I would learn it as a layperson...
- #4
DavidSnider
Gold Member
- 511
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Cosmos Part 8:
http://video.google.com/videoplay?docid=6004920772385548361&ei=GxnmSuOkNYy5lQeVz5Ee&q=cosmos+part+8&hl=en
http://video.google.com/videoplay?docid=6004920772385548361&ei=GxnmSuOkNYy5lQeVz5Ee&q=cosmos+part+8&hl=en
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- #5
sokrates
- 483
- 2
I hope you mean the "special relativity"..
I'd start with the basic postulates and have her/him accept those
(1) speed of light is constant for all non-accelerating observers contrasting everyday classical relativity...
(2) All physical laws are equivalent for non-accelerating observers.
You can even skip (2) in the beginning.
Then contrast (1) by giving an example: You run with 5 mi/h and a car passes by 10 mi/h (same direction) you'd "conclude" that it travels by 5 mi/h in the same direction. Have her/him accept it for a fact that with light your observation is always c!
Then the rest is easy: Two observers. One in a train, other on the ground. Put a mirror in the train (vertical), and the observers measure different lengths traveled by light, yet they observe the same speed of light. Then obviously their clocks must be running differently! Now you can easily jump to time dilation and the twin paradox (not mentioning how the paradox arises, or is resolved because they involve more subtle points). But that should be enough.
Voila!
I'd start with the basic postulates and have her/him accept those
(1) speed of light is constant for all non-accelerating observers contrasting everyday classical relativity...
(2) All physical laws are equivalent for non-accelerating observers.
You can even skip (2) in the beginning.
Then contrast (1) by giving an example: You run with 5 mi/h and a car passes by 10 mi/h (same direction) you'd "conclude" that it travels by 5 mi/h in the same direction. Have her/him accept it for a fact that with light your observation is always c!
Then the rest is easy: Two observers. One in a train, other on the ground. Put a mirror in the train (vertical), and the observers measure different lengths traveled by light, yet they observe the same speed of light. Then obviously their clocks must be running differently! Now you can easily jump to time dilation and the twin paradox (not mentioning how the paradox arises, or is resolved because they involve more subtle points). But that should be enough.
Voila!
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- #6
Pinu7
- 275
- 5
Einstein's Relativity which you can find at any bookstore.
I explained it to my little sister( 8th grade, but smart) starting with this.
Me: Let us say you were racing a cheetah, you are going 12 mile/hr and he is going at 32 miles an hour, how fast is does he LOOK LIKE he's moving to you.
Her: What do you mean?
Me: If you and the cheetah are moving at the same direction, it looks like he is going slow...
Her: Oh! 20 miles an hour!
Me: Good! How did you obtain that
Her: I subtracted.
Me: Good, this is known as Galilean Relativity. Which means if you are moving and another object was moving, you would subtract your speed form the object's speed to obtain how fast the object LOOKS LIKE it is moving. This is known as relative speed.
Her: Mmhhhhmmm... I get it.
Me: What about a beam of light? Let us say that light moves at c miles an hour, where c is just a positive number. And you moving at c-1 miles an hour, what is the relative motion of light.
Her: *thinks about it* one mile an hour?
Me: According to Galilean relativity, yes, you are correct. However, scientific experimentation done over a hundred years ago surprisingly found that the speed of light's relative speed is always c, no matter how fast you are moving.
Her: I'm confused, that makes no sense.
Me: It didn't to the scientists ,either, until Albert Einstein discovered that Galilean relativity is wrong and only worked approximately when your and the object's speed is far less than the speed of light, which is about 670 million miles an hour. He found another principal of relative speed called special relativity.
I explained it to my little sister( 8th grade, but smart) starting with this.
Me: Let us say you were racing a cheetah, you are going 12 mile/hr and he is going at 32 miles an hour, how fast is does he LOOK LIKE he's moving to you.
Her: What do you mean?
Me: If you and the cheetah are moving at the same direction, it looks like he is going slow...
Her: Oh! 20 miles an hour!
Me: Good! How did you obtain that
Her: I subtracted.
Me: Good, this is known as Galilean Relativity. Which means if you are moving and another object was moving, you would subtract your speed form the object's speed to obtain how fast the object LOOKS LIKE it is moving. This is known as relative speed.
Her: Mmhhhhmmm... I get it.
Me: What about a beam of light? Let us say that light moves at c miles an hour, where c is just a positive number. And you moving at c-1 miles an hour, what is the relative motion of light.
Her: *thinks about it* one mile an hour?
Me: According to Galilean relativity, yes, you are correct. However, scientific experimentation done over a hundred years ago surprisingly found that the speed of light's relative speed is always c, no matter how fast you are moving.
Her: I'm confused, that makes no sense.
Me: It didn't to the scientists ,either, until Albert Einstein discovered that Galilean relativity is wrong and only worked approximately when your and the object's speed is far less than the speed of light, which is about 670 million miles an hour. He found another principal of relative speed called special relativity.
- #7
jgens
Gold Member
- 1,593
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"When a man sits with a pretty girl for an hour, it seems like a minute. But let him sit on a hot stove for a minute and it's longer than any hour. That's relativity."
~Albert Einstein
Edit: I realize that this quote isn't really pertinent but it's the first thing that came to mind when I read your question.
~Albert Einstein
Edit: I realize that this quote isn't really pertinent but it's the first thing that came to mind when I read your question.
- #8
Jimmy Snyder
- 1,127
- 20
When I have the opportunity to do so, I explain using Pinu7's approach. I also point out that speed is distance divided by time. The only way that the speed of light can be the same for all observers is if distance, or time, or both get distorted somehow.
- #9
runner
- 27
- 0
Great replies so far, and I like the way the explanations are becoming easier and easier to explain so far. I may have some luck with my grandmother yet. 
- #10
WhoWee
- 219
- 0
Pinu7 said:
Try using dollars.
- #11
solarflare
- 177
- 0
Me: What about a beam of light? Let us say that light moves at c miles an hour, where c is just a positive number. And you moving at c-1 miles an hour, what is the relative motion of light.
Her: *thinks about it* one mile an hour?
Me: According to Galilean relativity, yes, you are correct. However, scientific experimentation done over a hundred years ago surprisingly found that the speed of light's relative speed is always c, no matter how fast you are moving.
Her: I'm confused, that makes no sense.
Me: It didn't to the scientists ,either, until Albert Einstein discovered that Galilean relativity is wrong and only worked approximately when your and the object's speed is far less than the speed of light, which is about 670 million miles an hour. He found another principal of relative speed called special relativity.[/QUOTE]
what was the experiment conducted and who conducted it. i would like to explore this in more detail. very interesting
Her: *thinks about it* one mile an hour?
Me: According to Galilean relativity, yes, you are correct. However, scientific experimentation done over a hundred years ago surprisingly found that the speed of light's relative speed is always c, no matter how fast you are moving.
Her: I'm confused, that makes no sense.
Me: It didn't to the scientists ,either, until Albert Einstein discovered that Galilean relativity is wrong and only worked approximately when your and the object's speed is far less than the speed of light, which is about 670 million miles an hour. He found another principal of relative speed called special relativity.[/QUOTE]
what was the experiment conducted and who conducted it. i would like to explore this in more detail. very interesting
- #12
mgb_phys
Science Advisor
Homework Helper
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http://en.wikipedia.org/wiki/Michelson–Morley_experimentsolarflare said:
- #13
OmCheeto
Gold Member
- 2,389
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runner said:Great replies so far, and I like the way the explanations are becoming easier and easier to explain so far. I may have some luck with my grandmother yet.
I see where you're going with this:
1. What is the purpose of explaining scientific concepts to a layperson?
The purpose of explaining scientific concepts to a layperson is to make complex information more accessible and understandable to a non-expert audience. It allows for the dissemination of knowledge and helps bridge the gap between scientists and the general public.
2. How should I approach explaining a scientific concept to a layperson?
When explaining a scientific concept to a layperson, it is important to use simple, everyday language and avoid technical jargon. Use relatable examples and analogies to help the layperson understand the concept better. It is also helpful to ask for feedback and make sure the layperson is following along.
3. What are some common mistakes to avoid when explaining to a layperson?
Some common mistakes to avoid when explaining to a layperson include using overly complicated language, assuming prior knowledge, and not taking the time to ensure understanding. It is also important to avoid oversimplification and to provide accurate information.
4. Are there any tips for making complex scientific concepts easier to understand?
One tip for making complex scientific concepts easier to understand is to break them down into smaller, more manageable pieces. Use visual aids, such as diagrams or images, to help illustrate the concept. It can also be helpful to relate the concept to everyday experiences or use real-world examples.
5. How can I gauge if the layperson has understood the scientific concept?
A good way to gauge if a layperson has understood the scientific concept is to ask them to explain it back to you in their own words. This will help you identify any areas that may need further clarification. It is also helpful to encourage the layperson to ask questions and actively engage in the conversation.
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