Where can I find massless string for physics experiments?

In summary, the conversation revolves around the topic of massless string and where to purchase it. Some suggest using dental floss or magician's thread as alternatives. Others point out that all string is essentially massless in the context of most experiments. The conversation also touches on other physics concepts such as standing waves and the Atwood machine.
  • #1
l_tunaboy
Hi,
I am new to the forum. lol.
I came here because in my physics class, many of the experiments call for massless string.

Does anyone know where I could purchase some?
I understand it is harder to come by, but I am willing to pay extra.

Thanks a bunch
 
Physics news on Phys.org
  • #2
But beware! A massless string must have zero volume and therefore zero diameter, unless there is a substance that has zero density. Therefore an envelope containing a massless string is difficult to distinguish from an empty envelope. :wink:
 
  • #3
Yeah. Someone is either having you on, or using bad terminology.
The closest thing that I can think of to what you want is actually called 'invisible thread'. Close-up illusionists use it to levitate things like cigarettes or coins. Any magic-supply house will have it in stock.
 
  • #4
We Norwegians sell tons of it to dumb Swedes.
 
  • #5
Just how does one weigh out 'tons' of something with no mass? :confused:
 
  • #6
Danger said:
Just how does one weigh out 'tons' of something with no mass? :confused:
Good question! But then, you are a Canadian, not a Swede.
 
  • #7
arildno said:
We Norwegians sell tons of it to dumb Swedes.

Sad, but true :frown:
 
  • #8
arildno said:
you are a Canadian, not a Swede.
That might explain it...
 
  • #9
l_tunaboy said:
Hi,
I am new to the forum. lol.
I came here because in my physics class, many of the experiments call for massless string.

Does anyone know where I could purchase some?
I understand it is harder to come by, but I am willing to pay extra.

Thanks a bunch
Try dental floss. It's strong and has a mass of nearly zero, except for particularly large values of zero.

It's also works very well to cut cake at parties.
 
  • #10
BobG said:
It's also works very well to cut cake at parties.

Picturing that really made me laugh. :rofl:
 
  • #11
l_tunaboy said:
Hi,
I am new to the forum. lol.
I came here because in my physics class, many of the experiments call for massless string.

Does anyone know where I could purchase some?

Are you using a precision microgram torsion balance? If not, all string is massless to within experimental uncertainty. That's what "massless" means in this context.
 
  • #12
lol, if you are looking for string with very insignificant mass, try fishing line or as danger pointed out, magicians string (or whatever you call it). I doubt that the mass of a string is going to ruin your experiments unless you're using shoe laces, and even in that case you could weigh it beforehand and subract it from your experimental data.
 
  • #13
radou said:
Picturing that really made me laugh. :rofl:
What's so funny about that?

Measure out the needed length of floss and dip it in a cup of water. Then you can visually lay out your cut, holding the floss over the cake, then lowering it as you slightly bring the string back towards your body. Perfectly straight cuts without that tendency to veer off to one side that frequently happens as you concentrate on the point where the knife is contacting the cake.
 
  • #14
Rach3 said:
Are you using a precision microgram torsion balance? If not, all string is massless to within experimental uncertainty. That's what "massless" means in this context.
If the poster has access to such a balance I suspect they would not have had to ask the question...:rolleyes:
 
  • #15
I looked at the post thinking it was about string theory!
 
  • #16
l_tunaboy said:
Hi,
I am new to the forum. lol.
I came here because in my physics class, many of the experiments call for massless string.

Does anyone know where I could purchase some?
I understand it is harder to come by, but I am willing to pay extra.

Thanks a bunch
I hope your experiment isn't on standing waves on a string. A massless string would tend to complicate your experiment.

On the other hand, that would provide one way to measure the mass of your string if you lacked a scale of sufficient precision.
 
Last edited:
  • #17
BobG said:
I hope your experiment isn't on standing waves on a string. A massless string would tend to complicate your experiment.
Why bother about them when we can partake in the glory of the Atwood machine? :confused:
 
  • #18
l_tunaboy said:
Hi,
I am new to the forum. lol.
I came here because in my physics class, many of the experiments call for massless string.

Does anyone know where I could purchase some?
I understand it is harder to come by, but I am willing to pay extra.

Thanks a bunch

:rofl: :rofl: I think you can buy them at the same place the sells the frictionless pulleys. :approve:

Oh, and from your username, it seems you'll probably really enjoy our current welcome fish...mackerel! :biggrin:
 
  • #19
Thanks everyone for the help.
I guess that my precision microgram torsion balance experiments will have to be put on hold.
For now, floss it is.
 

1. What is a massless string?

A massless string is a hypothetical concept in physics where a string is considered to have no mass. This means that it has no weight and does not contribute to the overall mass of a system.

2. Can a massless string exist in reality?

No, a massless string is purely a theoretical concept and cannot exist in reality. All objects, including strings, have some amount of mass, no matter how small it may be.

3. What is the significance of a massless string in physics?

Massless strings are often used in theoretical models and thought experiments in physics to simplify calculations and better understand certain phenomena. They also play a role in string theory, a theoretical framework that attempts to reconcile general relativity and quantum mechanics.

4. How is a massless string different from a massless particle?

A massless string and a massless particle are two different concepts. While a massless string has no mass but still has length, a massless particle has no mass and no volume. Massless particles, such as photons, are particles that travel at the speed of light and have zero rest mass.

5. Are there any real-world applications of the concept of a massless string?

While massless strings do not exist in reality, the concept is still used in various fields of physics, such as in the study of black holes and the behavior of particles at the quantum level. However, there are currently no known practical applications of massless strings in everyday life.

Similar threads

  • General Discussion
Replies
1
Views
927
Replies
47
Views
4K
  • General Discussion
Replies
14
Views
1K
Replies
3
Views
1K
  • Special and General Relativity
Replies
11
Views
1K
Replies
1
Views
47
  • New Member Introductions
Replies
2
Views
51
  • New Member Introductions
Replies
1
Views
72
  • General Discussion
Replies
4
Views
664
Back
Top