Where can I find massless string for physics experiments?

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    Massless String
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SUMMARY

The discussion centers around the challenge of sourcing massless string for physics experiments. Participants clarify that true massless string does not exist, as all materials have some mass, albeit negligible. Suggestions include using 'invisible thread' from magic supply stores or dental floss, which has an extremely low mass. The conversation also touches on the implications of using massless string in experiments, particularly in relation to precision measurements.

PREREQUISITES
  • Understanding of mass and density concepts in physics
  • Familiarity with experimental uncertainty in measurements
  • Knowledge of precision instruments like microgram torsion balances
  • Basic principles of physics experiments involving strings
NEXT STEPS
  • Research 'invisible thread' and its applications in physics experiments
  • Explore the use of dental floss in experimental setups for low-mass applications
  • Learn about precision microgram torsion balances and their use in measuring small masses
  • Investigate the principles of standing waves on strings and their experimental requirements
USEFUL FOR

Physics students, educators conducting experiments, and anyone interested in precision measurement techniques in scientific research.

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
 
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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:
 
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.
 
We Norwegians sell tons of it to dumb Swedes.
 
Just how does one weigh out 'tons' of something with no mass? :confused:
 
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.
 
arildno said:
We Norwegians sell tons of it to dumb Swedes.

Sad, but true :frown:
 
arildno said:
you are a Canadian, not a Swede.
That might explain it...
 
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. :smile:
 
  • #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. :smile:
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

:smile: :smile: 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.
 

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