Where can I find massless string for physics experiments?

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The discussion revolves around a user seeking massless string for physics experiments, acknowledging its rarity and expressing willingness to pay extra. Participants clarify that true massless string is theoretical, as all physical strings have some mass, albeit negligible for practical purposes. Suggestions include using "invisible thread," fishing line, or dental floss, which have minimal mass and can serve the intended purpose. The conversation also touches on the implications of using massless string in experiments, humorously noting that all string is effectively massless within typical experimental uncertainties. The user concludes that they will opt for dental floss for their experiments.
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.
 
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  • #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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