The Naked Scientists
  • Login
  • Register
  • Podcasts
      • The Naked Scientists
      • eLife
      • Naked Genetics
      • Naked Astronomy
      • In short
      • Naked Neuroscience
      • Ask! The Naked Scientists
      • Question of the Week
      • Archive
      • Video
      • SUBSCRIBE to our Podcasts
  • Articles
      • Science News
      • Features
      • Interviews
      • Answers to Science Questions
  • Get Naked
      • Donate
      • Do an Experiment
      • Science Forum
      • Ask a Question
  • About
      • Meet the team
      • Our Sponsors
      • Site Map
      • Contact us

User menu

  • Login
  • Register
  • Home
  • Help
  • Search
  • Tags
  • Member Map
  • Recent Topics
  • Login
  • Register
  1. Naked Science Forum
  2. General Science
  3. Question of the Week
  4. QotW - 21.05.24 - Are all snowflakes really unique?
« previous next »
  • Print
Pages: [1]   Go Down

QotW - 21.05.24 - Are all snowflakes really unique?

  • 15 Replies
  • 5480 Views
  • 2 Tags

0 Members and 1 Guest are viewing this topic.

Offline Adam Murphy (OP)

  • Global Moderator
  • Jr. Member
  • ********
  • 46
  • Activity:
    0%
  • Thanked: 1 times
  • Naked Science Forum Newbie
    • View Profile
QotW - 21.05.24 - Are all snowflakes really unique?
« on: 24/05/2021 16:14:04 »
Alan sent us this message about snowflakes:

"I have heard it said many times that no two snowflakes are the same. Given the billions and billions of them that have fallen to Earth, this really does seem unlikely. Since nobody has looked at them all, would you agree with me that the only thing to be said with any certainty, is that no researcher has ever found two the same?"

What do you all think?
Logged
 
The following users thanked this post: Zer0



Offline CliffordK

  • Naked Science Forum King!
  • ******
  • 6595
  • Activity:
    0%
  • Thanked: 59 times
  • Site Moderator
    • View Profile
Re: QotW - 21.05.24 - Are all snowflakes really unique?
« Reply #1 on: 24/05/2021 18:40:44 »
I've never really been able to successfully capture snowflakes.  But they come in a few different varieties.  At times one gets big fluffy ones.  And other times, small ones, perhaps more like a low density hail.  Generally all very much 3 dimensional.  And, I generally don't see the symmetry that 2 dimensional flakes are represented as.  Especially the amorphous big fluffy flakes.

And, of course, one sees the familiar splat of them on a car's windshield.

Then one gets into a question of what is sameness. 

Is it general morphological features, or does one get down to a single molecule?

If one takes Avagadro's number: 6.0221409 x 1023...   8)  602,214,090,000,000,000,000,000

Ok, so a mighty big number.  But, what is that really measuring?  The number of molecules in a mole.

Take the molecular mass (H2O)...  so, O:16 + 2x H:1 = 18, and one gets that many molecules in about 18 grams per mole of water.  (18.01528 g/mol)

So 18 grams would be a mighty big snowflake.  And, they would obiously vary a lot in size.  So, perhaps 1/100 or 1/1000 of a mole depending on the size of the snowflake.

So, at 1/1000 of a mole, one still has  6.0221409 x 1020 molecules  (602,214,090,000,000,000,000).

That would be a lot of different snowflakes.

Oof...   :o

That is just calculating the number of ways a single molecule could be different (in identical sized snowflakes).

But, really, it can be any or all of the water molecules could be in a different place... 

So, a factorial problem.
6.0221409 x 1020 !

Now that becomes a really big number!!!

But, perhaps that isn't calculating quite what one wants.

Snowflakes would be somewhat constrained by the crystalline structure of water.  So, internal to the crystal, the water molecules would be generally constrained.  It is only on the surface where the constraints are loosened. Does the water molecule exist?  Branch point?  Are there a couple of possible orientations?

So the number of choice points gets reduced, and it becomes a density/surface problem.  Nonetheless, it is still a LOT of different configurations on the molecular level.

Likely any chance for identical flakes would not be those big fluffy ones, but small low density hail.
Logged
 
The following users thanked this post: charles1948

Offline charles1948

  • Hero Member
  • *****
  • 713
  • Activity:
    0%
  • Thanked: 41 times
  • Naked Science Forum Newbie
    • View Profile
Re: QotW - 21.05.24 - Are all snowflakes really unique?
« Reply #2 on: 24/05/2021 19:47:48 »
Clifford's post is a brilliant example of modern science at its best.

Superb in analytical detail.  Though not answering the OP's question. For understandable reasons.

Personally, I'd bet that identical snowflakes do occur, perhaps quite frequently.

But there are too many ephemeral snowflakes for Science to ever prove it.
Logged
Science is the ancient dream of Magic come true
 

Online Bored chemist

  • Naked Science Forum GOD!
  • *******
  • 27210
  • Activity:
    100%
  • Thanked: 910 times
    • View Profile
Re: QotW - 21.05.24 - Are all snowflakes really unique?
« Reply #3 on: 24/05/2021 20:01:39 »
Quote from: charles1948 on 24/05/2021 19:47:48
Clifford's post is a brilliant example of modern science at its best.

Superb in analytical detail.  Though not answering the OP's question. For understandable reasons.

Personally, I'd bet that identical snowflakes do occur, perhaps quite frequently.

But there are too many ephemeral snowflakes for Science to ever prove it.
You may prefer a more detailed study.
https://www.thenakedscientists.com/forum/index.php?topic=6511.msg67939#msg67939
Logged
Please disregard all previous signatures.
 

Offline CliffordK

  • Naked Science Forum King!
  • ******
  • 6595
  • Activity:
    0%
  • Thanked: 59 times
  • Site Moderator
    • View Profile
Re: QotW - 21.05.24 - Are all snowflakes really unique?
« Reply #4 on: 24/05/2021 20:42:03 »
Oh, man, I forgot about Deuterium and Tritium, and various Oxygen isotopes.  Not particularly common, but there will be a few in that mole.  And that doesn't count other contaminants.  A nucleation particle?  What about a few rogue hydrogens giving H3O+ and OH-?

When one starts calculating factorials...  the numbers get really really big.

But, that is calculating the number of different possible snowflakes. 

In a sense, this is also the birthday problem.

We know that there are 366 different unique birthdays (ignoring the year).  But, it doesn't take 367 students to have two with the same birthday.  In a class of 30 students, there is about a 75% chance that two will have the same birthday.

Logged
 



Offline alancalverd

  • Global Moderator
  • Naked Science Forum GOD!
  • ********
  • 14222
  • Activity:
    91.5%
  • Thanked: 1079 times
  • life is too short to drink instant coffee
    • View Profile
Re: QotW - 21.05.24 - Are all snowflakes really unique?
« Reply #5 on: 24/05/2021 22:08:11 »
The classic experimental publication is "Snow Crystals" by Bentley and Humphries, who spent many happy hours in Vermont photographing snowflakes and frost. They selected some 2500 images from many, many more and certainly never found two alike.

Even if you found two structures with the same underlying fractal symmetry, they would almost certainly not have the same number of molecules.

But beware. A searching question in the 1966 Natural Sciences Tripos Part II Crystallography was "The average photograph of a snowflake is more symmetrical than a photograph of an average snowflake - discuss."
Logged
helping to stem the tide of ignorance
 

Offline evan_au

  • Global Moderator
  • Naked Science Forum GOD!
  • ********
  • 10238
  • Activity:
    32%
  • Thanked: 1228 times
    • View Profile
Re: QotW - 21.05.24 - Are all snowflakes really unique?
« Reply #6 on: 24/05/2021 23:34:51 »
The reason that a snowflake looks fairly symmetrical is because all sides of the same crystal took the same path through the varying temperature, pressure and humidity profile inside the cloud.

But these dynamic environmental conditions are not precisely uniform across the width of a snowflake.
- So is even 1 "arm" of a snowflake identical to the other arms?
Logged
 

Offline charles1948

  • Hero Member
  • *****
  • 713
  • Activity:
    0%
  • Thanked: 41 times
  • Naked Science Forum Newbie
    • View Profile
Re: QotW - 21.05.24 - Are all snowflakes really unique?
« Reply #7 on: 24/05/2021 23:49:10 »
Perhaps "all snowflakes are unique" has a similarity to another popular saying  "lightning never strikes twice in the same place".

Does anyone know what's at the back of it?
Logged
Science is the ancient dream of Magic come true
 

Online Bored chemist

  • Naked Science Forum GOD!
  • *******
  • 27210
  • Activity:
    100%
  • Thanked: 910 times
    • View Profile
Re: QotW - 21.05.24 - Are all snowflakes really unique?
« Reply #8 on: 25/05/2021 09:00:35 »
Quote from: charles1948 on 24/05/2021 23:49:10
"lightning never strikes twice in the same place".
It strikes things like the Eifel Tower fairly regularly.

Quote from: CliffordK on 24/05/2021 20:42:03
In a sense, this is also the birthday problem.

We know that there are 366 different unique birthdays (ignoring the year).  But, it doesn't take 367 students to have two with the same birthday.  In a class of 30 students, there is about a 75% chance that two will have the same birthday.
Except in this case there are vastly more days in the year than students.
Logged
Please disregard all previous signatures.
 



Offline alancalverd

  • Global Moderator
  • Naked Science Forum GOD!
  • ********
  • 14222
  • Activity:
    91.5%
  • Thanked: 1079 times
  • life is too short to drink instant coffee
    • View Profile
Re: QotW - 21.05.24 - Are all snowflakes really unique?
« Reply #9 on: 25/05/2021 14:52:39 »
Quote from: charles1948 on 24/05/2021 23:49:10
Perhaps "all snowflakes are unique" has a similarity to another popular saying  "lightning never strikes twice in the same place".

Does anyone know what's at the back of it?

It's demonstrably untrue. I have a friend who has been struck by lightning twice. Even if the "place" moves from one country to another (in Dave's case Norway to England) if your name is on the ticket, it will find you.
Logged
helping to stem the tide of ignorance
 

Offline charles1948

  • Hero Member
  • *****
  • 713
  • Activity:
    0%
  • Thanked: 41 times
  • Naked Science Forum Newbie
    • View Profile
Re: QotW - 21.05.24 - Are all snowflakes really unique?
« Reply #10 on: 27/05/2021 20:38:03 »
To get struck by lightning once, may be regarded as a chance misfortune.

To get struck twice, looks like some kind of heavenly signal that Dave is marked out for a special destiny.

Has he experienced any further omens or portents of what that destiny might be?
Logged
Science is the ancient dream of Magic come true
 

Offline alancalverd

  • Global Moderator
  • Naked Science Forum GOD!
  • ********
  • 14222
  • Activity:
    91.5%
  • Thanked: 1079 times
  • life is too short to drink instant coffee
    • View Profile
Re: QotW - 21.05.24 - Are all snowflakes really unique?
« Reply #11 on: 27/05/2021 23:19:52 »
Possibly as a result, he had the most amazing Afro hairstyle for a man born with a straight Caucasian thatch. And a belief that resurrection was only needed by the sort of wimps who died in the first place. So his destiny may well have been as a permanent model for hairdressers and soul bands.
Logged
helping to stem the tide of ignorance
 

Offline clara

  • First timers
  • *
  • 1
  • Activity:
    0%
  • Naked Science Forum Newbie
    • View Profile
Re: QotW - 21.05.24 - Are all snowflakes really unique?
« Reply #12 on: 01/06/2021 00:48:19 »
There is a lovely book by (mathematician) Prof. Ian Stewart called "What shape is a snowflake?" In it he explains more or less (if I remember correctly) that the hexagonal symmetry of snowflakes is due to the shape of the water molecule so that  property is always present, but the exact shape depends on the exact conditions encountered by the snowflake on its descent, temperature, pressure, wind, dust etc. Since it is highly unlikely that 2 conditions will be identical, it is highly unlikely that 2 snowflakes will be identical. But no one has seen them all to make sure.
Clara
Logged
 



Offline Zer0

  • Hero Member
  • *****
  • 903
  • Activity:
    0%
  • Thanked: 85 times
  • Homo EviliUs
    • View Profile
Re: QotW - 21.05.24 - Are all snowflakes really unique?
« Reply #13 on: 02/06/2021 19:16:54 »
Quote from: Adam Murphy on 24/05/2021 16:14:04
Alan sent us this message about snowflakes:
Hi Alan! & Thanks for such an Intriguing question.
🙏


"I have heard it said many times that no two snowflakes are the same.
Yes.
❄️
Given the billions and billions of them that have fallen to Earth, this really does seem unlikely.
Yes.
❄️
Since nobody has looked at them all, would you agree with me that the only thing to be said with any certainty, is that no researcher has ever found two the same?"

Yes.
❄️
What do you all think?
P.S. - Probability is Longer than Infinity, Only when you count the Alphabets used to describe them.
♾️
Logged
1N73LL1G3NC3  15  7H3  481L17Y  70  4D4P7  70  CH4NG3.
 

Offline Adam Murphy (OP)

  • Global Moderator
  • Jr. Member
  • ********
  • 46
  • Activity:
    0%
  • Thanked: 1 times
  • Naked Science Forum Newbie
    • View Profile
Re: QotW - 21.05.24 - Are all snowflakes really unique?
« Reply #14 on: 07/06/2021 17:54:43 »
Thanks everyone for your input, we've now published our answer to this question, and you can find it here:

https://www.thenakedscientists.com/podcasts/question-week/every-snowflake-unique
Logged
 

Offline Just thinking

  • Naked Science Forum King!
  • ******
  • 1009
  • Activity:
    0%
  • Thanked: 144 times
  • Naked Science Forum Newbie
    • View Profile
Re: QotW - 21.05.24 - Are all snowflakes really unique?
« Reply #15 on: 04/07/2021 12:08:48 »
Quote from: Adam Murphy on 24/05/2021 16:14:04
"I have heard it said many times that no two snowflakes are the same. Given the billions and billions of them that have fallen to Earth, this really does seem unlikely. Since nobody has looked at them all, would you agree with me that the only thing to be said with any certainty, is that no researcher has ever found two the same?"

What do you all think?
I believe that every single structure no matter what it is has its own unique shape size weight. Even a man made object let's say a steel ball bearing one may say it is made to exacting standards well the answer to your question lays their standards imply within a degree of tolerance so perfection is a concept, not a fact.
Logged
 
The following users thanked this post: Zer0



  • Print
Pages: [1]   Go Up
« previous next »
Tags: snowflakes  / hi 
 

Similar topics (5)

QotW - 15.08.24 - Why do major keys sound happy and minor keys sound mournful?

Started by thedocBoard Question of the Week

Replies: 10
Views: 50302
Last post 05/04/2018 03:06:55
by Monox D. I-Fly
QotW - 08.04.06 - Better to drink wine than to drink nothing?

Started by thedocBoard Question of the Week

Replies: 36
Views: 117796
Last post 07/08/2021 00:12:57
by Zer0
QotW - 18.08.02 - Why are non-stick pans non-stick?

Started by Adam MurphyBoard Question of the Week

Replies: 6
Views: 44057
Last post 18/01/2020 06:33:19
by evan_au
QotW - 10.03.28 - Is a human bite worse than a dog bite?

Started by thedocBoard Question of the Week

Replies: 11
Views: 54993
Last post 06/10/2021 16:43:29
by Liaata
QotW - 11.03.06 - How do pain medications target pain?

Started by thedocBoard Question of the Week

Replies: 7
Views: 17427
Last post 18/01/2018 21:08:11
by evan_au
There was an error while thanking
Thanking...
  • SMF 2.0.15 | SMF © 2017, Simple Machines
    Privacy Policy
    SMFAds for Free Forums
  • Naked Science Forum ©

Page created in 0.155 seconds with 75 queries.

  • Podcasts
  • Articles
  • Get Naked
  • About
  • Contact us
  • Advertise
  • Privacy Policy
  • Subscribe to newsletter
  • We love feedback

Follow us

cambridge_logo_footer.png

©The Naked Scientists® 2000–2017 | The Naked Scientists® and Naked Science® are registered trademarks created by Dr Chris Smith. Information presented on this website is the opinion of the individual contributors and does not reflect the general views of the administrators, editors, moderators, sponsors, Cambridge University or the public at large.