Random thoughts on snow flurries

  • #26
1,031
18
I think it's generally accepted as Brownian motion with drift.
I hadn't thought of it that way, but it's true. The motion of the flakes is ultimately determined by the sum of the impulses it receives from the molecules hitting it, along with a general downward drift. So I went out to track the micro wind patterns in a cubic meter of air. I started by tracking the molecules in the air and counting the individual hits as they bounced from flake to flake. This proved difficult and I soon tired of it. Then I reverted to watching the flakes themselves. Unfortunately, just as I got caught up in the wind-tossed life of a flake, a gust would take it away from me and I was overwhelmed by the sense of loss. I would focus on another, but you know how it is with snowflakes. Next, I gedanked about the following experiment. Place two film (not video) cameras at right angles to each other so that they cover the same volume of air. Their shutters should be synchronized somehow so that each frame from one camera can be matched to a frame from the other. Film for about a minute. Then see if you can identify the individual flakes from each camera. If you can, you will no longer need a weatherman to know which way the wind blows.
 
Last edited:
  • #27
Astronuc
Staff Emeritus
Science Advisor
20,150
3,722
I hadn't thought of it that way, but it's true. The motion of the flakes is ultimately determined by the sum of the impulses it receives from the molecules hitting it, along with a general downward drift. So I went out to track the micro wind patterns in a cubic meter of air. I started by tracking the molecules in the air and counting the individual hits as they bounced from flake to flake. This proved difficult and I soon tired of it. Then I reverted to watching the flakes themselves. Unfortunately, just as I got caught up in the wind-tossed life of a flake, a gust would take it away from me and I was overwhelmed by the sense of loss. I would focus on another, but you know how it is with snowflakes. Next, I gedanked about the following experiment. Place two film (not video) cameras at right angles to each other so that they cover the same volume of air. Their shutters should be synchronized somehow so that each frame from one camera can be matched to a frame from the other. Film for about a minute. Then see if you can identify the individual flakes from each camera. If you can, you will no longer need a weatherman to know which way the wind blows.
Or use a laser doppler anemometer.
 
  • #28
1,031
18
Or use a laser doppler anemometer.
Wow, I had one of these bad boys under a pile of old newspapers in the basement because I didn't know what it was. So I googled it. Here's what I found:

The Institute for Advanced Snowflake Studies said:
Laser Doppler Anemometry (LDA) is a technology used to measure velocities of flows or more specifically of small particles in flows.

http://www.nat.vu.nl/envphysexp/REAL%20Experiments/LDA%20exp/LDA.html" [Broken]

Well if that doesn't satisfy my curiosity, I don't know what it doesn't do. A little more googling reveals the answer to the OP's ponderism:

OP said:
I wonder if there are scientists who study the motion of flurries.
Yes.
 
Last edited by a moderator:
  • #29
1,031
18
Alrighty then. I dusted off the LDA and aimed it at my backyard. These laser jobs are much easier to use than the old hand crank ones. My results are as follows:

400 to 500 kph; no flakes
300 to 400 kph; no flakes
200 to 300 kph; no flakes
100 to 200 kph; no flakes
0 to 100 kph; 35425 flakes
-100 to 0 kph; 1 flake

I don't know what to make of it. I used histograms, pie charts, line graphs, bar graphs, you name it, but I'm getting nowhere. However, with a standard deviation like this one, you know I'm onto something.
 
  • #30
Astronuc
Staff Emeritus
Science Advisor
20,150
3,722
Alrighty then. I dusted off the LDA and aimed it at my backyard. These laser jobs are much easier to use than the old hand crank ones. My results are as follows:

400 to 500 kph; no flakes
300 to 400 kph; no flakes
200 to 300 kph; no flakes
100 to 200 kph; no flakes
0 to 100 kph; 35425 flakes
-100 to 0 kph; 1 flake

I don't know what to make of it. I used histograms, pie charts, line graphs, bar graphs, you name it, but I'm getting nowhere. However, with a standard deviation like this one, you know I'm onto something.
Now if you compare the LDA with the video cameras, you'd have a great experiment for next years Science Fair. It's going to be tough though to beat a cure for tuberculosis.
 
  • #31
turbo
Gold Member
3,147
53
:rofl: Excellent! I take it you've been to WVU, or know people who have, that you are familiar with the Mountain Lair? :biggrin:

Yeah, I'm originally from Jersey, but had the good sense to get out! :biggrin: :tongue:
Just looked up WVU, and I must say you've upgraded big-time (location-wise). That's a really pretty area. I used to do consulting work at the Westvaco mill in Luke MD, and stayed in Keyser WV. If I had to stay over a weekend, I'd spend time driving around the area. Some of those roads could be "exciting" if they were slippery with ice.
 
  • #32
1,031
18
I take it you've been to WVU, or know people who have, that you are familiar with the Mountain Lair?
This question wasn't directed at me, but I'll answer it anyway. I am not familiar with either of these, but I spent a delightful long weekend camping along Skyline Highway a few years ago. I saw a few bears scampering hither and yon, but the best was a doe and her fawn that wandered right into our campsite. She must have gotten used to people. When she saw me, even though she was slightly startled, she just situated herself twixt me and the fawn and ambled off.
 
  • #33
Moonbear
Staff Emeritus
Science Advisor
Gold Member
11,558
53
Now why would anyone leave a state that is so convenient to NY, PA, and DE?
I'm still conveniently close to PA...the pretty end of the state. :biggrin: Close enough to the others to visit, far enough not to be overrun with their bad drivers.

Just looked up WVU, and I must say you've upgraded big-time (location-wise). That's a really pretty area. I used to do consulting work at the Westvaco mill in Luke MD, and stayed in Keyser WV. If I had to stay over a weekend, I'd spend time driving around the area. Some of those roads could be "exciting" if they were slippery with ice.

Definitely. Though, the local area is now sprouting up with strip malls and chain restaurants, but you don't have to drive far to get back into pretty country again.
 
  • #34
turbo
Gold Member
3,147
53
I'm still conveniently close to PA...the pretty end of the state. :biggrin: Close enough to the others to visit, far enough not to be overrun with their bad drivers.

Definitely. Though, the local area is now sprouting up with strip malls and chain restaurants, but you don't have to drive far to get back into pretty country again.
You are very close to the "pretty end" of PA. Sometimes when I worked at Luke, I'd fly into Pittsburgh and drive down instead of flying into Baltimore. I had more flight options if I flew into Baltimore, but the drive out of Pittsburgh was LOTS prettier and there were fewer bad drivers to contend with.
 
  • #35
1,031
18
but you don't have to drive far to get back into pretty country again.
So you left the smells of NJ for the sights of nature. Just be careful, most people die of natural causes.
 
  • #36
Moonbear
Staff Emeritus
Science Advisor
Gold Member
11,558
53
So you left the smells of NJ for the sights of nature. Just be careful, most people die of natural causes.

:rofl: I lived in NJ long enough that there's still a chance I'll die the usual way...of cancer. :uhh: Every time I talk to anyone back in NJ, they know another 3 or 4 more people diagnosed with cancer.
 
  • #37
George Jones
Staff Emeritus
Science Advisor
Gold Member
7,519
1,307
Yesterday, I woke up to another 10 cm (4 inches) of fresh snow.

No new snow today, but the temperature was -19 C (-2 F) when I left for work.
 
  • #38
1,031
18
Yesterday, I woke up to another 10 cm (4 inches) of fresh snow.

No new snow today, but the temperature was -19 C (-2 F) when I left for work.
I hope you remembered to button up your vest.

I don't know who said:
As I set down one evening in a timber town cafe
A six foot-seven waitress, to me these words did say
"I see you are a logger and not a common bum
For no one but a logger stirs his coffee with his thumb

"My lover was a logger, there's none like him today
If you'd sprinkle whisky on it, he'd eat a bale of hay
He never shaved the whiskers from off his horny hide
But he'd pound 'em in with a hammer, then bite 'em off inside

"My lover came to see me one freezing winter day
He held me in a fond embrace that broke three vertebrae
He kissed me when we parted so hard it broke my jaw
And I could not speak to tell him he'd forgot his mackinaw

"I watched my logger lover going through the snow
A-sauntering gaily homeward at forty eight below
The weather tried to freeze him, it tried it's level best
At a hundred degrees below zero, he buttoned up his vest

"It froze clean down to China, it froze to the stars above
At one thousand degrees below zero it froze my logger love
They tried in vain to thaw him and if you'll believe me, sir
They made him into ax blades to chop the Douglas fir

"That's how I lost my lover and to this caffay I come
And here I wait till someone stirs his coffee with his thumb
And then I tell my story of my love they could not thaw
Who kissed me when we parted so hard he broke my jaw"
 
Last edited:

Related Threads on Random thoughts on snow flurries

  • Last Post
Replies
3
Views
12K
Replies
4
Views
958
Replies
10
Views
7K
  • Last Post
Replies
5
Views
2K
  • Last Post
347
Replies
9K
Views
271K
  • Last Post
107
Replies
3K
Views
94K
  • Last Post
91
Replies
2K
Views
115K
  • Last Post
161
Replies
4K
Views
145K
  • Last Post
9
Replies
212
Views
23K
  • Last Post
134
Replies
3K
Views
296K
Top