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-   -   Snowflakes (https://www.cableforum.uk/board/showthread.php?t=33700444)

Wittmann 26-03-2015 14:16

Re: Snowflakes
 
Quote:

Originally Posted by heero_yuy (Post 35767484)
Resolution and accuracy. Two entirely different things.;)

I do not understand what that statement is supposed to mean or refer to. Doed not appear to be related to anything on this thread.

But what I do understand is that guessing, estimating, call it what you like, the physical parameters of a snowflake in terms of accuracy, is an impossibility. Any estimate can only be a wild guess, but a wild guess is better than nothing.

Stop It 26-03-2015 14:22

Re: Snowflakes
 
Quote:

Originally Posted by Wittmann (Post 35767375)
Just out of interest - you can check it on the web, the largest snowflake ever observed was reportedly 15 inches wide and 8 inches thick. I assume wide means corner to corner.

This is the record-holder for the largest known snowflake. It was found in Ft. Keough, Montana in 1887.

I bet if that hit you on the head, it would be curtains.

One UK gallon of water weighs 10 lbs.

With a length from corner to corner of 15 ins. a regular hexagon has an area of 146.142 sq.ins. x depth of 8 ins, Volume = approx 1,169 cub.ins.

One UK gallon has a volume of 277.42 cub.ins.

That snowflake allowing for 50% air content would weigh - 0.5 x 1169 x 10/277.42 = 21 lbs.

That would descend at one hell of a speed and momentum - then BANG - you are gone !

Everyone else has already went over the mass, but, the assumption that the mass of a snowflake would decide its descent velocity is flawed at best.

As you already said, snowflakes are complex things, but one constant is that they all generally fall at a gentle rate compared to hail and rain because they are less dense than these items. So, while large, the density of the snowflake should be comparable to a small one, so should fall at the same rate.

After all, a feather weighing a tonne would still fall like a feather because it is other factors, like surface area and aerodynamics, drag etc that determine the fall rate, the same applies here. The reason it would've been able to be observed, and likely isn't a wind up is for that reason, it would likely have fell to the ground safely, like most snowflakes.

Wittmann 26-03-2015 15:11

Re: Snowflakes
 
Quote:

Originally Posted by Stop It (Post 35767538)
Everyone else has already went over the mass, but, the assumption that the mass of a snowflake would decide its descent velocity is flawed at best.

As you already said, snowflakes are complex things, but one constant is that they all generally fall at a gentle rate compared to hail and rain because they are less dense than these items. So, while large, the density of the snowflake should be comparable to a small one, so should fall at the same rate.

After all, a feather weighing a tonne would still fall like a feather because it is other factors, like surface area and aerodynamics, drag etc that determine the fall rate, the same applies here. The reason it would've been able to be observed, and likely isn't a wind up is for that reason, it would likely have fell to the ground safely, like most snowflakes.

Do you really believe all that you have said ? Preposterous.

You are wrong in practically every word. You must have left school whilst in short pants to say things like that. How utterly ridiculous.

If a feather weighed a ton, it would drop like a ton. It would no longer be a feather. Mass, shape and surface area determine drag. Terminal velocity is proportional to mass. The reason a feather floats down slowly is that it has a tiny mass and a large surface area. If it weighed a ton, it would drop like a ton and make a huge crater in Mother Earth`s crust on impact.

Come off it, pick up your text books and start again.

Have you never heard the oldie - "What falls faster, a pound of feathers or a pound of peas ?"

Stop It 26-03-2015 15:24

Re: Snowflakes
 
Quote:

Originally Posted by Wittmann (Post 35767545)
Do you really believe all that you have said ? Preposterous.

You are wrong in practically every word. You must have left school whilst in short pants to say things like that. How utterly ridiculous.

If a feather weighed a ton, it would drop like a ton. It would no longer be a feather. Mass, shape and surface area determine drag. Terminal velocity is proportional to mass. The reason a feather floats down slowly is that it has a tiny mass and a large surface area. If it weighed a ton, it would drop like a ton and make a huge crater in Mother Earth`s crust on impact.

Come off it, pick up your text books and start again.

Have you never heard the oldie - "What falls faster, a pound of feathers or a pound of peas ?"

Yey, you confirmed my thoughts exactly, unable to actually step back and think about what you're saying.

Not only do you disregard density completely, but do so in spectacular style. A quick question for you, how heavy is an iceberg? If the answer is "A lot" now ask why do they not fall to the bottom of the ocean? When you answer that, come back to me and remember that a pound of feathers only falls the same rate as a pound of peas in a vacuum.

If mass only determined rates of falling etc, planes would never work, birds couldn't fly etc etc.

Note: If a feather weighted a tonne, it would be flipping huge in area, and thus, the same dynamics of drag would apply. It would still fall, like a feather.

Edit: Remember, Mass and Weight are 2 different things. :)

GrimUpNorth 26-03-2015 15:28

Re: Snowflakes
 
Quote:

Originally Posted by Wittmann (Post 35767545)
Do you really believe all that you have said ? Preposterous.

You are wrong in practically every word. You must have left school whilst in short pants to say things like that. How utterly ridiculous.

If a feather weighed a ton, it would drop like a ton. It would no longer be a feather. Mass, shape and surface area determine drag. Terminal velocity is proportional to mass. The reason a feather floats down slowly is that it has a tiny mass and a large surface area. If it weighed a ton, it would drop like a ton and make a huge crater in Mother Earth`s crust on impact.

Come off it, pick up your text books and start again.

Have you never heard the oldie - "What falls faster, a pound of feathers or a pound of peas ?"

So you're saying that a small piece of lead with the same mass as a feather if dropped at the same time from the same height would fall to earth in a similar fashion to the feather and come to rest at the same time? Not on this planet with its atmosphere it won't.

Cheers

Mr North

Wittmann 26-03-2015 16:27

Re: Snowflakes
 
Quote:

Originally Posted by GrimUpNorth (Post 35767548)
So you're saying that a small piece of lead with the same mass as a feather if dropped at the same time from the same height would fall to earth in a similar fashion to the feather and come to rest at the same time? Not on this planet with its atmosphere it won't.

Cheers

Mr North

Wrong again Grim. Sorry old chum, ya can`t win `em all.

The feathers/peas/mass comparison is not dropping these objects from 2,000 feet where air resistance looms up - called drag in the industry. It concerns dropping them from a few feet, where gravity is the only factor in the equation.

A feather with the same mass as a piece of lead as per your example, when dropped from a few feet will both hit the ground at exactly the same time on this very Planet we all love.

Any idiot knows that air resistance or drag is paramount in determining the terminal velocity of a specific body mass falling from a great height and is proportional to body mass and surface area.

Ever heard of a parachute Grim ?

GrimUpNorth 26-03-2015 16:41

Re: Snowflakes
 
Quote:

Originally Posted by Wittmann (Post 35767562)
Wrong again Grim. Sorry old chum, ya can`t win `em all.

The feathers/peas/mass comparison is not dropping these objects from 2,000 feet where air resistance looms up - called drag in the industry. It concerns dropping them from a few feet, where gravity is the only factor in the equation.

A feather with the same mass as a piece of lead as per your example, when dropped from a few feet will both hit the ground at exactly the same time on this very Planet we all love.

Any idiot knows that air resistance or drag is paramount in determining the terminal velocity of a specific body mass falling from a great height and is proportional to body mass and surface area.

Ever heard of a parachute Grim ?

I'd stop digging if I were you. I point out the flaw in your argument (that you're ignoring drag) then you ask if I've ever heard of a parachute - which despite your post above would be quite useful to have even for a fall from below 2000 feet.

Admit you're a good example of a little knowledge being a dangerous thing and there are many people out there (and on here by the looks of it) who seem to know a little bit more about a lot more things than you do.

Waiting for you're FINAL post on the matter like you seem to do in all your threads.

Cheers

Mr North

Wittmann 26-03-2015 16:59

Re: Snowflakes
 
Quote:

Originally Posted by GrimUpNorth (Post 35767572)
I'd stop digging if I were you. I point out the flaw in your argument (that you're ignoring drag) then you ask if I've ever heard of a parachute - which despite your post above would be quite useful to have even for a fall from below 2000 feet.

Admit you're a good example of a little knowledge being a dangerous thing and there are many people out there (and on here by the looks of it) who seem to know a little bit more about a lot more things than you do.

Waiting for you're FINAL post on the matter like you seem to do in all your threads.

Cheers

Mr North

No need to be rude Grimbo although from your posts it must be difficult not to be.
If I have a little knowledge, then it is a hell of a lot more than the people you so kindly refer to.

OK Grimbo, I admit that I made a mistake and apologise for it. A stupid over-sight on my part. Start again.

Even at a few feet, shape comes into it since air resistance does matter when a body is light and has a relatively large area.

A single feather with the same mass as a piece of lead, both having the same shape when dropped from a few feet, will hit the ground last due to the feathers many segregated strands creating drag. But a bag of feathers weighing one pound and a bag of peas weighing one pound will hit the ground at the same time.

In a vacuum, the identical feather and lead particles will hit the ground at the same time.

Now Grimbo, I resent your insulting personal remarks,which are quite unnecessary, so you are going on my Ignore list.

Osem 26-03-2015 18:05

Re: Snowflakes
 
Having resorted to ignoring everyone, except the Mods, I reckon the OP will be arguing with himself soon. Maybe it's many years of 'distinctive and distiguished' experience doing just that which has led to him referring to himself in the first and third person in the same post... :D

Sirius 26-03-2015 18:43

Re: Snowflakes
 
Quote:

Originally Posted by Osem (Post 35767593)
Having resorted to ignoring everyone, except the Mods, I reckon the OP will be arguing with himself soon. Maybe it's many years of 'distinctive and distiguished' experience doing just that which has led to him referring to himself in the first and third person in the same post... :D

Just quote Mr North's posts. ;) :LOL:

heero_yuy 26-03-2015 19:18

Re: Snowflakes
 
Quote:

Originally Posted by Sirius (Post 35767599)
Just quote Mr North's posts. ;) :LOL:

Rate we're going everybody's gonna be on quotes. :LOL:

Sirius 26-03-2015 19:19

Re: Snowflakes
 
Quote:

Originally Posted by heero_yuy (Post 35767616)
Rate we're going everybody's gonna be on quotes. :LOL:

Ok :)

GrimUpNorth 26-03-2015 19:39

Re: Snowflakes
 
Think I'll use Mr North all the time from now on. I won't bother quoting our learned friend as I'm on ignore so won't get a response ;) but from my experience in life it's often the case that when someone feel the need to claim they are intelligent it's normally diametrically opposed to the reality!

The thing that astounds me is he wants a 'scientific' debate but I pointed out an error in a statement (quite politely for me I thought) and I end up being called Grimbo (quite like that one too - I could use that one at Christmas - Grimbo at Crimbo!!). I wonder what the response would have been if I'd have questioned the snowflakes are 50% air assumption?

Cheers

Mr North

Sirius 26-03-2015 20:14

Re: Snowflakes
 
Quote:

Originally Posted by GrimUpNorth (Post 35767627)
Think I'll use Mr North all the time from now on. I won't bother quoting our learned friend as I'm on ignore so won't get a response ;) but from my experience in life it's often the case that when someone feel the need to claim they are intelligent it's normally diametrically opposed to the reality!

The thing that astounds me is he wants a 'scientific' debate but I pointed out an error in a statement (quite politely for me I thought) and I end up being called Grimbo (quite like that one too - I could use that one at Christmas - Grimbo at Crimbo!!). I wonder what the response would have been if I'd have questioned the snowflakes are 50% air assumption?

Cheers

Mr North

Excellent

Hugh 26-03-2015 20:20

Re: Snowflakes
 
Quote:

Originally Posted by GrimUpNorth (Post 35767627)
Think I'll use Mr North all the time from now on. I won't bother quoting our learned friend as I'm on ignore so won't get a response ;) but from my experience in life it's often the case that when someone feel the need to claim they are intelligent it's normally diametrically opposed to the reality!

The thing that astounds me is he wants a 'scientific' debate but I pointed out an error in a statement (quite politely for me I thought) and I end up being called Grimbo (quite like that one too - I could use that one at Christmas - Grimbo at Crimbo!!). I wonder what the response would have been if I'd have questioned the snowflakes are 50% air assumption?

Cheers

Mr North

Surely the composition of air/snow depends on the size of the snow crystal - they start off as tiny dendritic snow crystals, as they grow in size the become hexagonal, and as they get bigger, they become dendritic again....


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