How does a shuttlecock know it's outdoors?

Discussion in 'Shuttlecock' started by petert1401, Aug 31, 2009.

1. petert1401 Regular Member

Joined:
Nov 19, 2007
Messages:
67
0
Location:
Maidstone, KENT
Here's a question for you physicists out there:

The standard speed test for a shuttle is to be able to hit it from the baseline to around the doubles long service line of the opposite court - a distance of around 42 feet.

However, if I hit the same shuttle outdoors I struggle to hit it much further than about 30 feet. Why the discrepency?

It's not down to breeze. If I turn around and hit in the opposite direction, it may go a foot or so further, but still nowhere near 42 feet.

It's not down to temperature (and therefore presumably air density) either. I typically play indoors at around 20 degC - at the same temp outdoors the shuttle flies nowhere near as far.

So how does that shuttle know that there is a roof up there and walls all around, so then it then flies the right distance? I must be missing something.

Just curious...

#1
2. gingerphil79 Regular Member

Joined:
Jul 18, 2007
Messages:
594
1
Occupation:
Sports massage therapist
Location:
Northern Ireland, UK
possibly because of the walls and roof, the air in there could be either more dense, or less dense therefore affecting the speed of the shuttle.

Only a guess thou lol

#2
3. petert1401 Regular Member

Joined:
Nov 19, 2007
Messages:
67
0
Location:
Maidstone, KENT
Not sure I buy that one. If the temperature is the same but the density was different, it would mean there was a partial vacuum indoors and the pressure (density) would equalise as soon as a window or door was opened.

A question for players from tropical climes: I assume that typically your badminton courts are air-conditioned and cooler than the outside temperature. Does a shuttle fly further outdoors than indoors where you are?

#3
4. 7SamuraiX Regular Member

Joined:
Dec 31, 2008
Messages:
136
0
Occupation:
university student
Location:
Malaysia, NZ
A question:
Did you check the differences in sea level? ie, how high above a structure is from sea level?

I suggest you try this test:
Hit the shuttle indoors and record the average distance travelled
Then, go just outside the badminton hall and hit the shuttle again
Record the average distance travelled and see how they compare

This way, i can at least try to ensure that almost all factors remain cosntant

#4
5. petert1401 Regular Member

Joined:
Nov 19, 2007
Messages:
67
0
Location:
Maidstone, KENT
Good idea. I'm playing tomorrow so I'll try that if it's not too windy.

#5
6. hhwoot Regular Member

Joined:
Sep 22, 2008
Messages:
163
0
Occupation:
Location:
Urbana, IL
There are several possibilities, I'll list some that I think are more likely.

1) Even though the temperature is the same, that does not mean the air density is the same. Water content, humidity, can also be a factor. It may be that the inside of your gym is more humid (less dense air) than the outside (more dense air).

2) Wind does not need to be parallel to the ground. It may be that there was a slight downdraft when you tested the shuttle outside.

3) Obviously the shuttle does not know that it's outside. However, you do know that you are hitting a shuttle outside. It is possible that you are unconsciously not hitting the same way outside.

#6
7. Lordofthefart Regular Member

Joined:
Aug 26, 2009
Messages:
150
0
Occupation:
Student
Location:
so the gravitational equation looks like this
fg= (GM1M2)/r^2, now are you suggesting that the difference of a couple of meters ie the radius is enough to make a significant change in the gravitational forces?

#7
8. petert1401 Regular Member

Joined:
Nov 19, 2007
Messages:
67
0
Location:
Maidstone, KENT
I'm not sure how air density varies with humidity, but I do know that sports halls in this country very rarely have any form of humidifiers (unless you count evaporated sweat, which I'd rather not think about too much). I think the humidity will probably vary only slightly between inside & outside.

Possible I suppose, but it seems to happen every time I try it, even when I can detect no breeze at all.

Can't argue with that one...

#8
9. cooler Regular Member

Joined:
Apr 25, 2002
Messages:
21,947
15
Occupation:
Surfing, reading fan mails:D, Dilithium Crystal hu
Location:
Basement Boiler Room

4) go measure the inside & outside actual temp. "It feel like similar temperature' measurement does not cut it if u want the precise answer to your question.

#9
10. petert1401 Regular Member

Joined:
Nov 19, 2007
Messages:
67
0
Location:
Maidstone, KENT
But I play indoors in temperatures between about 10 degC in an unheated hall in winter and about 25 degC at the height of summer; in all those temps I can hit the shuttle from one end of the court to the other.

But outdoors, no matter what the conditions, I can't. Maybe it's me.

Would someone mind nipping outside, trying it & reporting back? Please...

#10
11. Lordofthefart Regular Member

Joined:
Aug 26, 2009
Messages:
150
0
Occupation:
Student
Location:
you do realize that the air ratio is different indoors and outdoors right? like the particles out doors is different from indoors because most places have a circulating air that removes things like dust etc with its filters

#11
12. petert1401 Regular Member

Joined:
Nov 19, 2007
Messages:
67
0
Location:
Maidstone, KENT
I'm not sure what you mean by an air ratio.

Are you saying that the amount of dust is so much greater outdoors that it makes a shuttle fly only 2/3 as far as it does indoors? Going outdoors must be hazardous to your health...

#12
13. cooler Regular Member

Joined:
Apr 25, 2002
Messages:
21,947
15
Occupation:
Surfing, reading fan mails:D, Dilithium Crystal hu
Location:
Basement Boiler Room
i have tried testing shuttles outside. In my cases tho, outside is always colder than my inside testing. Average distance on outside testing is about 1 to 2 foot less than indoor. Outside temps were about 10-13 celsius degree lower than indoor.

#13
14. petert1401 Regular Member

Joined:
Nov 19, 2007
Messages:
67
0
Location:
Maidstone, KENT
Thanks for that Cooler, that's more the sort of figures I'd expect.

Looks like it's either just me or the UK has a permanent downdraft. I did hold a flag outdoors and it hung downwards so I guess that confirms it?
OK, it's just me not hitting the shuttle properly outdoors...

#14
15. cooler Regular Member

Joined:
Apr 25, 2002
Messages:
21,947
15
Occupation:
Surfing, reading fan mails:D, Dilithium Crystal hu
Location:
Basement Boiler Room

2(a) it maybe small but outside always has some kind of draft. This minor draft can affect your impact point inconsistently, ie., it is likely u would not hit at the sweetspot all the time like u do indoor. That's what i had experienced when i was testing outside, getting each shot hit the same strength, angle and sweetspot. My swing distance has to be shorter to ensure i hit the sweet sport each time (outside).

#15
Last edited: Aug 31, 2009