# Thread: How does a shuttlecock know it's outdoors?

1. ## How does a shuttlecock know it's outdoors?

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...

2. 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

3. Originally Posted by gingerphil79
possibly because of the walls and roof, the air in there could be either more dense
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?

4. 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

5. Good idea. I'm playing tomorrow so I'll try that if it's not too windy.

6. 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.

7. Originally Posted by 7SamuraiX
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
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?

8. Originally Posted by hhwoot
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).
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.

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

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.
Can't argue with that one...

9. Originally Posted by hhwoot
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.

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.

10. Originally Posted by cooler

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.
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...

11. 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

12. Originally Posted by Lordofthefart
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
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...

13. Originally Posted by petert1401
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...
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.

14. 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...

15. Originally Posted by petert1401
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...

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).

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