OT: Football "Physics"

I think the Pats know if you fill them in a hot room they'll be soft when exposed to outside temps.

Cheers

Guy-Lussac law using absolute pressure and including the compressiblity of nitrogen shows that physics could be responsible for a large portion of the drop

defeat-deflategate.html

It also depends on the temp and location of the compressor.

Place five numbered balls into five refrigerators at five temps, and make one a chamber that sits 10 degrees above normal ambient.

Use 72F as a std. ambient point.

Place the compressor tanks in each fridge as well, and let them all settle out for some hours.

Fill each to exact calibration center point. Make measurements.

Cycle the balls through each fridge, settle time and fill and measure events. That way, you rule out ball to ball differences.

Collect data which can then be used as a baseline expected rule of thumb.

On game day, all balls should be stacked into a vertical, clear plexiglass box for ALL to see at ALL times. The ball boy gets balls from there feeding out of the bottom of the box. Once filled and inspected, they should get their fill valves SEALED, and get placed into the sideline boxes. Easy Greasy.

Howard Hughes proved that liquids are compressible.

Gas most certainly is.

Any idiot understands the operational metrics of a bourdon tube.

Any others should likely remain out of the conversation(s).

b.

how about they just fill and check the pressure on side line before each ga me

-Lasse

I don't know the dynamics of the bladder of a football, but that much pressure drop doesn't seem to me to fit "natural" deltas. ...Jim Thompson

Oh! Are they nitrogen-filled? ...Jim Thompson

eat-deflategate.html

nitrogen should make it change less because it is dry

-Lasse

Can somebody explain to me why both teams don't just use one set of balls (either supplied by the league or the home team)?

Cheers

Maybe they fell for that tire inflation with N2 scam ?>:-} ...Jim Thompson

AIUI, each used to supply their own balls. Different balls would be used by the offense and the kicking team. Your question is a good one though. It seems absurd to have each team use different balls when they're supplied by one team. The NFL must be too poor to supply the balls. ;-)

Get online or whatever and watch some damned NEWS articles, dorky.

BOTH teams bring balls.

Like you, I have no idea why it is this lame.

The MLB folks , I think the Umpires bring a bevy of balls... Still, it is the league providing them.

The fact that the teams have access to them is kind of lame. I am sure it will now change.

So you insult me and then agree with me. You must be a hoot at cocktail parties.

Calling you 'dorky' isn't an insult, it is a poke in the ribs, at best.

Sheesh, should I call you an over-sensitive cry baby now?

Also... did you watch the State Of The Union Address the other night? If the answer to that is NO, then I say you SHOULD start watching more news. And especially so in areas you appear to take interest.

I mean if it is a hot discussion item here, does it not follow that it is likely a popular current news item as well?

Despite the CRAP going on inthe world, it happens to be several of the "top stories" right now.

I watched a bunch, but I also found it surprising as to what qualifies as "breaking news" today.

So, yeah... a little dorky.

Oh, and cocktail parties went out in the '70s... or should have. Only overpaid politicians and other gov factions get to have them any more.

We get the "Let them eat cake" variety and our penny ante poker games are considered illegal gambling.

Me. I want a number of them in jail for illegally gambling with our nation's economic stability.

But footballs? Top news?

It is truly a sad world.

By my math, the pressure drop (for 30F delta) should be about 0.72 PSI, actually less since the ball isn't rigid. Less than half of what the Prominent Boston Physicist got. Somebody could check this.

I get an 11.4 PSI drop. Go thee unto: Click on Solve for P2 T1 = 273 + 70C = 343K T2 = 273 + 40C = 313K Click on Calculate and it produces an 11.4 PSI drop in pressure.

Oops. I made the same mistake as the Prominent Boston Physicist. P1 = 12.5 PSI as the initial pressure. The calculated P2 = 11.4 PSI. Pressure drop is 12.5 - 11.4 = 1.1 PSI

I'm not gonna mess with PVT calcs, but just thought I would let you know that no pro football game has ever been played at 70C, and no pro football game has ever been at 40C, at least during the winter.

--- Joe