(You canna change) The Laws of Physics - on tennis courts

Interesting article on the physics of tennis courts - speed, height of bounce etc. Probably re-states much of what we know, but it adds some science and it's nice to see it in a succinct and scientific context.

http://www.grantland.com/story/_/id/6906922/the-physics-grass-clay-cement

The ITF currently recognises more than 160 different surfaces! Pity that we've seen the homogenisation of courts in the big tournaments when such a variety are available.

I have not read it entirely but already caught some flaws.

"The reason is obvious: The game is far too fast. Douglas Hofmann,7 a materials scientist at the Jet Propulsion Laboratory and Caltech and former assistant coach of the men's tennis team, explains why the speed of tennis makes thinking about physics all but impossible: "Let's say you're returning a serve at 125 mph," he says. "Given the length of the court, that means you've got about 0.4 seconds to execute your swing. It takes about .25 seconds just to execute a bodily movement. So that leaves just over a tenth of a second to actually think about what you want to do. If you're trying to do some computations, the ball is going right past you."

The fact is the ball is not going at 125mph all the way to the returner. It is in fact slowed down all the way with significant deceleration at inpact on the ground and even more so when the ball is hit 2 or 3m behind the baseline going at 45 mph at the baseline and dropping quickly further after...on grass so probably slower on sandy HCs.

Some HE graphs show a 0.6 sec to react at the baseline but over if taken after like those standing way far back. Fast of course, but let's face it, no-one wins a match on serve alone nowadays, unlike in teh 90s, so if anything the courts are too slow.

The slowing of the surface
From a few HE

Even if the average speed of the serve from racket to racket were 125 mph, which we know it isn't, given the height of the server's racket and the receiver standing only a couple of feet behind the baseline, and the ball not travelling in a straight line (i.e. bouncing) the time would be over 0.45 secs which would give twice the 'thinking' time stated in the article (0.2 secs).

However, despite a bit of mathematical inaccuracy, I think the point made - that there is no time to put into effect a higher knowledge of physics - still applies, even at 0.6 seconds. Although it's a bit obvious anyway.

JHM... I had soem analysis on Federer was better in 2006 thread.

"Court dimensions for singles (L x W) = 78 ft long x 27 ft wide.

Longest distance (diagonal) ~ 83 feet ~ 0.0155 miles

At 120 mph serve takes ~ 0.466 seconds.

A 90 mph winner takes ~ 0.62 seconds.

Return in 0.92 seconds, 1.24 seconds at the most for a round-trip along the longest side, which is not always the case.

Some amazing hand-eye coordination is required to execute a shot, and even more amazing movement to get to where the ball is in the first place.

The player who awaits for the ball to come back has a maximum of 0.62 seconds to make a decision where they need to be.

This applies to players in 1980s as well as 2010s. Tanner and Phillippousis could serve at such speeds earlier than 2011.

http://en.wikipedia.org/wiki/Fastest_recorded_tennis_serves

https://www.youtube.com/watch?NR=1&v=vBctFQT1Dxg

https://www.youtube.com/watch?v=sK-M2rSZ9zc&feature=related
"


https://www.606v2.com/t14760p450-was-federer-better-in-2006-poll-added

When I play tennis I augment my thinking time by accessing a subconscious parallel thought processor, and make use of "ready to go" logical units (functioning algorithms) that I have previously loaded into muscle memory.


ps: My next comment might have to be my last if I wish to preserve a 606 unity.

Hats off JHM, I never thought I'd see a reference to Star Treckin' on these here message boards.

Positively 4th Street wrote:Hats off JHM, I never thought I'd see a reference to Star Treckin' on these here message boards.

I have my uses!
Next topic - "World rankings - I am not a number, I am a free man!"

laverfan wrote:
Return in 0.92 seconds, 1.24 seconds at the most for a round-trip along the longest side, which is not always the case.

What do you call a round trip? for the ball to go back and forth?

https://www.youtube.com/watch?v=Nt3zCzgWW2E


Look at this first rally. 14 lengths in 19 sec or so...Nearly 1.36s per length only!

6 and 7 years ago I made an average calculation between Fed v Blake USO (06/07) and the time was 1.1 sec or so...even faster I believe. That's nearly 20% faster than grass 2008!


Look at 1mn 18sec ..look at the pace.....8 shots in less than 8 sec! That is a whopping 36% faster rally than Wimbledon 2008! oK they are not all that fast but they are considerably faster on average.

This support my arguments that those talking about stringer era nowadays don;t know what they are talking about. It was simply a different tennis played on different conditions. Conditions that simply did not suit Nadal's game.