11–20 of 173 posts
This article contains inaccuracies and says almost nothing novel for your average hacker new reader.
https://news.ycombinator.com/newsguidelines.html
What are the inaccuracies?
World record tennis serve is 144 miles an hour and a human can't really move across a court and return a ball moving at this speed. If they're lucky they can reach it and react in time to hit it. I'm a bit confused by an article that claims tennis players can react to and return serves up to 160 miles an hour. I think evidence suggests that returning balls anywhere near this fast is dependent on analysing factors bef…
'Players have an intuition about where the ball is going to go without having to look at and analyse the flight of the ball.' This is pretty easily observable with baseball players as well. After playing thousands of games while standing in the same (relative) place on the field I/they can anticipate where the ball is going to go based on a variety of variables in real-time... instantly.
Which is why practice is important. You're essentially strengthening certain neural pathways with continuous exposure to certain inputs.
But this strength also makes us susceptible to misdirection and slight of hand.
This article contains inaccuracies and says almost nothing novel for your average hacker new reader.
There is no analysis of the energy used by the brain to achieve anything or how much energy a computer uses for a similar task. So where is the discussion of efficiency?
I see how the term neuronal network reinforces this believe, but we (especially the researchers among us) should allow for the possibility that we are missing something.
One kind of efficiency which hasn't been talked about is the energy loss of things like state switching and keeping the current state enabled. I think that brains build on much more efficient primitives than the silicon transistors computer chips use and thus can perform far more computations for far less energy than a desktop CPU. Another difference between CPUs and brains is that brains are much less general purpos…
World record tennis serve is 144 miles an hour and a human can't really move across a court and return a ball moving at this speed. If they're lucky they can reach it and react in time to hit it. I'm a bit confused by an article that claims tennis players can react to and return serves up to 160 miles an hour. I think evidence suggests that returning balls anywhere near this fast is dependent on analysing factors bef…
'Players have an intuition about where the ball is going to go without having to look at and analyse the flight of the ball.' This is pretty easily observable with baseball players as well. After playing thousands of games while standing in the same (relative) place on the field I/they can anticipate where the ball is going to go based on a variety of variables in real-time... instantly.
This article contains inaccuracies and says almost nothing novel for your average hacker new reader.
> Please don't post shallow dismissals, especially of other people's work. A good critical comment teaches us something. https://news.ycombinator.com/newsguidelines.html What are the inaccuracies?
World record tennis serve is 144 miles an hour and a human can't really move across a court and return a ball moving at this speed. If they're lucky they can reach it and react in time to hit it. I'm a bit confused by an article that claims tennis players can react to and return serves up to 160 miles an hour. I think evidence suggests that returning balls anywhere near this fast is dependent on analysing factors bef…
The air resistance slowing the ball down is significant - combined with the energy the ball loses bouncing, the ball has lost more than half of its initial velocity by the time it gets to the returning player.
I found these speed guns stats on a tennis forum for the ball speed at different points:
Speed after being hit: 126mph
Speed before hitting court: 89mph
Speed after hitting court: 67mph
Speed at returner's baseline: 58mph
Even after doing the calculations correctly, there still isn't a lot of time for reactions, but it is more plausible than your initial analysis suggests. (Your units also seem off - should be seconds not milli-seconds).
Earlier quoted context omitted.
> Please don't post shallow dismissals, especially of other people's work. A good critical comment teaches us something. https://news.ycombinator.com/newsguidelines.html What are the inaccuracies?
The same accusation could be levied at the original artical.