h2g2 The Hitchhiker's Guide to the Galaxy: Earth Edition

I'm pretty sure the BBC coverage of the olympics includes coverage of just about everything these days doesn't it? The way it works is that you press the red button (sort of thing) and can just choose which event that is going on currently and just watch that as you wish. You can probably even watch stuff that's happened on catchup TV also I expect.

You don't get this sort of thing in the State?

Ugh... Olympic coverage in the States is just THE WORST!

It started nearly 30 years ago when NBC introduced something they called "Triplecast". It was a pay-per-view option in addition to the traditional 24 hour, single channel coverage that was typical of the aerial antenna age. NBC was asking up to $170 to get three channels "Red, White, & Blue" to see live coverage of various sports that normally would only be shown on tape delay during prime time hours. "Red" featured team sports (volleyball, basketball, water polo, &c).
"White" featured individual sports from gymnastics to rowing.
"Blue" featured only swimming the first week and track & field events the second week.

Sales were less than expected so discounts were offered (I don't believe they were offered to customers who already paid the original prices). In the end, NBC felt their "Triplecast" mainly just cannibalized their broadcast, advertiser funded viewership.

Now what they typically do is spread broadcasts across a few existing cable channels, but mostly focusing on the more popular sports. And notably, they focus mainly on sports that favor the US team. They've dropped coverage of a sport in the middle of the event when the US team fell out of medal contention!


I haven't really watched the Olympics since... Oh, I think it was probably the year Mary Lou Retton was the star. (Wow! that was way back in 1984!
However, my father watches the Olympics almost religiously. He watches everything he can. But he still can't watch some of the sports he's really interested in. So, I catch a bit of the Olympics every other year whether sort of vicariously.

It was his idea for running any events not being aired on the "official" network on other networks. But they won't do that because they're paying for exclusivity. "Watch what we show you or get stuffed!"

Small correction. Back in the aerial antenna days, coverage was NOT typically 24 hours. More like 12-16 hours tops.

Wowser.

Yes I do recall from the last Olympics hosted in the USA, when the beeb borrowed coverage from the US broadcasters that you could be watching a (say) 800 m race and just when they get to the home straight the camera could switch to the sixth place athlete, still in the 3rd quarter of the track - just because they were USAsia - and so miss the actual race at the front. So not improved - shame.

I went with my family to Maine in the late '90s to visit a distant cousin. This was during the Olympics. I had to sit through it on the motel television.

But I have to confess that I enjoyed Michael Phelps's swimming. That's my sport, and I like being able to root for someone who is so obviously better at it than I am.

"The displacement in time on both days can be described by integrating the two random speed functions"

Ah, I like that idea, caiman raptor elk

I might as well, if I completely understood what you're saying.

The displacement can be determined from graphically displaying the speed over time and calculating the surface area between the speed line and zero (so negative speed counts as negative displacement). This is easy at a constant speed. Displacement is just (elapsed time x speed). In cases of erratic speed profiles, the mathematical approach is to integrate, that is: calculate the partial surfaces of infinitessimally small chunks of time and add those up to the time where you want to know the displacement.

The other way round, you can determine the speed from the displacement over time.

Yeah... You're definitely over-complicating this. That's usually an indication someone's trying to find "the location" rather than simply prove there has to be "a location".

There is a rather simple way to explain why my statement is true, there has to be a location where the hiker will be at the same time of day on both Friday and Saturday. It's unavoidable.

I had another thought - we could consider the time to be not continuous, as it can only be measured to the second by the hiker's watch, so the set of all possible times going down is a subset of the set of all possible times going up.

The set of all possible positions is the same up and down, and since the hiker is larger than a single point, the set of possible different positions can be considered to be finite.

Thus there are two sets of items {(position, time)}.

Ah, no - I was going down the road of taking subsets of each set in turn, but that led into integration territory and trying to describe the point (h',t')...

I had a coworker threaten to write a computer simulation to disprove my assertion. But his code had a built in flaw in that it plotted points by second and offset the hikes up and down by 0.5 seconds. I pointed out that if you connected his plotted points, it still proved my assertion.


Since it's been a couple of days, I'll explain the two common proof methods. The first, as I said is graphical. As in the above example, if you plot the hiker's position along the trail (or altitude if you wish) against time of day and overlay the two days, you'll see that there is no way the two lines don't cross.

The other method (the one I used) was to consider the problem of one hiker on two days as equivalent to two hikers on one day. As long as they remain on the same trail, it's unavoidable that they will meet at some undetermined point along the trail.

I tried to introduce some RL friends to this puzzle again this weekend and one absolutely insisted on trying to guess the position even after my repeated insistence that is neither what I'm asking for or even possible.

Ah, yes - it is one thing to think of the situation as discrete points, but not to then add in new points, as that then leads to the ability to join the dots indeed!

That is fascinating that people like to try to guess the position even though you state the problem in vague enough terms...

Excellent method - a sort of topological solution that strips the problem down to the simplest possible thing, of two points on a 1-dimensional path

If the guy had infinite speed and walked up and down, he could even be at every location at the same time between 7 and 15h.

(and he would catch fire from the air friction)

He wouldn't just catch fire, he'd create a fusion explosion leveling everything within about a mile of the trail and a firestorm expanding dozens of miles beyond that.


See http://what-if.xkcd.com/1/

Now that was interesting to read…

Even if that wouldn't happen, there is still such a thing as escape velocity. (Tread carefully with those seven league boots, or you will leave the face of the earth)

He has a good one about orbital speed as well.

http://what-if.xkcd.com/58/


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