Nintendo DS Wireless in Freefall
Nicholas Roussos writes "Wired reports about four skydivers who decided to give the Nintendo DS wireless capabilities a try while they were freefalling. 'The four sky divers proved that an ad hoc network set up using the wireless functions of a Nintendo DS works perfectly at distances of nearly 400 feet while falling 120 miles an hour,' states the article."
I'll tell you what would be cool, ultralights with automatic paintball guns, heat seeking nerf missiles, and a HUD. Then have a dogfight, and when Mr. Farmer comes out of his house yelling at you for scaring the bejesus out of his livestock you make a second pass, *thunk* *thunk* *thunk* *thunk*
Wait, what was this article about again?
In this year of the Einstein centenary, these skydivers have managed to rediscover the Principle of Relativity - that it matters not how fast you are moving, the laws of physics are the same. Indeed, if radio waves failed to propagate for skydivers the entire structure of physics would have to be re-created from scratch.
So now when they kick you and your friends off the plane for using wifi while in flight, you'll be all good.
http://stashbox.fromtheshadows.tv/
or the actual torrent:
http://torrents.fromtheshadows.tv/fts_box1.0.avi.t orrent
It is good to read about some real world applications with todays technology. Usually these articles are so theoretical....
At speeds like that, how could the speed of light even hope to keep up?
They might have hit the ground before they booted up the game and loaded the level. ;)
Jimmy! PULL THE STRING!!
*waves hand* Just a second man
For the love of god! Deploy your parachute!
I just gotta get the high score, I'm almost there. *SPLAT*
... and in the DRM, bind them.
I get pretty bored skydiving too.
1) If Bob is in the baggage car of a train traveling north at 90MPH and Margaret is standing still 10 cars north of Bob, each car being approximately 40 feet long, home much time would pass before Bob crashes into Margaret? Show your work.
2) If I put two chickens in a bag and give you the bag, how many chickens do you have?
3) If radio waves from a Nintendo DS travel at roughly 186,000 miles per second, how fast would two parallel trains moving in the same direction have to travel before the conductor in each train could no longer receive signals from the other conductor's Nintendo DS?
4) If you were in a car travelling at the speed of light and you flashed your high-beams, would anything happen? Assume you're on the New Jersey Turnpike.
So I looked up the relativistic Doppler effect and plugged in some numbers.
.0017% of the total frequency range. Unfortunately, I don't know what the tolerances for 802.11b are, but I have difficulty believing that .0017% would cause much trouble.
For a relative velocity of 400mph you get an observed frequency of 2.39999856GHz.
Now, looking at the 802.11b spec available at the 802 working group site I see that it operates in the 2.4 - 2.4835GHz range.
So the Doppler effect at 400mph introduces a difference in frequency equal to
Now, backfiguring for a more common 5% tolerance, we get something like 500,000m/s or 1.1 million mph. So, yes, 802.11b probably won't work between passing spaceships. Aside from that, we're probably safe.
Not the theories of Relativity, the Principle. There is a difference. Einstein's theories of Relativity solved an increasingly important conflict between physicists beliefs that the Principle of Relativity was true (an intuitive belief) and their inability to put solid math around the way the Universe works.
The first chapter of this work should help. Basically, the principle of relativity is that physics is the same for all inertial reference frames; Einstien put that together with the fact that light appears to travel the same speed for all observers. Galilean relativity doesn't work with that; it has other contradictions inherent in it (it can't answer the Zeno paradox, again, see the linked work), but it takes longer to notice. There are other relativity theories that haven't panned out, either.
Pardon the pedantry, it's intended to be educational.