60 mph?
Kyle Ferrio
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Spoilers for TFON:
da...@netcom.com quoth:
>If B5's gravity is centrifugal, and the 'ground' is moving at 60 mph, then
>it has a radius of about 240 feet (88 ft/sec * 88 ft/sec / 32 ft/sec**2),
>but outside shots seem to suggest a diameter of closer to half a mile.
>What am I missing? (I'm assuming the various levels are fairly close
>together near the rim, as there's been no suggestion of widely differing
>gravities.)
Yup. You may find a couple of previous threads on this topic, starting
on Tuesday or Wednesday last. In my original post, I obtained the same
estimate as you.
And like you, I find the radius of 240 feet suspicious, especially since
that implies a rotational period of 17.2 seconds --- whoa I think I'm
getting dizzy looking out this window! Some have suggested that the
centripetal acceleration looked equivalent to only half earth-normal
gravity. I don't know, but a factor of two or three changes the radius
and period only in proprtion.
The quadratic influence of the rotation speed is more important. A garden
rotation speed of 200 miles per hour would have given a radius of 0.45
mile and a rotation period of 57 seconds.
But, hey, I get enough physics in my day job. So until the geometry and
rotation of B5 become plot points (which I guess they did in The
Gathering), I am content to sit back and listen to the song.
_________________________ __________________________________________
| Kyle Ferrio | Time to Season Three: 1 days, 9:7
| University of Michigan | Where were you at the
| Randall Laboratory | Dawn of the Third Age of Mankind?
Andrew Blanchard
we are talking about centrifugal force in the instance of Babylon 5, which
has no attraction at all. Descent of a free floating object is will be
at a *linear* rate depending on the force applied at point of "launch",
giving a slightly more realistic diameter.
Andy
/ Internet: The truth is out there... -------------------------------\
| -------- Andrew Blanchard -------- an...@zocalo.demon.co.uk -------- |
\-------------------------------- ...but I'm damned if I can find it. /
Kyle Ferrio
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Spoilers!
cmpa...@ingr.com quoth:
>Ok, I'm always one to jump in with half-assed justifications. For the
Welcome. You're in good company. :)
>last little bit of the fall, wouldn't you accelerate due to wind shear?
>So, maybe the station does rotate at about 200 miles per hour, but you
>would hit at around 60mph. Maybe (really stretching it), this is common
>knowledge (obtained by experience of kids throwing water balloons out
>of the monorail windows)?
This is a very good point, and others here have applied simple drag
models to answer your question. I think your idea has merit -- the
radially-growing "wind" (which always "blows" in the direction of
rotation) will tend to reduce the tangential component of Sheridan's
velocity relative to the statio surface.
My only objection is that Ivanova says (almost quoting) "...but the
surface is moving at 60 mph." Now we *could* interpret that
metaphorically in the reference frame of the falling dude.
I *like* it.
>Would it have helped any if Sheridan started blowing air from his mouth
>really hard to keep him near the axis longer?
ROTFL!
Cheers,
_________________________ __________________________________________
| Kyle Ferrio | Time to Season Three: 0 days, 3:23
Chris Barnabo
>Chris Palmer wrote:
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>
>> Would it have helped any if Sheridan started blowing air from his mouth
>> really hard to keep him near the axis longer?
>
>sence dictate that he throw himself out along the axis? (He could have kicked
>out of the doorway sideways and let air-resistance help) The way my
>deterministic systems text reads, that would have bump his hang time up a few
>seconds, and every second counts.
Hmmm ... yes, but he might have been being careful. Remember, his
lateral velocity (along the path of the shuttle) essentially remains
unchanged when he jumps out, except for change due to wind resistance.
If he drifts up and hits the shuttle track, it's like hitting the
ground at, well, however many MPH the shuttle travels.
Anyway, if he jumped upward to try to get to the axis, he probably
would have overshot and wound up falling on the *other* side of
the station, then Kosh would've had to fly a lot further to rescue
him (or maybe nobody would've noticed him growing smaller on the
other side of the shuttle at all, in which case ... *!)
On a tangent --- 60 *miles* per hour?!? I'd have thought that Earth
would have finally gone metric by then ... on the other hand, if
they're really using the English measurement system, maybe their
mechanics would have a shot at fixing my MGB. 8-)
-- Chris ________*________
____________ \_______________/ Chris Barnabo, iri...@ibm.net
\__________/ / /
__\ \_______/ /__ "The heck with the Prime Directive,
\_______________/(- let's destroy something!"
Isaac Ji Kuo
spoilers for The Fall of Night
In article <30A0FA...@mcimail.com>,
Brian Badger <bba...@mcimail.com> wrote:
>If he was going to bother to jump out of the core shuttle, wouldn't common
>sence dictate that he throw himself out along the axis? (He could have kicked
>out of the doorway sideways and let air-resistance help) The way my
>deterministic systems text reads, that would have bump his hang time up a few
Actually, Sheridan jumped in the ideal direction--the opposite
direction to his axial velocity. Viewed from the angle we saw,
the core shuttle is moving to the "right" as well as toward
the end of B5. Sheridan jumps to the left, counteracting the
righward velocity of the shuttle. This maximizes the time
he has before hitting the outer wall (if he got it dead on,
he'd just float there until the air currents moved him or
he was rescued). It did nothing to prevent him from running
into the end wall.
--
_____ Isaac Kuo (isaa...@tyrell.net or isaa...@OCF.berkeley.edu)
__|_>o<_|__ As the world looked on ... Earth's fate hung in balance ...
/___________\ The fight for survival ... now begins! ... FINAL BATTLE IN ...
\=\>-----</=/ TOMOBIKI-CHO!
Brad Ackerman
WARNING: Spoilers for TFON follow.
In article <47tuk4$1k...@news-s01.ny.us.ibm.net>, iri...@ibm.net (Chris
Barnabo) wrote:
> [TFON rescue of Sheridan deleted]
>On a tangent --- 60 *miles* per hour?!? I'd have thought that Earth
>would have finally gone metric by then ... on the other hand, if
>they're really using the English measurement system, maybe their
>mechanics would have a shot at fixing my MGB. 8-)
Earth has converted to metric, as far as I can tell -- 99% of measurements
in B5 are in metric. (Notable exceptions are this 60mph and Sheridan's
voiceover.) Also, the weight of B5 listed in "And Now for a Word" was
2.5M *tonnes* -- that spelling usually indicates metric, in my experience.
Actually, Earth converted to metric many years ago -- the lone holdouts
were the USA, UK (now converting), Burma, and Liberia. All international
commerce has been in metric, as well as the US space program. (Next time
you go to the grocery store, look closely at what you buy -- a lot of it
is in metric, i.e. soda, nutritional value label.)
So how do we explain Ivanova's discrepancy? Discontinuity, I suppose.
--
Brad Ackerman
br...@iag.net
Ben Violette
>>Chris Palmer wrote:
>>>
>>> ky...@engin.umich.edu (Kyle Ferrio) wrote:
>>> >Spoiler protection added for TFON:
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>>> >Spoilers for TFON:
I had thought that when Sheridan leaped out of the shuttle he wasn't thinking
about air resistance or making sure he jumped out along the axis, he was
thinking about not getting blown up in the shuttle by leaping out of it in
time. He could have whipped out a calulator or started doing mental
calulations on where exactly to leap out of the shuttle but then he would have
died.
Mark.O.Wilson
mouth
>> really hard to keep him near the axis longer?
>
common
>sence dictate that he throw himself out along the axis? (He could have
kicked
>out of the doorway sideways and let air-resistance help) The way my
>deterministic systems text reads, that would have bump his hang time
up a few
It would have taken a lot longer for Sheridan to get out of the
shuttle this way. Priority one is surviving the blast. The key to that
is getting away from the bomb as fast as possible. Stopping in order to
make a right hand turn slows you down a lot.
--
Mark.O...@AtlantaGa.attgis.com
It ain't charity if you ain't using your own money.
Just because a mob calls itself a government, doesn't make it so.
Democracy is two wolves and a sheep voting on what to have for
dinner.
People who claim that money doesn't matter, are usually living on
someone else's money.
Society is a mental construct, formed by those people who are too
insecure too handle the concept of people as individuals.