To techno-nerds like us, the characters aboard the starship
Enterprise are positively heart warming. The gorgeous Uhura (Zoe
Saldana) is not just a decoration, she's a linguistics-nerd. As an added
bonus for Trekies who have tried to figure out her first name for the last
30+ years, she finally reveals it. While the original Chekov mostly provided
comic relief--the standard joke: Russians were responsible for all modern
inventions--the new Chekov is a charming 17 year-old prodigy who positively
exudes enthusiasm as he deftly solves problems during desperate situations.
And Scotty, wow is he cool. He's the quintessential engineering nerd, not
just a guy who is fascinated by machines but one who does mathematics and
solves galaxy-class engineering challenges. Even the ultimate alpha-male
Captain Kirk is depicted as a brilliant reject who does the impossible in an
otherwise hopeless war game (the
Kobayashi Maru) by surreptitiously reprogramming a computer
simulation.
The new Bones is eerily like the real McCoy. He tells Kirk
he hates outer space and has only joined Star Fleet because he has just gone
through a nasty divorce leaving him stripped to the bone--a conversation
that explains the origin of his nick name. (Thank heavens the writers didn't
make it some dopy medical reference.)
As for the ultimate techno-nerd Spock, he looks, acts, and
sounds like the original. As a child, he was ridiculed and beaten up
(familiar nerd experiences) and subsequently rebelled by joining Star Fleet.
After Uhura dismisses Kirk's bar room advances, refusing to even tell him
her first name, we assume the obvious: Kirk and Uhura are going to get
together before the movie ends. So, who gets the girl? Spock! It gives us
hope.
Who can forget the TV episode when the old Sulu, under the
influence of a space malady, went swashbuckling though the halls of the
Starship Enterprise waving a foil about in a menacing manner while
failing to inflict harm. It was a moment of comic relief in an otherwise
serious scene, not the kind of moment that would convince us Sulu was the
man we'd want beside us in a fight. |
.... a new era of Star Trek
is a colossus
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Want to learn more about movie physics in Star
Trek and find out : |
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- how Star Tek compares to Star Wars
- what should and shouldn't be done in space battles
- what it takes to blast off and travel the galaxy
- the basics of orbiting
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Explore these topics and many more. Learn about physics through the lens
of Hollywood movies.
Check out the companion book to our website.
Quite possibly the most entertaining and readable physics book
available, yet packed with content for physics students, teachers, and
film buffs alike. |
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So, what happens when the new Sulu volunteers for a dangerous
mission requiring close combat skills? On the way to the mission fellow
volunteer Ensign Kirk (not yet proclaimed the boss) asks him what his
martial art is. Sulu replies, fencing. However, fencing in this case does
not refer to the kind done with a flimsy-looking foil. When the fight begins
Sulu unfolds a specially designed Japanese style sword and "fences" with the
ferocity of a Ninja. Given Sulu's previous depiction in the TV series, the
new fight scene is hilarious. The physics of the
scene are also hilarious. As part of the mission Sulu, Kirk, and another
volunteer must space-dive from an orbiting craft down to a platform
suspended in the atmosphere above the planet Vulcan. For the sake of
analysis we'll assume that Vulcan is similar to Earth. To remain over a
fixed point on Earth while orbiting, a spacecraft would need to be traveling
at a tangential velocity of 6,900 mph (11,000 kpm) at a height of 22,300
miles (35,900 km) above the surface. Even with the correct height and
velocity, it's only possible to remain directly over a fixed point if it's
on the equator. |
Dive out the bottom of an orbiting spacecraft and nothing
would happen. The diver would continue orbiting along with the spacecraft.
He would have to abruptly lose his tangential velocity relative to the
ground in order to fall to a point on the surface below the spacecraft. This
would require a rather large thruster. Assuming that
the targeted platform is no more than 3 miles above the surface and that the
problem of orbital velocity is magically solved, the free fall would take
around 8 hours and the space-diver would arrive at a speed of around Mach
30--a little stout for a parachute to function properly.
As the space-diver encountered the rarified upper
atmosphere, aerodynamic forces would become considerable. Even slight
amounts of unbalance in them would cause violent tumbling, enough to serious
injury if not tear the space-diver apart. The ejection seat of the highest
flying aircraft in the world, the now decommissioned SR-71 Blackbird, was
equipped with a small sized drag chute that would deploy shortly after
bailout in order to prevent tumbling of this type.
Of course, heating from friction in the atmosphere would
make the parachutist look like an incoming meteor. Aerodynamic forces, not
to mention high velocity winds in the upper atmosphere would make landing on
a small platform incredibly difficult if not impossible.
The
edge
of outer space is considered to be about 73 miles (118 km) above the
surface of Earth. To orbit at this height, a spacecraft would need to be
traveling at a speed of 17,500 mph (28,200 kph). Under these conditions, an
orbiting spacecraft could not possibly hover over a fixed point. It would be
traveling over 27,000 mph (43,500 kph) relative to the ground! In order to
hover, a spacecraft would need to slow down to zero speed relative to the
ground and then expend enormous amounts of energy by blasting large amounts
mass out its downward thrusters in order to counteract gravity.
The only other way to hover would be by using some form of
antigravity capability, based on an as yet unknown principle of physics. If
a spacecraft could hover at a height of 73 miles, a space-diver could still
not fall straight down. If he fell 70 miles to a 3 mile high platform, His
starting tangential velocity would be about 18 mph (30 kph) too low to match
the tangential velocity of the platform.
Assuming a space-diver somehow overcome the tangential
velocity problem, he would arrive at a three mile high platform in around 3
minutes with a downward speed of over Mach 4--still a demanding situation
for opening a parachute and landing on a small target, but maybe doable with
23rd century technology. |
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In possibly the worst bailout incident
on record, Bill
Weaver successfully parachuted to safety with only minor injuries after
the SR-71 Blackbird he was flying at Mach 3.2 and an altitude of 14.8 miles
(23.8 km) had an engine malfunction, went out of control, and disintegrated.
Nevertheless, he was about 58 miles (93 km) below the edge of outer space and traveling
significantly slower than Mach 4. Given this data and the fact that the
world record height for a parachute jump is only about 20 miles (32 km), a 73
mile jump would definitely be impressive.
The various orbital issues around the space diving
scene are reminiscent of early Star Trek TV episodes in which the impulse
engines were, for whatever reason, off line and the Enterprise in a decaying
orbit. Invariably there were only minutes left to solve the latest mystery
and get the engines back on line before burning up in the atmosphere.
Evidently, someone eventually told the writers that
using a decaying orbit as a plot device was silly. Later episodes dropped it.
Orbits do decay, but the whole point of being in an orbit is that it takes
almost no energy to stay there for lengthy periods of time. To remain in
continuous contact with an away-team on the surface of a planet, a spaceship
would have to be in a synchronous orbit at a height where there was
easily no
danger of spiraling downward and burning up.
Lower orbits could be used but would shorten
the length of time the spaceship would be overhead in a support position. These orbits
would cause the spacecraft to be over the opposite side of the planet for
half of the orbit. For example, a craft orbiting only 100 miles above
Earth's surface would be on the other side of Earth every 45 minutes for
about 45 minutes. During these times sensor or communication systems using
any part of the electromagnetic spectrum would be blocked by the planet. In fact, this
sensor blocking effect was a plot device in Star Trek 2009. The Enterprise
dropped out of warp speed behind Titan, one of Saturn's moons, to keep it
from being detected by the Romulan ship they were trying to
intercept.
The space-jumpers were attempting to land on a platform
suspended far below
the Romulan mining ship. From the platform the Romulans were using a
mechanism that looks like a cross between a rocket motor and a high energy
laser to drill a hole so that a black hole producing bomb could be dropped
into the center of the planet. Does the drilling device really need
to be in the atmosphere to work? Why can't it be used from outer
space? After all, the bottom two or three miles is where most of the air
resides, so if air attenuates the plasma's velocity, the attenuation would
be about the same from outer space. As it is drilling, where is all the
removed material going? Why is there no lava flowing
out of the hole? For that matter, how are they keeping the hole open?
Then there's the cable used to lower the platform. Carbon
nanotubes are currently about the strongest material known to science and
although no one has as yet made a cable out of them. it is at least
conceivable. A 73 mile long, 1.0 inch diameter
Carbon nanotube would weigh about 88 tons ( 80 metric tons) but would be
able to support a 1000 ton platform with a reasonable factor of safety.
Unfortunately, a carbon nanotube cable of such extreme length would
stretch like a rubber band. Gently setting a pair of space-divers on the
platform would stretch the cable by over a foot (0.3 m). The impact of landing
two space-divers, would make the platform bounce up and down. Even in a gentle
breeze the platform would swing sideways.
So, how do we know the cable is actually suspending the drilling
platform? If the gigantic spacecraft could hover with some type
of antigravity device why couldn't the platform have a smaller version of
the same device? We know the cable is used for suspending the drilling
platform because New Spock eventually attacks it in Old Spock's spacecraft and blasts
it in half. The platform subsequently crashes into San Francisco Bay.
A complicated mechanical bounce-preventer and powerful horizontal thrusters with a sophisticated computer
control could reduce the cable problems but why go to all that trouble?
The typical "deadly" black hole described in scientific articles has
enormous amounts of gravity producing mass in it--equivalent to many times the mass of the Sun
(sometimes billions of times the mass of the Sun)--and could indeed swallow a nearby
planet like a moviegoer finishing off a handful of popcorn. But, a black hole seeded with a few grams
of mass would be relatively harmless.
For example, if a black hole with of 2200 lb mass (1000 kg mass) suddenly appeared a meter away as you walked down the street, it
would pull you toward it with a force of roughly 10-6
lb (5 x 10-6 newtons). In other words,
you would not even feel the force. Yes, the 1000 kg black hole would still
"eat" nearby matter, but the key word is nearby, very nearby. It
would not be capable of drawing in matter from any appreciable distance.
On the other hand the temperature of a
black hole is inversely proportional to the mass. While black holes
containing billions of times the Sun's mass are near absolute zero, a 1000
kilogram black hole would be far hotter than the surface of the Sun
1. At such temperatures it would evaporate
by emitting very short wave length ionizing radiation--the kind that can
cause everything from a nasty sunburn to death. For that reason you
wouldn't want to stand near it although you would be in no danger of being
pulled into it. Fortunately, small black holes will tend to evaporate faster than they
grow.
If a black hole bomb were possible, there might be a
reason for setting it off at the center of a planet vs. at its surface.
Conceivably, the added pressure and heat at the center might slow the
evaporation process enough to allow the small-sized black hole created
by the bomb
to
actually grow. But, even if it worked--and it's doubtful--a small sized
black hole would take a considerable amount of time, possibly millions of
years, to swallow an entire planet. The idea that a syringe full of
"red matter" (if there were such a thing) could implode a planet into a black hole in a matter of minutes
is pretty silly.
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After losing Vulcan to the black hole bomb, Kirk challenges
young Spock's decisions to such an extent that Spock can stand it no
more. He subsequently maroons the young Ensign on a frozen planet. While it
may have nothing to do with physics, we're left wondering why Kirk isn't
confined to his quarters or to the brig. Marooning seems a little harsh
especially with no formal process such as a court martial.
As Kirk makes his way toward the planet's lone Federation
outpost he's attacked by what looks like an oversized sheep dog with enormous
incisors. The oversized sheep dog is then attacked by an even larger red
crab/spider beast that then pursues Kirk into a cave where old Spock scares
off the beast by waving a torch at it.
We're left wondering how a frozen wasteland is going to provide sustenance for two
major-sized predators. Why did the red crab/spider waste its energy chasing
Kirk after it had killed the much larger oversized sheep dog? For that
matter, why was the crab/spider red instead of white? It appeared to have an
ambush style of hunting prey. Wouldn't it need to be camouflaged?
In our preview of Star Trek 2009, we've already discussed the foolishness of toe-to-toe space
battles, fake-looking space explosions, and sound in space but the movie
offers up some noteworthy examples. At the beginning of the movie, in the toe-to-toe space
battle between the Federation starship USS Kelvin
and the much
larger Romulan mining ship Narada , the sound track cuts off as we
see a hapless soul drifting in space after being swept out of a hole blasted
in the ship. It's eerie and for a moment we stared in awe.
Then crash, bang, and music, the sound track returned shattering the mood
along with our hopes of witnessing a breakthrough in space movie sound
tracks.
During the battle, the smaller craft is so badly
damaged it's abandoned by all but acting captain George Kirk (James
Kirk's father). The elder Kirk subsequently rams the Kelvin into the larger craft
temporarily disabling it while sacrificing himself and the Kelvin in the process.
We're left wondering how a starship loaded with antimatter fuel could
forcefully collide with another ship and then explode without destroying
both. It seems like a MAD (mutually assured destruction) strategy
would be a major component of defense against close range attacks.
The final battle basically repeats the strategy of the
first but on a lesser scale. This time, after blasting the cable in half and
subsequently destroying the drilling rig, new Spock sets his
shuttle-sized craft on a collision course with the Romulan ship. He is then
beamed aboard the Enterprise. So, how's a collision with an even
smaller craft than the one used in the first battle going to destroy the Romulan
ship? This time there's an added element:
red matter. The collision sets off the remaining red matter creating
a black hole that swallows the Romulan ship.
This scene implies there was no need to drill an elaborate
hole and set off a red matter-based black hole bomb at the center of a
planet. If red matter could create a stable black hole without the
temperature and pressures existing deep within a planet then why not just
shoot a red matter warhead at the surface and create a black hole there? The
black hole would eat its way to the center of the planet
where it would have exactly the same effect as one initially created there.
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How to Calculate a
Black Hole's Gravity
The equation for calculating the gravity force at
a distance from a black hole is as follows:
F =
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G M m |
r2 |
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Where:
- G = universal gravity constant
- =
6.673×10−11 N
m2 kg−2
- M = mass of planet or black hole
- m = mass of an object
- r = distance from M's center of mass to m's
center of mass
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Notice
first, force is directly proportional to mass. Black holes with
billions of times the mass of the Sun will create tremendous
gravity forces. Second, force is inversely proportional to the
square of the distance (r) from the center of the black hole. Hence, a black
hole's gravity force approaches infinity as one approaches its
center. At a distance of 93 million miles (the distance from the
Earth to the Sun) a black hole with a billion times the mass of
the Sun would create a force of over 1020
pounds on a person who would weigh 176 pounds (mass = 80 kg) on
Earth. However, if a 176 lb person were
standing on Earth and Earth suddenly became a black hole the
gravity force it would exert on the person would still be only
176 lb, that is if the person could somehow remain at a distance
of Earth's original radius from the black hole.
Could a black hole with Earth's mass still create
the gravity forces required to break the chemical bonds that
hold materials together and then tear apart the remaining atoms?
Yes, but from a much closer distance. |
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Want to learn more about black holes? |
Susskind gives up-to-date information about black holes told
through the human story of the physicists who study them. He assumes that
the reader has little background in physics and often spends time explaining
basic details. |
On the
other hand, he does include some equations (thank heavens). The
more advanced reader can easily skip the elementary stuff and
the less advanced reader the equations, making the book a
reasonable compromise. We recommend the book as a good place to
start learning about black holes. |
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When the Romulan ship turns into a black hole Kirk has the
Enterprise's warp drive cores ejected in order to create a massive explosion
that blasts the Enterprise free from the newly formed black hole. Once
again, we're left wondering why bother? If the Romulan's ship did not have
enough mass to pull the Enterprise into it before becoming a black hole, then
it won't have enough to pull it in after becoming a black hole (assuming
that the Enterprise is at the same distance).
Finally, there is the matter of time travel. While it's doubtful
that time travel into the past could happen let alone in the manner
depicted, let's face it, it was a necessary plot device. Without it Star
Trek could not be rebooted with different story lines. With devices such as warp drives, transporters, inertial dampers, sub-space
communication, hand-held phasers, and so forth Star Trek always did go
beyond any known technology or even science when it needed to for the sake
of story.
Okay, Star Trek 2009 disappoints in many ways but we still can't help
liking it. It gives us a new opportunity to continue the Star Trek
adventure, yet remains true to its roots without taking itself too seriously.
Its many allusions to various TV episodes are hilarious. We hear the same noises aboard the
Enterprise and end the
movie with Captain Pike in a wheel chair. True, it's a modification of Pike's
original fate 2 in the TV series but retains the flavor and indeed
extends the
optimism of the original. Likewise, we can't help being optimistic about the
future of Star Trek even though we remain skeptical about it's
physics.
1. Leonard Susskind, The Black Hole War, 2008, p 160
2. In the TV series Pike was hideously injured. We
saw him as an expressionless head protruding from a boxy wheelchair-like
life support system. He could only respond to yes-no questions by blinking a
pair of lights.
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