Subject:
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Re: Wings [was: Re: Building big]
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Newsgroups:
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lugnet.space, lugnet.loc.au
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Date:
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Tue, 26 Jun 2001 10:17:08 GMT
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Reply-To:
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ssgore@superonline&StopSpam&.com
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Viewed:
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42 times
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>
> In lugnet.space, Shiri Dori writes:
> > In lugnet.space, Selçuk Göre writes:
Jesse Long wrote:
> I have heard that space craft with wings would become torn apart by the
> impact of flying in space. How do you know that these conditions will exist
> in space?
Sorry but although I read almost all messages I still can't find
anything can considered as "space craft with wings would become torn
apart by the impact of flying in space". All we said is particles and
debris (I mean sizes from a dust particle to a big rock) that impacted
to any spaceship traveling that fast cause very considerable amount of
wear and damage. It is not prediction but it is simple fact. Why:
The terms like kinematics, dynamics, velocity, kinetic energy, momentum,
acceleration, mass, velocity, force, etc. are already well defined since
Newton. Everything you use or utilize around are designed by using the
same principles, from your washing machine to your car. You may say that
Einstein proved Newtonian physics is wrong, you will be wrong, because
Newtonian Physics is still valid for most of the phenomenon in our life.
Any moving body has an kinetic energy of 0.5mv^2 where m is the mass of
the body and v is the velocity of it. As you can see, when velocity goes
higher, kinetic energy of the moving object goes even higher. And
remember that velocity is a relative thing, and must be considered as
the difference between the velocities of these two impacting bodies, in
our case.
The impact will cause an energy transfer between the two bodies (i.e.
the particle and the spacecraft) and the space craft must absorb (i.e.
transform) the energy resulted from the impact. I believe you already
know the conservation of energy rule, i.e. you can't create nor destroy
energy, you can just transform it from one form to another. The most
natural way (because the nature prefers it) of consuming this energy is
producing heat and deformation on impacting bodies. Remember the
conditions of cars after a traffic accident.
There are much more examples in which the impact velocities are higher
and one of the impacting bodies having considerably less mass compared
to the other (which is similar to our case, high speed spacecraft vs.
space debris). I can say that when a fighter aircraft crashes to a bird
when flying, it is not impossible to break the cockpit glass.
As another example I can give you the fact that antitank projectiles
used by battle tanks to attack other tanks are just bare metal arrows
(manufactured from very hard alloys containing tungsten) fired at very
high velocities, and they do not contain any explosives.
Why I gave you these examples? Because I'm an aeronautical engineer and
trained as a tank team commander during my military service. I've seen
with my own eyes that such a projectile broke apart the turret of an
M-48 MBT. And I've seen such damages caused by birds on aircraft.
If you still need further evidence, just try to imagine what a 10-20
gram mass of metal can make to your body when thrown at very high
velocities. You know small fire arms and bullets, I assume.
As another fact (not theory, we can already go out to space, we already
sent space craft till almost end of the solar system -Voyager and
Pioneer series), we have radio telescopes, satellites and such) there is
no continuous medium in space. And the density of molecules and bigger
debris in space is far from being considered as a fluid (as in air,
water, etc. -any liquid). And believe it or not (belief is nothing to do
with scientific methods) you can't have drag (friction) and lift, and
all the classic macroscopic fluid dynamics / thermodynamics methods will
not work for this case. Since there is not enough material around, you
can't consider the "space mass" as fluid, and all the "continuum"
modeling is invalid.
In this case you must consider individual behaviors of the molecules
(microscopic approach), rather than their behavior as a whole as a fluid
(macroscopic approach), since there is nothing like you could mention as
a fluid in that case, and continuum model is pretty not working, which
is the most basic thing in fluid mechanics.
So when people are saying "there is no friction in space" they are
completely true, since there is *really* no friction at all as we know
it, but there are impacts of individual particles.
What is the relation of all this things with the wings of a spacecraft:
* There is no lift in space, since there is no fluid filling space (is
that why we call it space?) so there is no need for wings in space. The
purpose of wings is to create lift, nothing at all.
* You said something like that there is friction (drag?) in space and
you should have wings. Wings do not decrease drag. They increase drag.
Any additional surface/volume exposed the medium increases drag,
including wings. Having a streamlined shape does not mean having wings.
The most streamlined thing you can imagine is the shape of a rain drop,
i.e. teardrop shape, which obviously has no wings. Any any more exposed
surface also increases the rate of wear from the impacting space debris,
too, so with appendages like wings, you must protect more surface area
from that wear.
* Wings can be used for secondary purposes like filling with fuel,
attaching extra cargo and weapons and such. But these are no primary
purposes, but practical ways to increase the usefulness of an appendage
that we *must* have to create lift. So if there is no need for lift,
then there is no need for wing, and you can put anything you consider to
put in/on/under the wings to other more covered/protected areas. I'm not
saying spacecraft without wings looks better, though.
> People thought many centuries earlier that the earth is flat yet
> is is almost perfectly spherical in structure and the theory of relativity
> by Albert Einstein was almost considered a law until very recently when that
> theory was proven false by science.
You need some more reading about what the science is, so you won't say
anything about this unrelated example of "people *believed* that the
earth was flat" in the future.
> We have organizations that say that
> they are committed to sending people to space yet we give these people
> billions of dollars so they can fly this glorified airplane named the Space
> Shuttle. If we were really committed about sending people into outer space,
> we would have already colonized the moon and Mars. I do not deny your
> intelligence but I do not find ease in your statements in response to my
> letters but I have also not applied for these courses in science yet at my
> college so maybe I am right or maybe I am wrong in my statements to you,
> Shiri and other people? The truth is even if wings were not needed in my
> space craft, the space craft would still be torn apart by particles in space
> and my space craft, as opposed to your space craft, not only use these wings
> as weapons platforms but as sources of power and to, as some people may have
> indicated in earlier letters, enter the atmosphere of planets. Your space
> craft do not possess this power of entering the atmosphere because there may
> be situations where hiding from the enemy may require a space craft to hide
> in the atmosphere of a planet. If your space craft do possess the power to
> hide in the atmosphere, please let me know how they enter the atmosphere. I
> am simply wanting to know more about space travel and how Lego space craft
> should be constructed by people.
At a time, you said that you are 21 years old, and now you are saying
that you are going to college. And at the same time you are trying to
compare two imaginary things (i.e. Lego space craft models) with the
most childish way I've seen. How you are this less knowledgeable about
common physics and going to college at the same time? And how can be a
man at age 21 be that cluelessly dare to oppose common scientific
knowledge without any base, even admitting it to himself? "My space
craft can enter into atmosphere, and yours can't!" Why? They are all
imaginary. How can you sure that his/her spacecraft doesn't have the
newly invented "inverse fabblesnorker anti-gravity power repulsor
coupling cells"? Man, do you ever need to sue Mr. Lucas about his
no-wings space craft like Millennium Falcon, Rebel Medium Transport,
Y-wing Fighter, Slave 1 and such are making atmospheric flight during
the films?
As a side note, this "entering the asteroid cave" scene of Millennium
Falcon was during the second film (Empire Strikes Back, Episode V), not
the first film. It is fact, not open to any discussion, so don't push
it.
> Jesse Long
> P.S. I do not want to be rude, Dori-san, but I want respect, not anger,
> from the rest of the people on the Lugnet bulletin boards.
Shiri was not angry, I was not, too. We are just reminding ourselves
with the high school level chemistry knowledge, by discussing a case,
not even the wings of your spacecraft, but the amount of mass in space.
Selçuk
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Message has 1 Reply:
 | | Re: Wings [was: Re: Building big]
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| (...) The first two messages I must say to you, Selcuk, is that how did you ever imagine that I said that Newtonian physics was wrong in life? I never said such a statement to you, Selcuk! The statement that I said was that the theory of relativity (...) (23 years ago, 26-Jun-01, to lugnet.space, lugnet.loc.au)
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Message is in Reply To:
| | Re: Wings [was: Re: Building big]
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| (...) I have heard that space craft with wings would become torn apart by the impact of flying in space. How do you know that these conditions will exist in space? People thought many centuries earlier that the earth is flat yet is is almost (...) (23 years ago, 25-Jun-01, to lugnet.space, lugnet.loc.au)
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