#1
|
||
|
Sweet fancy Moses, wtf??
I got this in an email today. Might be a good addition to DC:
MENTAL NOTE: NEVER GO TO IRAQ > > > > They run 10 mph, jump three feet, are a nocturnal, so only come out at > > night unless they are in shade. When they bite you, you are injected > > with Novocain so you go numb instantly. You don't even know you are > > bitten when you are sleeping, so you wake up with part of your leg or > > arm missing because it has been gnawing on it all night long. > > > > If you are walking around and you bump something that is casting a > > shadow over it, and the sun makes contact with it, you better run. It > > will instantly run for your shadow, and scream the whole time it is > > chasing you. > > > > PS. The one on the bottom is eating the one on the top. > > These Spiders are found daily in IRAQ by troops. > > > > Imagine waking up and seeing one of these in your tent!! > > > > > > I have checked with an ex-serviceman who's been over there > > &.......YES, they are for real ........................AAARRGGGHHHHHHH > > ! ! ! ! ! ! ! ! ! ! !
__________________
<This is an unsolicited post brought to you by a member of the 101st Spammers Association>
Read my column at AusBF |
#2
|
||
|
*yawn* BS
if they were real then id have seen them in a documentary. ive seen _a lot_ of spider documentaries *shudders*
__________________
<This is an unsolicited post brought to you by a member of the 101st Spammers Association> [subliminal message]Press Ctrl + W Now[/subliminal message] |
#3
|
||
|
No way, I'm having this same argument with Xy right now. I'm gonna research because this seems to real to be BS
__________________
<This is an unsolicited post brought to you by a member of the 101st Spammers Association>
Read my column at AusBF |
#4
|
||
|
Oh, fine, damn all you people for ruining my fun/fright:
http://www.ozforums.com/showthread.php?t=72909 As one of the guys in this link says, Huntsmans don't hurt you but they're still scary looking! And these are gonna give me nightmares And ok, so they don't "attack" people but running into your shadow because they feel exposed and threatened isn't attacking anyway.
__________________
<This is an unsolicited post brought to you by a member of the 101st Spammers Association>
Read my column at AusBF |
#5
|
||
|
I could have told you they were fake straight off, the world's largest spider is The Goliath Bird Eating Spider, and it measures 26cm from end of foot to end of foot.
I love being a general knowledge junkie
__________________
I like birds and trees cause I'm fruity! |
#6
|
||
|
I didn't think that said world's largest?
Anyway, it don't matter, I'm still going to have nightmares methinks
__________________
<This is an unsolicited post brought to you by a member of the 101st Spammers Association>
Read my column at AusBF |
#7
|
||
|
yeah, I didn't see you posted that link before I replied, my bad
And Spiders, pfft. Just don't make any sudden moves Mel...when you see a big hairy one...with 8 eyes, looking right at you...fangs glowing...
__________________
I like birds and trees cause I'm fruity! |
#8
|
||
|
Why is it I can handle venomous snakes and not big hair harmless spiders?
__________________
<This is an unsolicited post brought to you by a member of the 101st Spammers Association>
Read my column at AusBF |
#9
|
||
|
Because you relate all snakes back to a certain species - the aptly named 'Trouser Snake'?
Ok it's late, that's all from me. |
#10
|
||
|
i saw one of those spiders once...they imprgnated one of my friends with this gnarly alien creature that burst from his chest about a day later...the alien turned out to be a pretty good bloke once you got to know him though...he's a front man for a local band...
__________________
<This is an unsolicited post brought to you by a member of the 101st Spammers Association> <This is also an unsolicited post brought to you by a member of the 101st Oily Food Lovers Association> |
#11
|
||
|
Trouser Snakes are a good species...
__________________
<This is an unsolicited post brought to you by a member of the 101st Spammers Association>
Read my column at AusBF |
#12
|
||
|
i like snakes
__________________
<This is an unsolicited post brought to you by a member of the 101st Spammers Association> [subliminal message]Press Ctrl + W Now[/subliminal message] |
#13
|
||
|
spiders r fuked....& is that pic real? or photoshoped
|
#14
|
||
|
Azz, are you related to Godfish or something?
__________________
I like birds and trees cause I'm fruity! |
#15
|
||
|
noway...i spelt "fuked" like that so i wouldent get in trouble, but i do know him from school
|
#16
|
||
|
i think he was refering to your terrible spelling and sentence structure.
And yes, the photo is real, its just out of perspective. Trick of the camera angle. If you look closely, the spiders are only about as big as the guys hand
__________________
<This is an unsolicited post brought to you by a member of the 101st Spammers Association> [subliminal message]Press Ctrl + W Now[/subliminal message] |
#17
|
||
|
Yeah, what he said.
__________________
<This is an unsolicited post brought to you by a member of the 101st Spammers Association>
Read my column at AusBF |
#18
|
||
|
Those are camel spiders - we used to get them in Saudi. They're not actually spiders, they're a different family (solpugida I think it was). They run fricking fast, but they don't actually attack you - they're just trying to get into shadows to get under things. And I don't recall anyone being bitten by one, but the arabs claimed that they could eat half your face away if you were asleep, before you noticed. We used to sleep in the desert and I still have a (more or less) face - and we used to sleep in the open and find them about, so don't know about the veracity of that one.
|
#19
|
||
|
Welcome to yesterday Jantar
__________________
<This is an unsolicited post brought to you by a member of the 101st Spammers Association>
Read my column at AusBF |
#20
|
||
|
>>>>OWNED<<<<
__________________
<This is an unsolicited post brought to you by a member of the 101st Spammers Association> [subliminal message]Press Ctrl + W Now[/subliminal message] |
#21
|
||
|
Aww poor Jantar, he means well.
__________________
<This is an unsolicited post brought to you by a member of the 101st Spammers Association>
Read my column at AusBF |
#22
|
||
|
I don't think he was talking about Jantar, Mel
__________________
I like birds and trees cause I'm fruity! |
#23
|
||
|
Well that's a bit silly, I'd already corrected myself
__________________
<This is an unsolicited post brought to you by a member of the 101st Spammers Association>
Read my column at AusBF |
#24
|
||
|
What?
Just thought I'd correct a few urban (desert?) legends |
#25
|
||
|
er... if you followed the links youd find that copied almost word for word
__________________
<This is an unsolicited post brought to you by a member of the 101st Spammers Association> [subliminal message]Press Ctrl + W Now[/subliminal message] |
#26
|
||
|
Pft, sif follow links. I've been around them. When you can give me a full discourse on dimensionless numbers you can tell me to follow links
|
#27
|
||
|
A dimensionless number is a quantity which describes a certain physical system and which is a pure number without any physical units In physics and metrology, units are standards for measurement of physical quantities that need clear definitions to be useful. Reproducibility of experimental results is central to the scientific method. To facilitate this we need standards, and to get convenient measures of the standards we need a system of units. Scientific systems of units are a formalization of the concept of weights and measures, initially developed for commercial purposes.
Such a number is typically defined as a product or ratio of quantities which do have units, in such a way that all units cancel. For example: "one out of every 10 apples I gather is rotten." The rotten-to-gathered ratio is [1 apple] / [10 apples] = 0.1, which is a dimensionless quantity. Dimensionless numbers are widely applied in the field of mechanical and chemical engineering. According to the Buckingham p-theorem The Buckingham p theorem is a key theorem in dimensional analysis. The theorem states that the functional dependence between a certain number (e.g.: n) of variables can be reduced by the number (e.g. k) of independent dimensions occurring in those variables to give a set of p = n - k independent, dimensionless numbers. For the purposes of the experimenter, different systems which share the same description by dimensionless numbers are equivalent. Of dimensional analysis Dimensional analysis is a mathematical tool often applied in physics, chemistry, and engineering to simplify a problem by reducing the number of variables to the smallest number of "essential" parameters. Systems which share these parameters are called similar and do not have to be studied separately. The dimension of a physical quantity is the type of unit needed to express it. For instance, the dimension of a speed is distance/time and the dimension of a force is mass×distance/time². In mechanics, every dimension can be expressed in terms of distance (which physicists often call "length"), time, and mass, or alternatively in terms of force, length and mass. Depending on the problem, it may be advantageous to choose one or the other set of, the functional dependence between a certain number (e.g.: n) of variables can be reduced by the number (e.g. k) of independent dimensions occurring in those variables to give a set of p = n - k independent, dimensionless numbers. For the purposes of the experimenter, different systems which share the same description by dimensionless numbers are equivalent. An example The power < Electric power, often known as power or electricity, involves the production and delivery of electrical energy in sufficient quantities to operate domestic appliances, office equipment, industrial machinery and provide sufficient energy for both domestic and commercial lighting, heating, cooking and industrial processes. History Although electricity had been known -consumption of a stirrer with a particular geometry is a function of the <density> Density (ISO 31: volumic mass) is a measure of mass per unit of volume. The higher an object's density, the higher its mass per volume. The average density of an object equals its total mass divided by its total volume. A denser object (such as iron) will have less volume than an equal mass of some less dense substance (such as water). Again, D = m ÷ V where D equals density, m equals total mass, and V equals volume. Viscosity is a property of a fluid that characterises its perceived "thickness" or resistance to pouring. It describes a fluid's internal resistance to flow and may be thought of as a measure of fluid friction. Thus, methanol is "thin", having a low viscosity, while vegetable oil is "thick" having a high viscosity. Newton's theory When a shear stress is applied to a solid of the fluid to be stirred, the size of the stirrer given by its diameter, and the speed of the stirrer. Therefore, we have n=5 variables representing our example. Those n=5 variables are built up from k=3 dimensions which are: Length L [m] Time T [s] Mass M [kg] According to the p-theorem The Buckingham p theorem is a key theorem in dimensional analysis. The theorem states that the functional dependence between a certain number (e.g.: n) of variables can be reduced by the number (e.g. k) of independent dimensions occurring in those variables to give a set of p = n - k independent, dimensionless numbers. For the purposes of the experimenter, different systems which share the same description by dimensionless numbers are equivalent. The n=5 variables can be reduced by the k=3 dimensions to form p=n-k=5-3=2 independent dimensionless numbers which are in case of the stirrer Reynolds number The Reynolds number is the most important dimensionless number in fluid dynamics providing a criterion for dynamic similarity. It is named after Osbourne Reynolds (1842-1912). Typically it is given as follows: Re = L\\over \\eta} or Re = L\\over u} \\; . With: vs - mean fluid velocity, L - characteristic length (equal to diameter 2r if a cross-section is circular), ? - (absolute) dynamic fluid viscosity, ? - kinematic fluid viscosity: ? = ? / ?, ? - fluid density. (This is the most important dimensionless number; it describes the fluid flow regime) Power number The power number Np (also known as Newton number) is a dimensionless number relating the resistance force to the inertia force. In engineering, this number, along with the Reynolds number, is one of the most widely employed dimensionless numbers. The power-number has different specifications according to the field of application. E.g., for stirrers the power number is defined as: (Describes the stirrer and also involves the density of the fluid) Listing of dimensionless numbers There are literally thousands (to be precise: infinite) dimensionless numbers including those being used most often: (in alphabetical order, indicating their field of use) Abbe number In physics and optics, the Abbe number, also known as the V-number or constringence of a transparent material is a measure of the material's dispersion (variation of refractive index with wavelength). Named for Ernst Abbe (1840-1905), German physicist. The Abbe number V of a material is defined as: V = \\frac where nD, nF and nC are the refractive indices of the material at the wavelengths of the Fraunhofer D-, F- and C- spectral lines (589.2 nm, 486.1 nm and 656.3 nm respectively). Low dispersion materials have high values of V. Dispersion in optical materials Archimedes number An Archimedes number, to determine the motion of fluids due to density differences, is a number in the form Ar = \\frac Where g - gravity acceleration (9.81 m/s2) ?l - density of the fluid ? - density of the body µ - fluid absolute viscosity Motion of fluids due to density differences Biot number The Biot number (Bi) is a dimensionless number used in unsteady-state and heat transfer calculations. It relates the heat transfer resistance inside and at the surface of a body. It is defined as follows: Bi = \\frac Where: h - overall heat transfer coefficient L - charcteristic length ?b - Thermal conductivity of the body Values of the Biot number larger than 1 imply that the heat conduction inside the body is slower than at its surface, and temperature gradients are non-negligible inside it. Surface vs volume conductivity of solids Bodenstein number: residence-time distribution Capillary number: fluid flow influenced by surface tension Damköhler numbers: reaction time scales vs transport phenomena Deborah number The Deborah number is a dimensionless number which characterizes how "fluid" a material is. Even solids "flow" if they are observed long enough; the origin of the name is the line "The mountains flowed before the Lord" in a song by prophetess Deborah recorded in the Bible. Formally, the Deborah number is defined as the ratio of the polymer characteristic relaxation time (lambda) and the Rheology is the study of the deformation and flow of matter. The term rheology was coined by Eugene Bingham, a professor at Lehigh University, in 1920, from a suggestion by Markus Reiner, inspired by Heraclitus' famous expression panta rhei, "everything flows". In practice, rheology is principally concerned with extending the relatively straightforward disciplines of elasticity and Newtonian fluid mechanics to more complicated and realistic materials. of viscoelastic fluids Drag coefficient The drag coefficient is a number that describes a characteristic amount of aerodynamic drag caused by fluid flow, used in the drag equation. Different objects with the same drag coefficient will behave in similar ways, after scaling for differences in size. A cylinder is given a default drag coefficient of one. That means that two cylinders of the same size will have the same drag, one twice as large will have twice the drag. Less streamlined shapes will have higher values, while smoother shapes will have lower values. Flow resistance Ekman number The Ekman number, named for V. Walfrid Ekman, is a dimensionless number used in describing geophysical phenomena in the oceans and atmosphere. It characterises the ratio of viscous forces in a fluid to the fictitious forces arising from planetary rotation. It is defined as: Ek=\\frac - where D is a characteristic (usually vertical) length scale of a phenomenon; ?, the kinematic eddy viscosity; O, the angular velocity of planetary rotation; and f, the latitude. The term 2 O sin f is the Coriolis acceleration. Frictional Viscosity is a property of a fluid that characterises its perceived "thickness" or resistance to pouring. It describes a fluid's internal resistance to flow and may be thought of as a measure of fluid friction. Thus, methanol is "thin", having a low viscosity, while vegetable oil is "thick" having a high viscosity. Newton's theory When a shear stress is applied to a solid forces in Geophysics, the study of the earth by quantitative physical methods, especially by seismic reflection and refraction, gravity, magnetic, electrical, electromagnetic, and radioactivity methods. It includes the branches of: Seismology (earthquakes and elastic waves) Gravity and geodesy (the earth's gravitational field and the size and form of the earth) Atmospheric electricity and terrestrial magnetism (including ionosphere, Van Allen belts, telluric currents, etc.) Geothermometry (heating of the earth, heat flow, volcanology, and hot springs) Hydrology (ground and surface water, sometimes including glaciology) Physical oceanography Meteorology Tectonophysics (geological processes in the earth) Exploration and engineering geophysics Euler number The Euler numbers are a sequence En of integers defined by the following Taylor series expansion: \\frac = \\sum_ ^ \\frac \\cdot t^n (Note that e, the base of the natural logarithm, is also occasionally called Euler's number, as is the Euler characteristic.) The odd-indexed Euler numbers are all zero. The even-indexed ones (sequence A000364 in OEIS) have alternating signs. Some values are: Hydrodynamics (pressure forces vs. inertia forces) Friction factor The Darcy friction factor is a dimensionless number used in internal flow calculations. It expresses the linear relationship between mean flow velocity and pressure gradient. It is defined as: f = \\frac ) D_h} where: \\frac is the pressure drop per unit length D_h is the hydraulic diameter ? is the fluid density Fluid Flow Froude number The Froude number is the reciprocal of the square root of the Richardson number. It is usually used in the context of the Boussinesq approximation and is defined as } where u is a representative speed, g' the reduced gravity (see Boussinesq approximation), and h a representative vertical lengthscale. Strictly, this is known as the densimetric Froude number. Wave and surface behaviour Grashof number The Grashof number is a dimensionless number which approximates the ratio of buoyancy force to the viscous force acting on a fluid. Gr = ( g ß (Ts - Tinf) L3 ) / ?2 g gravity ß volumetric thermal expansion coefficient Ts source temperature Tinf quiescent temperature L characteristic length ? kinematic viscosity Free convection The Knudsen number is the ratio of the molecular mean free path length to a representative physical length scale. Continuum approximation in fluids The Laplace number (La) is a dimensionless number used in the characterisation of free surface fluid dynamics. It is related to the ratio of the surface tension to the momentum-transport inside a fluid. It is defined as follows: La = \\frac where: s = surface tension ? = density L = characteristic length µ = absolute viscosity Free convection with inmiscible fluids Lift consists of the sum of all the aerodynamic forces normal to the direction of the external airflow. Lift is created by forcing air downward. The pushing (accelerating) of the air downward creates an equal and opposing force upward on wing (see Newton's third law.) The displacement of air downward during the creation of lift is known as downwash. The diversion of the airflow downwards can be seen to create a higher pressure below the wing and a lower one above it. An aerofoil is so shaped to accomplish this as efficiently as possible. One puzzle is why the airflow "sticks" to the wing as it changes direction - this is known as the Coanda Effect, but the reason for it is not fully understood. An airfoil (or aerofoil in British English) is a specially shaped cross-section of a wing or blade, used to provide lift or downforce, depending on its application. Airfoils have a characteristic shape which is that of a curved streamline, with a rounded leading edge and a sharp trailing edge. For an understanding of the various ways of explaining lift, see lift. This force can be harnessed to lift an aircraft, or, in an inverted position, to hold a car or other vehicle to the ground. Airfoils are also found in propellors, fans, and turbines. Angle of attack is a term used in aerodynamics to describe the angle between the wing's chord and the direction of the relative wind, effectively the direction in which the aircraft is currently moving. The amount of lift generated by a wing is directly related to the angle of attack, with greater angles generating more lift. This remains true up to the stall point, where lift starts to decrease again because of airflow separation. Planes flying at high angles of attack can suddenly enter a stall if, for example, a strong wind gust changes the direction of the relative wind, an effect that is seen primarily in low-speed aircraft. If an object travels through a medium, then its Mach number is the ratio of the object's speed to the speed of sound in that medium. It is a dimensionless number, typically used to describe the speed of aircraft. Mach 1 is equal to the speed of sound, Mach 2 is twice that speed, etc. Since the speed of sound increases as the temperature increases, the actual speed of an object traveling at Mach 1 will depend on its altitude and the atmospheric conditions. High speed flight can be classified in six categories: Subsonic M < 1 Sonic M = 1 Supersonic M > 1 Transsonic 0.8 < M < 1.3 Hypersonic 5 < M < 10 Hypervelocity M > 10 and above The Nusselt number is a dimensionless number equal to the dimensionless temperature gradient at the surface in a convection situation. It therefore measures the heat transfer occurring at that surface. Nu_L = \\frac where L = characteristic length kf = thermal conductivity of the fluid h = convection heat transfer coefficient Ohnesorge number: Atomization of liquids In physics, the Péclet number is a dimensionless number relating the forced convection of a system to its heat conduction. It is equivalent to the product of the Reynolds number with the Prandtl number. There are various definitions of the Péclet number. The most typical are as follows: Pe = l * v / a Pe = l * v * ? * cp / ? Pe = l2 * ? * cp / ? / t ..... Click the link for more information. : Forced convection Power number: Power consumption by agitators Prandtl number Forced and Free convection Rayleigh number : Buoyancy and viscous forces in free convection Reynolds number : Characterizing the flow behaviour Richardson number : whether buoyancy is important Rockwell scale : Mechanical Rossby number : Inertial forces in Sherwood number : Mass transfer with forced convection Stokes number: Dynamics of particles Strouhal number : Oscillatory flows Weber number: Characterization of mulitphase flow with strongly bended surfaces Weissenberg number : Viscoelastic flows Dimensionless physical constants The system of natural units chooses its base units in such a way as to make several physical constants such as the speed of light into simple dimensionless constants by definition. However, other dimensionless physical constants cannot be eliminated, and have to be discovered experimentally. These are often called fundamental physical constants These include: the fine structure constant the electromagnetic coupling constant the strong coupling constant the gravitational fine structure constant
__________________
<This is an unsolicited post brought to you by a member of the 101st Spammers Association> [subliminal message]Press Ctrl + W Now[/subliminal message] |
#28
|
||
|
Follow links.
__________________
<This is an unsolicited post brought to you by a member of the 101st Spammers Association> [subliminal message]Press Ctrl + W Now[/subliminal message] |
#29
|
||
|
It's any wonder maths isn't my forté.
I'll just stick with basic sums
__________________
I like birds and trees cause I'm fruity! |
#30
|
||
|
That wasn't a bad read actually explosive, well googled young lad! (It's scary that I've used basically all those numbers, a few new ones though!)
Though I still ain't following no steenkin' leenks! I asked for you to give me a discourse, not a regurgitation! (Especially links to the OzF pages, I'd never be seen there! ) |
Thread Tools | Search this Thread |
Display Modes | |
|
|