Owner: future of physics URL:http://softcracked.googleapges.com/pb.html Join Date: Thu, 11 Oct 2007 04:25:46 -0500 Rating:0 Site Description: Discipline of Science dealing with the properties of matter and energy. !!!---This blog is particualy for question that will be asked and their answers!!! It is not for journal and research work or an article. Site statistics:Click here
Do sound waves weigh anything? 2007-11-19 01:30:00 There are two ways one might answer this question. Technically, the wave itself is a mechanical pressure gradient (differential air pressure) and has no mass and therefore has no weight. However, the wave is propagated by collisions of air molecules (nitrogen, oxygen, carbon dioxide, etc) which do have mass even though it is very very small. Read more:anything
Why does folding paper make it stronger? 2007-11-27 05:11:00 A piece of paper
is of a certain strength. If you fold paper, you do notincrease the strength of the paper, but by there being two sheets (throughfolding), each can hold at least the same amount and so the folded sheetcan hold more.This happens however many times you fold the sheet or if you add more sheets.The top sheet will hold as much as it can, if that is too much for it,instead of tearing, the next sheet down will try to hold it. Read more:stronger
What causes the circular motion of particles in a surface wave? 2007-11-27 05:05:00 Ocean surface
waves are mechanical waves that propagate along the interface between water and air; the restoring force is provided by gravity, and so they are often referred to as surface gravity waves. As the wind blows, pressure and friction forces perturb the equilibrium of the ocean surface. These forces transfer energy from the air to the water, forming waves. In the case of monochromatic linear plane waves in deep water, particles near the surface move in circular paths, making ocean surface waves a combination of longitudinal (back and forth) and transverse (up and down) wave motions. When waves propagate in shallow water, (where the depth is less than half the wavelength) the particle trajectories are compressed into ellipses (also see shallow water equations). As the wave amplitude (height) increases, the particle paths no longer form closed orbits; rather, after the passage of each crest, particles are displaced a little forward from their previous positions, a phenomenon kno Read more:causes
Contradiction in Big Bang Theory 2007-11-24 09:02:00 It gets more absurd all the time.Galaxies supposedly moved to their present vicinity in a fraction of a second before the laws of physics began.The big bang does the same things God does, except God does it through the laws of physics, and the big bang doesn't. (To Cosmic Inflation, below)Physicists painted themselves into a corner in their incremental development of the big band theory, and it forced them into an extremely absurd end point.They first based the theory on the simplest logic. Everything seemed to be moving away from the Earth, as if it were an expanding explosion. Then they set distances based upon the speed of light. But when they added everything together, there wasn't enough time for matter to travel to its present location. So they said it got there almost instantly, and then the laws of physics began.Why didn't the laws of physics begin when matter got half way to its present location? What caused the laws of physics to begin? The whole purpose is to deny the ex Read more:Theory
, Big Bang
, Big Bang Theory
Is probability a function of time? 2007-11-30 02:16:00 You get arguments as to what "probability" is. Some schools of thought, aka "mechanist" or "frequentist", seem to think it is some sort of fixed and immutable value that is attached to a system that we could always know exactly if we knew enough about the system (i.e. a perfect true coin always has a probability of 0.5 of either outcome). Mathematicians have their definition (a measure defined over a space, always between 0 and 1 over any subset of the space, and such that the sum over the whole space is exactly 1). And then the subjective school of thought (aka "Bayesian" after Rev. Thomas Bayes) comes in saying that probabilities are subjective estimates (that may or may not be based on real data) made by humans about the behavior of systems. For example, if you put a tack in a jar, it can end up point up or point down after shaking the jar. What's the probability of those two results? Or, if a hurricane is approaching the coast, what is the probability that it will cross the coast Read more:function
Why can't a re-entering space craft slow down to avoid intense friction? 2007-11-30 02:15:00 The simple answer is that it is theoretically possible for spacecraft toslow down to a more reasonable speed before re-entry. The problem is thatit would require some opposing force over a distance, which means energy isrequired. This would most likely have to come from a descent engine, whichwould require fuel. This is how manned lunar modules landed on the moon.Of course, gravity on Earth is much greater than that of the moon, so moreenergy and more fuel would be required. At the end of the day, it's morepractical to add a heat shield and use the atmosphere to slow down onEarth. On the moon, there is no atmosphere, so a descent engine is the onlyoption.There are other practical considerations. Heat shields are passive and workwell as long as they are structurally sound. An engine is more complicatedand could fail for any number of reasons.
Transparent Plasma Production and Conductivity 2007-12-07 22:16:00 There are optically thin plasmas and optically thick plasmas, but I'm not sure what you mean by transparent plasma. Perhaps you mean that it is low enough energy (or high enough) to not radiate visible light? Perhaps you just mean it is a cold ion stream? I assume you are asking about atmospheric LIPCs, so here goes. The plasma created with a LIPC (typically with pulsed UV lasers) is very short-lived and is actually quite visible. The UV radiation ionizes the nitrogen in the air causing it to radiate visible green or purple light depending on the energy of the initiating beam. The achieved conductivity is not all that high - less than that of stainless steel. I'm just not familiar with the term "transparent plasma." If you mean optically thin (a plasma that can pass light of particular wavelengths) then the conductivity can be as high as you want (within limits). The conductivity of a plasma depends on the density of the gas that is ionized, the current density, the ion species charg Read more:Production
, Plasma
, Transparent
paradoxical relation between the ease of flipping and coefficient A 2007-12-07 22:16:00 This appears to be degenerate perturbation theory.There are two benzene states |a> and |b> with the same unperturbed energyE_0. There is a small perturbation V that connects the states, with A=. Thus, "the easier the flipping back and forth between thetwo states, the higher the coefficient A".This gives a 2X2 matrix |E_0 A | | A E_0|.The perturbed energies are obtained by diagnolizing this matrix,resulting in energies E_1=E_0+A and E_2=E_0-A.Thus, "the higher the coefficient A, the higher the energy separationbetween the two states."
Explain why salt water forms cubic crystals and ice is hexagonal? 2007-12-07 22:14:00 Purification by selective crystallization is not well supported by theory. Thermodynamics can explain after observation but often not usefullypredict before. http://cst-www.nrl.navy.mil/lattice/struk/b1.html http://webmineral.com/data/Halite.shtml sodium chloride (halite); cubic http://www.lsbu.ac.uk/water
/ice1h.html http://en.wikipedia.org/wiki/Ice_Ih http://www.tms.org/pubs/journals/JOM/9902/Schulson-9902.html Ice, hexagonalThe drug industry desperately funds research to predict crystal structurefrom molecular structure. After more than a decade of efforts not much hasobtained. Crystal structure of simple ionic salts depends on radius ratiosof the ions,J. Chem. Ed. 62(3) 215 (1985) http://www.chem.ox.ac.uk/icl/heyes/structure_of_solids/Lecture3/Lec3.html It's complicated! http://www.lsbu.ac.uk/water/phase.htmlWater is tremendously studied. Water is not well understood. http://www.chemguide.co.uk/physical/phaseeqia/saltsoln.html Even if we don't understand it we can observe i
Why does boiling water only release vapor once the gas is turned off? 2008-03-11 11:20:45 What is one difference between having the gas on and having the gas off? The main difference is the temperature of the air that flows up around the pot and mixes with the air and water
vapor inside the pot. Warm air mixing with the air and water vapor does not cause a cloud (or fog, or mist), but the cooler air (when the gas is off) mixing with the air and water vapor does cause a cloud to form. What you are experiencing is the clear version of water vapor (steam) above the water surface while the gas is on, and the cloudy (foggy, or misty) version of water vapor after the gas is turned
off. The water vapor is there all the time, but invisible while the gas is on because the air rising up to mix with the water vapor is too warm for the vapor to condense into visible tiny droplets (mist, or Read more:boiling
What is the difference in production at the atomic level of EM energies? 2008-03-07 23:16:07 It's a good bit more complex than what you've mentioned, actually. Bremsstrahlung, for example, creates some of the highest-energy gamma rays. One difficulty here is that we have arbitrary human ranges which we've applied to the electromagnetic spectrum. Another is that there are many, many mechanisms of generating electromagnetic radiation. For example, hot objects emit a range of radiation: Hot objects emit radio waves, microwaves, infrared, and can (if hot enough, such as some types of violent astrophysical objects) emit significant amounts of their radiated energy in a continuous spectrum all the way up to the x-ray range. Emission at discreet wavelengths requires an antenna or emitter of comparable wavelength or energy. Microwaves and radio waves are often emitted by molecular transi Read more:difference
, level
No title 2008-03-06 05:44:23 Why does the magnetic field of an electron reverse direction. A copper wire moving at right angles through a magnetic field creates a net drift of electrons in one direction (one end positive the opposite negative). The interaction of the magnetic field of the electron and the external magnetic field determines the direction (induced current).I believe I have that figured out Question: At the atomic level what is the mechanics behind the magnetic field of the electron in one direction moving up through the field as opposed to when the electron in the wire is moving down through the field. I can vilualize the electron as having a magnetic field which interacts with the external magnetic field to cause a net drift in one direction for a given direction i.e. up however for the net drift to re
What is the difference between an NPN transistor and a diode? 2008-03-04 01:27:00 A diode is not a switch, it is a passive, two terminal device. One terminal is the cathode and the second terminal is the anode. A diode has the ability to conduct electrons from the cathode to the anode and to block electron current from flowing from the anode to the cathode. For example, by placing a diode in a circuit with alternating current (AC), the diode will only pass current in one direction and not the other direction converting the AC current to direct current (DC). This is very useful for making DC power supplies from an AC source such as that supplied by electrical utilities. There are a number of power supply circuits that use 1, 2 or 4 diodes. A transistor is a 3 terminal active device with an emitter electrode, a base electrode and a collector electrode. The NPN transistor Read more:difference
Would a rope stretched from one side of the continent to the other bend? 2008-03-02 02:14:41 indeed it would bend. The curvature of the planet alone would prevent youfrom pulling it into a straight line. Even if you had a perfectly flat 4000 mile distance, however,the weight of the rope alone would cause it to sag. On such a long span, even a very small force in thecenter will be sufficient to do this. On much shorter distances, this effect is important in certain roperescue systems known as highlines, and the matter has been studied. Refer to "Life on a Line, 2ndedition" page 171. There you will find the catenary equation: Y = (T/w) * cosh where Y is the vertical sag at distance X from the center point T is the horizontal component of tension in the rope w is the weight per unit length of the rope X is the horizontal distance along the rope Read more:stretched
what makes a splash? 2008-02-29 22:41:55 Splashes tend to happen in two phases. First, the falling body will directly impact some of the water near its outer edges and impart momentum to it. So you have an initial spray heading outward. The body continues down and displaces water, effectively creating a "hole" in the water. Once the body passes by, the sides of this hole, being made of liquid, collapse inward. When they meet, the kinetic energy of the inrushing water does not just "disappear" but ends up sending some of the water skyward, as well as creating waves that travel outward from the impact site. If the collision is energetic enough (large meteors hitting the ocean, for example) you can have further effects (vaporization of both the water and the impacting body, for instance) and thus more explosive phenomena. Read more:makes
If you were on the Titanic, how long would you survive? 2008-02-27 02:55:00 The short answer to your question, If you were in the farthest back compartment of the Titanic
, would you survive
long enough to see the bottom of the ocean? is "No. The Titanic sank at night, so deep underwater it would be completely dark. Even if you were alive when you reached the bottom of the ocean, you would see nothing." You suggest that perhaps someone might find refuge in a small section of the aft compartment that contained an air pocket. I don't know the layout of the ship, but let us suppose for the sake of argument that it is possible. The only way to prevent water from filling that pocket would be to close off that small section of the ship completely: block all the doors and hatches and so forth. In that case, one would be blocking off all views of the outside world, so, aga
what happens to a photon contacted by an atom from the side 2008-02-27 02:54:22 A photon can either be completely absorbed or not at all. There is nopartial absorption. The interaction between a photon and an atom in motionis an interaction of two traveling wave packets. Quantum mechanics can beused to predict the probability that the photon will be absorbed, given theinitial wave functions of the photon and the atom.
Have the decay constants of any elements been calculated from first principle 2008-02-25 00:32:13 The calculation of *atomic* decay has indeed been calculated from first principles (where an excited atom decays to a less-excited version of the same atom.) But I think you're specifically talking about nuclear decay, which is far more complicated -- and I think the answer is generally no. Certainly not for most nuclear decay processes... The best chance would be decays governed by the weak nuclear force, but even then you would need to know the details of the nuclear structure. I suppose it's possible that one could get enough information about this structure from experiments, and then calculate the decay rate, but I'm not sure it has ever been done. (It's usually far easier to measure the halflife!) The one exception is the lightest unstable nucleus -- a bare neutron! (Turns out neutron Read more:elements
Why does spinning in ice get a can colder than sitting in a freezer? 2008-02-22 02:15:13 It’s an interestingproblem concerning the physics of heat flow. Essentially, you’re observingdifferences in energy flow due to a property called “conduction”.Heat and temperature are forms of energy. In fact, “temperature” itself isjust a consequence of how much energy an object has. The transfer of heatis normally from a high temperature object to a lower temperature object,until both come to the same temperature where they have the same internalenergy.“Conduction” is way of describing how this happens. Heat transfers bymeans of molecular agitation (atoms in an object wiggling) within amaterial without any motion of the material as a whole. If one end of ametal rod is at a higher temperature, then energy will be transferred alongthe rod toward the colder end because th Read more:spinning
Empirical Observation of the Electroweak Force? 2008-02-19 23:43:51 The electroweak force is a unified force that manifests as an electromagnetic force and a weak force at "standard" conditions in the universe around us. The electromagnetic force is easily measured and observed with high-school lab equipment. The weak force is a force that happens mostly inside an atomic nucleus [1]. This means it cannot be "directly" observed with the same ease one would observe an apple or the magnetic force. However, it manifests in the decay of elementary particles, such as neutrons, but also in mesons and in leptons. The decay of a wide variety of particles can be described in the framework of the weak interaction. This can be seen as evidence of the weak force, and given the vast amount of different interactions and decay times that can be used to verify the theory, Read more:Observation
, Force
How does gravitation work near the surface of a torus? 2008-02-19 01:58:26 you have to use the same methods to compute the gravitational field of a torus as you have used for a sphere. Since the gravitational force between two bodies is always attractive, in the direction of the connecting line and only depends on their distance, it shows a spherical symmetry. And therefore, the calculation of spherical problems is especially easy. An important tool in doing the calculations is choosing an appropriate coordinate system. In case of spheres involved, one better uses spherical coordinates; whenever cylinders are involved, one should use polar (cylindrical) coordinates. In the case of a torus, polar coordinates are also advisable, i.e. the coordinates are: the radius (distance from z-axis) r, the azimutal angle phi, and the height z. It is clear that far away from th Read more:surface
The effect of 'distributed' mass compared to concentrated mass in a golf club 2008-02-16 21:26:05 The physics of golf clubs has many people interested! Golf-club designers continue to attempt to design the "perfect driver". But the subject is extremely complicated, and there are no simple answers. That being said, there is some information easily available on the Internet concerning the distribution of mass in golf clubs. Use Google (or your favorite search engine) to search on club head twist inertia and you will find many useful web pages. Your second question deals with collisions (the golf club collides with the golf ball). And you have actually guessed at the correct solution: the stiffness of the ceramic head apparently causes the time interval during which the club and ball are in contact to be less than the less stiff heads. But there are other possible contributing causes: - t Read more:effect
Why we cann't create a completely black material yet? 2008-02-16 21:25:24 material is visible because it reflects light of different wavelengths. Our eyes receive the reflected light rendering the object visible. A true 100% black material would have to possess several characteristics; the material would have to absorb all light at all wavelengths which means that it would also not reflect any light at any angle of incidence. These are very unusual characteristics for any material to possess because the atomic and molecular structure dictates what light is absorbed and what is reflected. What makes it difficult to manufacture a material with these characteristics is that we don’t know in a precise and exact way what electronic and molecular configuration would produce a material with such characteristics. We have some idea how to get close to such a solution, Read more:create
, completely
, material
1 meter scale is same lentgh in earth and in outer most receding galaxy. 2008-02-15 00:52:37 The idea that it's the *measurement* that makes moving objects appear shorter is wrong, I'm afraid. To an observer holding a stationary meter stick, a moving meter stick is shorter than one meter -- no matter how far away it is. It's not because the stick is viewed with light, either; effects due to lightspeed propagation that can actually make a photograph of a moving meter stick appear *longer* than a meter!
Can increase in relavistic mass creates black holes? 2008-02-15 00:51:34 The short answer is no: the so-called "relativistic mass increase" doesn't really exist, because higher velocities don't really increase the mass of the object (it's just a shorthand way to calculate the relativistic change to energy and momentum). Fast-moving objects certainly don't have a larger gravitational field; you couldn't have an object be a black hole in one reference frame and not a black hole in another!
BPM 37093 'lucy' is a diamond? 2008-02-11 03:38:55 You are quite right to think there must be more to this news story than itfirst appears! Diamond, as you know, is composed of a crystal lattice ofCarbon atoms. The white dwarf in question, BPM 37093, is also thought tohave a crystalline structure, and may well be made predominantly of Carbon.However, as you've realised, the density of the white dwarf is much muchgreater than any material found on Earth, and so calling it a giant diamond
is taking a bit of liberty with language.That said, the true nature of white dwarves is every bit as fascinating andexotic. When a star ceases nuclear reactions in its core, it collapsesunder its own intense gravity, and forms a superdense plasma in which theatoms are literally crushed together so they overlap, and further collapseis only prevented by so-
what is the biggest galaxy that we know of? 2008-02-08 03:20:26 The word "biggest" could mean either the galaxy with the largest size (in kilometers) or the largest mass (in kilograms). In either case, the biggest galaxies are called cD galaxies. These exist in the centers of large clusters of galaxies, and are formed by the merger of many smaller galaxies. Big cD galaxies can have 100 times the mass of a galaxy like the Milky Way, and they can emit 10-20 times as much light as our galaxy does. A good example of a cD galaxy is the giant galaxy M87.
Why do mylar balloons shrink more than latex balloons in cold air? 2008-02-08 03:19:58 Charle's Law describes the relationship of a volume of gas and the temperature.V1 / T1 = V2 / T2V1 / V2 = T1 / T2Where: V1*T2=V2*T1V1&2 equals the Volume of gasT1&2 equals the Temperure KelvinK = C + 2731 liter of gas at 22 C will equal what volume at 0 C?1*273=V2*295273/295 = V2 = 0.9LNow I'll assume that your experiment didn't fill the 2 balloons with the same volume of gas which may account for the unrecognizable difference. Next time you perform the test, grab a ruler and mark a 50 millimeter line on the balloon and then place the balloon in the freezer. Give the balloon a little time to come to temperature. Quickly remove the balloon from the cold and quickly measure the line. The line should get smaller due to the volume of gas decreased. Oh and please don't pop your balloon with a s Read more:shrink
what would happen if a star passed through the oort cloud ? 2008-02-05 00:27:47 If another star got as close as the Oort cloud, several things could happen. Almost certainly the orbits of quite a number of comets will be disrupted or changed, probably resulting in anincrease in the number of comets entering the inner solar system. If the star is massive enough, itwill disrupt the orbits of some of the planets and Kuiper belt objects as well.The exact results will certainly vary depending on the mass, speed, anddirection of approach of the star. A low mass star just grazing the outer portions of the Oort cloud (which mayextend as much as a light year outward from the Sun) will certainly have much less effect than a20-solar-mass supergiant getting into the inner part of the Oort cloud. Read more:passed
which shape will provide better aerodynamics 2008-02-05 00:27:13 It depends how fast you are going, how much turbulence there is and the thickness of the boundary layer. The Reynolds Number (see Wikipedia) will give you some idea of turbulence for an object of a given size.If you look at nature you will find that some birds, and some fish, go for a pointed nose. Once again the best V angle depends on your speed – make it too shallow and there is too much area for the fluid to drag on.The whale, in fact has the best idea (for an object of its size). Its answer is a hemispherical front end and gently tapered rear. But it also has a GREAT idea, Its skin is flexible and MOVES (in ripples) as it passes through the water. This REDUCES drag!Much of the drag is caused by eddies set up by the passage of the animal (or plane). In the case of the plane this is m Read more:better
, aerodynamics
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