• If the earth was a magnet, how would of a bar magnet react to it? How would a compass react?

    Best answer: The earth HAS a magnetic field. The N pole is not at the rotational axis, but offset away from it.
    A bar magnet or a compass, if free to move, will align along the earth's magnetic lines of force, their south poles towards the north magnetic pole.
    Best answer: The earth HAS a magnetic field. The N pole is not at the rotational axis, but offset away from it.
    A bar magnet or a compass, if free to move, will align along the earth's magnetic lines of force, their south poles towards the north magnetic pole.
    4 answers · 1 day ago
  • If you have more than one propeller on the same shaft does it increase the amount of thrust from the same power?

    Best answer: it would not add much because the air would already be in motion when it reached the downstream props. The thrust comes from pushing air backward, making the plane go forward. If the air is already moving backward at a rate pretty close to the fastest the prop can make it move, then the thrust value will be a lot... show more
    Best answer: it would not add much because the air would already be in motion when it reached the downstream props. The thrust comes from pushing air backward, making the plane go forward. If the air is already moving backward at a rate pretty close to the fastest the prop can make it move, then the thrust value will be a lot less (less acceleration is possible so less force is attained). There is a minor benefit from the increase in mass that the prop would be able to handle, but that would be secondary. There are a lot of other issues that come into play such as the movement of air is not as a perfect tube with no boundary layer issues, and other such things, but those are secondary to trivial in this general discussion.

    In effect, there is a limit to what can be taken as thrust by moving air. Unless the prop is a very inefficient one, adding a second one down-stream will not be of major benefit, and it will carry a cost. Much better to make the primary prop more efficient.
    5 answers · 3 days ago
  • What exactly is a light year ? Does it mean a year of traveling at light speed? Or is a year in light the measurement? Confused?

    Best answer: A light year is the distance a beam of light would travel in a year
    Best answer: A light year is the distance a beam of light would travel in a year
    9 answers · 5 days ago
  • Do humans emit electro magnetic radiation? if so, what are some cool facts about it?

    Best answer: Yes, humans emit heat as infrared and radiation. while infrared radiation is invisible to human beings it is not invisible to cats and dogs and other animals that hunt at night.. "...36 Amazing Facts about Infrared Radiation 1. Almost half of the energy arriving to the Earth... show more
    Best answer: Yes, humans emit heat as infrared and radiation. while infrared radiation is invisible to human beings it is not invisible to cats and dogs and other animals that hunt at night..

    "...36 Amazing Facts about Infrared Radiation
    1. Almost half of the energy arriving to the Earth from the sun comes as infrared light.

    2. Anything which has a temperature puts out heat or infrared light.

    3. Infra Red waves are also given off by stars, galaxies, lamps, flames and anything else that’s warm – including you...

    ...4. One of the advantages of IR observation is that it can detect objects that are too cool to emit visible light. This has led to the discovery of previously unknown objects such as comets, asteroids and wispy interstellar dust clouds.

    5. Everything has some heat and puts out infrared light. Even things that we think of as being very cold, like an ice cube – put out some heat.

    6. Infrared light can travel through thick smoke, dust or fog, and even some materials.

    7. In firefighting, infrared cameras are being used to locate people or animals in heavy spots and to detect hot spots in forest fires.

    8. Humans, at normal body temperature, radiate most strongly in the infrared at a wavelength of about 10 microns. (A micron is the term commonly used in astronomy for a micrometer or one millionth of a meter.)...".

    http://www.infrared-light-therapy.com/in...



    "...
    9 answers · 5 days ago
  • What is the difference between temperature and thermal energy?

    Best answer: ... temperature is by definition the AVERAGE kinetic energy of the particles in an object but thermal energy is the TOTAL of that energy in an object so you could have a cup of coffee with a high temperature but when you compare the total energy in the cup to the total in a lake at low temperature the lake wins the... show more
    Best answer: ...
    temperature is by definition the AVERAGE kinetic energy of the particles in an object
    but thermal energy is the TOTAL of that energy in an object
    so
    you could have a cup of coffee with a high temperature
    but when you compare the total energy in the cup to the total in a lake at low temperature
    the lake wins the race running away

    it's sort of like density
    you could have a small bit of lead like a bullet with high density
    and compare that to a wooden log
    the log weighs more but has a lower density

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    4 answers · 2 days ago
  • Why do we believe people who cannot prove there ideas?

    Best answer: Many people lack the critical thinking skills to properly evaluate complex scientific ideas. This is exacerbated by the popular press, which is more interested in sensationalism than nuanced understanding. The most common failure in approaching scientific knowledge is the assumption of absolute truth. ALL of our... show more
    Best answer: Many people lack the critical thinking skills to properly evaluate complex scientific ideas. This is exacerbated by the popular press, which is more interested in sensationalism than nuanced understanding. The most common failure in approaching scientific knowledge is the assumption of absolute truth. ALL of our knowledge, scientific and otherwise, is provisional, based on our limited access to reality and subject to revision as more facts become available.

    When it comes to black holes, fortunately, misapprehension of their nature is not going to have consequences for most of us beyond perhaps exposing our ignorance. Much of Hawking's work on black hole theory remains hypothetical, but their existence and certain aspects of their behavior have been observed. How else, for example, would you explain Sagittarius A*? Besides clear evidence of supermassive black holes in galactic centers, there are a number of observable stars in our galaxy in orbit with what appear likely to be black holes.

    As to why we follow this regardless of our ability to evaluate or even comprehend, I think it's because the idea feeds our sense of wonder.
    12 answers · 7 days ago
  • Is Michio Kaku insane?

    Best answer: Well he’s up there in age and probably thinking about his mortality.
    Best answer: Well he’s up there in age and probably thinking about his mortality.
    4 answers · 2 days ago
  • Can we make difference between the subatomic particles of two elements?

    Subatomic particles of all the elements are exactly alike. What makes the difference is their number in an atom. So if electron of an Aluminum and Zinc are not made up of Al and Zn respectively then how do we differentiate between the electron of Al and Zn if analyzed separately? Further, At what minimum size of... show more
    Subatomic particles of all the elements are exactly alike. What makes the difference is their number in an atom. So if electron of an Aluminum and Zinc are not made up of Al and Zn respectively then how do we differentiate between the electron of Al and Zn if analyzed separately? Further, At what minimum size of any matter say Zn started showing up its physical appearance as a substance of Zn if we zoom out from the nucleus of its any atom as an element is indistinguishable at the individual subatomic particle level.
    4 answers · 2 days ago
  • Is physics accurate?

    Best answer: The most sensitive experiments can measure things to 10 digit accuracy or better. And our current theories have been stable for a long time, because they agree with those experiments to the last decimal point. I'd say that's "accurate". It's always possible that an experiment will be found... show more
    Best answer: The most sensitive experiments can measure things to 10 digit accuracy or better. And our current theories have been stable for a long time, because they agree with those experiments to the last decimal point. I'd say that's "accurate".

    It's always possible that an experiment will be found that disproves or requires revision in, for instance, general relativity. But keep in mind that any theory that explains such a new experiment will also have to reproduce the old theory's accuracy in agreeing with the old experiments. For relativity, that's 100 years of experiments so far.
    5 answers · 4 days ago
  • When you move a pin away from a magnet, is there a point that it no longer pulls at the pin?

    No matter how far away you move the pin, there must be a point where the magnet switches off completely or has a forever decreasing (but always there) force pulling at the pin. If you were in space with a permanent magnet in your pocket and you had forever. Could you not simply point that magnet in the direction of... show more
    No matter how far away you move the pin, there must be a point where the magnet switches off completely or has a forever decreasing (but always there) force pulling at the pin. If you were in space with a permanent magnet in your pocket and you had forever. Could you not simply point that magnet in the direction of your choice, knowing that the magnet will pull you there once it gets your mass moving. Even though its pull on the planet you are pointing at is so minute, time isn't a problem so doesn't that make your little magnet a vehicle?
    5 answers · 4 days ago
  • Is it scientifically possible to live outside of time?

    Best answer: No. Time is defined by ongoing events. An interval of time is defined by the temporal difference between two events. As these events take place in three dimensional space, the space we live in, then we cannot live outside of time any more than we can live outside 3D space. Which is to say, it's space.time. ... show more
    Best answer: No.

    Time is defined by ongoing events. An interval of time is defined by the temporal difference between two events. As these events take place in three dimensional space, the space we live in, then we cannot live outside of time any more than we can live outside 3D space. Which is to say, it's space.time. If we live within the one we must also live within the other.
    13 answers · 1 week ago
  • Can this occur in relativity?

    Best answer: First a couple of clarifications. Time NEVER slows down for you. You will always see time proceed normally for YOU. In special relativity, all inertial frames are equivalent, so either frame can be considered at rest and the OTHER frame to be moving. So, both observers will see the other’s clock running slower.... show more
    Best answer: First a couple of clarifications.

    Time NEVER slows down for you. You will always see time proceed normally for YOU.

    In special relativity, all inertial frames are equivalent, so either frame can be considered at rest and the OTHER frame to be moving. So, both observers will see the other’s clock running slower. There is no contradiction or paradox because each observer is measuring the other observers clock in terms of their coordinate times. You can set up this scenario with two observers undergoing exactly the same acceleration and then decelerating in exactly the same way so they both become inertial in a perfectly symmetrical scenario.

    If you want to compare elapsed time (something called proper time) between two observers, you need to measure the proper time that has elapsed when both observers start in the same inertial frame and end in the same inertial frame. In this case, the proper times will be different if there is some asymmetry in the acceleration/deceleration scenario. This is the most meaningful scenario and is usually illustrated with twins - one in a spaceship undergoing an acceleration and returning to earth where the other twin has remained in an inertial frame. In either case, each twin sees time proceed normally for them. When they get back to the same frame of reference, one will be younger than the other.

    So, the only way to make your scenario work is if everything in the universe were accelerated, while you remained inertial. When everything in the universe is decelerated back to your inertial frame, two weeks may have elapsed for you, but two days for everything else in the universe. Not a very likely scenario.
    10 answers · 7 days ago
  • Do smooth surfaces reflect sound?

    Best answer: They can. And the reflection will be coherent (not chaotic, not scattered in many directions). However, amount of reflection itself is not a function of the smoothness of the surface, it is a function of the amount of absorption of energy that the new substance performs. A perfectly smooth surface could have... show more
    Best answer: They can. And the reflection will be coherent (not chaotic, not scattered in many directions). However, amount of reflection itself is not a function of the smoothness of the surface, it is a function of the amount of absorption of energy that the new substance performs. A perfectly smooth surface could have essentially no reflection of sound, if the new material either absorbed or transmitted the sound instead of "rejecting" it back to where it came from.
    8 answers · 6 days ago