General and Special Relativity

Gravity is not a 'wave', it is a field of curvature of space-time caused by objects with mass. A black hole contains the mass of a star, compressed to the space of a single atom (a singularity), the compression of so much mass into such a small space, is why the black hole has such a powerful gravitational pull.

The Top, Charm, and Up quarks have +2/3 of an 'elementary' charge.

The Bottom, Strange, and Down quarks have -1/3 of an 'elementary' charge.

You can calculate it yourself, with the formula for acceleration in uniform circular motion. The centripetal acceleration, with circular motion, is v2 / r (velocity squared divided by the radius). Since the Earth's gravitation is about 9.8 meters per second square, solve the equation v2 / r = 9.8, for variable v. r (radius, of the Earth) should be converted to meters. The velocity will be in meters per second.

Note that this exercise assumes the Earth is rigid. In practice, if Earth really rotated that fast, it would flatten out a lot, and in fact be torn apart.

You can calculate it yourself, with the formula for acceleration in uniform circular motion. The centripetal acceleration, with circular motion, is v2 / r (velocity squared divided by the radius). Since the Earth's gravitation is about 9.8 meters per second square, solve the equation v2 / r = 9.8, for variable v. r (radius, of the Earth) should be converted to meters. The velocity will be in meters per second.

Note that this exercise assumes the Earth is rigid. In practice, if Earth really rotated that fast, it would flatten out a lot, and in fact be torn apart.

You can calculate it yourself, with the formula for acceleration in uniform circular motion. The centripetal acceleration, with circular motion, is v2 / r (velocity squared divided by the radius). Since the Earth's gravitation is about 9.8 meters per second square, solve the equation v2 / r = 9.8, for variable v. r (radius, of the Earth) should be converted to meters. The velocity will be in meters per second.

Note that this exercise assumes the Earth is rigid. In practice, if Earth really rotated that fast, it would flatten out a lot, and in fact be torn apart.

You can calculate it yourself, with the formula for acceleration in uniform circular motion. The centripetal acceleration, with circular motion, is v2 / r (velocity squared divided by the radius). Since the Earth's gravitation is about 9.8 meters per second square, solve the equation v2 / r = 9.8, for variable v. r (radius, of the Earth) should be converted to meters. The velocity will be in meters per second.

Note that this exercise assumes the Earth is rigid. In practice, if Earth really rotated that fast, it would flatten out a lot, and in fact be torn apart.

When two objects are moving with respect to each other at different speeds, and that difference is a good fraction of the speed of light, then the rate of time passing on one object would seem to an observer on the other object to be different.

To be frank, we do not yet know for sure even if there is an end of time. At present, we know that the Universe has an accelerated expansion, and we expect it to go on, and in such a scenario, there isn't really an "end", we would have a cold universe that goes on and on presumably!

An object surrounded by fluid is buoyed up by a force equal to the weight of the

displaced fluid. It doesn't matter whether the fluid is water, as in the case of a

canoe, or air, as in the case of a blimp, or any other fluid.

With the possible exception of some circuits that have inductance and capacitance

in parallel and are excited by a pulse or an alternating voltage, the currents in two

parallel branches of a circuit are ALWAYS in the same direction.

In relativistic physics, the energy carried by a photon is given by the equation E=hf, where E is the energy, h is Planck's constant, and f is the frequency of the photon. The energy of a photon is directly proportional to its frequency, meaning photons with higher frequencies have higher energies.

The theory of relativity has three effects: time dilation, length contraction, and mass-energy equivalence. Time dilation refers to the slowing down of time for objects in motion relative to each other. Length contraction describes how objects appear shorter when they are moving at high speeds. Mass-energy equivalence, as described by E=mc^2, highlights the relationship between mass and energy.

New discoveries are happening all the time in all branches of research. Not a day or week goes by that something new is discovered: be it in branches of the physical sciences or biological sciences. Most discoveries don't normally come to the attention of the general public.

There is so much new knowledge that it exceeds all the information in the Library of Congress several times over on an annual basis. Things that peak the publics interest are usually the result of some major publication i.e magazine, newspaper or electronic media printing something which goes viral or some new technological application from the physical or biological sciences.

It is unlikely for a glass water pipe to get hot enough to melt plastic with just a BIC lighter. Glass has a high melting point and requires more intense heat to melt compared to plastic. However, caution should always be exercised when heating glass with a flame to avoid any potential damage or injury.

-- Get a pure piece of it. The size of the piece doesn't matter.

-- Measure the mass of the piece.

-- Measure the volume of the piece.

-- The density of the substance is mass of the piece/volume of the piece.

Einstein described his general relativity (gr) hypothesis in November of 1915. It predicted that the path of light from a distant star would appear to bend* when it passed near to our Sun. Such an effect could only be observed during a solar eclipse, and only with very sensitive instruments. Einstein admitted that a failure to observe the effect EXACTLY as predicted would mean all of gr would have to be abandoned -- there was pretty no "fudge factor" that would permit a modification of his basic idea to meet experimental results.

Einstein was able to show that gr explained an anamalous precession of the perehelion of Mercury. This was an unexpected early "test" of his hypothesis, but was hardly proof. It simply meant that gr explained a known fact of nature better than other ideas, but that did not mean it was the ONLY possible explanation.

The first observational test of light bending -- a test that would unambiguous prove or disprove gr -- was done by Arthur Eddington in 1919 May, and the results, when announced in November of that year, made Einstein a world celebrity literally overnight. More exact observations done in 1922 showed, beyond any dispute, that this bending was exactly as Einstein had predicted.

* I say "appear" because, in actuality, space is being warped and the light is simply following the space through which it is traveling.

The period of a pendulum is not affected by the angle of the bob. The period depends only on the length of the pendulum and the acceleration due to gravity. The angle of the bob will affect the maximum height the bob reaches, but not the time it takes to complete a full swing.

Yes, a frame of reference is necessary to accurately describe motion. This is because motion is relative and depends on the observer's point of view. By defining a frame of reference, we establish a standard from which to measure and describe the motion of objects.

Albert Einstein developed the general theory of relativity and the special theory of relativity in the early 20th century. These groundbreaking theories revolutionized our understanding of gravity, space, and time.

Throughout history, populations have tended to expand up to a point, contracting violently when resources become strained.

An observer who measures an object moving past him will measure that the

object's mass has increased, its length in the direction of its motion has shrunk,

and timekeeping devices aboard the moving object, such as clocks, decay of

radioactive nuclei, oscillators, and beating hearts, are running slow. These effects

increase with increasing speed of the moving object. They head towards the

situation where, if the object could move at the speed of light, its mass would be

infinite, its length in the direction of motion would be zero, and timekeeping devices

would be stopped.

These effects have been confirmed in thousands of experiments and observations

over roughly the past 100 years. Adjustments for them are built into the GPS system ...

the system wouldn't work without 'relativistic' corrections, because of the satellites'

speed in their orbits.

Length, Height, Width, Time, Spatiality. You'll get an argument on the last one. Actually you'll get an argument on the fourth one too. There are three spatial dimensions--L X H X W. Time is only a temporal dimension. Further dimensions should not be thought of as extensions of any of these. Dimensions are physic/mathematical constructs that can't necessarily be understood except as analogies. See: http://en.wikipedia.org/wiki/Fifth_dimension The Fifth Dimension is a musical group popular about 1970. "Fifth Dimension's lush, airy sound embodied a glossy showbiz vibe that couldn't have been more at odds with the values of the hip, rock underground."

In a small room, sound waves can quickly bounce off the walls, ceiling, and floor, leading to multiple reflections that can interfere with each other and cancel out the echo. This phenomenon is known as acoustic interference, which can dampen or eliminate the perception of an echo in a small space.

To be straight in answering,I would write that if that particular object has its density nearly equal to the density of fluid displaced by its submerged part then only the object will be likely to float in the fluid.

-- It takes more force to accelerate an object with more mass.

... Gravity exerts more force on an object with more mass.

-- It takes less force to accelerate an object with less mass.

... Gravity exerts less force on an object with less mass.

Whatever the mass of the object happens to be, gravity always exerts just the right

amount of force to accelerate it at always the same rate ... 9.8 meters per second2.

Mass is a measure of the amount of stuff of which a person or a thing is made.

There's no reason the environment should have any effect on that amount. The

object's mass doesn't change, whether it's in air, vacuum, maple syrup, or water,

unless or until a piece falls off.