Using the velocity of light,devise and execute a strategy to find out when the Crab Nebula actually occurred?
457633
the question is impossible to solve with out knowing how far away the nebula is. to find out when the nebula occured you would need to know how far away it is.\nit could be really close and have formed not-so-long ago \nor\nit could be really far away and have formed a long time ago\nfortunately i researched it and the nebula is at a distance of about 6500 ly from Earth\nthe crab nebula was created in 5446 BC \nalso using your \nD=R*T you plug in the Numbers to get a simple algebraic equation:\n6500=186000*T and yout solve for T after converting a few things
807253
nu = c / lamda\n\nsolve for lamda - you want wavelength.\nc is the speed of light = 3 x 10^8 m/sec\nnu is your frequency = 3.2 e-2\n\nplug into the calculator: 9.375 e9 meters
264542
We can use the formula c=v(lambda) where c=speed of light (=3.0x10^8 m/s), v is the frequency, and lambda is the wavelength\n\nSo we get:\n3x10^8 m/s = (3.22x10^16 s^-1)(lambda)\nlamda = 9.32x10^-9 m\nLambda = 932 nm
671170
Are you including the stars that are being created, as well as those that do not actually exist anymore but have died out/ supernova'd/ etc. that we are just still seeing since the light has to travel so far?  \n\nI would be interested in how you determined this number ^_^
917979
Albert said it, you can't get there from here. Let's assume you have the infinite power source you will need to push the near infinite relativistic mass you have as you approach the speed of light and you are deep space with no air friction or other forces to worry about, in other words, the ideal (but impossible) case.\n\nVelocity is acceleration times time. Light travels at 186000 miles per second.  One Gravity is 32 feet per second squared. So, we work backwards from the desired velocity and doing unit conversion from miles to feet . 186000=96/5280*T\nThe answer is 186000*5280/96 which is 10,230,000 seconds, which at 86400 seconds per day means 118.4 days.\n\nWhich does not sound nearly long enough...
561186
First of all, it is fundementally impossible to go at the speed of light. Therefore, the question as stated is invalid.\n\nHowever, it may or may not surprise you that, indeed, it is THAT VERY QUESTION that Albert Einstein surmised in 1896.  Here is his quote:\n"If I pursue a beam of light with the velocity c (velocity of light in a vacuum), I should observe such a beam of light as a spatially oscillatory electromagnetic field at rest.  However, there seems to be no such thing, whether on the basis of experience or according to Maxwell's equations.  From the very beginning it appeared to me intuitively clear that, judged from the standpoint of such an observer, everything would have to happen according to the same laws as for an observer who, relative to the earth, was at rest.  For how, otherwise, should the first observer know, i.e., be able to determine, that he is in a state of fast uniform motion?  One sees that in this paradox the germ of the special relativity theory is already contained.  Today everyone knows, of course, that all attempts to clarify this paradox satisfactorily were condemned to failure as long as the axiom of the absolute character of time, viz., of a simultaneous, unrecognizedly was anchored in the unconscious.  Clearly to recognize this axiom and its arbitrary character really implies already the solution to the problem."\n\nTherefore, In 1905 he realised how it could be that light always goes at the same speed no matter how fast you go.  Events that are simultaneous in one reference frame will happen at different times in another that has a velocity relative to the first.  Space and time cannot be taken as absolute.  On this basis Einstein constructed the theory of special relativity, which has since been well confirmed by experiment.\n\nNow, I can't explain any more than that.  So there :P
994577
I think what you’re wanting is a way to calculate the Sun’s altitude and azimuth for a given time and location.  The calculations are bit involved—you’d need to determine the Julian (Ephemeris) Date, solve Kepler’s equation to determine eccentric anomaly, then true anomaly, the Sun’s radius vector to obtain the Sun’s longitude, the obliquity of the ecliptic to determine latitude, then transform the RA and dec coordinates to altitude and azimuth.  I’m probably leaving something out.  Anyway, I do have the formulae, but thought I’d see if that’s what you’re really wanting before I do a lot of typing.\n\nPerhaps a more sane approach would be to modify a telescope (a Meade or other) and let its mounting do the tracking for you?  Just an idea.\n\n[edit]\n\nMy apologies for the delay in updating my answer.  Here’s how to calculate the Sun’s RA and dec:\n\nFirst, calculate the Julian Day (JD).  (note: Julian Day begins at Greenwich mean noon, or 12h Universal Time).\n\nLet\nYYYY = year\nMM = month\nDD.dd = day (fraction of day derived from hours, minutes, seconds past 00:00:00 UT; convert local time to Universal Time before doing this)\n\nIf MM > 2, then\ny = YYYY\nm = MM\n\nIf MM = 2 or 1, then\ny = YYYY – 1\nm = MM + 12\n\nIf date >= October 15, 1582 (in your case it will be), calculate\nA = INT(y / 100)\nB = 2 – A + INT(A / 4)\nelse (not in your case)\nB = 0\n\nJulian Day is then:\n\nJD = INT(365.25 * y) + INT(30.6001 * (m + 1)) + DD.dd + 1720994.5 + B\n\nNext, calculate the time T (measured in Julian centuries of 36525 ephemeris days from the epoch 1900 January 0.5 ET):\n\nT = (JD – 2415020.0) / 36525\n\nNote: since T is expressed in centuries, it should be calculated with a sufficient number of decimals; an error of 0.0001 in T corresponds to an error of 0.37 day in the time.\n\nThen, geometric mean longitude of the Sun (in degrees):\n\nL = 279.69668 + 36000.76892 * T + 0.0003025 * T^2\n\nSun’s mean anomaly (in degrees):\n\nM = 358.47583 + 35999.04975 * T – 0.000150 * T^2 – 0.0000033 * T^3\n\nEccentricity of the Earth’s orbit:\n\ne = 0.01675104 – 0.0000418 * T – 0.000000126 * T^2\n\nHere, I opted for an easier method that doesn’t require the solution of Kepler’s equation; the Sun’s radius vector isn’t needed:\n\nSun’s equation of center C (in degrees):\n\nC = + (1.919460 – 0.004789 * T – 0.000014 * T^2) * sin(M) + (0.020094 – 0.000100 * T) * sin(2 * M) + 0.000293 * sin(3 * M)\n\nSun’s true longitude (stl) is:\n\nstl = L + C\n\n(The true anomaly (M + C) is not needed.)\n\nSun’s apparent longitude (sal) is then:\n\nsal = stl - 0.00569 – 0.00479 * sin(259.18 – 1934.142 * T)\n\nThen calculate the obliquity of the ecliptic (oe):\n\noe = 23.452294 – 0.0130125 * T – 0.00000164 * T^2 + 0.000000503 * T^3\n\nTo correct for apparent position:\n\noe = oe + 0.00256 * cos(259.18 – 1934.142 * T)\n\nThen, for RA and dec:\n\ntan(RA) = cos(oe) * sin(sal) / cos(sal)\nsin(dec) = sin(oe) * sin(sal)\n\nor\n\nRA = arctan(cos(oe) * sin(sal) / cos(sal))\ndec = arcsin(sin(oe) * sin(sal))\n\nYou can convert RA from degrees to hours by dividing by 15.\n\nAssuming I didn’t overlook something or typo, this should get you the Sun’s RA and dec for a given time.  Do you also need a method to transform RA and dec to altitude and azimuth for a given time and location?  (I’m thinking yes)
601530
Agree with terror_2287.\nThe speed of light is something basic. You will use speed of light to measure 'a meter', not to use 'meter' to measure speed of light.\nThink about it. Where did "one meter" come from? Before 1983, it was the standard meter placed somewhere in Europe (sorry, didn't remember where is it :D). But you know that even a very, very precisely cut rod of metal can still have error to the size of an atom, which is NOT negligible in quantum physics. So we must have a better definition and speed of light came up. A meter is the distance light traveled in 1/299792458 sec in vacuum. => speed of light (in vacuum) is 299792458m/s, with no error, no better measurement, no digit after the '.' And if you have your speed of light like this 299792458.12m/s or 299792458.00m/s you are having misconception.\nOf course we can, and have to, measure the speed of light in media, not vacuum. We do that by comparing the speed of light in the medium to that in vacuum (not by how many "standard meter" per second).\nAn easy and rather precise way to measure the speed of light in media involve the use of interferometers, with the earliest and still be in use is those of Reilegnh and Michelson which has good axplanation in Wiki (link below)\nRahul's way of measuring the speed of light with a microwave oven is rather like measuring the speed of sound, using stop wave. But there is a mistake: You will only get 'the meter', not the speed. You will have very exact 'centimeters' that way. Yea, that's a good way to 'recalibrate' your ruler, I think. But you will not get anything out of 'speed of light'.
144613
light rays do not move faster or slower than the speed of light.  the speed of light is the speed of light, period.\n\nthat said, light often travels *slower* than c, which is a constant defined as the speed of light IN A VACUUM, approximately 3x10^8 m/s.  here is a way you can actually observe some honest-to-god light traveling slower than c:\n\nstep 1.  find a window.\nstep 2.  look at it.\n\ncongratulations, you have observed light traveling slower than c.  in ANY medium (air, glass, water - you name it) the speed of light is slower than the speed of light in a vacuum.  \n\nin fact, the so-called index of refraction (n, which equals 1.4 for glass) is defined as the ratio of c to the speed of light in that material.  generally, denser materials have a higher index of refraction, and people have been able to make light go REALLY slow by making some very dense materials.  all of this is perfectly consistent with general relativity.\n\nas for FASTER than c:  under certain conditions, it is possible to make photons with a "phase velocity" that is greater than c.  however, when people speak of the speed of light, they usually refer to the "group velocity".  the distinction between phase velocity and group velocity is kind of technical; but phase velocity refers to the speed at which the individual phase fronts propagate through space.  \n\nit is possible to make these phase fronts go faster than c; but because the energy or information or whatever carried by the light travels at the group velocity, the actual speed (as far as stuff like general relativity is concerned) is still less than c.\n\nanyway, all of these results are entirely consistent with general relativity.  in fact, i don't know of any published results of a scientific experiment which are not consistent with GR.  \n\nthe fact that einstein's theory, largely concocted out of the blue from basic principles and logical reasoning, has stood the test of time for so many years is a testament to the genius of the man's work.\n\nhere are some links to learn about phase velocity, group velocity and the speed of light:\nhttp://en.wikipedia.org/wiki/Group_velocity\nhttp://physicsweb.org/articles/news/4/7/8/1
1123630
1) 10 full wave-length passed by 120 sec so the wave period is 12 sec. f=1/T so f=0.083333 Hz\n2) First of all, light speed=3 x 10^8 m/s.\nSecondly, f=v/lambda\n(where v=light speed and lambda=wave-length)\nso f=3X10^8 / 6.6 x10^(-7)=4.5454 x 10^14 Hz (approx. 4500 GHz = Giga Hertz)
661036
Yes. Theoretically, if you try to determine the 'place' of a photon 'exactly' as if it is a particle, you will not be able to detect it's velocity. And when you want to know its 'exact' speed, you will have no idea about where it is, just like a wave.
974250
This page gives a very nice table listing who, when, how, how accurately the speed of light has been measured including the first time when Olaus Roemer did it in a really neat way 330 years ago!\n\nhttp://math.ucr.edu/home/baez/physics/Relativity/SpeedOfLight/measure_c.html
499544
There are numerous problems with your assertion: you measure the universe's size using the farthest object viewed from earth (13.7 billion ly).  Then you assume (from your equations) that earth is at the center of the universe (a somewhat egotistical idea), also, you forget to measure in the opposite direction (galaxies are visible at 180 degrees of the one observed to be 13.7 billion ly from here). Add to all these your interesting equivalent of the speed of light...apparently you believe the speed of light to be somewhere around 34.2 meters per second (a mere 226.4 times slower than the space shuttle).  If you are going to try to figure out the size of the universe, do a little more research and brush up on your math...for example: \n\n"From new data collected from a space probe examining the Cosmic Background Radiation, astronomers estimate the universe is at least 156 billion light-years wide. Actually, it’s long been known that the universe was a lot wider than 27.4 billion light-years; this latest research tells us how much wider.\n\nAccording to researchers writing in the journal Physics Review Letters, the universe must have expanded much faster than light in its early stage." *\n\nSo take into account that one light year is 9,467,280,000,000 km ** and you get...\n\n1.476895680 x 10^24 km\n\nthat's 1 octillion, 476 septillion, 895 sextillion, 680 quintillion kilometers wide (or 1 quadrilliard, 476 quadrillion, 895 trilliard, 680 trillion kilometers wide for those following the European system of counting)...and that disregards the continued expansion since the observations.\n\nOf course there are also quite a few scientists who affirm that the universe is infinite, so, in the end, nobody really knows.
976652
1 km from p the light is √10 km away\n\nusing v = rω and ω = 4*2π radians/minute = 8π*60 = 480π rad/hr\nv = √10 * 480π km per hour at right angles to the radius\nThe angle between the velocity vector and the beach\n= the angle between the line from p to the lighthouse and the position 1 km up the beach to the lighthouse\n\nSo V along the beach = √10 * 480π * cos (angle)\n= √10 * 480π * 3/√10\n= 1440π km/h\n≈ 4524 km/h (no wonder they flash so fast!!! LOL)
604912
These astronomical questions require astronomical answers. How to start and how to end?\n\nFact is, our existence is only a very very very very.......... small portion of time to calculate. To find how old, we have yet to discover evidence mainly because we cannot reach outside our very own galaxy to explore. Considering that it will take lightyears to travel the enormosity of time and space boggles all that best is people to come with a reasonable reason that will be hard to disprove. No one can. All can theorise.\n\nSo the universe is so large, it is beyond our perception, beyond our present ability to fully comprehend, and though we are making small progresses with probes and telescopes, it is still too huge and complex to grasp. We can theorise based on understanding of our surrounding and equating everything else to what we know. This is our limitation. \n\nUniverse has been around even before our gaalxy is formed bbillion zillions years ago. The acceptable theory is that a big bang ceated our galaxy and out solar system. Something must happen, and people theorise it must be sudden, that is why the bang. And it just happen like that that our galaxy was formed, and then our solar system. No one can track back and so this is so. Hence, theory is what we can do to try to explain to ourselves.\n\nSupernova is a dying star, giving its last burst of energy befre collapsing. Death of stars is something little understood because it is rare. Stars take million of light years to reach us and so we are watching history when some event occurs. So far, only a few supernova had been documented. And these stars actually died millions years beforehand.\n\nIt is theorised that when a star dies, it collapse into itself, as stars are suppose to be like our sun, all gaseous. It is theorise that the star will collapse into a very dense body with very high gravitational pull that it sucks everything nearby into itself. This is the black hole.. It is theorise that it will be so dense that even light cannot escape. So far possible sighting of black hole has been done by noting the bending of light in the universe, since the black hole cannot be seen \n\nSo, outside our atmosphere, we have theories to try to explain everything we see. We need a reason to justify the things we see in space, rather than accepting that they are there even way before life begins on earth, and that there will be many flawed theories because at this time, it is just beyong our ability to check it out.
11463
The changes propagate at the speed of light, so I guess the time taken is,\n\nt = r/c where c = speed of light
977701
I found this interesting article about an ancient black hole scientists have located near our solar system.  They determined the exact route and speed at which this monster has been traveling.\n\nConducting a bit of astronomical archaeology, researchers have dug up 43-year-old photographic evidence of an ancient black hole and used the information to learn that the object has been wandering at high speed on an odd, looping path through the Milky Way Galaxy for 7 billion years.\n\nThe study, discussed in the Sept. 13 issue of the journal Nature, represents the first measure of a black hole's movement through space, said researchers involved in the work.\n\nThe object's travels take it above and below the main plane of the galaxy, where the Sun and most other stars reside and orbit around the galactic center in relatively orderly fashion. The wayward black hole zooms along at 90 miles per second (145 kilometers per second) relative to the Earth, currently carving an arc up and over our solar system.\n\nIn pinning down the vagabond's trajectory and piecing together a picture of its past, researchers say they are adding pages to at least one chapter in the book that explains how the galaxy formed. \n\nThe object is estimated to have been around more than 2 billion years before our Sun was born, a time when the Milky Way was a toddler of a galaxy.\n\n"We believe that hundreds of thousands of very massive stars formed early in the history of our Galaxy, but this is the first black hole remnant of one of those huge primeval stars that we've found," said lead researcher Felix Mirabel, an astrophysicist at the Institute for Astronomy and Space Physics of Argentina and the French Atomic Energy Commission.\n\nAccording to what I read, I would have to assume that the rate and speed at which a black hole travels has much to do with its' size.\n\nI would recommend you finish reading the article.  It is very interesting. Thanks for your question.