He estimated the distance from Syene to Alexandria as 5, 000 stades, and estimated the Earth's circumference was 250, 000 stades.

They first travel to the Puppeteer home world, where they learn that the expedition's goal is to explore a ringworld: an artificial ring about one million miles wide and approximately the diameter of Earth's orbit ( which makes it about 600 million miles in circumference ), encircling a Sol-type star.

That alternative route, different from the theoretical eastward route, was based on calculations of the Earth's circumference made by Columbus which showed the measurement to be substantially less than the classic 10, 000 mile figure given by Eratosthenes in the 3rd century BC.

* 500 – Aryabhata accurately computes the Earth's circumference, the solar and lunar eclipses, and the length of Earth's revolution around the Sun

* The Hellenistic period Mathematician Eratosthenes estimated the radius of Earth's circumference to be 252, 000 Stadia, a figure between 2 %- 20 % off modern measurements.

Together with ʿAlī ibn ʿĪsā al-Asṭurlābī in 827, he measured at 35 degrees north latitude, in the valley of the Tigris, the length of a meridian arc and thus the Earth's circumference, getting a result of 40, 248 km ( or, according to other sources, 41, 436 km ).

He measured the Earth's circumference, getting a result of 40, 248 km ( or, according to other sources, 41, 436 km ).

Posidonius measured the Earth's circumference by reference to the position of the star Canopus.

Posidonius was informed in his approach to finding the Earth's circumference by Eratosthenes, who a century earlier used the elevation of the sun at different latitudes to arrive at a figure of 250, 000 stadia ( which he rounded to 252, 000 so that it would be divisible by 60 ).

Both men's figures for the Earth's circumference were uncannily accurate, aided in part in each case by mutually compensating errors in measurement.

Ptolemy's approval of Posidonius's result, rather than Eratosthenes's earlier and more correct figure, caused it to become the accepted value for the Earth's circumference for the next 1, 500 years.

the Earth's circumference is 3, 200 Yojanas according to Vārāhamihira and slightly less so in the Āryabhatiya, but is given to be 5, 026. 5 Yojanas in the Suryasiddhānta.

* The Earth's polar circumference is 39. 94 Mm.

240 BC – Eratosthenes measures the Earth's circumference and diameter

In the last decade Thom's proposed length for the Megalithic yard has been extensively reused as such in many controversial books which claim this unit of measurement is a subdivision of the Earth's circumference in an alleged 366-degree geometry.

He is credited with being the first person to measure the Earth's circumference.

From 1882 to 1925 Juvisy-sur-Orge was the location of the astronomer Camille Flammarion's observatory, as well as the 1740 Pyramid erected to memorialize the work of Jean Picard and Nicolas Louis de Lacaille in measuring the Earth's circumference.

Al-Biruni also solved a complex geodesic equation in order to accurately compute the Earth's circumference, which were close to modern values of the Earth's circumference.

In contrast to his predecessors who measured the Earth's circumference by sighting the Sun simultaneously from two different locations, al-Biruni developed a new method of using trigonometric calculations based on the angle between a plain and mountain top which yielded more accurate measurements of the Earth's circumference and made it possible for it to be measured by a single person from a single location.

Of Mark Antony De Wolfe Howe the philosopher Whitehead said the Earth's first visitors to Mars should be persons likely to make a good impression, and when he was asked, `` Whom would you send ''??

Three years later it was found in nature, although it is the least abundant element in the Earth's crust among the non-transuranic elements, with an estimated total amount of less than at any given time.

The AU was originally defined as the length of the semi-major axis of the Earth's elliptical orbit around the Sun.

The first manned flight of Apollo was in 1968 and it succeeded in landing the first humans on Earth's Moon in 1969 through 1972.

The reference he used to this effect was the Earth's magnetic field direction, which at that time was believed to be invariant.

In retrospect the name change was unfortunate, not only because the Greek roots alone do not reveal the anode's function any more, but more importantly because, as we now know, the Earth's magnetic field direction on which the " anode " term is based is subject to reversals whereas the current direction convention on which the " eisode " term was based has no reason to change in the future.

The idea that immediately suggested itself was that the star's declination varied because of short-term changes in the orientation of the Earth's axis relative to the celestial sphere – a phenomenon known as nutation.

This star was seen to possess an apparent motion similar to that which would be a consequence of the nutation of the Earth's axis ; but since its declination varied only one half as much as in the case of γ Draconis, it was obvious that nutation did not supply the requisite solution.

Whether the motion was due to an irregular distribution of the Earth's atmosphere, thus involving abnormal variations in the refractive index, was also investigated ; here, again, negative results were obtained.

The tangent galvanometer was used to measure currents using this effect, where the restoring force returning the pointer to the zero position was provided by the Earth's magnetic field.

In that early form of chemical science, it was believed by many that the best way to heat certain materials was to mimic the supposed natural processes, occurring in the Earth's core, by which precious metals were believed to be germinated.

At the peak of the Cretaceous transgression, one-third of Earth's present land area was submerged.

His suggestion that the continents had been pulled apart by the centrifugal pseudoforce ( Polflucht ) of the Earth's rotation or by a small component of astronomical precession was rejected as calculations showed that the force was not sufficient.

* Third, there was the problem of why some parts of the Earth's surface ( crust ) should have solidifed while other parts were still fluid.

He developed a method of measuring the horizontal intensity of the magnetic field which was in use well into the second half of the 20th century, and worked out the mathematical theory for separating the inner and outer ( magnetospheric ) sources of Earth's magnetic field.

The reference he used to this effect was the Earth's magnetic field direction, which at that time was believed to be invariant.

In retrospect the name change was unfortunate, not only because the Greek roots alone do not reveal the cathode's function any more, but more importantly because, as we now know, the Earth's magnetic field direction on which the " cathode " term is based is subject to reversals whereas the current direction convention on which the " exode " term was based has no reason to change in the future.

On June 21, 2004, Space Ship One became the first privately funded aircraft to make a spaceflight, opening the possibility of an aviation market capable of leaving the Earth's atmosphere.

* In the episode " 11: 59 " of Star Trek: Voyager's fifth season ( original air date: May 5, 1999 ), Earth's first self-contained ecosystem known as " The Millennium Gate " is referenced and described as one kilometer tall and having begun construction in 2001.

During an international space symposium in May 1966, attended by space scientists from the United States and Soviet Union, he first proposed that manned landings on the moons would be a logical step after a manned landing on the Earth's moon.

Marcus Vitruvius, in the first century B. C., described a philosophical theory of the hydrologic cycle, in which precipitation falling in the mountains infiltrated the Earth's surface and led to streams and springs in the lowlands.

His other reputed achievements include the discovery of Earth's precession, the compilation of the first comprehensive star catalog of the western world, and possibly the invention of the astrolabe, also of the armillary sphere, which he used during the creation of much of the star catalogue.

At that time it had lost the first page, but the second ( the current beginning of the Ynglinga Saga ) starts Kringla heimsins, " the Earth's circle " of the Laing translation.

* 1979 – America's first space station, Skylab, is destroyed as it re-enters the Earth's atmosphere over the Indian Ocean.

Archaeologists have unearthed the remains of more than 20 successive settlements in Jericho, the first of which dates back 11, 000 years ( 9000 BCE ), almost to the very beginning of the Holocene epoch of the Earth's history.

Lorentz showed, that this effect is canceled to first order by the electrostatic charge ( produced by Earth's motion ) upon the conductors.

An early triumph of Luthor's first term occurs during the Our Worlds at War comic book crossover, in which he coordinates the U. S. Army, Earth's superheroes, and a number of untrustworthy alien forces to battle the main villain of the story arc, Imperiex.

The gram was first introduced in 1795, with a definition based on the density of water ( so that at the temperature of melting ice, one cubic centimeter of water would have a mass of one gram ; while the meter at the time was defined as the 10, 000, 000th part of the distance from the Earth's equator to the North Pole ).

The episode " Better Than Martians " ( 1994 ) deals with the first manned mission to Mars returning to Earth, but, encountering difficulty upon re-entering Earth's atmosphere and splashing into the ocean, leaving seaQuest to find the capsule before an unfriendly foreign confederation can.

The heroic Avatar travels first to the year 1887, then on to Mars to rescue many of Earth's scientists, celebrities, and politicians stranded there by accident.

The Earth's magnetosphere was first measured in 1958 by Explorer 1 with instruments designed by James A.

* 1997 – The first supersonic land speed record is set by Andy Green in ThrustSSC ( United Kingdom ), exactly 50 years and 1 day after Chuck Yeager first broke the sound barrier in the Earth's atmosphere.

The Cambrian Period witnessed the most rapid and widespread diversification of life in Earth's history, known as the Cambrian explosion, in which most modern phyla first appeared.

* Eratosthenes ( 276194 BC ), who made the first known reliable estimation of the Earth's size.

At first, oxygen would quickly combine with other elements in Earth's crust, primarily iron, as it was produced.

When switching from 700 stadia per degree to 500, he ( or Marinos ) expanded longitude differences between cities accordingly ( a point first realized by P. Gosselin in 1790 ), resulting in serious over-stretching of the Earth's east-west scale in degrees, though not distance.

The first novel was filmed as At the Earth's Core ( 1976 ), directed by Kevin Connor and starring Doug McClure as David Innes and Peter Cushing as Abner Perry.