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The Theory of (nearly) Everything

The Theory of (nearly) Everything

The Theory of (Nearly) Everything 2019

In this special issue, the editors of BBC Science Focus explain the fundamental concepts of science, and reveal the latest cutting-edge research that will change our world. IN THIS ISSUE… - The Universe's history and how it will end - Clear explanations of key scientific concepts - Science facts, stats and expert opinion - Stunning images of life on and off Earth

País:
United Kingdom
Língua:
English
Editora:
Immediate Media Company London Limited
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Nesta edição

12 minutos
the story of the universe

The year 2009 could go down in the astronomical textbooks as the one when a revolution in our understanding of the Universe began. The protagonist at the centre of this upheaval was not a person but a machine: a space probe called Planck. Named after the great German physicist Max Planck, the spacecraft was launched by the European Space Agency that year and was tasked with detecting the ‘blueprint’ of the Universe – capturing a snapshot of the seeds of the stars and galaxies that surround us today. Prior to its launch, cosmologists had spent over a century constructing mathematical theories to describe the story of the Universe, from the earliest moments to the present day. But analysis of the data returned by Planck has revealed a number of plot holes…

1 minutos
the key experiment

The Horn Antenna at Crawford Hill in New Jersey was built for use with satellites, so the shape of it was designed to minimise interference from the ground and provide the best possible measurement of the strength of radio noise from the sky. The nature of this radiation depends on the temperature of the radiating object. The amplifiers used in the receiver were cooled to 4.2 Kelvin (-268.8°C) using liquid helium, and Penzias devised a ‘cold load’, cooled by liquid helium to about 5 Kelvin, which was used to calibrate the system. By switching the antenna from observations of the cold load to observations of the sky, they could measure the apparent temperature of the Universe (expected to be 0 Kelvin), then subtract out known factors, such as the interference from the…

1 minutos
timeline

1929 Edwin Hubble discovers the distance of a galaxy from us is directly proportional to the velocity implied by its redshift. Georges Lemaître had published this in 1927, but nobody had noticed. 1931 Lemaître writes: “We could conceive the beginning of the Universe in the form of a unique atom, the atomic weight of which is the total mass of the Universe.” 1948 Ralph Alpher (left) and Robert Herman calculate that the leftover radiation from the primeval fireball should still fill the Universe today, with a temperature of about 5 Kelvin (-268°C). 1964 Arno Penzias and Robert Wilson discover a weak hiss of radio noise coming from all directions in space. The following year, this is explained as the leftover radiation from the Big Bang. 1989 Launch of the Cosmic Background Explorer satellite (COBE), which detected tiny irregularities (ripples)…

1 minutos
need to know

COSMOLOGICAL REDSHIFT A stretching of light, or other electromagnetic radiation, caused by the stretching of space between the galaxies as a result of the expansion of the Universe. This is not a Doppler effect, because it does not involve motion through space, but is measured in units of velocity. The cosmic background radiation is light from the Big Bang with a redshift of 1,000. HUBBLE’S LAW Actually first proposed by Georges Lemaître, the law says that the redshift ‘velocity’ of a galaxy is proportional to its distance. So a galaxy twice as far away is receding twice as fast, and so on. This does not mean we are at the centre of the Universe, however. The law works the same way whichever galaxy you observe from. MICROWAVES Microwaves are radio waves with wavelengths in the…

1 minutos
from the makers of science focus magazine

ONLY £9.99 EACH INCLUDING P&P* Experts reveal the science behind what really works when it comes to losing weight, eating right, keeping fit and sleeping well. Brighten up your day with the help of science! Discover the best ways to reduce the stress of daily life and improve your mental well-being. Take a guided tour of the systems in your body that pump your blood, digest your food, fight off infection and deal with pain. Truth is often stranger than fiction, as the 222 mind-blowing answers to what seem like simple questions demonstrate in this Special Edition. Find out how technology from half a century ago took humans to the Moon and how Neil Armstrong avoided a crash landing on the lunar surface. From wormholes and dark matter to dinosaur gaits and AI… experts explain the…

9 minutos
the composition of stars

The philosopher Auguste Comte wrote, in 1835, that “there is no conceivable means by which we shall one day determine the chemical composition of the stars”. So much for philosophy. By the time Comte died in 1857, astrophysicists were well on the way to finding out what stars are made of. Indeed, spectroscopy, the tool they would use to do it, had already been invented decades before Comte made his pronouncement. In 1802, the British scientist William Hyde Wollaston was studying sunlight by passing it through a slit to make a narrow beam and then through a glass prism to spread the beam into a solar spectrum. By doing so, he noticed that the colours were separated by dark bands – two in the red part of the spectrum, three in…