THE SCIENCE LAB
3 million light years away
SO, WHAT IS IT?
Explaining some of the sciencey wiency smeg of Red Dwarf in terms that a stuffed iguana can understand
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A black hole is a little like a vacuum cleaner; matter in outer space is pulled towards it, but instead of that matter being 'sucked' in, it's gravity that pulls the matter in. Some physicicts hypothesise that black holes could puncture a tunnel (wormhole) through to another part of the same universe, or perhaps even another universe altogether, where the matter would be expelled by a white hole. In this scenario, one can see that white holes are essentially being hypothesised to balance a rather complex astronomical equation; what goes in, must come out....somewhere. So, the matter being expelled by a white hole, would be that which has fallen into a black hole.
It’s important to understand that white holes are – at present – only hypothesised to exist. That is, no one has actually ever observed one. Some physicists argue that white holes cannot exist in the real world and are simply the other end of a mathematical equation.
It was the Russian theoretical astrophysicist, Igor Novikov, who in 1964, became the first person to point out that general relativity permits the existence of white holes.
Refs:
Novikov, I.D. 1964. Soviet Astronomy 41, 1075 [translation of Astronomicheskii Zhurnal 8, 857]
The word 'quasar' is short for quasi-stellar radio source or quasi-stellar object. They are extremely bright star-like objects that exist at the edge of the visible universe. In fact, quasars are the brightest objects in the known universe. If you look at a quasar through a telescope, they look like faint red stars, perhaps not what you might expect for the brightest objects in the universe. But they appear faint by virtue of the fact that they are so extremely far away.
There is a fairly broad consensus in the world of astronomy that quasars are supermassive black holes which are surrounded by an accretion disc. An 'accretion disc' is a disc of material that is being drawn in by gravity to a celestial object with an intense gravitational field, in this case, a supermassive black hole. As the material comes in, it spins around the central body. The collision of matter creates a huge output of energy and light, something which is a distinctive feature of quasars.
Quasars appear red because they are ‘redshifted’. Different colours have different light frequencies. For example, if you look at an object that is moving away from you, you will see light that has a longer wavelength than it had when it was emitted (redshift), but if you look at an approaching object, you will see light that is shifted to a shorter wavelength (blueshift). This is known as the 'Doppler Effect'. The Doppler effect is essentially the change in the frequency of sound and light.
Red shift is one way that astronomers can gauge how far away an object is.
Camille: We're androgynous, but I suppose you could call him my husband. (Red Dwarf, Camille)
Androgyny is where an organism has both masculine and feminine characteristics. By 'characteristics' this means as in appearance, attitude, or behaviour. So, when a lifeform is androgynous, they have characteristics that are not distinguishably masculine nor feminine. This is different to being a hermaphrodite, which is where an individual has​ the reproductive organs of both sexes.
Rimmer: How do you calculate acceleration? (Red Dwarf, Balance of Power)
Acceleration is the rate at which an object changes its speed. You can calculate acceleration using the following equation:
Acceleration = change in speed ÷ time taken
Lister: I don't even know how to make oxygen...it's got something to do with plants and ends in osis. (Red Dwarf, White Hole)
First of all, let's look at what the word 'photosynthesis' means. 'Photo' is the Greek word for 'light' and 'synthesis' is the Greek word for 'putting together'.
Broadly speaking, photosynthesis is how plants eat. Plants can make their own food providing they have three things: light, carbon dioxide and water. Light is actually electromagnetic energy, and that energy is absorbed by the chlorophyll in the leaves of green plants.
Leaves are made up of lots of cells. These cells contain tiny little units called chloroplasts. Chloroplasts are what makes leaves green, and they are also what converts the light, carbon dioxide and water into a sugar called glucose. So, plants 'synthesise' food from carbon dioxide and water by using the energy they obtain from light. A by-product of this process is oxygen.
The large amount of oxygen produced by tropical rainforests is why they are often referred to as the 'lungs of the world'.
Image: Artist's rendering of ULAS J1120+0641, a very distant quasar powered by a black hole with a mass two billion times that of the Sun.
(Image: Wikimedia Commons. ESO/M. Kornmesser).
Image: Kruskal diagram for an eternal black hole.
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(Image: Wikimedia Commons. TimothyRias) |
Lister: What's an iguana? (Red Dwarf, The End)
The short answer is that an Iguana is a genus of herbivorous lizard which is native to the Caribbean, and South and Central America.
The long answer involves explaining what a genus is. Taxonomy is the academic discipline of defining groups of biological organisms based upon shared physical characteristics and giving names to those groups. Every known lifeform on Earth (both living and extinct) has been named by scientists according to a set of rules, and all scientists adhere to those rules.
Rimmer: In answering the question, "What does the red spectrum tell us about quasars?" -- write bigger -- there are various words that need to be defined. What is a spectrum, what is a red one, why is it red, and why is it so frequently linked with quasars? (Red Dwarf, Balance of Power)​
Cat: So, what is it?
Kryten: I've never seen one before -- no one has -- but I'm guessing it's a white hole. (Red Dwarf, White Hole)
The process of photosynthesis
(Image: Wikimedia Commons. At09kg)
If you have any Red Dwarf related science questions you'd like answered, or you'd like to leave a comment or make a suggestion for inclusion on any part of the site, just send me a tweet.
Dobro vece! Katerina
LEFT: The major taxonomic ranks. Intermediate minor rankings are not shown (Image: Wikimedia Commons)
The taxonmic classification system is hierarchical. Each species belongs to a genus, each genus belongs to a family, and so on through order, class, phylum, and kingdom. You will notice when looking at the 'Creatures with sci-fi potential' section, that every organism has a two word scientific name. The name is made up of a 'genus' and a 'species'. An example is Homo sapiens. This is the scientific name for human beings. 'Homo' is the genus name and 'sapiens' is the species name.
The taxonomic naming system was established in the eighteenth century by Swedish zoologist Carl Linnaeus. A genus name is always written with a capital letter. The species name follows the genus name and should all be written in lowercase. The whole name should always be italicized (or underlined if it is not possible to italicize, such as when writing by hand).
Kochanski: Do you know what a comet is made of? ... It's made of ice (Red Dwarf, Blue)
Comets are sometimes referred to as 'dirty snowballs', because they're made up of dirt, ice and frozen gases. Comets are the leftovers from the formation of planets and stars.
Broadly speaking, a comet is made up of two main parts: one part is an icy rock nucleus (centre), which is also the only solid part of a comet. The other part is called the 'coma'. The coma is a cloud of dust and gas that surrounds the nucleus of the comet.
Comets are extremely difficult to detect in the outer solar system because they remain frozen and are comparatively small objects. However, as a comet approaches the inner solar system, the heat from the sun causes gas to melt. This gas escapes from the nucleus (along with dust), and creates the coma. You can think of the coma as a rather fragile atmosphere around the nucleus. Solar winds (from the sun) then blow that gas and dust away, and this is what creates the comet's characteristic tail.
Because of the solar winds, if a comet is travelling towards the sun, its tail will be behind it, but if the comet is travelling away from the sun, then its tail will be in front of it. Millions of fusion reactions take place on the sun every second and each of those reactions superheat surronding gases, creating plasma. That plasma bursts out into space a little bit like a volcano spewing out material. It is this which creates the solar wind.
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Diagram of a comet. (Image: Wikimedia Commons. NASA Ames Research Center/K. Jobse, P. Jenniskens) |
Holly: Well, the thing about a Black Hole - it's main distinguishing feature - is it's black. (Red Dwarf, Marooned)
Actually, black holes aren't black, not really. Black holes are certainly very dark, but they give off a glow, called ‘Hawking radiation’. As you might guess, this radiation is named after the legendary Professor Stephen Hawking at Cambridge, who was the first person to hypothesise about the existence of this radiation. Because black holes are constantly emitting Hawking radiation they are always losing mass, and will eventually evaporate altogether if they don’t have another source of mass to sustain them, such as interstellar gas or light.
What makes this all even more interesting is that it's currently thought that smaller black holes give off Hawking radiation faster than larger black holes. So they will evaporate quicker. Why is this interesting? Well, it's because some scientists predict that the Large Hadron Collider - currently busy whacking protons together at collosal speed beneath the Franco-Swiss border near Geneva, Switzerland - will create tiny holes as a result of particle collisions, which would enable the decay of these holes to be studied through the radiation. Cool ay!!
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Simulated view of a black hole (center) in front of the Large Magellanic Cloud. Note the gravitational lensing effect, which produces two enlarged but highly distorted views of the Cloud. Across the top, the Milky Way disk appears distorted into an arc. (Image: Wikimedia Commons) |
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Cherenkov radiation glowing in the core of the Advanced Test Reactor, a research reactor at the Idaho National Laboratory, located east of Arco, Idaho. (Image: Wikimedia Commons) |
Holly: We're travelling at the speed of light. Me bottle's gone. (Red Dwarf, Future Echoes)
The speed of light in a vacuum is a constant 186,000 miles per second (which roughly translates to 300 million metres per second), but light doesn’t always travel through a vacuum. Although light speed remains the 'speed limit' of the universe, when it is travelling through a substance it can travel much slower. For example, when travelling through water, light travels at around three quarters of its usual speed, that's about 140,000 miles (225 million metres) per second.
In nuclear reactors, some particles can be forced to travel at speeds which are within a fraction of the speed of light. If the surrounding light happens to be travelling through a substance which slows it down, then the particles end up travelling faster than the light around them. When this happens it creates a blue glow that is called 'Cherenkov radiation' - in many ways it's like the light equivalent of a sonic boom, and this is the reason that underwater nuclear reactors glow blue.
The slowest speed that light has been recorded travelling at is approximately 38 miles per hour (17 metres per second), which was through rubidium cooled to near absolute zero. This creates a peculiar state of matter called Bose-Einstein condensate.
Ref: Hau, L.V., Harris, S.E., Dutton, Z., Behroozi, C.H. 2009. Light speed reduction to 17 metres per second in an ultracold atomic gas. Nature 397, 594-598.