A student shows his mates a label with a name from the table but he can´t see it. Then he has to make questions about himself and the rest of the class will answer yes or no.
The student should try to know who he or she is.
Brass instruments are simply brass tubes, narrow at one end and gradually widening until it reaches the bell. They are coiled or bent in some way for easy handling. Some common brass instruments are trumpet, horn, trombone and tuba. Same as wind instruments, tone is produced by blowing breath in the tube, however the pitch is determined by a specially shaped mouthpiece. Slack lips produce low notes while tight lips produce high notes. The quality of tone produced depends on the shape of the mouthpiece. Shallow cup-shaped mouthpiece as used in trumpet forms higher harmonics and brilliant tone. Horn, which use deeper funnel-shaped mouthpiece sounds more mellow.
Woodwind instruments are usually made of wood, however, flutes and piccolos are more often made by metal, for oboes and clarinets are occasionally made of ebonite. All wind instruments are made to sound by causing to vibrate inside a hollow tube. Different instruments have theirs own particular ways of playing them. The pitch of the note produced depends on its columns of air: long columns of air produce low notes while shorter columns result higher notes. Wind players are able to control tone production by a method called tonguing. The syllable "tu" is formed silently by the player, and he can give every note a clear start by using his tongue. Then, he can go smoothly from note to note by not using it.
Musical instruments are made of many different materials and are played in many different ways. Due to their characteristics, they are mainly grouped into five main categories, which are Woodwind, Brass, Percussion, String and Keyboard.
STRINGS
All musical instruments with strings are known as string instruments, such as the violin family, harp, guitar and so on. The pitch of the note is decided by the length, thickness and tension of the string. String instruments are basically divided into two groups: bowed string instruments and plucked string instruments. The most common type of bowed string instruments are the violin family. The violin, viola, cello and double bass are members of violin family. The reason they known as bowed strings is because players have to use bow to make the string vibrate. The bow that had made sticky with resin is drawn across a string of the violin, keeps on catching the string and pulling it, thus produce sound. All of them have common characteristics, yet the chief difference between them is their size, increase from violin to the double bass. Each of them plays different role in orchestra, as violin has wide range of tone qualities, and the rest of them are act as base of the orchestra since they have lower pitch compared to violin. The harp, guitar, lute, mandoline and banjo are examples of plucked string intruments. The main difference between them and the violin family is that they are not played with a bow, but plucked the string with fingers. Therefore, the tone dies away more quickly and usually they have been used mainly to accompany the voice, most often the singer plays the instrument himself.
Here you are a images with the instruments descripted.
Primary Colors: Red, yellow and blue In traditional color theory (used in paint and pigments), primary colors are the 3 pigment colors that can not be mixed or formed by any combination of other colors. All other colors are derived from these 3 hues.
Secondary Colors: Green, orange and purple These are the colors formed by mixing the primary colors. Tertiary Colors: Yellow-orange, red-orange, red-purple, blue-purple, blue-green & yellow-green These are the colors formed by mixing a primary and a secondary color. That's why the hue is a two word name, such as blue-green, red-violet, and yellow-orange.
And now you can find some images which explain the mix of the primary colors in order to get the others
Watch the video about insecst and arthropods and read the transcript
Video
transcript
Insects and arthropods
More than three quarters of the world’s animal species are arthropods.
They are an essential part of our ecosystem.
Although arthropods come in all shapes and sizes they all have some
things in common. They are all invertebrates. This means they don’t have a
backbone. They all have a skeleton on the outside of their bodies called an
exoskeleton.
Their bodies are made up of segments and they have many pairs of jointed
legs.
They also have bilateral symmetry. This means that the left side of an
arthropod is a mirror image of the right.
The largest group of arthropods is insects. An insect’s body is divided into three parts:
the head, the thorax and the abdomen.
The second largest group is crustaceans. This group includes lobsters
and crabs.
Arachnids include spiders and scorpions. Nearly all arachnids live on
land and are hunters. Like insects, arachnids have a segmented body. However,
whilst insects have three pairs of legs, arachnids have four pairs.
The last group of arthropods is the millipedes and centipedes. These
creatures have many pairs of legs, one or two on each body section.
To survive, all arthropods need shelter, food and a safe place where
they can reproduce. They can be found in many different environments and
arthropods can adapt to their habitats. Spiders spin webs to catch prey, while
hermit crabs use empty shells to give them protection and camouflage.
Bees take their food from the nectar in the plants around them.
Some arthropods such as beetles live alone. Others such as ants and bees
live in huge well-organised communities.
All arthropods want to reproduce. Because there are so many different
types of arthropods there are different ways in which they are born, develop
and grow. Some arthropods like spiders and bees lay many eggs in protected
places, for example under leaves or in a hive. When they hatch, the young look
like the adults.
A few arthropods like the
scorpion give birth to live young, which are carried until they are able to
survive alone. Some arthropods have a life cycle where the egg hatches to
reveal a larva, a grub-like creature. After a while the larva becomes a pupa.
It will now gradually change or metamorphose to become an adult. A butterfly’s
life cycle is a good example of this
Mammals, from giant whales to
small mice, and to great apes much like ourselves, are among the most advanced
of earth’s creatures. All mammals share two traits – we feed our young with
mother’s milk and we have hair, more or less.
Mammals nursing their young
produce fewer offspring than other animals but the youngsters have a much
higher rate of survival than newly hatched birds, reptiles and insects. This
young orangutan will stay with its mother for eight years.
Hair, like the coats worn by
these high alpine guanacos, offers mammals another advantage. Hair, and the
sweat glands that come with it, helps mammals stay warm in cold climates and
mammals have moved into nearly all of earth’s habitats. Polar bears have adapted
to life in the Arctic where the inhospitable cold makes fur coats essential.
Marine mammals like porpoises
and humpbacked whales thrive in cold oceans. They still have a few hairs around
their mouths but a more efficient underwater insulator is a thick layer of fat
keeping heat in and cold out.
Elephants battle heat. Their
skin, covered in fine hairs, is wrinkled making it easy to trap cooling mud in
the creases.
Spots on the coats of leopards
and cheetahs help them to hide. Their fur works to camouflage the big cats
stalking prey in tall grasses.
There are 7 500 species of
reptiles and amphibians and some 8 600 species of birds, only 4 100 species of
mammals exist but they dominate the land and the sea.
Mammals have evolved with
greater speed and agility than most other animals. Limbs that are lined up to
support weight and drive mammals forward help browsing mammals run from
mammalian predators, armed with tooth and claw.
And when natural advantages
fail, some mammals fashion tools to help them out. This orangutan is working on
a spoon to help him scoop ants out of a tree.
Tool-making was once thought
to be a skill exclusive to the human mammal but all great apes and some other
animals make tools.
So what separates us from the
rest of the mammals?
Our ability to communicate? To
parent? To show emotion?
Perhaps a better question is
to ask what makes us all so alike?
A little florescent dye illuminates
a complex circulatory system beneath the leaf’s surface. But what drives the
pattern of these veins?
This question has intrigued
physicist Marcelo Magnasco for years.
‘I guess that simply because
of the mysterious beauty of the patterns.’
This network provides
structure, transports water and nutrients and does it in the face of bugs,
fungus and other attackers.
‘The network is built to
withstand life, right. Leaves have been strongly optimised over millions and
millions of years to be, you know some of the most remarkably adapted organs
that we can find in this planet.’
And to a mathematical
physicist like Magnasco, this evolutionary adaptation can be understood with
numbers. Assuming evolution has shaped the geometry of the network, you can
think of this pattern as the optimal solution, the best answer to a puzzle that
takes into account the job of the leaf and the challenges facing it.
Magnasco along with research
fellow, ‘my name is Elena Katifori’, wanted to understand what problems this
lemon leaf’s loopy pattern solves.
‘And then what we do is an
insanely huge calculation in which we make many many random perturbations to
the network. ‘
One perturbation to the
network could be vein damage, and this is where their cool florescent
demonstration comes in. Katifori shows the advantage of alternate pathways
here.
‘Yep, so I punch the hole in
the leaf which you can see here. In this little vial here I have the florescent
dye and then as soon as I put this in you are going to slowly start seeing the
dye travelling through the veins and you will see the trajectory of the dye.’
‘This, you know, pretty close
to obvious that if you want your network to be resilient to damage you will
want to have some loops, exactly how many and how big is the question we are
addressing in our work.’
The calculation revealed that
resilience isn’t the only advantage of this loopy structure.
‘If the demand at every single
point where you’re distributing fluctuates’ – for instance the sunny side of
the leaf may need water when the shady side doesn’t, that’s a fluctuation in
demand – ‘if those fluctuations happen you achieve efficiency not by having
lines dividing into lines but by having essentially circles dividing into
little circles.’
So their calculations revealed
that changes in demand and potential for damage make the circle-within-circle
structure optimal and this is similar to the way the lemon leaf’s network
looks. But it’s worth noting that not all plants have come up with this
particular solution.
Take the ancient ginkgo.
‘It has survived for millions
of years so it’s doing pretty well.’
And obviously designing optimal
networks for transport isn’t a problem that only leaves space.
‘The question of how to
deliver stuff has been posed since the times the aqueducts were built in Rome
so this is a question that has been studied a lot in the context, not so much
of the natural science but in the context of delivering goods.’
But perhaps even more
seductive than the practical applications here, is just how cool it looks.
‘That’s the profound and
interesting thing about elegance and beauty that they are not really devoid of
utility and practicality, right. I mean have you seen a Ferrari? They become
pretty by being highly optimised and so there’s a deep connection between beauty
and utility that I personally don’t understand but I make use of it.’
Happy Valentine’s Day from
Science Friday. I’m Flora Lichtman.
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