Title: Stars of science!
1Stars of science!
- What did the famous scientists actually discover?
- Were they always good discoveries?
2Sir Issac Newton
Ist Law of Motion An object at rest will remain
at rest unless acted on by an unbalanced force.
An object in motion continues in motion with the
same speed and in the same direction unless acted
upon by an unbalanced force. This law is often
called "the law of inertia".
2nd Law of Motion Acceleration is produced when a
force acts on a mass. The greater the mass (of
the object being accelerated) the greater the
amount of force needed (to accelerate the
object).
3rd Law of Motion For every action there is an
equal and opposite re-action.
3Robert Goddard
- Goddard was the first person to suggest the
interesting idea of multi-stage rockets. - If all the rocket fuel is held in one big
container, that container has to be carried very
high into space. However what if the rocket were
made of smaller compartments fitted together?
Once the fuel in the first compartment is
finished, that compartment can be thrown away.
The remaining rocket doesn't weigh so much and so
less fuel is needed for it to carry on its
journey. Modern rockets generally have 2 or 3
stages (as the containers are called) to make use
of this idea.
4Galileo Galilei
- In the late 1500's, everyone thought that heavy
objects fall faster than lighter ones. Galileo
Galilei is reputed to have challenged this by
dropping two different weights from the town's
Leaning Tower.
When the objects are released, the heavier object
will have more inertia to overcome than the
lighter one. As it turns out, the inertia of the
object perfectly balances the stronger
gravitational pull for the object with the
greater mass and the objects fall to the earth
with the same acceleration
5Archimedes 287 BC- 212BC
Archimedes discovered much about why things float
whilst other things sink.
- Archimedes the strength of the upthrust was
equal to the weight of the water that was moved
out of the way to make room for the object
immersed.
Less dense liquids can provide less upthrust to
counteract the weight of the immersed
object. What would happen to a ship sailing from
a freshwater river into a salty sea?
6Charles Darwin
- Chalres Darwin is famous for his work into
evolution. - The natural variation within a population of
living things means that some individuals will
survive and reproduce more successfully than
others in their current environment. - For example, the peppered moth exists in both
light and dark colours in the United Kingdom, but
during the when there were lots of factories many
of the trees on which the moths rested became
blackened by soot, giving the dark-coloured moths
an advantage in hiding from predators. This gave
dark-coloured moths a better chance of surviving
to produce dark-coloured offspring, and in just a
few generations the majority of the moths were
dark
7Thomas Edison
- Thomas Alva Edison (February 11, 1847 October
18, 1931) was an American inventor, scientist and
businessman who developed many devices that
greatly influenced life around the world,
including the phonograph, the motion picture
camera, and a long-lasting, practical electric
light bulb.
8Andre Marie Ampere(1775 1836)Count Alessandro
Giuseppe Antonio Anastasio Volta (1745-1827)
- Ampere - a French physicist and mathematician who
is generally regarded as one of the main
discoverers of electromagnetism. The unit of
measurement of an electrical current is named the
ampere (the number of charged electrons moving
past a point in one second) - Volta - An Italian physicist known especially for
the development of the first electric cellin
1800. The voltage of a power supply is the
measure of the energy it gives to that charge
moving around a circuit. A 1.5 battery supplies
1.5 Joules to each coulomb ( lots and lots of
electrons) that passes through.
9Alexander Graham Bell 1847- 1922
- A special scale called the decibel scale, named
after Bell, is used to measure the loudness of
sound. - 20 dB leaves falling
- 40 dB quiet talking
- 80 db cars on a street
- 100 dB sound of a rock group
- 120 dB shuttle launching
10Dilemma Good or Bad science?
- Is science always a good thing?
- Lets consider the work of three different
scientists. You decide if what they invented was
a good or a bad thing - Alfred Nobel
- Marie Curie
- Fritz Haber
11Alfred Nobel
In 1867 I patented my most famous invention,
dynamite. Dynamite was a safe convenient way of
storing the explosive nitroglycerine so that it
could be used for construction work, it helped to
build roads, tunnels and canals across the world.
Some people said it could be used as a weapon but
I knew it was much to terrible for anyone to use
it in such a way.
I set up the Nobel prizes using the fortune I
made from selling my inventions around the world
12The darker side of the invention
- Dynamite was one of the most destructive forces
of the 19th century, it killed thousandsAlfred
was so obsessed with using nitroglycerine he kept
working on it even after his brother died during
their experiments. - Alfred's father was also an inventor, he invented
mines which floated just below the surface of the
water and destroyed several British ships in the
Crimean war.
13Marie Curie
In 1903 I presented my ideas about radioactivity
to the scientific world. I had studied the
element radium and coined the words radiation
and radioactivity. I received two Nobel prizes
for my work.
The work almost killed my husband, we didnt
realise how dangerous it could be. Radioactivity
was used to help patients suffering from cancer.
This was my initial idea but research into
radioactivity has lead to all sorts of advances
nuclear power, irradiation of food, all sorts of
real progress for the human race.
During world war one I used my expertise to set
up mobile x ray units which my daughter and I
took to the front line to help as many people as
we could.
14The Darker side of the discoveries
- Her daughters worked with her in her later years,
and her son in law Fred worked with scientists in
France who went on to work on the Manhattan
Project in the USA. The Manhattan Project made
the first two atomic bombs in the world which
were dropped on Hiroshima and Nagasaki. Millions
died, war, and the world changed forever.
Generations of people were affected by the bomb
dropped years ago.Even when bombs are not
dropped the people of Chernobyl can vouch for the
fact that mistakes in nuclear power stations can
last longer than a lifetime.
15Fritz Haber
I worked on a process to make ammonia from its
two constituents nitrogen and hydrogen. Ammonia
is an incredibly useful chemical, it can be used
in fertilisers and can produce better crops
around the world. In this overcrowded world we
need to be able to grow as many crops as we can,
as efficiently as we can. Ammonia is a vital
ingredient in fertilisers it provides plants with
the nitrogen they need.I feel this is an
essential discovery for the human race. I also
received a Nobel prize for my work.
16The darker side of the discoveries
- Firstly he did not make ammonia to make
fertiliser, this was a happy coincidence. Ammonia
is used for explosives and this is why he was
working on it, his discovery of the Haber Process
is thought to have extended the first world war
by a year. Thousands more died because more
explosives could be made.He was also very
involved in the use of chemical weapons in world
war I He was the driving force behind the use of
chlorine gas in the trenches, a particularly
cruel way to die..
17But dont forget, we can all be great scientist
- Making a lava lamp!
- Amazing materials
- Balloons and flames
18Always remember to carefully observe and think
hard!
Banana flake
19A raisin
20A clover plant
21A bottle top
22A strawberry plant leaf
23A 2P coin
24A bran flake