Veritasium
Why Does the Moon Orbit Earth?
- Title
- Why Does the Moon Orbit Earth?
- Runtime
- 1:35
- Date posted
- 16 years ago
- Description
- It takes the moon about 27 days to orbit the Earth. What makes it go round? It is the gravitational attraction of the Earth on the moon. Due to the moon's velocity, the Earth keeps pulling the moon towards it without the moon actually getting closer to the Earth. This is similar to how satellites orbit the Earth.
- Title
- What Forces Are Acting On You?
- Runtime
- 2:25
- Date posted
- 16 years ago
- Description
- What forces (i.e. pushes or pulls) are acting on you right now? Most people can identify the gravitational force down, but there must be something else otherwise you would accelerate down towards the center of the Earth. The other main force on you is called the normal force. It is a force perpendicular to the surface that supports you, like the ground or the seat of your chair. You compress this surface and it acts like a spring, pushing you up.
- Title
- What is a Force?
- Runtime
- 3:40
- Date posted
- 16 years ago
- Description
- Force is a central concept in physics. By analysing the forces on an object, its resulting motion can be determined. But what exactly is a force? The word force is used in everyday language in a variety of contexts, only some of which reflect the scientific definition of force. In this video, people at Victoria Park in Sydney are interviewed on their ideas of force and the forces that act on them.
- Title
- How Far Away is the Moon? (The Scale of the Universe)
- Runtime
- 1:50
- Date posted
- 16 years ago
- Description
- If the Earth were the size of a basketball and the moon a tennis ball, how far apart would they be? Diagrams that are not to scale make us think that they're closer than they really are.
- Title
- Gravity (Scientific Version of John Mayer's Gravity)
- Runtime
- 3:55
- Date posted
- 16 years ago
- Description
- A song about Gravity set to the tune of John Mayer's Gravity.
Gravity is working with me
And Gravity, keeps me on the ground
All mass attracts all other mass
a force proportional to mass one and two
and inversely to the distance between them squared
Oh, gravity is working with me
and gravity, makes apples fall to ground
Oh twice the mass has twice the pull
but the force on each is still equal
It keeps the moon and the satellites
going round
Oh twice the mass has twice the pull
but the force on each is still equal
It keeps the moon and the satellites
going round
Oh gravity, the force that makes weight on me
Woah, gravity, now general relativity (how can that be?)
The force between us all is
The force between us all is
The force between us all is
Gravity between us all is
Gravity between us all is
Gravit...
- Title
- Egg Experiment to Demonstrate Inertia
- Runtime
- 1:10
- Date posted
- 16 years ago
- Description
- If you spin a raw egg and then stop it, it will start spinning again without you having to touch it. A boiled egg, on the other hand, stops and stays stopped. Why is this? Well a raw egg contains a yolk that moves inside the egg independently of the shell. If you stop the shell, the yolk inside continues to move due to its inertia and it therefore gets the egg spinning again.
- Title
- The Difference Between Mass and Weight
- Runtime
- 3:15
- Date posted
- 16 years ago
- Description
- There is a common perception that weight and mass are basically the same thing. This video aims to tease out the difference between mass and weight by asking people what makes a car difficult to push. The standard answer is that it is difficult to push because it's heavy. But heaviness is a measure of weight, the gravitational pull of the Earth attracting the car to Earth's center. When the car is pushed on a flat road, the force of gravity does not oppose the motion. Instead the resistance felt is an indication of the car's mass which determines its inertia. Inertia is the property of matter that means it tends to resist acceleration - the greater the mass, the less the acceleration for a given amount of force.
- Title
- Scientific Notation - Example
- Runtime
- 1:47
- Date posted
- 16 years ago
- Description
- If the sun were entirely made of protons, how many would there be in the sun? How can this be worked out using the Google search field?
- Title
- I'm Atoms (Scientific Cover of Jason Mraz's I'm Yours)
- Runtime
- 3:38
- Date posted
- 16 years ago
- Description
- Well an atom's made of protons, neutrons, and electrons
the first two in the nucleus, the third around it
it's mostly empty space, but it feels solid in any case
The elements are all the different types of atoms
they differ by the number of protons in the middle.
Hydrogen has only one, but Uranium has a ton
It's just chemistry that you and me are made of these atoms
Well atoms bond together to form molecules
Most of what's surrounding me and you
Water, sugar, things yet undreamed of of of of
Look around you, see the combinations in a eucalypt tree
Mendeleev's periodicity
gives us sand and water and the air above ove ove ove ove
It's just chemistry that you and me are made of these atoms:
Hydrogen, Oxygen, Carbon, Nitrogen, make up the world's life forms
Do do do you, do do do do
but do you wonder how
matter forms somethi...
- Title
- Scientific Notation - Explained!
- Runtime
- 5:13
- Date posted
- 16 years ago
- Description
- Scientists have to work with some very large and some very small numbers. To represent these numbers more easily, they use scientific notation. Scientific notation relies on powers of 10. This video gives examples of how to represent a large and small number and explains powers of ten.
- Title
- Cathode Rays Lead to Thomson's Model of the Atom
- Runtime
- 3:13
- Date posted
- 16 years ago
- Description
- In the mid 1800's scientists successfully passed an electric current through a vacuum in a glass tube. They saw a glow from the tube that seemed to emanate from the negatively charged plate called the cathode. Since scientists didn't know what the glow was they called it a cathode ray. There was debate over whether the cathode ray was a wave phenomenon like light or a stream of negatively charged particles. JJ Thomson effectively resolved the debate in 1897 by performing a clever experiment that determined the charge to mass ratio of the particles making up the cathode ray. He also showed that this same particle was in all different cathode materials so it must be a constituent common to all atoms. This changed our understanding of the atom from the previous billiard ball model to Thomson's plum pudding model of the atom.
- Title
- Thomson's Plum Pudding Model of the Atom
- Runtime
- 2:17
- Date posted
- 16 years ago
- Description
- JJ Thomson proposed the first model of the atom with subatomic structure. He had performed a series of experiments and was credited with the discovery of the first sub-atomic particle, the electron. He therefore proposed a new model of the atom called the plum pudding model. In this model, the plums represent negatively charged electrons which can be plucked out of the atom, leaving behind some positively charged pudding. In this film, cherry tart is used as a delicious substitute for plum pudding.
- Title
- Atomic Theory
- Runtime
- 2:33
- Date posted
- 16 years ago
- Description
- This is the first Veritasium science video. It addresses one of the most fundamental concepts in science: the idea that all things are made of atoms, tiny particles that are in perpetual motion. They attract each other when a little distance apart and repel when squeezed together.
- Title
- What causes the seasons?
- Runtime
- 2:49
- Date posted
- 16 years ago
- Description
- There are a few persistent misconceptions about what causes the seasons. Most believe it is the distance between the Earth and sun which varies to give us seasonal temperature variations. However it is actually the directness of the sun's rays leading to more intense sunshine in summer and less in winter.
- Title
- How long does it take for the earth to go around the sun?
- Runtime
- 1:13
- Date posted
- 16 years ago
- Description
- A recent survey of scientific literacy in Australia found 30% believe it takes one day for the Earth to go around the sun. This video provides qualitative evidence for the finding from Sydney's Eastern beaches.
