Transcript scale
Scaling the Universe Human Hair 10-4 meters (Size of KY) Human Cell 10-5 meters (Distance to Frankfort) Bacteria 10-6 meters (Size of UK, a kilometer or so) Virus 10-8 meters (Size of 10 meter) Small Molecules 10-9 meters (Size of 1 meter)) Atom 10-11 meters (Size of 1 centimeter) Nucleus 10-15 meters (Size of a Bacteria) Nice sketch and image of an atom Size of atom and nucleus Typical atomic size 1 x 10-10 meters That means 20 million atoms lined up end-to-end are about this long Typical nucleus size 1 x 10-15 meters That’s about 100,000 times smaller. Nucleus takes up about 0.0000000000001% of the space in an atom. What makes up the other 99.9999999999999% of the atom? If the Nucleus is a grape on the 50 yard line in Commonwealth Stadium, then the electrons are tiny gnats flying in the cheap seats So, given all of this information: What really makes up you and me ? Virtually NOTHING !!! Don’t Believe Me? The Matrix has you. Now for a Magic Trick I am going to make you levitate in your seats. Isn’t that Cool So without forces, like the electromagnetic force between charges, we would pass through walls (if they could exist), through mountains, even through the Earth. So what are these forces? In the Standard Model, forces arise from the exchange of particles. Some of these particles are real and some are virtual. You aren't really only empty space The electromagnetic force arises from an exchange of particles by charged particles. The particles that get exchanged are called photons. Photons are what we usually refer to as “light”. The correct name is electromagnetic radiation. Now for Something a Little Different Look in my hand. When do you see? I mean, WHEN do you REALLY see? Speed of Light The Speed of light is really, really, really, really, really, really, really, really, really, really, fast. It’s 186,000 miles per second. That’s 3 x 108 meters per second If you are 3 meters from me you are seeing me as I looked 0.00000001 seconds ago. That's 1 x 10-8 seconds The Moon – 1.5 light seconds away The Sun – 8 light minutes away Here is Mars Here is the Spirit Rover on Mars Here is a NASA engineer practicing to run the Spirit Rover on Mars Alpha Centauri – 4.5 light years away A light year A light year is a distance. It is the distance that light travels in one year. So you know the speed of light: 3 x 108 meters/second The number of seconds in a year is 3.14 x 107 seconds Answer: 9.4 x 1015 meters or 9.4 x 1012km or 5.9 x 1012 miles or 6.3 x 104 A.U. Let's scale the big stuff now. Our Solar System to scale Voyager space craft are about 12 billion km away or about 11 light hours away. NGC 346 as it looked 210,000 years ago M 31 as it looked 2.2 million years ago NGC 4676 – 300 million years ago Remember that on this scale the distance from the Sun to Alpha Centauri is the head of a pin. About 1 millimeter. The Earth by comparison would be the size of a single atom! If you aren't feeling small and insignificant yet then consider that there is 10 times more mass in this photo than what we can see. Dark Matter It makes up 23% if all the mass-energy of the Universe. The stuff we are made of “normal matter” or baryons only contributes 4% Best current candidates are WIMPS Where is the rest of the mass-energy?