https://padlet.com/lorenzaamenta38/relativity_ en-us 2019-05-16 19:11:29 UTC 2019-06-09 14:11:56 UTC hello@padlet.com lorenzaamenta38 https://padlet.com/lorenzaamenta38/relativity_/wish/360953640

At rest: when the position of body with respect to its surroundings doesn't change it's said to be AT REST

In motion: if the position of an object is changing, it's IN MOTION

]]> 2019-05-16 19:14:35 UTC https://padlet.com/lorenzaamenta38/relativity_/wish/360953640 lorenzaamenta38 https://padlet.com/lorenzaamenta38/relativity_/wish/360956363 An object will continue to remain at rest unless acted upon by an external unbalanced force.
This is the first law of dynamics;it was understood by Galilei that described it in 1632 and then it was enunciated by Newton in 1687. The law  also states that an object  will stay in a state of constant velocity, called uniform motion, in the absence of an unbalanced force.
It means if there was no frictional or any other force the body would never stop. ]]> 2019-05-16 19:21:09 UTC https://padlet.com/lorenzaamenta38/relativity_/wish/360956363 lorenzaamenta38 https://padlet.com/lorenzaamenta38/relativity_/wish/360959390 Inertia is the tendency of an object to stay at rest or in motion. ]]> 2019-05-16 19:28:58 UTC https://padlet.com/lorenzaamenta38/relativity_/wish/360959390 lorenzaamenta38 https://padlet.com/lorenzaamenta38/relativity_/wish/360963166 The Newtonian dynamics appeared to have defenitively solved the question of describing motion and its causes]]> 2019-05-16 19:39:29 UTC https://padlet.com/lorenzaamenta38/relativity_/wish/360963166 lorenzaamenta38 https://padlet.com/lorenzaamenta38/relativity_/wish/360963693 In classical mechanics speed is not absolute but always relative to a reference frame]]> 2019-05-16 19:41:16 UTC https://padlet.com/lorenzaamenta38/relativity_/wish/360963693 lorenzaamenta38 https://padlet.com/lorenzaamenta38/relativity_/wish/360964635 Galileian law for the addition of velocities is also valid]]> 2019-05-16 19:44:31 UTC https://padlet.com/lorenzaamenta38/relativity_/wish/360964635 lorenzaamenta38 https://padlet.com/lorenzaamenta38/relativity_/wish/360965907 Dilation is the act of expanding something]]> 2019-05-16 19:48:56 UTC https://padlet.com/lorenzaamenta38/relativity_/wish/360965907 lorenzaamenta38 https://padlet.com/lorenzaamenta38/relativity_/wish/360966309 Contraction is the act of contracting something]]> 2019-05-16 19:50:26 UTC https://padlet.com/lorenzaamenta38/relativity_/wish/360966309 lorenzaamenta38 https://padlet.com/lorenzaamenta38/relativity_/wish/360966506 Inertial frame is the particular refence system where the Newton's 1^st law is valid]]> 2019-05-16 19:51:09 UTC https://padlet.com/lorenzaamenta38/relativity_/wish/360966506 lorenzaamenta38 https://padlet.com/lorenzaamenta38/relativity_/wish/360967672 Galilean transformation of coordinates relation between the coordinates of an event as observed from two inertial reference frames]]> 2019-05-16 19:55:22 UTC https://padlet.com/lorenzaamenta38/relativity_/wish/360967672 lorenzaamenta38 https://padlet.com/lorenzaamenta38/relativity_/wish/360968061 There is not such things as absolute motion or absolute rest. Object move relative to each other. Therefore nothing is ever at absolute rest or absolute motion, things just move relative to each other.]]> 2019-05-16 19:56:41 UTC https://padlet.com/lorenzaamenta38/relativity_/wish/360968061 lorenzaamenta38 https://padlet.com/lorenzaamenta38/relativity_/wish/366480482 Medium is an intervening substance through which something is transmitted or carried on]]> 2019-06-08 11:40:51 UTC https://padlet.com/lorenzaamenta38/relativity_/wish/366480482 lorenzaamenta38 https://padlet.com/lorenzaamenta38/relativity_/wish/366480605 Ether is an all-pervading, infitely elastic, massless medium]]> 2019-06-08 11:43:00 UTC https://padlet.com/lorenzaamenta38/relativity_/wish/366480605 lorenzaamenta38 https://padlet.com/lorenzaamenta38/relativity_/wish/366480632 Vacuum is absence of matter]]> 2019-06-08 11:43:32 UTC https://padlet.com/lorenzaamenta38/relativity_/wish/366480632 lorenzaamenta38 https://padlet.com/lorenzaamenta38/relativity_/wish/366480683 Simultaneity when two events happening at the same time]]> 2019-06-08 11:44:26 UTC https://padlet.com/lorenzaamenta38/relativity_/wish/366480683 lorenzaamenta38 https://padlet.com/lorenzaamenta38/relativity_/wish/366480711 Elementary particle are any of subatomic particle that compose matter and energy]]> 2019-06-08 11:44:53 UTC https://padlet.com/lorenzaamenta38/relativity_/wish/366480711 lorenzaamenta38 https://padlet.com/lorenzaamenta38/relativity_/wish/366481074 Rest frame the coordinate axes in terms of wich position or movement may be specified]]> 2019-06-08 11:53:35 UTC https://padlet.com/lorenzaamenta38/relativity_/wish/366481074 lorenzaamenta38 https://padlet.com/lorenzaamenta38/relativity_/wish/366481115 Stationary is a time-invarian quantity, such as a constant position or temperature]]> 2019-06-08 11:54:34 UTC https://padlet.com/lorenzaamenta38/relativity_/wish/366481115 lorenzaamenta38 https://padlet.com/lorenzaamenta38/relativity_/wish/366481957 The Newtonian dynamics appeared to have definitively solved the question of describing motion and its causes. In classical mechanic speed is not absolute but always relative to a reference frame; if a law of dynamics is valid in a reference frame K, it must be valid in all reference frame K' moving with uniform linear motion in relation to K. The Galileian law for the adiction of velocities is also valid. Maxwell developed the theory of electromagnetism around 1870, in electromagnetism the speed of light in a vacuum is costant.
This is the fundamental postulate of special relativity, called invariance of the speed of light.]]> 2019-06-08 12:15:07 UTC https://padlet.com/lorenzaamenta38/relativity_/wish/366481957 lorenzaamenta38 https://padlet.com/lorenzaamenta38/relativity_/wish/366482434 Pheraps a privileged reference frame exists. It was called by Aristotele "Ether". The M-M experiment had the aim to demonstrate the ether existence]]> 2019-06-08 12:22:43 UTC https://padlet.com/lorenzaamenta38/relativity_/wish/366482434 lorenzaamenta38 https://padlet.com/lorenzaamenta38/relativity_/wish/366482456 The Ether is an invisible massless nothing, it’s very rarefied and highly elastic substance formerly believed to permeate all spaces, including the interstice between the particles of matter. Maxwell believed electromagnetic waves, such as light, to be vibration in the ether. Its only physical property is that it allows light propagate through.]]> 2019-06-08 12:23:01 UTC https://padlet.com/lorenzaamenta38/relativity_/wish/366482456 lorenzaamenta38 https://padlet.com/lorenzaamenta38/relativity_/wish/366482943 If a sound wave travels through air, light waves must travel through a medium as well. A famous lluminiferous aether, in fact as the sound requires air, so the light requires the ether to move from a place to another.]]> 2019-06-08 12:32:36 UTC https://padlet.com/lorenzaamenta38/relativity_/wish/366482943 lorenzaamenta38 https://padlet.com/lorenzaamenta38/relativity_/wish/366482944 When the measure of speed of light (c) became possible, testing the predicted effect of the ether on the speed of light became possible too.]]> 2019-06-08 12:32:37 UTC https://padlet.com/lorenzaamenta38/relativity_/wish/366482944 lorenzaamenta38 https://padlet.com/lorenzaamenta38/relativity_/wish/366483307 In 1887 Michelson and Morley conduct an experiment and they needed an experimental precision never had before. The idea was: the Earth orbits around the Sun at a speed of 30 km/s and it moves inside the ether, so the speed of light has to be different when the Earth moves in the same direction of the light in the ether or in a transverse direction.
M-M never detected such a difference: their results were inconsistent with the existence of the ether, but they were consistent with the point of view of Einstein. It's turning point in the history of science and in modern physics.]]> 2019-06-08 12:40:25 UTC https://padlet.com/lorenzaamenta38/relativity_/wish/366483307 lorenzaamenta38 https://padlet.com/lorenzaamenta38/relativity_/wish/366483561 The Michelson-Morley experiment was an attempt to measure the motion of the Earth through the luminous ether. Though often called the Michelson-Morley experiment, yhe phrase actually refers to a series of experiments carried out by A.Michelson in 1881 and then again (with better equipement) at Case Western University in 1887 along with chemist E.Morley. Although the ultimate result was negative, the experiment key is that it opened the door for an alternative explanation for the strange wave-like behaviour of light. ]]> 2019-06-08 12:46:26 UTC https://padlet.com/lorenzaamenta38/relativity_/wish/366483561 lorenzaamenta38 https://padlet.com/lorenzaamenta38/relativity_/wish/366483972 Muon's an instable subatomic particle like an electron but it has a much great mass and a very short life. The muon exist in the uppest atmosphere. When the cosmic rays, that are high energy proton, collide with the molecules in the atmosphere, the products are muons. The muons travel at relativistic speed. If a muon is stationary it has a lifetime of 2.2 microseconds, theyare created 10 km above the surface of our planet.The muons can reach the ground, even if they take 34 microsecond to reach the ground, they are detected in cloud chambers. They don't all decay before they reach us it's possible because with the Einstein's Special Theory of relativity the  lifetime of the muons depends on the frame reference of the observer. This is the real evidence of the Einstein's Special Theory of relativity.]]> 2019-06-08 12:54:41 UTC https://padlet.com/lorenzaamenta38/relativity_/wish/366483972 lorenzaamenta38 https://padlet.com/lorenzaamenta38/relativity_/wish/366485294 2019-06-08 13:14:16 UTC https://padlet.com/lorenzaamenta38/relativity_/wish/366485294 lorenzaamenta38 https://padlet.com/lorenzaamenta38/relativity_/wish/366485324 2019-06-08 13:14:40 UTC https://padlet.com/lorenzaamenta38/relativity_/wish/366485324 lorenzaamenta38 https://padlet.com/lorenzaamenta38/relativity_/wish/366485365 2019-06-08 13:15:21 UTC https://padlet.com/lorenzaamenta38/relativity_/wish/366485365 lorenzaamenta38 https://padlet.com/lorenzaamenta38/relativity_/wish/366485429 2019-06-08 13:16:30 UTC https://padlet.com/lorenzaamenta38/relativity_/wish/366485429 lorenzaamenta38 https://padlet.com/lorenzaamenta38/relativity_/wish/366486353 2019-06-08 13:31:11 UTC https://padlet.com/lorenzaamenta38/relativity_/wish/366486353 lorenzaamenta38 https://padlet.com/lorenzaamenta38/relativity_/wish/366486415 2019-06-08 13:32:18 UTC https://padlet.com/lorenzaamenta38/relativity_/wish/366486415 lorenzaamenta38 https://padlet.com/lorenzaamenta38/relativity_/wish/366486575 2019-06-08 13:35:29 UTC https://padlet.com/lorenzaamenta38/relativity_/wish/366486575 lorenzaamenta38 https://padlet.com/lorenzaamenta38/relativity_/wish/366486600 2019-06-08 13:35:49 UTC https://padlet.com/lorenzaamenta38/relativity_/wish/366486600 lorenzaamenta38 https://padlet.com/lorenzaamenta38/relativity_/wish/366486630 2019-06-08 13:36:26 UTC https://padlet.com/lorenzaamenta38/relativity_/wish/366486630 lorenzaamenta38 https://padlet.com/lorenzaamenta38/relativity_/wish/366486673 2019-06-08 13:37:04 UTC https://padlet.com/lorenzaamenta38/relativity_/wish/366486673 lorenzaamenta38 https://padlet.com/lorenzaamenta38/relativity_/wish/366486763 I liked this kind of lessons because learn something in English, even if is more difficult than learn something in our mother tongue, is very important, because nowadays english is the most important language due to the globalization. The lessons were very simple and accessible to all the students, we had the possibility to improve our English skills, but I think during this kind of lessons the student should have more time to conversate in english, maybe we didn't this due to the time. The lessons were well structured, even if the topic is hard the material and the lesson were appropriated. Beautiful work teacher 😊, sorry for my long opinion, but i felt the need to share my opinion.

]]> 2019-06-08 13:38:45 UTC https://padlet.com/lorenzaamenta38/relativity_/wish/366486763 https://padlet.com/lorenzaamenta38/relativity_/wish/366559395 Your padlet is really well organized.
Thank a lot for your useful comments.
Just a few mistakes in the dictation.
The evaluation is A]]> 2019-06-09 14:11:49 UTC https://padlet.com/lorenzaamenta38/relativity_/wish/366559395