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## What would happen if all the planets would align?

Nothing. Almost nothing. No earth quakes, no tidal waves. The influence of other planets on Earth would be so small that that they would be impossible to see. The Moon has more influence over our tidal waves than even the Sun.

Actually, the Moon has 3x more stronger tidal force than the Sun and tens of thousands of time than Jupiter or Saturn. Due to the high distance to the planets an alignment cannot influence anything on Earth. The last question in the video is quite interesting: what if you replace the Moon with Jupiter. Then the tidal forces would be so high on Earth that we would have volcanic activity and tidal waves like it crazy and it is doubtful we would have a nice life in here.

Mystery solved.

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## Why does the Earth keep spinning?

The answer can be simple: because things in motion stay in motion. First law of motion from Newton. It is all about inertia: hen you set things in motion, if there are no forces acting upon an object, that object stays in motion.

Once an object is moving you do not need a force to keep that object moving. On Earth the friction with ground or air will stop the object from moving, but not in space. The same holds true for spinning objects. Get a spinner spinning and put it in a vacuum room and levitating using some magnets and you will see that spinner spinning for a long time.

Nick Lucid explains it more intelligently and with formulas too. What’s not to love when it comes to physics? Nothing.

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## Crazy machines: the Stirling Engine

What you see in the video from above is the Stirling Engine, a simple engine in which hot air moves a piston in ways you never knew possible. As you see, the piston is smaller than the cylinder it’s in. When the lower metal place is heated, the air that is at the bottom will heat up and then push the piston while going up.

Then the cool air from above the piston will be pushed down and heat up. The cycle begins again. While such an engine isn’t extremely practical, it serves quite well as an example of what engines are: devices that transform energy into mechanical work. That’s all there is to know about engines. Way for the Stirling Engine.

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## The particle zoo of 400 or so subatomic particles

Via Wikipedia:

In particle physics, the term particle zoo[1][2] is used colloquially to describe a relatively extensive list of the then known “elementary particles” that almost look like hundreds of species in the zoo.

In the history of particle physics, the situation was particularly confusing in the late 1960s. Before the discovery of quarks, hundreds of strongly interacting particles (hadrons) were known. It was later discovered that they were not elementary particles, but rather composites of the quarks. The set of particles believed today to be elementary is known as the Standard Model.

Michel van Biezen from ILectureOnline.com explains how many particles there are and what they do. Of the more than 400 subatomic particles most of the matter is created by a number of 20 or so elementary subatomic particles. The rest are composite particles.

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## Science craze: 7 hours of science. I dare you watch them all in one day!

Yesterday and Saturday were lazy days for me. I had some work to do, but otherwise made sure to spend hours upon hours watching documentaries, online videos of courses.

In the first video you see a team from Fermilab, US talking about a specific topic, like what are neutrinos or the importance of an operator for the particle accelerator they have at Fermilab. The guys at Fermilab have discovered the up quark, bottom quark and the tau neutrino.

Moving on to the next movie, you will learn from Prof. Melvin Pomerantz of UC Berkeley what science is and what we do know and what we do not know in the field of physics. For example we do not know what energy or charge is, but we do knot a ton of things about how they work and how we can make them work for us.

See the video:

Had enough physics? Let’s learn about a great Englishman called Robert Hooke. He is associated specifically with the elasticity laws when we use springs, but he was also an inventor and the one go gave the idea to Newton that gravity is a force which can be calculated using calculus. Check out more:

We then go to our Periodic Table of Elements to find out more info about some of them. For example, Telurium has a smell and taste much like garlic and, coincidentally, was first discovered in Romania, Transylvania, Zlatna, not far from the Dracula Castle (Bran village). Video:

And we end up our list of videos by probing our minds using neuroscience. How do thoughts come into existence, how does our brain work? We are able to learn, move and evolve because there are already some underlying structures in our brain, like specific neurons linked and positioned in a certain way which would permit us to learn. Some concepts are already hardwired/hardcoded in our brains.

Yes, we already have notions of up and down, here and there and so on, but we strengthen them via experience, via our sensors:

Do not want to spend 7 hours by watching all these 5 videos? Then speed up the process by choosing Speed 2. You will still be able to understand the core concepts and ideas of the videos. Try it out.

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## Quantum mechanics: here we come [video course]

One of the favorite physics and math teachers on YouTube, Michel van Biezen, has prepared a new series about quantum mechanics. In this new series we learn about why the atoms and subatomic particles behave in different ways than the matter we see around us.

We also learn that energy, mass and momentum come in quantized chunks, meaning that there is no continuum, but instead a sum of fixed sized quantities of energy or matter.

Make sure to subscribe to that channel and be ready to be amazed. You can’t unlearn what you’re about to see.

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## How Digital Light Processing (DLP) works

Ben Krasnow, from Applied Science, explains how a projector works. He is one of the most skilled guys I’ve seen on Youtube. If he does not have a tool or device, he builds it and then moves on.

Digital Light Processing (DLP) works by using a ton of microlenses that reflects the light corresponding to one pixel to a screen. As opposed to LCD projectors, Digital Light Processing has smaller energy consumption and a better image quality.

The fact that you can use microlenses, lenses that are only 10 micrometers in length, and that you can move them is an incredible feat. In the video from above you will see how such microlenses are looking when using a scanning electron microscope. Awesome!

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## How far can a human eye see? What is its power?

Michel van Biezen makes great educational videos and you can learn a lot of things from there. One of his videos teaches us how to calculate the power of the eye.

It turns out that the human eye, with an aperture of 4mm in the iris, can distinguish two objects that are 3 meters apart from a 20 km distance. Of course, you need perfect vision, weather and the object need to have some contrast.

The formula used to calculate this is
sin Î¸ = 1.22 Î» / D
Î» – is the wavelength of the light
Î¸ – is the angle at which you see the objects and is very, very small
D – is the diameter of the iris, 4 mm average

You can make
sin Î¸ = tan Î¸ = d / L
d – is the height of the object or the distance between two points
L – distance to object

This way you will be able to see an object that is 3 meters height or two objects that are 3 meters apart at 20 km. At 100 m you can see an object as small as 1.5 cm. Yup, the eye is pretty amazing.

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## Nope. Jumping on a falling elevator won’t save your life.

The theory says that if you just up with high enough force right at the moment of impact, when the elevator hits the ground, then you can save yourself.

The truth is that you won’t be able to pull up such a stunt. Timing or strength are not on your side. If the lift falls, you’re toast. In any case a falling elevator is a very rare event. In Romania we had a couple of such instance, but here is happened due to the ignorance of the people. When an elevator needs repairing, then you won’t use it. Case closed.

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## Quantum Physics, a poem

It is true that science needs very good PR. Anti-science groups, usually religious ones, are doing a fairly good job to further their cause, but science needs more boost. Until science reaches pop-culture in such a way that it will never leave the center of our lives is a very long road.

In the video from above you can see a quantum physics poem. A great one, if you ask me. Science needs all the support it can get. Only through science we can go to stars. Literally.

Also, here are links to his QM videos he recently created.
Understanding Quantum (Part 1): http://youtu.be/6ttVoTcpvHU
Understanding Quantum (Part 2): http://youtu.be/TXOMFU_sNJs