https://www.youtube.com/watch?v=HeQX2HjkcNo&t=166s


Use of set theory to definitively prove 1 + 1 = 2

Except in Climate Seance. ;)

Of tiles and crystals:

https://www.youtube.com/watch?v=48sCx-wBs34

The bizarre behavior of rotating bodies:

https://www.youtube.com/watch?v=1VPfZ_XzisU

There you go, a bit of a feast for the mind, assuming you have one.

Jovial Monk wrote on Aug 25^th, 2021 at 3:06pm:

The bizarre behavior of rotating bodies: https://www.youtube.com/watch?v=1VPfZ_XzisU

i have seen this one.

Really cool. I assume this one is the video where the Russians first observed it in space and kept it quite for 10 years.

Yup.

Kepler’s laws of planetary motion:

1. Each planet's orbit about the Sun is an ellipse. The Sun's center is always located at one focus of the orbital ellipse.

2. The radius vector from the sun to a planet sweeps equal areas in equal times.

3. The ratio of the square of the period of revolution and the cube of the ellipse semimajor axis is the same for all planets.

(For a circle each axis = 1 diameter. An ellipse has a major (longer) and a minor (shorter) axis. A circle has one centre, an ellipse has two and an ellipse has two radii.)

Newton took Kepler’s three Laws and derived his much more useful laws of motion from them.

Einstein showed Newton’s Laws were an approximation. They are still used and useful until speeds get to a small but measurable fraction of the speed of light.

Newton’s Laws summarised motion. Einstein’s theory predicted relativistic changes to motion. A scientific Law is not a theory!

The secret of synchronisation:

https://www.youtube.com/watch?v=t-_VPRCtiUg


Avrogardo’s Number:

Avogadro's number is defined as the number of elementary particles (molecules, atoms, compounds, etc.) per mole of a substance. It is equal to 6.022×10²³ mol-1 and is expressed as the symbol NA. Avogadro's number is a similar concept to that of a dozen or a gross. A dozen molecules is 12 molecules.

Yes, I am a bit bored, shoulder joints and lower back giving me a more than bit of gyp and I am stuck here until Aussie’s fruitcake is cooked. But this stuff IS fascinating if you have an ounce of curiosity in your body. (Remember: curiosity only kills cats!)

Jovial Monk wrote on Aug 25^th, 2021 at 3:06pm:

The bizarre behavior of rotating bodies: https://www.youtube.com/watch?v=1VPfZ_XzisU

my 11 year old found that 'cool' .

I have to admit I agree with him.

I 'get' the oscillating one only because it is logical. As for the mathematical explanation....no idea.

That tennis racket thing, I can follow but it makes no logical sense to me.

John Smith wrote on Aug 25^th, 2021 at 8:13pm:

Jovial Monk wrote on Aug 25th, 2021 at 3:06pm: The bizarre behavior of rotating bodies: https://www.youtube.com/watch?v=1VPfZ_XzisU my 11 year old found that 'cool' . I have to admit I agree with him.

Glad you two enjoyed it.

Aussie wrote on Aug 25^th, 2021 at 9:06pm:

I 'get' the oscillating one only because it is logical. As for the mathematical explanation....no idea. That tennis racket thing, I can follow but it makes no logical sense to me.

More than one axis of rotation, each with different moments of inertia. “Moment of inertia” is used in place of speed in rotating objects.

Aussie wrote on Aug 25^th, 2021 at 9:06pm:

I 'get' the oscillating one only because it is logical. As for the mathematical explanation....no idea. That tennis racket thing, I can follow but it makes no logical sense to me.

my 11 year old is smarter than you ... he got it :P :P

John Smith wrote on Aug 26^th, 2021 at 4:58pm:

Aussie wrote on Aug 25th, 2021 at 9:06pm: I 'get' the oscillating one only because it is logical. As for the mathematical explanation....no idea. That tennis racket thing, I can follow but it makes no logical sense to me. my 11 year old is smarter than you ... he got it :P :P

Yeah...well fuq him!