Recent content by robbertypob

OK, so I'm right in the middle of watching Interstellar and I've just seen the part where they have docked with the 'mothership' and they fire up their engines to get it to rotate. This is so they can generate a centrifugal force to simulate gravity. My question is - first the ship was not...

Absolutely fascinating.

But when people think of concepts like a soul, or just that feeling that people are 'people', more than just a physical mass, that isn't true. That is a subjective interpretation and not 'truth'.

So there is nothing 'inherent' about things at all, if that makes sense. If I look over at my friend Fred, Fred doesn't actually exist at all. He is just the result of atoms assembled into a system that I interpret as my friend Fred. Deep stuff!

It's pretty incredible really isn't it, to think that something as unimaginably complex as a human being can arise according to preset laws. It makes me think about emotions and awareness. What are these things? Are they just an illusion? It's mind boggling to think that these things are just...

Do we understand how the physical laws of the universe created biology? How can we explain cell division, consciousness, evolution, as a product of matter operating in a universe governed by laws?

Here's what I think. If you are holding one end of the string and standing still, your friend pulling at 99N will exert 99N of force on the string. If you then start pulling at 99N in the opposite direction, the total force on the string is 198N. The forces are equal and opposite so the string...

Imagining a bicycle wheel moving forward, from the perspective of the cyclist and using the right-hand rule, the direction of the torque would be to the left, correct? But the rider doesn't feel a sensation of being 'pulled' to the left by the torque. How can this be? Is there an opposing force...

Thank you. So if the object doesn't actually travel in the direction of the torque then when does the torque direction become relevant? Does the direction have any effect on anything? On the second point - is the angular momentum actually generating torque on the axil? Would we say that? There...

Hi I've been learning about angular momentum and torque, and today I learned that torque actually has a direction that is not simply the direction of rotation. I saw about the right-hand rule to establish which direction the torque is going in. My question is - if an object is rotating, will...

The feather and cannonball are in a vacuum chamber on Earth. So Earth's gravity is the only force working on them. The vacuum removes the 'distraction' of air resistance for this purpose.

OK, hang on a minute, I had thought from this thread that the force of gravity is influenced by the mass of the two objects and their distance apart. Vacuums and magnetic fields are not relevant if I have understood correctly.

The magnetic field? The magnetic field is an influence on the gravitational force?

Yes, this is what I was mystified by.

That is so interesting. I'm just about getting my head around the Newtonian idea of gravity... Einstein's bending spacetime may have to wait until I've had some coffee.