Recent content by docroc

I'm having a bit of trouble believing the LTD anecdote: kerosene/diesel has the equivalent of a very low octane rating, since it is manufactured to explode just from the pressure and warmth of the piston's compression. Putting diesel in gasoline-engined car should result in unbelievable...

If I understand your question -- and I am not a physicist, only an avid reader of stuff about physics -- I think your concern can be stated basically as "why don't I experience the changes due to relativity while they are happening? Are they real?" The answers to this all are why relativity is...

Thanks for your clear answer, Dave

I'm still confused - maybe my question wasn't clear about what I don't get. With a satellite orbiting earth, I understand that the Earth's gravitation keeps the satellite in orbit rather than flying off in a tangent to the orbit (?) and this requires a velocity of around 25k miles/hr for the...

The probe landed, but Rosetta (the mother ship) is up there watching.

News stories make it sound like Rosetta is orbiting the comet. But presumably the comet's gravity is negligible, which means that orbiting it would require continuous acceleration (and therefore continuous use of energy) in order for Rosetta's motion to conform to a circle/ellipse, rather than...

Thanks Nathanael. After posting my question, I found some relevant replies, but didn't fully understand them. Yours seems to explain it clearly (though I may only be deluding myself that I understand). So does this mean that, with the Earth as one endpoint, a=F/m will always solve to 32...

As a non-scientist, this question has been bothering me, but probably has a laughably simple answer. In high school physics (which, for me, was long time ago) we were taught that 2 objects dropped from a height fall toward Earth with the same acceleration regardless of mass (the so-called Tower...