Recent content by avicenna

You are dead right! The night star is Jupiter. I look for the star at 9pm tonight but the Singapore (not Ecuador) sky was cloudy. At 11.30pm, the sky cleared and there was the lone, but bright star. It was clearly shifted west by an appreciable arc , say 20-30deg. What confused me...

If it was Jupiter and Venus, then it was a strange coincidence that I watched at 10pm and 6am when one planet replaced the other. I will watch tonight at 9.pm and follow up after to see if it sets. They almost have the same brightness, the brightest stars I have ever seen.

If it is a planet, it would move with the stars. But it is not moving. I will try watching at 10pm and then 3am tomorrow. At 6am today it was "there".

That's also my understanding. I don't understand why my location is needed, say Ecuador. The fact is it is at the same location and does not rise and set with the sun. I can't understand.

I am looking slightly towards east; altitude is about 60 degree from horizontal. Sky not cloudy at 10pm and not a single other star visible. At 6am, also no other stars. sunrise about 7am. [edit] I don't want to reveal my location fro privacy reasons. The point is taht it is at the same location...

Something strange! There is a very bright geostationary satellite visible in our nigh sky quite recently. It was there at 10 pm and was there at 6am at the same position which means it is stationary above a fixed position relative to the earth. But the internet says we cannot see geostationary...

I surrender! My level of physics has not reached the level where the mass of the electron may change. Give me time to do some catch-up!!!

I have never ever said that an electron on its own can have potential energy. I only said it is a matter of semantics whether we associate the amount of energy to the electron or to tha atom(the system). The amount is the same! From my physics textbook, pg 984: ... The further the electron is...

It is just debating on semantics. An electron coming to a proton from infinity has PE = -K/r. Its total energy relative to proton (theory same for mass center ) T = PE + 1/2 mv², v is relative velocity to proton. The textbooks do identity "a potential energy of an electron".

I only know Bohr's theory. Tell me if my reliance on it misled me into wrong conclusions.

You set me thinking. I can't yet give you a proper reply now - probably later. I have some observations to make relating to the solar system. You would then say the earth does not have potential energy on its own, only the solar system has potential energy. But in the real world, we calculate...

Correct.

The energy absorbed by the electron is E=hf; it is the increase in the total energy of the electron relative to the mass-center (kinetic+potential).

The electron's total energy (kinetic + potential ) increases by E = h f

Bohr's theory is clear about how an electron of an atom (nothing about free electrons) absorbs a photon; the electron goes to a higher energy state.