"How can a one way signal from the moon get you ranging data? You'd have to know the exact time in which the signal was sent in order to determine distance, something which can't be known precisely in a one way transmission originating from the lunar surface. "
Plenty of work arounds. A...
Russ - yes I meant to write 2.3 -2.6 seconds. In effect if the reflected beam has been reflected back over an area of 4 miles square as the Nasa article was suggesting the rotation perhaps isn't important. It sounds a little bit like detecting someone flashing a very dim pen light on the moon...
Does anyone know the reference and when the results of this was first published? My apologies, but my scientific literature searching skills are limited to biological science.
I can't help wondering if given the state of the technology of the early 70s whether this might not have been...
I guess in the thermos flask on Earth you would also have the coffee being heated by IR radiation from the outside.
Is it possible to estimate the rate of those two heat exchanges?
Yes, I was aware of that and hoped I made that clear when I (mis)wrote
"As there [are no] molecules heat transfer can only be through radiation"
[] represents my poor original writing corrected.
So as an analogy would it be correct to say that the rate of heat loss of coffee in thermos...
A very non specific question about heat loss in a vacuum.
If you threw a human into space (with out worrying about his/her lungs bursting out) is there a rule of thumb about how fast he/she would cool down.
As there is molecules heat transfer can only be through radiation, and assuming...
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So how do you falsify it?
As I understand the reason that we "know" helium does not accummulate is because we "know"
1) The Earth is x billion years old
2) The rate at which it is cooling
3) The fact in order to have the x billion we need an additional source of heat
4) That source of...
I was reading that helium does not accummulate in the Earth's atmosphere due to the fact (a claim) that it is too light to be retained by gravity and diffuses out into space.
Does anyone know the physics that prevent the atmosphere seeking the vacuum at whooshing out into space.
Is there a...
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Stressing that I am completely non-expert but your
Sounds suspect. I think acceleration is acceleration.
But the acceleration from 29 km/s to 30 km/s spread over a 6 month period is not going to be detectable except via instrumentation.
Thank you for all your links.
I think we...
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So if I understand my elliptical orbits correctly the Earth should be traveling it's fastest when it is closest to the Sun and at its slowest when furtherest away from the Sun. At least that is the case with comet ellipitical orbits.
Although the difference is only about 4% (between...
Bring back the Epicycle, that I could understand.
So I guess my basic confusion is the ellipse that the Earth does around the sun so close to circular to be not noticed in normal life?
But presumably the Earth's orbit is well known and pretending we are in the two body system (which for...
As someone who only studied first year physics and maths and have taken no interest in it since than I was rather surprised to wake up one morning and realize along with 99.5% of the population that I really had no idea how the planets orbits worked beyond the vague word ellipse which I didn't...