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Space Forum / Space Flight / April 2006Cosmic Microwave Background Radiation,
Hi I have two question 1. The CMB (Cosmic Microwave Background Radiation) Scientist say that it isotropic through out our universe , could it be just left over radiation of Nebulae which founded our solar system so its just locally 2. Apollo mission which laded on the moon left US flag , is it possible for Earth based telescopes to view it, ? TIA > Hi I have two question > > 1. The CMB (Cosmic Microwave Background Radiation) Scientist say that it > isotropic through out our universe , could it be just left over radiation of > Nebulae which founded our solar system so its just locally No. > 2. Apollo mission which laded on the moon left US flag , is it possible > for Earth based telescopes to view it, ? No. > TIA Your welcome. I'd imagine it will not be that long till an earth based telescope would have the resolution, with adaptive optics to in theory, see such a small thing, but why wait? We can already bounce lasers off the corner cubes left at the sites perfectly well, if you are suggesting that it would be proof we were there! There are some probes planned that will be able to at least see the LEM bottom stages, I imagine. Cosmic microwave background is an interesting one, as presumably, what we 'see' is reflections and refractions from the bodies in the Universe. I understand its not as uniform in its distribution as first thought, and I am not sure if this result is right, as any radiation must have a polarity, and surely, with all that bouncing about, it will be pretty chaotic by now, so any tendency for the receiver system to favour a polarity, would upset the readings, and of course, you can get summing and cancellation when equal amounts of a given frequency are received with different phase relationships, and with the obvious doppler effects spreading your dominant frequencies, ie those not absorbed by molecules already, you may end up proving nothing worth worrying about! Brian untrained independent thinker :-)  SignatureBrian Gaff....Note, this account does not accept Bcc: email. graphics are great, but the blind can't hear them Email: briang1@blueyonder.co.uk ______________________________________________________________________________________________________________ > Hi I have two question > [quoted text clipped - 8 lines] > > TIA > I'd imagine it will not be that long till an earth based telescope would > have the resolution, with adaptive optics to in theory, see such a small > thing, but why wait? We can already bounce lasers off the corner cubes left > at the sites perfectly well, if you are suggesting that it would be proof we > were there! I suspect we'll never see an Earth-based telescope with that resolution (adaptive optics is helpful, but there are limits). But yes on the corner cube reflectors. > Cosmic microwave background is an interesting one, as presumably, what we > 'see' is reflections and refractions from the bodies in the Universe. No, opaque objects are, cosmically speaking, very few and far between, and only a tiny fraction of the microwave background photons have ever bounced off one. Most of the microwave background photons have travelled uninterrupted from the fireball of the Big Bang (specifically, T+100k years or thereabouts - when the primordial hydrogen and helium cooled and thinned enough to become transparent). > I > understand its not as uniform in its distribution as first thought, and I am [quoted text clipped - 6 lines] > frequencies, ie those not absorbed by molecules already, you may end up > proving nothing worth worrying about! It turns out to be not that chaotic or complicated - it's pretty much pure black body radiation, with only the small nonuniformities predicted by the inflationary version of the Big Bang theory (these nonuniformities being what eventually condensed into galaxies). Signature"Always look on the bright side of life." To reply by email, replace no.spam with my last name. > Hi I have two question > [quoted text clipped - 4 lines] > 2. Apollo mission which laded on the moon left US flag , is it possible > for Earth based telescopes to view it, ? Do you own homework. The Flag? No, too small. The Laser reflector? You bet. > Hi I have two question > [quoted text clipped - 8 lines] > > TIA > Apollo mission which laded on the moon left US flag , is it > possible > for Earth based telescopes to view it, ? The earth was overhead at all apollo landing sites so a properly erected flag would be almost invisible from above. Luckily for your idea most of the flags were blown over by pre-launch hot-fire tests and the actual launches. Unfortunately, the flags are less then a metre across, and a telescope on earth would have at best 10 metre resolution, and probably worse, so the flags can not be seen from Earth. > > Apollo mission which laded on the moon left US flag , is it > possible > > for Earth based telescopes to view it, ? [quoted text clipped - 3 lines] > idea most of the flags were blown over by pre-launch hot-fire tests > and the actual launches. Umm, hot-fire tests? I don't think so. They pushed the button once and took off. Not hot-fires. > Unfortunately, the flags are less then a metre across, and a telescope > on earth would have at best 10 metre resolution, and probably worse, so > the flags can not be seen from Earth. > 1. The CMB (Cosmic Microwave Background Radiation) Scientist say that it > isotropic through out our universe , could it be just left over radiation of > Nebulae which founded our solar system so its just locally The best place for this question would have been sci.astro.research. The CMB isn't exactly isotropic, but it's pretty close. Current research is mostly concerned with characterizing the anisotropies. But to answer your question, one of the interesting properties of the CMB is that it is opaque: the brightness temperature equals the color temperature. This fact is often neglected in popular accounts, but what it means is that any object we can see must be closer than the CMB. Or in other words, the CMB must be farther away than the farthest object we can see. You might also do a web search on "Sunyaev-Zeldovich effect," which (among other reasons it's important) is evidence that the CMB is more distant than large clusters of galaxies. You can see some photographs taken by spacecraft in orbit around the Moon (not from the Earth) which do show vague hints of the Apollo hardware. Look at http://stupendous.rit.edu/richmond/answers/lunar_lander.html Michael Richmond |
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