I assume that most of the water on our planet came from the inter-solar "soup" which formed into our planets whether through the initial formation of our planet or through impacts from moisture laden comets.  If so, where did that water come from? 

Since all heavy elements were formed inside of stars, what was the process where such large amounts of oxygen and hydrogen teamed up to form water?  Water seems to be a competent of all planetary bodies (obviously, some more than others), and the stuff is still whizzing by us periodically in the form of comets.

How could such huge amounts of water come into existance?

Thank-you.

Dictionary.com says a billion is "a cardinal number represented in the U.S. by 1 followed by 9 zeros, and in Great Britain by 1 followed by 12 zeros." It also seems it indicate that British definition is no longer used, although it's unclear on that.

Does a billion still represent two different numbers among scientists? If not, when did this change? Wouldn't older papers still use the old definition? Has this discrepency caused any practical problems in scientific projects--particularly in relation to astronomy and physics?

Cheers,

John

After reading about the precession of the equinoxes and the change of the seasons over thousands of years, I was wondering if the equinoxes and solstice dates are actually getting earlier or later to compensate for this phenomena?  I've always known them to be on the 21st December and 21st June (with a bit of fluctuation), I also know the Gregorian calendar changed from the Julian calendar, was this because of this phenomena, please help.

If we are hit by a CME what may happen? Also, can we predict them and how? What can we do to protect ourselves?

Lois Pasteur demonstrated that life comes from life. That is rotten meat doesn't spontaneously produce flies. And Darwin postulates that all life evolved from earlier forms of life. The paradox here is, as I see it, that when we extrapolate back to the creation of the planet we're told that it was a sterile hot and hostile place. The leading theory seems to be that the hotch potch of chemicals in the primitive earth somehow came together to form life. My query is just how "simple" does a molecule have to be to be on the border between life and non life?

Over the billions of years that the Earth has been orbitted by the Moon, its rotation has slowed by the slight resistance to the tide as it travels round the planet (relative to the Earth of course, it would appear static relative to the Moon).  The tide is of course caused by the gravitational pull of the moon and the equal and opposite gravitational forces of the Earth and the Moon keep the Moon nicely in orbit around the Earth.

As the force causing the braking effect of the tide is exerted by the Moon's gravity, there should be an equal and opposite force to the braking that is being exerted on the Moon.  As the tide is working as a brake on the rotation of the Earth, it would be expected that the bulge of tidal water is slightly ahead of the Moon with the Moon's gravity pulling it back.  I suspect that this bulge slightly offsetting the Earth's centre of gravity out of line with the Moon's centre of gravity and the Moon's centre of rotation might have some such effect.

Admittedly the effect would be rather small, but over the periods of time such as the time it has taken for the Earth's rotation to change from 6 hours per day to 24 hours per day surely there has been some effect.  If so, am I right in thinking that the Moon's orbit has quickened over time?  If so, I hope the Moon has stayed in equillibrium by adjusting its altitude (is that the right word?) and isn't thinking of leaving us to it once it has built up an escape velocity...

The inflation model is apparently needed to explain why the universe is homogeneous at large scales as there would be not be enough time for photons to travel between points if inflation had been constant.

Feynman's QED series says that there are small probability amplitudes for photons travelling faster than the usual speed of light.

In the early universe where space was small in each dimension, wouldn't the Uncertainty Principle have caused photons' velocity to fluctuate wildly and be above the general speed of light much more often than normal, thereby allowing signals to move from one part of the early universe to another very quickly and removing the need for an exponential inflation theory? Please can someone inform me what is wrong with this logic =)

As we know, Spiral, irregular, elliptical, Lenticular are 4 shapes of galaxies. Have they merely evolved into something stable which takes these forms, assuming irregular ones are still evolving to come upto something stable only or what factors exactly influence galaxies to take this shape ?

In reading any classical description of the ‘Doppler Effect’ the question of the energy of a photon is never discussed.

The energy of a photon is E=hv. Where h = Planck constant and v = frequency. Ignoring Planck constant we can simply say the energy of a photon is equal to its frequency.

The ‘Doppler Effect’ states that the measured frequency of light at a receiver will be altered by the motion of the source or the receiver.

I can then rewrite the ‘Doppler Effect’ to read the measured energy of a photon will be altered by the motion of the source or receiver.