Robittybob1
Senior Members-
Posts
2916 -
Joined
-
Last visited
Content Type
Profiles
Forums
Events
Everything posted by Robittybob1
-
Connection between metabolism of fats and carbonhydrates?
Robittybob1 replied to Nomegusta's topic in Homework Help
What exactly was the question? Where was the question in the OP? Got it now it was in the title of the thread. Very efficient! -
Does anyone care to agree that there is partial mixing in the Asteroid Belts prior to accretion (using the NASA idea that they are planet construction zones). OK I accept I was not fully correct in my guess (that Asteroid Belt bodies would have similar isotopic arrangements) but there are regions of the Asteroid Belt and families of asteroids which do suggest similarity of some degree blending. The larger Asteroids appear to have internal structure. The process of differentiation implies that there will be different minerals or materials found on the surface and deeper in compared to the asteroids that were called rubble piles (non-differentiated). So after an impact resulting in ejecta some of these samples are found on Earth as meteorites.
-
How do you know that there was no atmosphere?
-
I think I'm getting a better understanding of it now. There are families of asteroids and not all of these are in the Asteroid Belt e.g the Haumea family is "beyond Neptune's orbit". Within the families there could be isotopic similarities. I never claimed there will be no difference in the isotope ratios I just said "similar". These families are found in regions, even regions within the Asteroid Belt so there was not complete mixing in the Belt prior to accretion. OK I accept I was not fully correct in my guess, but there are regions of the Asteroid Belt and families of asteroids which do suggest similarity of some degree.
-
Thanks but from that I can't tell if it supports my OP statement or not. What inference did you get out of it? Was the material in the Asteroid Belt mixed prior to accretion or not? Not all asteroids have their origin in the Asteroid Belt.
-
As I said yesterday "Take the asteroids of the Asteroid Belt I would guess that they all have a similar isotopic profiles too due to the fact they were all accreted from the same region of the protoplanetary disc." (spelling corrected) Does anyone know? All I could get from a video on the Dawn Mission was that of all the meteorites striking the Earth some percentage are known to have come from just 3 bodies, Mars, the Moon and Vesta (protoplanet of the Asteroid Belt). I presume there are many more from unknown origins. Will there be a way of knowing where they come from? NASA site define asteroid belts this way:http://www.nasa.gov/multimedia/imagegallery/image_feature_1651.html So there is a region in space orbiting a star where you find this construction site. Now what I contended is that over a period of time the objects in the belt are becoming mixed. This would be due to collisions affecting the speed of the objects and hence their orbital period. Larger protoplanetary sized bodies would not pass each other very often but the physics would not disallow this. The laws of physics would mean that Vesta and Ceres could pass each other in orbit. They might have established a resonance with another planet or each other which makes this less likely. Does anyone know? Vesta Orbital period: 1,325 days Ceres Orbital period: 1,680 days If this is true for the larger objects surely the same applies to the smaller objects in the Asteroid belt. It appears someone has calculated the chances of Ceres and Vesta colliding. So that makes it rather a slim chance.
-
Fashion accessories as indicators of personality
Robittybob1 replied to petrushka.googol's topic in Psychiatry and Psychology
What are cozzies? -
Evolution could well have used the same sensory mechanism and given it a different purpose. I was thinking about how light sensitive pigments have evolved and how spatial recognition was reused to give colour vision. (So I have been told) Could animals walking on land lose the sense of magnetic orientation and global positioning and use the magnetite orientation system for some other form of perception? I don't know but it certainly would be worth considering. As an aside you didn't use the word "not". So the meaning of what you wrote previously was unclear.
-
I'll have to look into that again. It was a good point you have raised. Yes there is a link and I'll email it to you for the thread was rather chaotic and on the whole not such a good read. It needs to be rewritten at some stage. The models change with time. I am open to changing my view for sure.
-
Did these all those meteorites come from the Asteroid Belt? I'm taking a guess that the objects in the Asteroid belt predominantly \ accreted from the material in their vicinity, material that had been thoroughly mixed within that region prior to accretion. It is a prediction that may or may not be confirmed in due time. There was no paper written up about the Yo-yo Moon Capture theory, for it was tentative hypothesis that developed from a 2 year project over on another forum and the ideas were developed there. It ended up having a lot of useful features IMO. All these things which were completely out of my scope to verify but I have kept an eye on developments and this latest news item being discussed here was a challenge but in the interim I don't feel it negates Moon capture either. If you say "the Earth is highly unlikely to have captured the Moon" that is because of our current concept of what the early Earth was like limits us. If it was like a water world Earth as some of the other planets found during the Kepler Mission this objection is overcome somewhat. I wouldn't say any of the concepts involved are easy to comprehend but in the end there was a set of ideas that I believe fitted the evidence so far. Now that I have retirement to look forward to it is a possibility to refresh the ideas and maybe write up a paper.
-
Thanks. Well the concept of tidal acceleration and deceleration is simply and primarily dependent on the rates of orbit compared to the rate of spin. If the Moon orbits the Earth slower than the Earth spins on its axis (day length) there will be tidal acceleration and if the orbit (lunar month) is less than the day length it will decelerate (come in closer to the Earth) I had proposed some years ago, the Moon upon initial capture orbited the Earth faster than the Earth's day length. It is complicated for the mass of the Earth has to be varied to allow this. Then there was a period they stopped approaching each other and then later as the Earth's volatile mass decreased still further and the Earth's gravitational pull decreased the Moon started its widening orbit to be in the position it is today. I called this the Yo-yo Moon Capture hypothesis. Some of you may be aware of this hypothesis already.
-
Was there a link to Ryans video? Could it be posted again please?
-
If there are magnetite crystals inside nerve cells or wherever that has the potential to be a type of magnetic recorder or recording possibly it the alignment could be held for any length of time. The animals that use magnetite for navigation must have an intracellular mechanism for reading that alignment. You might not like my example but it did occur.
-
My argument go like this: Take the asteroids of the Asteroid Belt I would guess that they all have a similar isotopic profiles too due to the fact they were all accreted from the same region of the protoplanet disc. Now if that is accepted and if the Earth and Theia were accreted from a region of a thoroughly mixed (hence isotopically similar) region of the protoplanetary disc that could be the reason they are identical more so than the potential collision between the two bodies. I have always advocated the Moon was captured by the Earth. OK I read that news article and thought that it still hasn't eliminated co-accretion from the same protoplanetary region plus or minus a collision.