Robittybob1
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Everything posted by Robittybob1
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Telescope to see a person on another planet
Robittybob1 replied to kos's topic in Astronomy and Cosmology
I would imagine there will be a limit to our ability to resolve the image from a distant star. We can see the star but not the planets around it, and we definitely cannot see things on the planets. To have enough photons to create an image at such a distance would mean it would have to be glowing or reflecting extremely brightly in the first place. -
Questions regarding human microbiota
Robittybob1 replied to HenryLewis's topic in Ecology and the Environment
I seem to recall this as well. Is this covered in the OP? Can we discuss T. gondii? -
Time Travel is Impossible and if not Impractical
Robittybob1 replied to HPositive's topic in Modern and Theoretical Physics
The molecules existed before and after the "time machine". So does the machine exist before the machine is made? What is the machine going to do to go backward or forward in time? Was it some mechanical manipulation? What do you imagine a time machine will do? Is it just like going to a museum, being surrounded by a bit of the past? -
Can differentiation be used to solve an equation?
Robittybob1 replied to king kyle's topic in Analysis and Calculus
on the spreadsheet E3 = D3 and then you are surprised that B6 = C6! They are calculating with the same values to start with aren't they! -
Can you get a mass to go at the speed of light? I thought the answer might be "no", therefore the equation r = 2G.M/v^2 will not work at light speed.
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The mass component is the denominator when one looks to the period, but period is inverse to speed. So two objects will fall faster with higher combined mass, OK it then takes a shorter time for it to happen. The two nebulae will combine faster if their combined mass is greater. I think this is correct. The period will be smaller with higher mass for they will move faster toward each other. (This was not directly proportional but in proportion to the sqrt of the combined mass.)
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Could two nebulae fall toward each other? You could just give each one a specified spherical radius and compare the mass within that sphere. They would "fall" toward each other in proportional to the sqrt of their combined mass. I don't know if it would be useful at all, for I was at a loss as to think what else this knowledge could be used for.
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When the hammer and the feather are dropped together the Moon is not attracted to each of them separately but to the combined dropped mass. Therefor the very small amount the Moon moves is one distance not two distances, so the hammer and the feather fall at the same speed, not at two speeds with an insignificant time difference because of distance.
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I had checked it wasn't the sqrt(2) and left it at that. It is good to know that, thanks. Two objects will fall with a period "The ratio of the times is the ratio of the roots of the masses". This might be applicable situations of colliding galaxies or collapsing nebulae.
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Might be a good one to test out the formula above. C - D beat A - B and regardless of the gap size and the ratio of the times always equals 1.38013. Now that is rather weird!
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can a strictly steady repeatable diet delay (or even prevent) aging?
Robittybob1 replied to minaras's topic in Speculations
Restriction of calories. -
Why dinosaurs probably evolved to birds?
Robittybob1 replied to Paramecium8's topic in Evolution, Morphology and Exobiology
Good point. Have dinosaurs and mammals got a common ancestor? -
can a strictly steady repeatable diet delay (or even prevent) aging?
Robittybob1 replied to minaras's topic in Speculations
Years of longevity. -
what is meant by "limit"?
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I see you really understand it well.
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Can you explain why there is a crossover?
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Can you explain that again please?
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So do you think that the density of the balls has no effect on the free fall time? I was getting faster falling with increased density, but your graph is "difference" in fall times. Maybe the difference in times stays the same but that seems unlikely. What is your understanding on that please? I did have the Excel referring to the wrong cell and now when the gap is zero I'm getting the answer of zero time. Thanks for that.
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In another test of the rates of attraction I increased the density to 10 kg/m^3 the time to impact was reduced by about a 1/3rd. I wonder if the time to impact is the time for the spheres to touch their outer edges. I should be able to test this if I make the gap = 0 then T should be zero as well. Strangely enough when the gap is zero the time is exactly 1 so that is a bit odd for it should also be zero. I'll have to see if this is a true result or some calculation error. It seems to be a direct result of the arccosine part for that comes out to 1. It doesn't make sense to have this extra bit to me for there are no angles involved.
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Is that the same equation as we are already using as presented in the Wikipedia article? https://en.wikipedia.org/wiki/Free_fall#Inverse-square_law_gravitational_field
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I gave the material a density of 1 kg/m^3, which is a bit stupid for it would be a very light material, but both balls have the same density, so their masses were proportional to the cube of their radii via the equation for volume of a sphere. I'll check another time whether density has an effect on the rates. I have checked at the low density: "I wonder at what gap they would be equivalent? It was between a gap of 80 - 81 meters that the rates changed. Beyond a gap of 80 - 81 meters B - C would be faster than A - B (according to that formula) using that density.
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t={ (gap+r1+r2)3 / 2G(M1+M2) }1/2 * { [(r1+r2)*gap]1/2/(r1+r2+gap) + arccos[(r1+r2)/(r1+r2+gap)]1/2 } slight error in the formula you have to do the fraction, then take the square root then find the arc cosine of that. t={ (gap+r1+r2)3 / 2G(M1+M2) }1/2 * { [(r1+r2)*gap]1/2/(r1+r2+gap) + arccos[(r1+r2)/(r1+r2+gap)1/2] } might be closer. the result with r1 =10 m and r2 = 1m and gap = 10 m gave result of 64246.08 secs where as with r1 =10 m and r2 = 10 m and gap = 10 m gave result of 73251.79 secs So that clearly shows that A-B beats B-C. the result with r1 =10 m and r2 = 1m and gap = 20 m gave result of 110390.14 secs where as with r1 =10 m and r2 = 10 m and gap = 20 m gave result of 119619.05 secs So that clearly shows that A-B stills wins. I wonder at what gap they would be equivalent? ( Note I have edited this as I made an error) It was between a gap of 80 -81 meters that the rates changed.
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when u doze off into dreams and amt move
Robittybob1 replied to newclass's topic in Science Education
First time I was aware of it it was "an explosion of my whole brain". That time if felt like someone had fired a bullet through my head. It is all over in a split second. It is a really disturbing experience but it it must be able to be controlled since it is only happening here once a month or so. -
when u doze off into dreams and amt move
Robittybob1 replied to newclass's topic in Science Education
I had another jolt of EHS last night. I have two places that I sleep during the week, 3 nights here and 4 elsewhere, and so far all the EHS attacks have occurred here. I was thinking about pulling a microwave apart and then it was like I had an electric shock through my head. There was the crack of the electrical spark and the episode was over. I went back to thinking about the same subject but it didn't repeat. I was deliberately trying to see if I could get it again. It seems random but it is only happening here just in the time before I go to sleep. -
can a strictly steady repeatable diet delay (or even prevent) aging?
Robittybob1 replied to minaras's topic in Speculations
Slowing the effects of aging might be a good thing. Look at the difference between the Queen of England and my mum. Both born at the same time and place but a much varied diet since then. I just can't stop thinking the care that the royals take has had a bearing on their longevity, allowing her to have 63 years in the same job!