positional astronomy - SDSS: Inclination of a Field?

I am working with the Sloan Digital Sky Survey CasJob service.

I am trying to determine the ellipticity of a galaxy using the stokes parameters $U$ and $Q$ from which I can deduce $e$ and $phi$. But $phi$ is relative to the CCD chips. How can I get the real $phi$ (relative to the equator). If I am correct I would know the inclination if I knew what field the object is on and I knew the inclination of the field.

Each field belongs to a stripe. So I'm there if I know the inclination of the stripe? And How do I know the inclination of a stripe?

Is my problem realates with the column like phioffset_r described as Degrees to add to CCD-aligned angle to convert to E of N (I have no clue what this means)?

Note: I am not sure whether this is the right place for this question. Is there a better place?

Note 2: If this is the right place, then it would be nice if somebody could create the tag sloan-digital-sky-survey or SDSS. I could not figure out what existing tag would fit, so I did take positional-astronomy.

binary star - Peculiar orbit of circumbinary planet

I've created a Mathematica notebook file which should theoretically allow one to simulate any n amount of bodies. Whilst looking at a three-mass system where $m_1=m_2=2000m_3$, I noticed some peculiar orbital characteristics when the "planet" comes close to the "stars".
.

Pretty, but hardly what I expected. Are these kind of orbits viable, or is something going wrong here? Note in this case, the "stars" orbit each other in a near perfect circle.

For those with Mathematica, the notebook may be found here:

http://s000.tinyupload.com/index.php?file_id=07893360971974925836

astrophysics - Create heatmap from significance

I am working on my project in astrophysics and I would like to create my heatmap from the significance which is obtained by the gaussian fitting my histogram.

I get this map :

First picture : convolve heatmap at 2' - convolve completeness map at 2'
Second picture : convolve heatmap at 8' - convolve completeness map at 8'
Third picture : first one - second one

I plot the histogram and the gaussian which is fitting it :

And I obtain this values :

Mean value : -0.0138901955853

Variance value : 0.00824390390031

Sigma value : 0.0907959464971

I would like to get something like this :

==> Question :

How I can process in order to get the same significance map (Signal to Noise) ?

moonlanding - What instruments/science goals have the highest priorities for a combined orbiter and lander to Europa?

A NASA mission to Europa seems to have a friend in congress. What would be the most important instruments and science goals for such a mission? Seismometry, radar, surface chemistry, a drill/melter, hopper. What are the most important of the feasible kinds of instruments on a first mission to Europa that could be launched in maybe 5 years, say, for a Cassini kind of budget?

n body simulations - How to scale down solar system data to simulatable values

Okay, I am seriously ashamed for asking this especialy when I geniualy study on physics but there is something that bugs me with the simulation I am working on.

I am re-creating the solar system in an n-body simulation that i programmed before. And I've a problem with scaling down the solar data. So even if I use kg and km for the metric units, the values are far bigger than the variables can hold in programming. Also as some of you know, bigger the value is, bigger the floating point error it makes. (error noise in data) Also it makes it slower to process.

I decided to scale down the data with a reference point, and for that, I took the earth's radius as 1 unit. And scaled down every other distance and radius according to it. (So a unit is 6371 km just to be clear)

But I am not sure whether if I should scale down the mass or not. My common sense says that I should scale down the mass so density of each body should remain same. So I took the density, and calculated a new mass value for each body, with the new scaled down radius.
But I am somehow couldn't conviced myself about If it's true or not. So here I am, asking to you :) Should I also scale down the mass?

PS.1: I used using F = GMm/r^2 equation for the calculactions as usual. (Iterating it through each body pairs)

If there are other programmers like me interested in making a simulation like this, how did you accomplish this data size problem? Are there any better solutions than scaling down the values?

PS. I have created an excel file that does the scale conversion. So I am sharing the sheet in OneDrive. (http://1drv.ms/1NIekGo) If you can check my calculations and values, that I'd also be really helpful to me. Thanks for any help.

gravity - Why is it strange that outer stars are travelling with the same speed as inner while the total mass is also increasing?

This is accounted for in real models of the rotation curves of galaxies. The rotation curve of a galaxy is more complicated than the motion of planets in the solar system, for the reasons that you describe.

A trivial model would consider the galaxy as spherically symmetric and would use the shell theorem to estimate the centripetal acceleration of a star at radius $r$. Thus
$$ m r omega^2 = Gfrac{m M(r)}{r^2},$$
where $m$ is the mass of the star, $omega$ is the angular velocity and $M(r)$ would be the mass of all gravitating matter at radii $<r$. Note that this only applies to a spherically symmetric distribution of mass.

To make further progress demands that you know the density distribution of the gravitating matter. Let's just assume that density $rho$ is constant for the moment. Then
$$ r^3 omega^2 = G int rho 4pi r^2 dr = frac{4pi}{3} G rho r^3$$
$$ omega = sqrt{frac{4pi G rho}{3}}$$

Thus the angular velocity would be constant with radius and the rotation speed, $v = omega r$ would increase with radius. This I think is the situation that your question supposes and so yes, if there was a constant (or perhaps slowly declining) density of material in the Galaxy then this would produce a rotation curve that increased (or was flat).

The trouble is that the density of material in our Galaxy inferred from the matter that we can see is not constant with radius. It declines rapidly and exponentially, such that there is very little visible matter beyond a radius of about 15 kpc. If we take a situation where we go to radii beyond the gravitating matter, then a similar treatment to the above suggests that
$$ m r omega^{2} = Gfrac{mM}{r^2},$$
where $M$ is now the total mass of the (visible) Galaxy. In this case
$$ omega = sqrt{frac{GM}{r^{3}}}$$
and the rotation velocity $v = omega r$ should decline as $1/sqrt{r}$ (like it does in the solar system).

It is the fact that the rotation velocity of stars and gas at large radii ($>15$ kpc) continues to be flat or even increase that leads to the conclusion that the mass that we can see is not all that there is. i.e That we need "dark matter" to explain the high rotation speeds at radii where there is very little visible matter.

Realistic models of the galaxy do not make the assumption that the visible matter is spherically symmetric (it isn't). But the conclusions I qualitatively set out above hold in the same way.

What would the night sky look like if the interstellar medium didn't exist to absorb or block light?

The main effect would be that the Milky Way would become much more prominent and asymmetric.

At the moment, our view into the Galactic plane is limited to around 1000-3000 parsecs by dust. If you look at the Galactic latitude distribution of naked eye (Aren't there more naked-eye-visible stars in the Milky Way plane? ) you see that most naked eye stars are much closer than this and there is only a modest concentration towards the Galactic plane.

What I think this means is that there would not be a big increase in the numbers of resolved naked eye stars. It is the sensitivity of our eyes, rather than dust that limits how far we can see them. However, the numbers of unresolved stars in the Milky Way would be greatly increased. The number of stars in the resolution element in your eye would increase as distance squared, but the light received decreases as distance squared. This means each "shell" you add contributes equally to the observed brightness.

The Sun is in a 30000pc diameter Galactic disc, about 8000pc from the centre. Thus I estimate that going from being able to see stars to 2000pc, seeing them to anywhere from around 7000pc (away from the Galactic centre) to 23000pc (through the Galactic centre) will increase the brightness of the Milky Way by factors of 3-10, strongly concentrated towards the Galactic plane (more so than now), depending on which way you look. This asymmetry will be increased by the increasing stellar density towards the Galactic centre.

In addition, the "bulge" would become more prominent. This is a pseudo-spherical region of diameter 4000pc, with a greater density of stars, centred on the Galactic centre. The bulge is mainly hidden by dust now, but without dust we would see a brighter, roughly circular blob towards the Galactic centre (Saggitarius), with an angular diameter of 30 degrees.

Does 2 merging black holes necessarily make a quasar?

Does 2 merging black holes necessarily make a quasar?

Basically no. While the merging of 2 black holes is a very interesting event, a quasar is what you get when 1 very large black hole eats a whole bunch of matter and the light from the quasar comes from the intense heat and interactions from that tightly bound, rapidly spiraling and very excited matter.

Quasar's were probably most common when galaxies are young but there are a few more recent ones (see examples in comments). Quasar

Related Question

If the size is smaller than what would be considered as a supermassive
black hole would it not be a quasar?

Almost all large galaxies have a super-massive black hole in their center. Source. The sizes vary with the size of the galaxy. Quasars are much more rare, only in a few galaxies.

As for the specific size of black hole that can form a quasar, credit to Rob Jeffries below.

evolution - When has an organism evolved enough to be called a new species?

I think LuketheDuke's answer is an oversimplification of the biological species concept (possibly resulting from the dictionary having a poor definition). The definition he gives is one of many which are in current use, and is made redundant by many types of organism.

It is important to recognise that because reproduction is not the same process in all organisms, genetic differentiation between individuals occurs in different ways for different groups.

Let's take the definition given in LuketheDuke's answer...

The major subdivision of a genus or subgenus, regarded as the basic category of biological classification, composed of related individuals that resemble one another, are able to breed among themselves, but are not able to breed with members of another species.

Under this definition, lions and tigers (see ligers and tiglons, which are sterile hybrids between the two) would be considered one species, as would donkeys and horses (see mules and hinnys, again sterile hybrids). There are hundreds of other examples of pairs of animal species which can hybridise to produce sterile offspring.

However, these animal hybrids usually only take place with human intervention, by delibrate breeding efforts. Thus we could extend the previous definition to include them...

The major subdivision of a genus or subgenus, regarded as the basic category of biological classification, composed of related individuals that resemble one another, are able to breed among themselves, but do not breed freely with members of another species in the wild.

That last part takes care of the ligers and tiglons. But what if we consider plants? Under the definition I just gave, most grasses (around 11,000 species) would have to be considered as one species. In the wild, most grasses will freely pollinate related species and produce hybrid seed, which germinates. You might then think we could just modify the definition to specify that the offspring must be fertile (i.e. able to reproduce with one another)...

The major subdivision of a genus or subgenus, regarded as the basic category of biological classification, composed of related individuals that resemble one another, are able to breed among themselves, but do not breed freely with members of another species in the wild to produce fertile progeny.

Unfortunately, the situation is still more complicated (we've barely started!). Often wild hybridisation events between plants lead to healthy, fertile offspring. In fact common wheat (Triticum aestivum) is a natural hybrid between three related species of grass. The offspring are able to breed freely with one another.

Perhaps we could account for this by taking into account whether the populations usually interbreed, and whether they form distinct populations...

The major subdivision of a genus or subgenus, regarded as the basic category of biological classification, composed of populations or meta-populations of related individuals that resemble one another, are able to breed among themselves, but do tend not to breed freely with members of another species in the wild to produce fertile progeny.

This accounts for the grasses, but it still leaves a messy area when you have a hybridisation which establishes - until the hybrid population is segregated away from the parent populations it is unclear whether they still count as the same species.

We could probably live with this situation, except for the fact that bacteria refuse to conform to it at all. Bacteria of the same species, or even very different species, can freely transfer genes from one to the other in conjugation, which combined with fission can result in perfectly replicable hybrids. This is such a common occurence that it breaks even the 'tend to' part of the previous definition, and members of a population can be doing this almost constantly, which negates the segregation requirement.

Richard Dawkins had a go at defining around this, by stating that...

two organisms are conspecific if and only if they have the same number of chromosomes and, for each chromosome, both organisms have the same number of nucleotides

This partly gets around the bacterial problem and means that bacteria which result from conjugation are a new species. Unfortunately under this definition we might as well not ever bother trying to classify bacteria as billions of new species would be created every day - something which the medical profession might have something to say about. This definition would also mean that those with genetic diseases like trisomy 21 are not human. The final nail in the coffin of this attempt is that there are many species, including frogs and plants, which are very certainly considered a single species by taxonomists but which have some variety in the presence of small accessory chromosomes, which occur in different combinations between individuals.

Let's consider one last option. We now live in the era of genomics where data about genomes of thousands of organisms is accumulating rapidly. We could try to use that data to build a species definition based upon similarity at the nucleotide level. This is often used for bacteria, by considering organisms with less than 97% nucleotide similarity to be different species.

The major point I've been trying to make, though, is that species is not a natural concept. Humans need to be able to classify organisms in order to be able to structure our knowledge about them and make it accessible to people trying to link ideas together. But the natural world doesn't care about our definitions. Ultimately the species concept is different for different groups of organisms and will continue to change over time as our analytical methods and the requirements of our knowledge change. Note that I've deliberately skipped over many historical species concept ideas.

The direct answer to your horse question is "it depends how you want to define a horse".

What effect does the Moon have on the near Earth asteroid population?

Does the big (0.012 Earth masses) Moon of Earth clear away NEAs, Earth orbit crossing asteroids, in a significant way? Venus and Mars don't have large moons, do they therefore have larger or smaller population of near asteroids than Earth would have if it were in the same orbit?

The outer planets have large moons, but also lots of captured asteroids, trojans and centaurs. Does a large moon even help gathering such objects, rather than ejecting them? Moonless Mercury and Venus seem to be pretty clean.

ceres - Age of Occator Crater

Has any official information been published regarding the estimated age of the Occator crater on Ceres? I ran some quick searches but couldn't find anything putting a definitive (or even speculative) date on the moment of impact.

I ask because based upon my own very amateur analysis of the imagery:

...there seems to be a marked decrease in the amount of secondary cratering visible within a fairly uniform radius of the main crater.

My assumption is that when the impact occurred, the surrounding area was likely blanketed by material kicked up from the impact site, obscuring most pre-existing craters (smaller ones, in particular). Kind of like fresh snowfall, except made of rock.

So for a (small) secondary crater to be visible near Occator, the impact would have to have occurred after the impact that created Occator crater. Meaning that the relative lack of small craters near Occator would seem to imply a fairly recent impact ("recent" in terms of Ceres geological timescales), I believe?

Is there any official data that would confirm or refute this?

software - Divide a star catalogue to optimize star search

I'm continue working on my Planetarium software and I have a doubt.

At this moment my star catalogue is very small, but I'm planning to use a bigger one. To optimize the search inside this catalogue I think I have to divide it in regions.

These regions will be delimited by right ascension and declination.

Using stars' right ascension and declination, how can I divide the sky to optimize my search?

I want to retrieve all stars visible at this moment. Maybe not all of them, only the visible by the user. For example, if user is looking to the North, he/she won't see the stars at the South. The region will be the area visible by the user at this moment, and I want to get all stars for that given region using also a limit magnitude.

fundamental astronomy - Are any other planetary bodies warming up as well in the Solar System?

The short answer to your question is "decades", only for Mars, and only a two Mars decades (about 4 Earth decades)

I don't know if your question was related to climate change, as there were a number of extremely unscientific arguments made that Pluto and Mars are getting warmer, "and there are no SUV's on Mars" . . . so, maybe it's not the CO2 but those claims weren't science.

Silly articles and bad arguments aside, global temperature on other planets is a legit scientific question and there were scientific articles that said Pluto is getting warmer (2002, story below) and Mars is getting warmer (2007, also below), so there is some truth to this. I'll give an answer as best I can. Each planet deserves it's own bit of research, so this will be longish.

Pluto

Here's an article on Pluto, the title is iffy but the article is good. It's from 2002, so it's long before New Horizon's fly-by, it's even before New Horizon was launched, but "pluto is getting warmer" was a real scientific story in 2002, and Mars, in 2007 was real science too, but some of the conclusions drawn, loosely based on those two stories were ridiculously bad.

The gist of the article is, we can't see Pluto's atmosphere well, even with Hubble, but they were able to measure some aspects of Pluto's atmosphere by watching what happens when a star passes behind Pluto and that was measured twice, in 1988 and again in 1997.

Pluto's Perihelion was in 1989 and most everyone figured that the little ball of ice/dwarf planet would get colder after 1989 when it passed it's closest point to the sun and stated moving further away but the readings said otherwise, and that was one of those really cool "oh, wow, things are more interesting than we thought they were" moments. Pluto's atmosphere had apparently gotten thicker and it was about 2 degrees warmer. Not what anyone expected.

The problem is, the sun couldn't make Pluto 2 degrees warmer while it moved further away without making the Earth 20 degrees warmer at the same time, so, clearly, something else was at play and it wasn't the sun warming Pluto. Generally speaking, the warmest periods aren't necessarily precisely timed to closest to the sun, and there's a lag time caused (on Pluto) by sublimation of the frozen gases on it's surface, which thickens the atmosphere adds trace amounts of Methane and can warms the planet past Pluto's perihelion, just as on the Earth, June 21 isn't the warmest day on the Northern Hemisphere, nor December 21st the coldest, and 12:00 noon isn't the hottest time. Could that seasonal "lag time", apply over a number of Earth years on Pluto? It's plausible.

But we should remember, that's just two data points, which isn't nearly enough. Or, 3 data points now with New Horizons, but it's still just 3 data points spanning 27 years on a planet where one year is 248 earth-years, so, there's a lot we don't know about seasons on Pluto.

New Horizons got better data on Pluto's atmosphere and frozen surface than we've ever had before, and what I remember reading about it, though I'm very far from well read on the subject, is that Pluto has a much more dynamic atmosphere and surface than anyone expected.

Gas Giants

you asked:

Do we have a few decades worth of surface temperature data to compare?

Surface temperature isn't well defined on gas giant planets because we can't see the surface. Also (I think all 4, I know for sure Jupiter and Neptune), they give off more heat internally than they receive from the sun. Temperature on the visible surfaces / upper atmospheres of the gas giants has more to do with circulation than anything else.

Mars

There's a number of articles on Mars warming, but there's still a lot we don't know about Mars' climate. It's not too difficult using modern technology and with Mars' thin atmosphere, to read surface temperature on Mars by measuring the infra red light that comes from it's surface. The surface temperature on Mars was first measured in 1920 (see 4th paragraph from the top), and NASA says here that they've been taking accurate surface temperature readings on Mars for 30 years (article from May 2007), so it's pretty safe to say we have about 38-39 Earth years (20 or so Mars years) of reasonably good global temperature readings on Mars and a few decades more than that with less accuracy.

There's many problems with reaching any kind of conclusion on Mars based on that data though. Mars has significantly greater eccentricity than Earth, so it may be prone to larger temperature swings than Earth and just 20 Mars years of data is too few.

Winter to Summer on Mars' enough CO2 can freeze to reduce it's atmosphere by as much as 25% and that can drive temperature changes and mars is also prone to planet wide dust storms that can last months. These can have the effect of blocking sunlight and after settling, darkening the ice caps, which lowers albedo. Like Pluto, Mars' atmosphere, climate, temperature and orbit are dynamic and there's still a lot we don't know about how they worth together to form a predictable climate on Mars.

As an FYI, dust storms are nothing like in the movie the Martian, but they can cause a visible haze over the planet that can obscure viewing it's surface. A nice short article on Mars' dust storms here and here.

I think it's kind of cool that Mars forms an annual "cloud", not unlike how parts of Earth form annual snow and ice covers in winter that thaw in Summer, but we don't know nearly enough about Mars, even with 20 Mars years of observation, to make good long term predictions on Mars' climate.

Venus

Venus, as far as I know, pretty much never changes. It's the same temperature, Winter, Summer, Pole, Equator. There might be some slight variation of Venus temperature depending on elevation, like the gas giants, but I'm not sure. Venus traps heat so effectively that is changes very little, in fact, I've never seen one article mentioning Venus' surface temperature changing as much as 1 degree. Venus reflects most of the sunlight that hits it away anyway, so it would be less prone to solar variation anyway.

I won't do Mercury cause I don't know enough about it, but that's 7 out of 8 anyway.

. . .

If your question is about having a good understanding of climates on other planets, then decades of surface temperature data wouldn't be enough even if we did have it. Centuries of accurate surface temperature data, you could begin to recognize patterns, for the inner 4 planets anyway, but decades isn't enough to differentiate between a baseline, a natural fluctuation or a transition period.

If anyone tells you there are no SUV's on mars, so how could Mars be warming, get away from them as fast as you can. They're not interested in science.

data analysis - What must/do astronomers reveal beyond their academic papers?

If you read scientific papers (at least in astronomy, as far as I am concerned), you will always read of a section which is called Observations and data, or similar.

There you (as author) have to explain which kind of data you used and the detailed method for data reduction.

Most of the time, this section goes along with a table in which all used data are described in detail: the observation log. The guide principle in this section is that, any reader can reproduce your results.

In the same section, information about instrument calibration is also reported in detail. Also, error sources and error determinations. Basically, everything that is included in your published data.

Of course, mistakes can happen, and sometimes we do not consider variables which are important. I do not know the details of the two examples that you mention, but they are not the first and will not be the last.

Paradoxically, what you report is exactly the reason for disproving those experiments. Both major and minor results are always tested twice or thrice or more, by different groups, different facilities/observatories, different software versions. There is no way you can guarantee for a breakgrounding result without being "differently" tested.
In the end, the method works well in this way! If I can't reproduce your results by following your description, either you are a bad writer, or your experiment is going to be confuted.

All the rest is explained well in the answer from OP @moonboy13, with the only exception that, for my experience, when data are private, they are released after 1 year.

evolution - Is Behe's experiment (evolving the bacterial flagellum) plausible in the lab?

You may be interested in this paper and a video that summarizes it. It seems to be made quite clear that 1) effectively all of the parts of the flagellum are not original to it, and 2) there is a reasonable evolutionary path (one involving only increment/refine steps) that could have been responsible for it.

The video mentions but doesn't describe experiments that were in support of the proposed model. I assume they might involve refinement or statistical issues of the environment, not the whole-thing-at-once as Behe outlines. Obviously, if you can show that each step is independently adaptive, then the whole chain is shown to be possible evolutionarily, without trying to set up an experiment where you win the lottery n times simultaneously.

Personally I think the fact that the most awesome thing about the flagellum -- the rotation -- already exists in ATP synthase steals a lot of the flagellum's thunder. :)

Edit (Douglas S. Stones): Following the above references led me to this paper:

M.J. Pallen, N.J. Matzke "From The Origin of Species to the origin of bacterial flagella" Nature Reviews Microbiology 4 (2006), 784-790. (pdf)

In this article the authors discuss the possibility of designing a lab experiment to reproduce (steps of) the evolution of the flagellum.

Scott Minnich speculated in his testimony that studies on flagellar
evolution need not be restricted to sequence analysis or theoretical
models, but that instead this topic could become the subject of
laboratory-based experimental studies. But obviously, one cannot
model millions of years of evolution in a few weeks or months.

So how
might such studies be conducted? One option might be to look back in
time. It is feasible to use phylogenetic analyses to reconstruct
plausible ancestral sequences of modern-day proteins, and then
synthesize and investigate these ancestral proteins. Proof of
principle for this approach has already been demonstrated on several
NF proteins[69–75]. Similar studies could recreate plausible ancestors
for various flagellar components (for example, the common ancestor of
flagellins and HAP3 proteins). These proteins could then be reproduced
in the laboratory in order to examine their properties (for example,
how well they self-assemble into filaments and what those filaments
look like).

An alternative, more radical, option would be to model
flagellar evolution prospectively, for example, by creating random or
minimally constrained libraries and then iteratively selecting
proteins that assemble into ever more sophisticated artificial
analogues of the flagellar filament.

Another experimental option might
be to investigate the environmental conditions that favour or
disfavour bacterial motility. The fundamental physics involved
(diffusion due to Brownian motion) is mathematically tractable, and
has already been used to predict, for example, that powered motility
is useless in very small bacteria[76,77].

[For readability, I've added some line breaks to the above. There's too many cited references to list them all.]

general relativity - Does a spinning mass follow a straight trajectory in empty space? Or is it curved like a golf ball?

In principle yes, but in practice they would follow the same trajectory. At least if you want to be able to actually use them for something useful.

The reason a spinning ball curves is due to its interaction with the air. If the ball is spinning clockwise as seen from above, and it is moving toward 12 o'clock, this pushes the incoming air a bit to the left, say, toward 7 o'clock.

By conservation of momentum, the ball must then move a bit to the right. This is called the Magnus effect.

For a ball of radius $r$, spinning at a rate $s$ and moving with velocity $v$ through a gas of density $rho$, the force is of the order (ignoring the dependency on the roughness of the ball's surface)
$$
F sim frac{16pi^2}{3} r^3 s rho v.
$$

In interplanetary space, the density is roughly $10^{-23},mathrm{g},mathrm{cm}^{-3}$. The Voyager space probes have reached maximum velocities of $sim60,mathrm{km},mathrm{s}^{-1}$ wrt. the Sun. Approximating the space probe as a spherical cow with radius 2 m (the disk is smaller, but the arms are longer), the force amounts to $sim (10^{-8},mathrm{N})$ times $s$. With a mass of $msim700,mathrm{kg}$, to accelerate it up to even 1 picometer per second per second, you would need to spin it at roughly 100 revolutions per second. In which case it would be difficult to use it for anything.

General relativistic approach

After your comment I realize you're interested in knowing about the effect of a rotating object on (empty) space itself, i.e. the effect known as frame-dragging. In the vicinity of massive, rotating object, space rotates along with the object. The closer to the rotating object, the faster space is "dragged along". A point-like test particle close to the object will start orbiting the object. If the test particle is extended, it will feel a "torque", causing it to rotate in the opposite direction of the object.

This means that two space probes sent off with opposite directions will speed up each others rotation, although this effect is miniscule for objects that aren't black holes. You can view the experiment from the frame of reference of their center of mass, in which they are stationary except for their rotation. The frame-dragging would look something like this:

Due to the symmetry, they wouldn't start rotating around each other, and would neither decrease of increase their inter-distance. However, due to regular gravitational attraction ($F=Gm_1m_1/r^2$), they would start to attract each other, and would in fact collide after the free-fall time
$$
t_mathrm{ff} = frac{pi}{2} frac{d^{3/2}}{sqrt{2G(m_1 + m_2)}},
$$
where $d$ is the distance between them, and $m_1$ and $m_2$ are their masses. For two masses of $700,mathrm{kg}$, separated by a distance of 10 m, they will collide in 32 hours.

special relativity - In theory, is there anywhere in the universe where velocity=0?

The question itself is wrong, actually.

There is no such thing as absolute velocity, which is what you're assuming in your question. Velocity is always relative to a frame of reference.

Your speed relative to your chair is zero, but it's not zero relative to the airplanes flying over your house.

When you say "a point in space where nothing is moving and velocity is essentially 0", you must add "relative to such-and-such frame of reference", otherwise your statement makes no sense.

By that token, any object in any point of space has zero speed relative to any frame of reference rigidly attached to it, and non-zero speed relative to other frames. You can't talk about speed unless you specify the frame against which it is measured.

Speed doesn't even exist by itself. It's always relative to a frame. It's not a property of an object or (even worse) a property of "a point in space". It's a relation between an object (the moving thing) and another object (the frame). "Points in space" don't have properties themselves, space is featureless.

Cars may seem like they have a speed as an intrinsic property, but that's just their speed relative to the ground. The car's speed relative to its driver is very different (and hopefully equal to zero). And the car's speed relative to a comet in the Solar System is yet again different.

Any further considerations, such as the flow of time, etc., are invalid as long as you're not asking the right question. Again, speed can only exist relative to something and, as such, it depends on the choice of the frame. And time depends on that whole causal chain.