space travel - What would the cost be of visiting an asteroid?

I'm trying to think through what the cost would be of an unmanned mission to a nearby asteroid. To me it seems like the high-level costs would be the fixed cost of the "spaceship" itself (including any scientific or mining equipment required to carry out the mission), the cost of getting into orbit which would depend on the ship mass, and the fuel to get there and return (which would be a function of fuel cost, ship mass, how fast you want to get there, and the mass of anything collected at the asteroid site that would be returned). Is there anywhere that this is discussed or has anyone thought this through further?

orbit - Two body transient solution

There is no transient part

In solving a linear ode y'' + ay' + by = f(x), one finds that the solution is the superimposition of a general solution of y''+ay'+by=0, and a particular solution of the ode. In the situation in which the ode represents damped harmonic motion, the general solution part is said to be transient. This is a particular solution to this ODE, and not a general technique for solving all differential equations, and does not apply to the ode that describes newtonian gravity.

However there is another way of solving the newtonian equations, in the case of a two body problem, and that is Kepler's laws of planetary motion. These give a complete solution, and there is not transient part. Given a body's initial state, you can immediately find it's orbit using Kepler's laws. The body will be in an elliptical orbit, and return to its starting point, having made one complete orbit.

dna sequencing - protocol for pulldown of DNA breakpoints?

The paper you cite says that the break points are single stranded DNA which have specific proteins bound to them.

I'm not an expert here, but if thats the cause of meitotic break points there are some interesting possibilities for detecting them:

you could detect them with a tiling array. - that's an micro array which has an oligomer every 40 bp or so of the genome. The array could be used in a CHP experiment that detects the same proteins as in this paper.

Its possible that the array could possibly hybridize the single stranded DNA from the genome too if the conditions were right. This sounds noisy though.

On the cheap side it might be possible to use PCR to copy the single stranded DNA from a chromosomal DNA prep. if the oligos you use are labelled with streptavidin say, you could isolate it , re amplify it and sequence cheaply.

any of these sound like a good bit of work :)

Shadows of Light = Space or Dark Matter?

You cannot have dark without light.

Not true in the case of dark matter (for the general case, see below). Dark matter is called "dark" because it appears that it doesn't absorb or emit electromagnetic radiation - light! It can interact with light via gravitational lensing, but dark matter particles have no electromagnetic charge (we think) and so are considered "dark".

The only thing faster than light is dark (i.e. shadows)

This is true, as the video explains.

Does this make "dark matter" mere shadows of extremely bright objects?

This is the meat of the question, and the answer is a clear "no". First, any "bright objects", while capable of casting a shadow of something else, will emit electromagnetic radiation.

Okay, so why can't there just be non-extremely luminous objects casting a shadow? One reason is that the dark matter simply isn't where these shadows should be. Many galaxies have a dark matter halo that extends far beyond the galactic plane. Any light sources emitting light (that is then shadowed) would have to be on the opposite side of the galactic disk. This is simply not the case.

The second, more convincing, reason is that dark matter has mass. In fact, that's the reason the idea was first conceived (to account for anomalies in galactic rotation curves)! Shadows don't have mass; therefore, dark matter cannot be explained by shadows.

Is that also why it has to get dark before we can really see the majority of stars (subjective experience)?

No. I don't know for sure, but I believe that that's because the Sun's light is still blocking out the light of distant stars.^{[citation needed]}

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Addendum after edit to question

Can you provide sources for your claims?

I think that they're pretty well sourced! The first section can easily be checked via Wikipedia (which I assumed you had seen). The rest seems to be well-sourced, too (aside from the last bit, which is, admittedly, unsourced but only tangential).

Also I didn't say you can't have DARK MATTER without Light , I said you can't have Dark, as in Darkness. I think you're getting hung up on Dark Matter which is a big part of my question, but not the entire question.

Okay, I may have misinterpreted this.

Darkness is, by definition, the absence of light (electromagnetic radiation). So no, you don't have to have light for there to be darkness.

Also, are you claiming that all darkness in space is dark matter? I don't like to assume but for scientific purposes (not an accredited scientist) would we not agree that the measures made on dark matter were on a sample, and not the entire universe?

I never said that, but you did. Your original question asked if dark matter could be shadows. The answer is no.

So to further question this, do shadows not exist in space?

They exist. Any object blocking a light source casts a shadow:

This happens to have been used in the video, so it shouldn't be new to you.

the sun - When was the nearest star discovered?

When historically did we realize that the Sun is a star, like all the others?

An answer was posted, then the question was put on hold. I would like to answer:
If indeed someone asserted that the Sun was a star 2500 years ago, that is rather humbling. That it took until about 100 years ago for it to be proven is even more humbling!

People level a lot of claims against science and scientists. But if a field of knowledge takes over 100 generations to prove a true statement, perhaps they have a right to criticize. So, I think that science needs to do a better job of proving its theories. Either that, or people need to have more common sense, not to recognize something that has been staring billions of people in the face for all time. Perhaps, we should all be a bit more humble about the state of knowledge, even in obvious areas?

Maybe if we had taken the people who proposed this fact, and the concept of atoms, seriously at the time, we would be on our way to other stars by now instead of still having only visited that big white thing nearby (forgot the name just now) and that not for the past 40 years.

distances - How do astronomer measures the size of any celestial objects?

The main tool to measure the diameter of a star is interferometry combined with a parallax-based distance measurement - a brief review by Kervella (2008) might be useful. The principles behind interferometry are described here.

Interferometry involves measuring the light from a star using two (or more) telescopes that are separated by some distance. Together, the signals from these telescopes can be combined to give an angular resolution that can be (in the best circumstances) equivalent to a telescope with a diameter equal to the telescope separation. These measurements give the angular size of the star, which must then be multiplied by their distances to get a physical diameter.

One of the most successful experiments is the Chara array, which has yielded diameters for many nearby stars. Precisions can be as good as a few percent, but more usually 10% and of order 100 (predominantly nearby) stars have had their radii measured in this way.

A second main direct technique is to use eclipsing binary systems. The measured light curve can be used in an almost model-independent way to estimate the radii of the two stars involved. Of course most eclipsing binaries are close pairs with short orbital periods and with orbital inclinations that allow us to see the eclipse. They are therefore highly prized objects. Radii can be measured with precisions of 1%. A reasonably complete catalogue of the $sim 100$ known eclipsing binaries with precise radii can be found here.

Another technique is lunar occultation. The passage of a star behind the limb of the moon results in a changing diffraction pattern that can be used to estimate the angular size of the star. Again a distance is required to convert this into an actual diameter.

More distant stars are inaccessible - their angular diameters are simply too small. At the moment only indirect estimates of their radii are possible. For example, if we were to assume that a star radiates as a blackbody, then its luminosity ($L$), radius ($R$) and temperature ($T$) are related by Stefan's law.
$$ L = 4pi R^2 sigma T^4,$$
where $sigma$ is the Stefan constant. If the star has a measured flux at the Earth and we know how far away it is, then $L$ can be estimated. If we take a spectrum and estimate its temperature, then the equation above can be rearranged to give the radius in terms of the measured luminosity and temperature. Real stars are more complicated than blackbodies, but the principle is the same.

Neither of the above techniques can work for black holes, and the sizes (event horizon or Schwarzschild radius) of black holes have not yet been directly measured. The physics of a black hole is relatively simple(!) and so there is a direct relationship between their Schwarzschild radii and their masses (modified somewhat by rotation). Basically it is 3 km multiplied by the mass in solar units. Therefore a measurement of the black hole mass gives its "radius". The masses of black holes are measured by looking at the motions of stars and gas around them and applying our knowledge of how gravity works.

human biology - How many, and how severe, are known single gene polymorphisms for obesity?

MC4R, TMEM18, GNPDA2, KCTD15, NEGR1, BDNF, ETV5, MTCH2, and SH2B1 have also been identified as being associated with adult onset obesity risk, however FTO currently appears to be the one with the strongest evidence. For example see Thorleifsson et al. (2009), Elks et al. (2010) and Willer (2009)