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Hmm, this is a tricky question because there are so many factors that go into making life possible that it's hard to really be sure about what changes we could make to physics that would still allo...
Within general relativity at least, I think this is impossible. The metric tensor of a pseudo-Riemannian manifold is usually taken to be everywhere nondegenerate (see e.g. this source. A metric is ...
I finally found how to calculate the mass in the general case. Here is an answer summarizing my comments and calculations (but I'm still not an expert in general relativity, so please take it with ...
I think I can now answer my own question, having come across some decent references I hadn't found before asking it. I found the equation for the gravitational strain $h$ - the proportional change ...
According to this site, the kinetic energy of the two alpha particles emitted is 4.273 MeV. As you said, these aren't neutral atoms yet with balancing electrons. So, they are a charged plasma. Im...
Lets consider how hard it would be to spot this object with visible light astronomy. This isn't quite the right way to go about things, but it is a start. Most things are easier to see in IR than t...
Yeah sure photoproduction can dominate, no problem. A neutron's proper lifetime is a fixed property of the particle, but the mean free path length that a neutron can travel without interacting wit...
In reality, if you want to build a star, you need to specify a mass and a chemical composition, and then use the equations of stellar structure. This requires some numerical integration, and it's f...
You asked "Is there any way to calculate it?". The answer is yes, but it's not going to be as simple as plugging a few numbers into a simple formula. You'll need a general circulation model. The ...
The first step is to give a look (pun intended) at the retina of most birds eyes, which have a 4th cone type to see UV. Differently than mammals, their cones have an oil drop to better constrain th...
No, that setup is not stable There do not appear to be any stable orbits for another moon, of any size, outside the orbit of Luna I ran a simulation in rebound to see what would happen with this ...
First, references: Bosch and Hale, 1992 has cross section and S-function values for the D and T reactions, as does Nuclear Cross Sections for Technology from the US Department of Commerce, 1979. ...
Is it possible that a planet/moon will have inverse direction comparing to the rest orbiting material? For example Mars would go in counter direction comparing to other planets in solar system. I...
So, I've heard that while Alcubierre drives might present a semi-plausible way of getting around the light speed limit (if you can get ahold of negative energy), they do so at the expense of creati...
If you're studying radio signals from Earth, is it possible to calculate whether a radio source is 'near' as in near Earth or 'very far away' as in somewhere far out in space from velocity, or velo...
Both the (current) answers to the question state that it is not possible for your idea to work. Aside from the fact that you are explicitly not asking for a feasibility study, the obligatory XKCD r...
First I want to say that 7 billions people doesn't celebrate christmas, it's only about 2 billions. Also I want to say that the cookies and milk aren't per person, they are per family (each normal ...
Without energy to matter converters or desktop controlled fusion (to create one element from another), you need to have as input every element that you want in your output. You don't need every ele...
For raw resources, as a baseline, I would say that you need everything non synthetic on the periodic table, with some advisory on which radioactive elements you want (they can be useful in applicat...
First, a back-of-the-envelope calculation: power output of sun / surface area of sphere of radius 1 AU = ~1368 W/m^2 You MUST radiate this much (on average) from every square meter of your sphere...
It all depends on the scale and surface brightness of the nebula. For instance, the famous Orion Nebula is 1,344 light years. The Orion Nebula is a fairly bright nebula. However, if we replaced ...
As I'm sure you know, four more exoplanets were recently discovered around TRAPPIST-1 (Gillon et al. (2017)), bringing the total to seven "” all, amazingly, presumably rocky and near the star's hab...
First off, there is no realistic way to limit an FTL drive because there is no such thing as a realistic FTL drive in the first place. That is to say, any drive that allows you to physically move f...
Make the aiming difficult If the lowest precision of coordinates you can aim at still has an error margin greater than the typical size of a solar system your method would not be usable for travel...
Say that the run-up acceleration to FTL has to be about 10% of light speed, that FTL depends upon a discovery involving a violation of symmetry in the Lorentz contraction (a consequence of relativi...
