Jump to content


Resident Experts
  • Posts

  • Joined

  • Last visited

  • Days Won


Janus last won the day on September 28 2021

Janus had the most liked content!


About Janus

  • Birthday August 28

Contact Methods

  • Website URL


  • Atom

Profile Information

  • Favorite Area of Science

Recent Profile Visitors

The recent visitors block is disabled and is not being shown to other users.

Janus's Achievements


Primate (9/13)



  1. From your image: Depth of the hole would be the difference in gravitational potential. The " steepness" at any point is local gravitational strength. So, from this diagram, local gravity would be zero both inside and outside of the "hole". The walls (if straight up and down) would represent infinite gravitational strength over zero distance. (Not a realistic scenario) The edges between the walls and the flat areas would have an infinite tidal force. Since gravitational time dilation is related to difference in gravitational potential and not a difference in gravitational strength, Time would run slower at the "floor" of the hole by an amount determined by by the depth of the hole.
  2. That idea fails on many levels. For one, for diamagnetism to exert a "force", there has to a variation in field strength. Diamagnetic materials will tend to move towards the weaker part of the field. So for it to even work to explain dark matter, you would need the field strength to be greater outside of the galaxy than inside it. So the field would need to have low strength "pockets", one for every galaxy. In addition, magnetic fields have an orientation, and for this to have any chance of working right, would have to be oriented properly for each individual galaxy. But galaxies are not all oriented the same, so the field would have to have different orientations at different points. This runs contrary to how magnetic fields behave. So your idea involves invoking a "magnetic field" that behaves nothing like a magnetic field would.
  3. Finnish: kuusi palaa could translate to any of the following: The spruce is burning The spruce returns The number six is burning The number six returns Six of them are burning Six of them return Your moon is burning Your moon returns Six pieces
  4. I remember seeing it back when it was originally aired.
  5. Further objects only have a larger red-shift due to the fact that the universe is expanding. If the universe did not expand, there would not be any change in red-shift with distance. The amount that the red-shift of any particular galaxy will have changed over the period we have been measuring them is too small to notice. But that doesn't mean that we can't measure how fast the universe was expanding in the past. When we look at the light from a galaxy, that light tells us the state of that galaxy when the light we see now left it. The further the galaxy is away from us, the longer it takes the light to reach us. Thus, as we look at galaxies further and further away, we are seeing them as they were when the universe was younger and younger than it is now. That includes how fast they were receding from us, and the red-shift that the recession produces. If the rate of expansion had been constant over time, you would see a one to one relationship between distance and red-shift measurements of recession speed. If you measure anything else, that means that the rate of expansion has changed over time. It is that simple.
  6. What are the same are the speed of light (in a vacuum) and the speed of gravity waves. Gravity waves are not gravity itself, but more like ripples traveling through the gravitational field. Put another way, you can't have gravitational waves without there already being a gravitational field, but you can have a gravitational field without gravitational waves. Light interacts with the gravitational field, which is "already there" As already mentioned, light has no "rest mass". However, it still can interact gravitationally. While in Newtonian physics you need mass to do so, under our more recent understanding of gravity(General Relativity), mass is just one factor that can contribute to gravity. Energy is another, and light does have energy.
  7. So I assume either Norway or Sweden or possibly Denmark? (Finland is not actually a part of Scandinavia). My paternal grandfather was born about 100 miles south of the Arctic circle, and some ancestors from further North.
  8. Ah, but here's the beauty of it: Everyone will be wanting to go to Canada, but only 0.2% of the US population has any claim to Finnish ancestry at all. Having 4 Finland-born grandparents should put me at the front of the line! (Besides, I was born and raised in Northern Mn, cold is nothing new to me.)
  9. Today I learned, that if I chose to, I could move to Finland. If you want to stay in Finland longer than the 90 days allowed by a visa, you need to apply for a residence permit. Here are a few reasons you could be granted one: You've been hired for a job in Finland. You have immediate family( spouse, child under 18.) that already live there. You are going to school there... But the one that would apply to me is "remigration"; If you have Finnish roots, or a close connection to Finland. So, for example, if a grandparent had been born in Finland. This is me. All 4 of my grandparents were born in Finland( as were their parents, and so on) And while most of the other methods of getting a residence permit requires that you can show that you have sufficient funds/income to support yourself, remigration doesn't. Not that I have any plans to do so, but it is nice to have it my back pocket in case things really go sour here in the US ( civil war breaks out, e.g.)
  10. The maximum mass for a neutron is star is ~2.17 solar masses, and one that massive would have a radius of ~15 km. The event horizon for a BH with that mass is ~6.43 km, and has a photon sphere at ~9.65 km. At the surface of the Neutron star, escape velocity would be ~ 0.463 c and orbital velocity would be ~0.33 c, both well short of c.
  11. They say it this way when trying to communicate the idea of non-euclidean spacetime to a general populace that has no idea what non-euclidean geometry is. The animation is not meant to represent "reality", it is a "translation" of non-euclidean geometry using euclidean geometry. It is an attempt to represent an abstract concept in a way that is easier to visualize.
  12. Well, for one, the mechanism you use to explain this frequency shift ( quoted above) would not result in the type of frequency shift we see. All these types of interactions are wavelength dependent, meaning that the effect you get from them depends on the wavelength of the light (An example of this type of wavelength dependent effect would be light at the blue end of the spectrum being scattered more by our atmosphere*) Thus you would see different amounts of shift in spectral lines at different points of the spectrum, and not the uniform shift we see across the whole spectrum. It's not enough to say you can relate energy to frequency when the mechanism that you attribute this change to would not produce the results we observe. * In fact, the very mechanism you base your argument on would also produce scattering. We do not see significant scattering in light from distant galaxies. (because, quite frankly, there isn't enough stuff out there between our galaxy and them to produce it. The amount of material a photon passes on its way between a galaxy 13 billion ly away and our galaxy is roughly equivalent to the amount it passes crossing 1 meter of air at sea level.)
  13. Exactly, a lot of this background on " how things work" on a starship(BTW, the info I provided came from the Star Trek The Next Generation Technical Manual by Rick Sternbach and Micheal Okuda ) are loose guidelines to maintain some continuity, but they are not allowed to get in the way of a good story line.
  14. Most likely by magnetohydrodynamic generator. Where you pass plasma through a magnetic field to generate electricity. This seems to fit with other nomenclature in the franchise. There are references to the EPS (electro plasma system), which seems to be how they tap energy for running ship systems from the PTC (power transfer conduit), which contains and carries plasma from the matter-antimatter reaction chamber to the warp field generator coils.
  • Create New...

Important Information

We have placed cookies on your device to help make this website better. You can adjust your cookie settings, otherwise we'll assume you're okay to continue.