Timeline for Blind spot in the Solar System
Current License: CC BY-SA 3.0
10 events
| when toggle format | what | by | license | comment | |
|---|---|---|---|---|---|
| Aug 25, 2015 at 19:47 | comment | added | Joshua | They're using an Alcubierre drive. They don't have real velocity. | |
| Aug 25, 2015 at 16:03 | history | edited | Jim2B | CC BY-SA 3.0 |
corrected spelling, grammar, punctuation, and tried to make it more readable.
|
| Aug 25, 2015 at 15:59 | comment | added | Jim2B | It also depends upon neutrino type but we know that they oscillate. I was wrong. A neutrino's "mean free path" through lead is greater than 1 light-year. But, you should read this hyperphysics.phy-astr.gsu.edu/hbase/particles/neutrino3.html. FYI, for neutrinos with only moderate energy levels - this goes up to a thousand light-years of lead. | |
| Aug 25, 2015 at 11:02 | comment | added | JDługosz | "(a neutrino has a 50% chance of passing through 6,000,000,000,000 miles of lead)" that is not true. The cross section depends strongly on the energy of the neutrino. "A neutrino" implies that they are all alike. | |
| Aug 25, 2015 at 3:53 | comment | added | Jim2B | Also whether a fission reactor produces neutrinos or antineutrinos (probably) depends upon the type of "fission" (neutron, alpha, beta, positron, or true fission). IIRC, neutron -> no neutrinos, alpha -> no neutrinos, beta -> 1 anti neutrino, positron -> 1 neutrino, and fission I would think is none but could be something depending upon the reaction. | |
| Aug 25, 2015 at 3:48 | comment | added | Jim2B | But the more power they use the harder it is to remain unseen. It probably follows the inverse square law. Also if you radiate at an unusual frequency, (e.g. not thermal), you're more likely to be observed ("hey, look at that glowing blue rock!") | |
| Aug 25, 2015 at 3:47 | comment | added | Jim2B | Rocks DO radiate heat and reflect light (it's the fact that they can't reflect sunlight when they come from the inner solar system that makes them hard to find). You can figure their luminosity and compare to ship luminosity and it shows that reasonable size ships NOT operating in high power mode could "hide" (aka not broadcast their presence) pretty easily. | |
| Aug 25, 2015 at 2:36 | comment | added | Christopher King | The reason that rocks in space have stealth is because they produce no heat, and do not increase entropy. A ship necessarily would (indeed, life forms produce entropy all on their own.) | |
| Aug 24, 2015 at 20:56 | comment | added | celtschk | The neutrine argument is interesting. Note that the sun produces neutrinos, but a fission reactor produces antineutrinos. So in principle, a strong signal from a reactor could be distinguished from the solar signal. Of course if the ship uses fusion, it should produce neutrinos, just like the sun. | |
| Aug 24, 2015 at 15:40 | history | answered | Jim2B | CC BY-SA 3.0 |