3 ms·
Non-physicist here. If the modulation is annual, does that imply that the Dark Matter they're detecting is stationary, relative to the Sun (meaning it orbits th
by ubercore 15y ago
Non-physicist here. If the modulation is annual, does that imply that the Dark Matter they're detecting is stationary, relative to the Sun (meaning it orbits the Milky Way on the same path as our Sun)?
- patrickyeon 15y agoThat's possible. It's also possible that it does not rotate in the Milky Way at all. Earth would still be passing through it faster for the part of the year where our rotation around the sun has us going at a faster velocity around the center of the galaxy. If it helps, think of your car's tire as you drive down the road at speed v. The part of the tire that touches the road at any instant has no speed (relative to the road), and the opposite point on the tire is travelling at 2*v (still relative to the road).
- ubercore 15y agoAhh, right. Thanks for clarification.
- mattheww 15y agoClose. It is widely assumed that the dark matter is, on average, stationary with respect to the Milky Way. The amplitude of the modulation is a lot smaller in this case than what you described.