3 ms·
About this: "It is pretty obviously not that useful to ask a dog to sniff the sky or a homing pidgeon to navigate to Alpha Centauri, or something." That examp
by lkrubner 8y ago
About this:
"It is pretty obviously not that useful to ask a dog to sniff the sky or a homing pidgeon to navigate to Alpha Centauri, or something."
That example might be bad, but there are others that are valid. For instance, in healthy human women, the menstruation cycle seems to be the exact length of the moon's orbit. Is that a coincidence, or do human bodies have a way of gaining data from the moon? If so, what is that data? Maybe the mechanism is as simple as a springy protein that can absorb tidal forces and convert it to an information signal. Or perhaps something novel is going on.
There are potentially a lot we can learn about the universe by making simple observations here on Earth.
- SketchySeaBeast 8y ago> For instance, in healthy human women, the menstruation cycle seems to be the exact length of the moon's orbit. That seems to be absolute coincidence. If there was a value in syncing to the lunar cycle it would stand to reason there would be a synchronization with the characteristics of the lunar cycle - ie ovulation on the 14th day or something. As it is, there is no link between when a woman's cycle and the lunar cycle begin, they just happen to occur with the same (ugh) period. I don't know what tidal forces women could be keying into that would result in totally seperate start and end dates. It's also important to note the 28 days falls on the average, but the range is anywhere from 21 to 35 days for normal women. It's in no way the exact length of the moon's orbit.
- ncmncm 8y agoWhen there is any kind of weak forcing function, they synchronize. Artificial light is a new phenomenon. Before, moonlight was extremely important to everyone.
- acqq 8y ago> Maybe the mechanism is as simple as a springy protein that can absorb tidal forces and convert it to an information signal. Tidal forces don't have periodicity of a month, but change twice a day: https://oceanservice.noaa.gov/education/tutorial_tides/tides05_lunarday.html https://oceanservice.noaa.gov/education/tutorial_tides/tides... "High tides occur 12 hours and 25 minutes apart. It takes six hours and 12.5 minutes for the water at the shore to go from high to low, or from low to high." To detect the tidal forces in some organism that can't sample the sea level you'd need an organism of an immense size, not something of the size of any animal on the plant today. > There are potentially a lot we can learn about the universe by making simple observations here on Earth. We are making observations, but they aren't simple anymore. It started with simpler methods than today's: there were ancient Greeks (more than 2000 years ago!) who correctly estimated the diameter of Earth and then also quite correctly calculated the distance of Earth to the moon, who haven't had too precise instruments. E.g. Hipparchus: https://en.wikipedia.org/wiki/Hipparchus#Orbit_of_the_Moon https://en.wikipedia.org/wiki/Hipparchus#Orbit_of_the_Moon "According to Pappus, he found a least distance of 62, a mean of 67 1⁄3, and consequently a greatest distance of 72 2⁄3 Earth radii. With this method, as the parallax of the Sun decreases (i.e., its distance increases), the minimum limit for the mean distance is 59 Earth radii – exactly the mean distance that Ptolemy later derived." We today precisely measure that distance to be 60.32 Earth radii. Think about that it was more than 100 years before that famous "birth", that is, at least 120 years BC! Still the bigger advances started when we used the instruments that enabled us to capture more signal than what just our senses without the instruments, or with the most primitive instruments, would. The first was Galileo's use of telescope to discover: https://en.wikipedia.org/wiki/Galilean_moons https://en.wikipedia.org/wiki/Galilean_moons
- ncmncm 8y agoSome people have noticed that the amount of light at night, absent artificial lighting, varies markedly by the month. I know that my cats notice. Indeed corals worldwide notice, despite lacking eyes.