What if the moon was gone?

[Justforfun000]

I was talking to a friend in the bar about the ocean tides and how the moon affects them and we got to wondering how significant the moon's effect on the earth and it's environment really is. What if the moon simply vanished out of our universe? I don't know if this is even possible whether by massive comet smashing it to bits or pushing it out of it's orbit and us losing it for example....but I'm not really interested in the how just what would happen to the earth? Would it have catastrophic consequences in many ways or would it be relatively insignificant? Anyone know?

[Kanastrous]

If it had happened long enough ago, Earth might be very different; there are theories suggesting that Luna skimmed off a good deal of excess atmosphere early on, which certainly affected the development of the biosphere.

[rhoenix]

Isaac Asimov wrote two essays about this subject, they're the first and second chapters of his non-fiction book (and one of my favorite books of all time) The Tragedy of the Moon. His first essay argues that we as a species would've been better off society-wise without a moon; his second argues that without a moon, the tides caused by the moon's gravity that helped life to form on this world may not have worked out the same way, or at all.

Well, they go into much more detail, but that's the extreme ADD Cliff's Notes version.

[Samuel]

If it had happened long enough ago, Earth might be very different; there are theories suggesting that Luna skimmed off a good deal of excess atmosphere early on, which certainly affected the development of the biosphere.

I think that was debuncked.

If the moon vanished, space flight and astronomy would be more difficult. ALso, the Earth would have shorter days as the moon wouldn't have been slowing it down (the Sun still has an effect, just not as extreme)..

his second argues that without a moon, the tides caused by the moon's gravity that helped life to form on this world may not have worked out the same way, or at all.

THat was definately debunked- they have alternate orgin theories than the primordial soup.

[Count Chocula]

In addition, how would the human and other mammalian fertility cycles have developed? From my observations, the female's cycle closely matches the moon's cycle.

And our coastlines would be a lot less interesting.

Oh yeah, another factor/question: would the lack of a moon have affected Man's development of agriculture? I mean, we have the sun going up and down every day, but I imagine that "look big moon now" 12x a year would have been easier for our distant ancestors to comprehend. Of course, I'm half in the bag and could be way off base here, since both SOLstices - important data for farmers - are measured by the sun.

[Junghalli]

The moon has an important function in stabilizing Earth's axis. If you took away the moon the axis would start to slew all over the place like Mars's does, sometimes going up to 80 degrees or more (which gives you an Earth tilted on its side like Uranus). The good news is this cycle goes on over hundreds of thousands of years (comparable to the timescales ice ages happen on already), so in the immediate future we should be OK.

Basically, as far as I know, if you took away the moon now you wouldn't have much in the way of short term effects, but long-term we'd have to worry about an unstable climate.

If the moon never existed, this process would have been happening since the formation of Earth, and the biosphere would undoubtedly be very different as a result. The Big Whack probably knocked off some of our atmosphere and water, so the oceans might be around 1 km deeper and the atmosphere somewhat denser (about 15%). The day/night cycle would be only 8 hours (4 hours of light, 4 hours of darkness). The fast rotation would create powerful winds. The scenario is discussed in detail in Neil F. Comins's book What If The Moon Did Not Exist?.

[Kanastrous]

Big Whack = Terra/Theia collision?

[Junghalli]

Big Whack = Terra/Theia collision?

Yes.

[Count Chocula]

Killer Data wrote:

Your old lady doesn't let you eat pussy during the full moon either?? (I just find your wording here utterly hilarious.)

No I don't - MY CHOICE. Hmm. Maybe that's why she don't howl at the moon any more.

Sorry about that Testing side track.

Oh, remembered another one. No Werewolf legends. No Michael Jackson Thriller video. All my Moon references seem to be cultural.

[Kanastrous]

From my observations, the female's cycle closely matches the moon's cycle.

Your old lady doesn't let you eat pussy during the full moon either?? (I just find your wording here utterly hilarious.)

First thing that made me think of, was Blood on the Moon.

[CaptainChewbacca]

Earth's seasons would vary WILDLY. Right now the moon stabilizes the 'wobble' of earth's axis to within a few degrees of variance. Without it's influence, the Earth would tumble like Mars and our axial tilt could vary from zero to forty or even fifty degrees over much shorter timescales.

[Serafina]

In addition, how would the human and other mammalian fertility cycles have developed? From my observations, the female's cycle closely matches the moon's cycle.

They would have evolved someway (if life as we know it had evolved it).
While the lenght may not be pure coincidence, the lenght itself is not really important.


If the moon would vanish for some reason (an eclipse SSD blowing it up...), there would be various problems:

-Tides would vanish. Not instantly, but over a longer time, they would. As tides are important for lots of ecosystems
(all life close to the coasts, as well as other maritime life), those would collapse (they could not adapt fast enough,
and lots of species are highly specialised).
This would also affect the ground-water level, but the effects would propably be very small.

-After several years, the earth axis would begin to de-stabilize. This would severly change climate: The stable climate
at the equator would vanish, leading to the collapse of the whole climate.
Later, overall seasons would shift everywhere. Life would have to adapt to this: Greater climatic tolerances would
evolve. Thus, specialist would be replaced with generalists. This would be great for mammals and birds, but bad for
reptiles and insects. Overall, a severe paradigm shift would occur.

AFAIK, there is/was a theory that the moon served as a "meteor shield", guarding earth from meteor/asteroid impacts.
Does anyone know what todays scientists say to this?

[Lord of the Abyss]

Another difference I'd expect would be a decrease in geological activity. The tidal forces of the Moon affect rock as well as water, constantly stressing Earth's crust; and that energy eventually ends up as heat.

[DaveJB]

If the moon would vanish for some reason (an eclipse SSD blowing it up...), there would be various problems:

<snip>

There'd be much bigger problems than that if the moon was actually destroyed instead of just suffering spontaneous existence failure. It'd take about 1E29J minimum to blow up the moon, and any significant proportion of that directed at Earth would fuck the planet's surface up, big time.

[Ender]

In addition, how would the human and other mammalian fertility cycles have developed?

I'm sure the lengths of the cycles are pure coincidence. Note that most other mammals don't have the bizarre monthly cycles of humans at all, and I can't think of any mechanism that would explain causality from the moon.

Discovery channel video I saw a few months back posited that on nights of a full moon there was enough light for hunting. Thus the men would be gone, trying to bring back food. On nights with no moon, it was too dark to hunt, so the men were back at camp. Women whose fertility cycle was in line with the nights of no moon got pregnant more often and passed on their genes.

Of course AFAIK the fertility cycle of a woman can vary greatly (including women getting "in sync" as it were), so I'm not sure the logic there tracks.

[General Trelane (Retired)]

In addition, how would the human and other mammalian fertility cycles have developed?

I'm sure the lengths of the cycles are pure coincidence. Note that most other mammals don't have the bizarre monthly cycles of humans at all, and I can't think of any mechanism that would explain causality from the moon.

Discovery channel video I saw a few months back posited that on nights of a full moon there was enough light for hunting. Thus the men would be gone, trying to bring back food. On nights with no moon, it was too dark to hunt, so the men were back at camp. Women whose fertility cycle was in line with the nights of no moon got pregnant more often and passed on their genes.

Of course AFAIK the fertility cycle of a woman can vary greatly (including women getting "in sync" as it were), so I'm not sure the logic there tracks.

The Skeptic's Dictionary addresses this here:

Despite the fact that there is no evidence of a significant correlation between phases of the moon, the menstrual cycle, and fertility, some people not only maintain that there is, they have a "scientific" explanation for the non-existent correlation.* Some think the light of the moon affects fertility in women, the way it does in corals. The light of the moon is a very minor source of light in most women's lives, and is no more likely than the moon's gravitational force to have a significant effect on a woman's ovulation. Furthermore, the average menstrual cycle is 28 days but varies from woman to woman and month to month, while the length of the lunar month is a consistent 29.53 days.* Some of us have noticed that these cycles are not identical. Furthermore, it would seem odd that natural selection would favor a method of reproduction for a species like ours that depended on the weather. Clouds are bound to be irregularly and frequently blocking moonlight, which would seem to hinder rather than enhance our species' chance for survival.

Some mythmakers believe that long ago women all bled in sync with the moon, but civilization and indoor electric lighting (or even the discovery of fire by primitive humans) have disturbed their rhythmic cycle. This theory may seem plausible until one remembers that there are quite a few other mammals on the planet that have not been affected by firelight or civilization's indoor lighting and whose cycles aren't in harmony with the moon. In short, given the large number of types of mammals on our planet, one would expect that by chance some species' estrus and menstrual cycles would harmonize with lunar cycles (e.g., the lemur). It is doubtful that there is anything of metaphysical significance in this.

[starslayer]

Another difference I'd expect would be a decrease in geological activity. The tidal forces of the Moon affect rock as well as water, constantly stressing Earth's crust; and that energy eventually ends up as heat.

This heat is so low as to be negligible. Heat from radioactive decay outstrips this by many orders of magnitude. There'd be the same amount of geological activity today if the Moon were not here.

[Akkleptos]

Another difference I'd expect would be a decrease in geological activity. The tidal forces of the Moon affect rock as well as water, constantly stressing Earth's crust; and that energy eventually ends up as heat.

This heat is so low as to be negligible. Heat from radioactive decay outstrips this by many orders of magnitude. There'd be the same amount of geological activity today if the Moon were not here.

Would the gravitational pull on the crust be as negligible (not regarding the heat issue, but rather regarding the mechanical strain)? Or is the moon gravitational effect on Earth's crust that minimal?

Also,

The moon has an important function in stabilizing Earth's axis. If you took away the moon the axis would start to slew all over the place like Mars's does, sometimes going up to 80 degrees or more (which gives you an Earth tilted on its side like Uranus). The good news is this cycle goes on over hundreds of thousands of years (comparable to the timescales ice ages happen on already), so in the immediate future we should be OK.

More importantly, how would this event's effects be when it comes to Earths biology, or the development thereof?

[Samuel]

Would the gravitational pull on the crust be as negligible (not regarding the heat issue, but rather regarding the mechanical strain)? Or is the moon gravitational effect on Earth's crust that minimal?

I believe the Sun has a larger effect.

More importantly, how would this event's effects be when it comes to Earths biology, or the development thereof?

Life will find a way. I'm not sure there is a direct correlation though- Venus and Mercury don't tilt as much as Mars.

[Junghalli]

Would the gravitational pull on the crust be as negligible (not regarding the heat issue, but rather regarding the mechanical strain)? Or is the moon gravitational effect on Earth's crust that minimal?

There are ground tides, measured in inches. I'm not sure how they effect geology.

More importantly, how would this event's effects be when it comes to Earths biology, or the development thereof?

I imagine it would lead to a less diverse terrestrial biosphere, as climatic zones would fluctuate wildly. Generalists would do best on such a world. Lifeforms capable of surviving extreme heat and cold would be favored, as they'd be best at surviving the periods of high tilt. Deciduous trees that were good at water retention and had deep roots would probably be favored; they'd be well adapted to the high tilt period winters and summers, when you get little or no sunlight for months and blistering heat and probably little rain for a similar period. I wouldn't be surprised if a lot of plant life was thorny or poisonous, for the same reason cacti are. You'd probably see a lot of small plants and maybe animals with fast generation cycles and hardened seeds (or eggs) designed to stay dormant over periods of extreme cold or heat.

Additionally, with the day being only 8 hours long you'd get high winds. Plants would probably grow low to the ground, and would have small needle-like leaves like pines (to avoid them being blown away). Animals would likely be low to the ground as well.

I'm not sure there is a direct correlation though- Venus and Mercury don't tilt as much as Mars.

My suspicion (purely my own reasoning, mind you) is that may have something to do with the sun. The solar tide is a lot stronger on those planets, so the sun may perform the same function for them that the moon does for us. IIRC both planets have solar tides as strong or stronger than our lunar tide, and both planets have axis aligned within a few degrees of their orbital plain, which would make sense if that was what was happening (note: Venus technically has a 177 degree tilt because it's considered to be "upside down" - because of its retrograde rotation IIRC - but when you ignore the "upside down" status that's an axis tilt of only 3 degrees).

[Kanastrous]

Saw a chunk of one of those horrendous "world ends in 2012" programs (on the fucking History Channel, which really ought to be renamed) wherein some crystal-fondler was blabbering about how "the moon is going to pull the Earth off its axis of rotation and everything will go sideways."

:headfloor:headfloor:headfloor

[Sky Captain]

Saw a chunk of one of those horrendous "world ends in 2012" programs (on the fucking History Channel, which really ought to be renamed) wherein some crystal-fondler was blabbering about how "the moon is going to pull the Earth off its axis of rotation and everything will go sideways."

:headfloor:headfloor:headfloor

So now it`s not Nibiru, but our old trusty moon that is going to fuck up us all .