Does the force of Earth's gravity change over time

Maybe i'm wrong, but weren't plants and tree's also a few scales larger in dino days as in present day ?

Is there a connection?

a reply to: EartOccupant

From my understanding yes they were. The carbonic acid that formed in the atmosphere from C02 and watervapor was very good for plantlife.

Studies have shown their is a marked increase in size and yield from plants fertilized with carbonic acid gas.

a reply to: eManym

The carbonic acid that formed in the atmosphere from C02 and watervapor was very good for plantlife.

Yeah. Plants love acid rain.

Yes, plants sure love that carbonic acid, Phage. Its been known since the 20's.

Carbonic Acid to Fertilize the Air

a reply to: eManym

Dr. Riedel therefore believes that carbonic acid works for supplying agriculture will before long be quite as common a feature as electricity and gas works, the large industrial centers at the same time becoming centers of increasing agricultural production.

www.sealevel.info...

I wonder what happened. I mean, there was a 300% increase in potato productivity. That's awesome. Maybe something about the experiments was wonky. But I understand that low soil pH can be problematic for plants.


I don't think plants were much larger then than they are now, in general.

While the earth is constantly gaining mass although very slowly over time it will indeed over a long range of time therefore have a slight increase in gravity...
As for the size of plants and dinosaurs a major contributing factor to their greater size as well as longevity was very likely due to a much more abundant ozone layer then we have today...

a reply to: Phage

You make a good point there. There are hundreds of plant species that thrive in an acidic environment. Conifers were the dominant plant in the Jurassic period. They thrived in an acidic environment.

a reply to: eManym

Conifers were the dominant plant in the Jurassic period.

I didn't know that.

They thrived in an acidic environment.

As they thrive, to this very day. Unless we cut them down, of course.

I put my foot in my mouth on this one. In order for the atmosphere to be dense enough to provide buoyancy for large dinosaurs it would need to be as dense a light wood material. Not practical, the best theory I could find involved dinosaurs had efficient breathing systems that were interlaced with their bones, similar to today's birds, making dinosaurs not as massive as many speculate. Also, their birthing practice of laying eggs instead of carrying their young around to gestate for years. Makes sense.

While the earth is constantly gaining mass although very slowly over time it will indeed over a long range of time therefore have a slight increase in gravity..

a reply to: 5StarOracle

If i could add to your reply.

The increase would be at the centre. But. As the ground of the Earth grew further from the centre. The Gravity would be weaker. At the surface.

The greater the altitude. The weaker the Gravity.

originally posted by: blackcrowe

While the earth is constantly gaining mass although very slowly over time it will indeed over a long range of time therefore have a slight increase in gravity..

a reply to: 5StarOracle

If i could add to your reply.

The increase would be at the centre.

In a simplified theoretical model, yes, but you don't have the correct simplified theoretical model. In reality all the particles of the Earth have gravity and they don't all have the same density which makes a simplified model inaccurate, but let's look at what a simplified model predicts.

But. As the ground of the Earth grew further from the centre. The Gravity would be weaker. At the surface.

The greater the altitude. The weaker the Gravity.

It's true that gravity gets weaker with the inverse square of the distance to the center (the radius), but how does the mass increase with the increasing radius? What's the formula for the volume of a sphere? Assuming everything is the same density (not a good assumption in reality but again let's look at the simplified model which assumes that), as the radius increases, mass increases with the cube of the radius, right? And the cube of the radius beats the inverse square of the radius, so gravity would increase as the radius increases in the simplified model.

In reality, I don't know the average density of the debris landing on the Earth, but I did some back of the envelope rough calculations to see the effects of adding various densities of mass to the Earth. If the density of the added material is the same as the Earth, 5.5 g/cc, then gravity increases when mass is added.

The current average radius of the Earth is about 6371 km. I made a simple model of Earth with radius 6300 km, density of 5.5 g/cc, and then I added 100 km lower density material to bring the Earth radius to 6400 km. If I did my math right, if the density of the extra 100 km radius is roughly 3.03 g/cc then surface gravity will be about the same. So, if density is greater than that, gravity increases with the extra mass, and if density is lower than that, gravity decreases with the extra mass. It's not an exact calculation, since the density of the Earth isn't exactly 5.5 g/cc etc, but it gives me some idea.

I know there are iron meteorites with much higher densities than 3, but I also know the cosmic dust can have densities much lower than 3, but I don't know how it all averages out.

Density of Meteoroids and their mass influx on Earth

That article says the Earth gets about 40 tons a day of additional mass from various objects with densities ranging from 0.1 to 8, but it doesn't state any overall average density. I wouldn't be surprised if the average density of the meteoroids discussed was in the range of 3-4, but that's just a guess and perhaps the authors don't know the true average density of that 40 tons a day?

Look up Membrane theory, it has some interesting implications that may mean that many so called fixed laws of physics such as the force of gravity may be variable over time, this is not down to the earth however but more down to interactions between brane universe's in super-space as they collide and come into and out of contact with one another.

However from a fixed perspective no and yes, the earth is slowly getting heavier as it accumulate millions of ton's of space dust every year most of which burns up in the upper atmosphere, it means' that the earth is imperceptibly to us and over a long time period getting ever larger but only by a minuscule amount since the majority of the dust in our solar system long ago got dragged into the planets or blown away by the solar wind that come's off of the sun itself but remember the planets formed from such dust and gravel when it was more plentiful and formed what is known as an accretion disc around our sun.

Though that accretion disc is more or less gone some dust still remain's and periodically falls into the planets gravity well's getting pulled down to add to there mass, this increase in mass even in a static universe model mean's that the earth is slowly getting bigger so it is slowly getting more and more gravity as a result.

Yeah, I always thought the gravity would have increased with the earth impact events. The different densities of the impact materials. Imagine the earth being impacted with a meteor of gold or a huge comet or a fragment of a brown dwarf star that didn't pass through and was absorbed. So with the less gravity the dinosaurs would have been able to easily stand and fly. I always envisioned before the impact events, the dinosaurs lived on a planet mostly covered in shallow water and their tale was used to help them maneuver better in the water.

a reply to: Arbitrageur

Thanks Arbitrageur for more explanation.

I was simplifying my reply.

I had only read this page when i replied. My bad.

As i said. The greater the altitude. The weaker the effect of Gravity at the surface. Gravity changes by location.

The Earth is constantly changing. For example. When a mountain range forms. The effect of Gravity would be weaker higher up the mountains than before they formed at closer to sea level.

Even without added mass. The effect of Gravity would change by location over time as different events occurred to the Earth.

Maybe i should have read the OP first.

Thanks.

a reply to: blackcrowe

The Earth is constantly changing. For example. When a mountain range forms. The effect of Gravity would be weaker higher up the mountains than before they formed at closer to sea level.

That sort of depends on the circumstances. The mass of the mountain itself produces gravity so for gravity to be weaker the mountain would have to be high enough to overcome that effect.

a reply to: Phage

Thanks Phage.

That sort of depends on the circumstances. The mass of the mountain itself produces gravity so for gravity to be weaker the mountain would have to be high enough to overcome that effect.

The Earths surface bulges at the Equator and has slightly different Gravity than at the Poles.

Gravity is greater towards the Poles.

It is slightly different all around the Earth. And, depending on your location.

If you gain altitude. You would experience less Gravity.

How much depends on the altitude.

As i already said. I didn't read the OP first. My bad.

a reply to: blackcrowe

The Earths surface bulges at the Equator and has slightly different Gravity than at the Poles.

The bulge is very slight and again, you have more mass under you than you do at the poles. The net force of gravity is less at the equator due mostly to Earth's rotation, "centrifugal force" counteracts gravity a bit. You'd be a pound or so lighter at the equator than at a pole because of it.

If you gain altitude. You would experience less Gravity.

For sure. If there isn't the mass of a mountain beneath you. If there is, it makes it a little more complicated.

a reply to: Phage

The measurable difference of a change in Gravity would only be slight. As you suggest. And i also said slightly different.

For sure. If there isn't the mass of a mountain beneath you. If there is, it makes it a little more complicated.

Why?

The mountain range was an example. Maybe not a good choice. But, i thought was enough.

It doesn't matter where your location. If you gain altitude. Gravity is slightly weaker.

a reply to: blackcrowe

Why?

Because the mountain has mass.