What if the gravity on earth increased?

[Crown]

Not that I am a civil engineer or anything, but with Aerospace when we design a plane strcuture we factor in a safety factor of 1.5-2. Meaning that if civil engineers did the same, as well as mechanical engineers, our buildings should still be around. Wouldn't be as 'safe' as before obviously since it will now be operating in or on the saftey factor but there you have it.

9G-10Gs is the maximum a human being can sustain before, well bad things happen. However over short periods (sever hundreds of a second) the human body can cope with thousand G's. Much like professional Rugby/Gritiron players.

My thoughts for the day.

[Tsyroc]

Just imagine all the extra stress on wonderbras and breast implants.

[Vympel]

I thought the moon was the original pure evil from the Fifth Element?

[XaLEv]

I thought the moon was the original pure evil from the Fifth Element?

You'd think that, but if it happens every five thousand years, we should have a whole hell of a lot of moons. Unless some of them are stopped way the hell out there and only two have ever gotten close.



Anyway, you could also expect massive landslides in hilly or mountainous areas.

[Darth Wong]

Not that I am a civil engineer or anything, but with Aerospace when we design a plane strcuture we factor in a safety factor of 1.5-2. Meaning that if civil engineers did the same, as well as mechanical engineers, our buildings should still be around. Wouldn't be as 'safe' as before obviously since it will now be operating in or on the saftey factor but there you have it.

Keep in mind, however, that this safety factor is intended to compensate for variability, unpredictability, etc; it does not mean that every structure is precisely 1.5 times stronger than it needs to be. I think we would probably see a vastly increased rate of structural collapses and problems, some right away and some over a longer period of time, although I'd agree we wouldn't see every building collapse right away.

You would also see a vastly increased rate of spinal-chord injuries. Certain forms of exercise such as jogging would become extremely difficult to endure, leading to increased rates of serious joint injuries, particularly in the knees. That is in addition to the huge number of heart failures you would see; all obese people would probably croak in short order.

As previously mentioned, the aerospace industry would be massively fucked. Not only would the planes require structural reinforcement to hold together, but they would also need 1.5 times as much aerodynamic lift to stay in the air. ICBM's would have to be re-designed. And the energy requirement to reach escape velocity would increase by 1.5, which would be a huge problem for the space industry.

Also, people would become dumber (I'm not kidding). The increased gravity would decrease the amount of blood reaching the brain for any given amount of heart activity. Over prolonged periods of time, this would probably lead to a significant decrease in the overall reasoning abilities of the average person. Only those with very powerful heart action would be able to compensate, unless they make a point of remaining in a prone position most of the time. Therefore, I would expect religious fundamentalism and gangsta rap to continue increasing in popularity.

However, the biggest problem would probably be from the Earth itself. The increased gravitational constant would probably cause the planet to compress significantly, which would in turn cause massive seismic problems, disruption of tectonic plates, etc., and probably kill everyone on the surface, thus making all of the above points moot. Moreover, the gravitational potential energy of the planet would become 1.5 times its current magnitude, so we would have roughly 1.2E32 J of energy being released, probably in the form of heat. This would melt the entire surface and boil off the oceans in a flash.

In short, we'd be fucked. So it's a good thing that it won't happen.

[Andrew J.]

If it went on long enough, natural selection would produce people with stronger hearts, yes?

[Darth Wong]

If it went on long enough, natural selection would produce people with stronger hearts, yes?

That's somewhat moot since the entire surface will be vapourized, isn't it?

[His Divine Shadow]

If it went on long enough, natural selection would produce people with stronger hearts, yes?

That's somewhat moot since the entire surface will be vapourized, isn't it?

Well if it took like a 100 million years, then it could go slow enough not to vaporize the surface.

I think, I'm just babbling.

[Andrew J.]

If it went on long enough, natural selection would produce people with stronger hearts, yes?

That's somewhat moot since the entire surface will be vapourized, isn't it?

Oh, okay.

[Darth Wong]

The scenario calls for a 24-hour timeframe. By the way, one other consequence: the Sun would heat up. It might even undergo some kind of nova, or at the very least, extremely violent activity. Not that this would matter to the vapourized inhabitants of Earth, of course ...

[His Divine Shadow]

The scenario calls for a 24-hour timeframe. By the way, one other consequence: the Sun would heat up. It might even undergo some kind of nova, or at the very least, extremely violent activity. Not that this would matter to the vapourized inhabitants of Earth, of course ...

Well, I was merely asking a what-if

[Durandal]

Moreover, the gravitational potential energy of the planet would become 1.5 times its current magnitude, so we would have roughly 1.2E32 J of energy being released, probably in the form of heat. This would melt the entire surface and boil off the oceans in a flash.

How do you figure? This would be true if the gravitational constant decreased -- you'd have less binding energy, and thus the differential energy would have to go somewhere, but an increase in the gravitational constant would force an intake of energy from somewhere.

An increase in the gravitational constant would also have profound impacts on the speed of light, mass-energy equivalence, space-time curvature and just about anything else you can think of. The universe may even reverse its expansion and begin to contract. An increase in the gravitational constant would also completely redefine the potential energy levels in orbital systems (yes, there are discrete orbitals in a gravitational system, just like an atomic one; the difference between the levels just happens to be very small) like binary stars (which make up a good percentage of star systems), galaxies, superclusters and the like.

[Darth Wong]

Huh? An increase in the gravitational constant would make the GPE of the system increase in a negative direction (the binding energy is negative), so it would release energy.

Anyway, yes, it would have all sorts of side-effects as you mention. But I'm not sure how else the Earth's gravity is supposed to become 1.5 times stronger. Not unless somebody compresses the planet so that the surface is closer to the centre of gravity, and that would be pretty destructive too

[Slartibartfast]

I know it's kinda crazy but what if it increased without explanation from 1G to 1.5G in the timespan of 24 hours?
How would the world be affected, and how would it cope with this change?

Everything would become heavier

Also, same question, but with 2G's

Everything would become twice as heavy

[Larz]

I would be dead either way... no way in hell do I need nor want to wiegh 420 lbs...

[BlkbrryTheGreat]

You could probably increase the gravity of a planet by using the artificalgravity generators found in so many Sci Fi shows (they dont exist though). It would probably require a large amount of energy to do this though. (Not that you would want to.... though this would be an interesting idea for a Sci Fi planet killer......)

[Slartibartfast]

The snack food industries would go out of business because all of their customers would be dead.

I've heard we are slowly losing the Moon on the Discovery Channel is that true?

Yes, the Moon will be gone in several trillion years *PANICS*

[His Divine Shadow]

Yes, the Moon will be gone in several trillion years *PANICS*

No time to loose.

[Durandal]

Huh? An increase in the gravitational constant would make the GPE of the system increase in a negative direction (the binding energy is negative), so it would release energy.

Damn negative signs. Damn them to Hell.

[Crown]

Totally of topic; But to all the engineers out there, for solid mechanics (beam theory) did you all use compression as negative sign convention or is that just me?

[Darth Wong]

Totally of topic; But to all the engineers out there, for solid mechanics (beam theory) did you all use compression as negative sign convention or is that just me?

Assuming you're referring to structural stress analysis (terminology doesn't always make it across the ocean intact), it really doesn't matter which way you do it. From an energy standpoint, it should be positive regardless of direction, because a beam in compression or tension has positive potential energy. When I was in school, we just referred to "deflection" rather than compression or tension anyway, since pure compression or pure tension are somewhat theoretical, rather than practical concerns (a real loaded member will typically have significant compression, tension, and shear simultaneously).

[David]

If it went on long enough, natural selection would produce people with stronger hearts, yes?

No, no matter what a person's genetic makeup, muscles increase or decrease in strength according to how they are used. For example, two bodybuilders could have a whimpy kid if the kid never exercised.

[Darth Wong]

If it went on long enough, natural selection would produce people with stronger hearts, yes?

No, no matter what a person's genetic makeup, muscles increase or decrease in strength according to how they are used. For example, two bodybuilders could have a whimpy kid if the kid never exercised.

Actually, it's a combination of both genetics and conditioning. If the human race weren't vapourized (thus making all of this moot), it would indeed change and evolve. Mind you, we're always evolving, and a massive environmental change would greatly accelerate that process.