Do us humans have our own gravity?

[Mormolyce]

F=GmM/r^2

Where G = 6.67384*10^-11, m and M are the two masses and r is the distance between them.

So if you're 1m away from me, assuming we both weigh 80kg then we have a gravitational force of 4*10^-7N, or 0.4 of a millionth of a Newton. By contrast, the gravitational force of the earth is about 9.8N.

- - - Updated - - -

How are you guys so smart... I was tested to be above average in high school, yet a decent bit of stuff even from the cave man Cosmos show leaves me drawing blanks. Do you know all of this because you are passionate about it and read up on it, or are you so smart you get it the first time you gear it. After a minute or so of straight information my brain blanks out and I forget anything else I heard, or do not understand it.

To retain information you must be interested in it.

In fact the human mind is essentially designed to remember stories. That's why you can't remember half the things they teach you at school but you know the entire plot of [insert favourite movie/TV show/book/video game here]. If you can turn the thing you're trying to remember into a story, you'll remember it.

(Also, I forget lots of details so that's where Google comes in :P)

[Zaqwert]

Everything with mass has gravity. It's just very miniscule for small amounts of mass.

[Chickat]

While I do watch a lot of sciency things on the Internet (SciShow, Fermilab, etc) or TV (Cosmos, Through the Wormhole,) the fact that all things with mass have gravity is something I learned in high school physics. This sort of shit fascinates me though, so these facts stay with me. If it weren't for the math, I probably would have tried to become a physicist.

Well I had a bad childhood, and while my IQ was above average, unfortunately my grades were not. I dropped out of School in the 10th grade because of personal family reasons and got my GED a few years later. I wish I had payed more attention in school, but its too late now. I feel like I do not know basic things people should as an adult. I even forget how to divide on paper. How pathetic is that. Anyways, I imagine I would get better with stuff like this if I put more time into it, but not understanding things is a turn off.

- - - Updated - - -

I wonder if a room that removes the gravity from outside but leaves yours intact is possible. I want it made so I can see particles of sand and dust floating around me.

[Nathanyel]

Gravity is just a theory. I believe god pulls things down. Teach the controversy.

No, it's the devil pulling us down towards hell! The development of Antigravitation is the path towards salvation! Until then, pray Zero G Flights become more affordable soon.

I wonder if a room that removes the gravity from outside but leaves yours intact is possible. I want it made so I can see particles of sand and dust floating around me.

Well it's all theory yet, but that's how it is expected, outside influence is cancelled, while gravity generated by objects inside remains. Though, don't expect swarms of particles swirling around you, I'd guess any noticeable speed would be enough to escape your gravity.

[Frozenbeef]

I wonder if you get obese enough it can start to affect things :S

[Arkenaw]

Stay in school kids.

[glo]

Photons don't have mass. Anything that moves at the speed of light cannot have mass. Therefore they don't have gravity (Something with mass cannot move at the speed of light) Everything is affected by gravity, whether it has mass or not.

Mass (in theory) can definitely travel at the speed of light according to special relativity, the initial mass would just become infinite. Big bang kinda stuff.

I even forget how to divide on paper.

I think the vast majority of the adult population forgets how to do that after school. There's no practical use for it in 99.9% of people's lives. Calculators are everywhere now. Even beyond that when you need to solve something simple, most common division can be solved mentally or at least roughly estimated.

[Bepples]

I wonder if you get obese enough it can start to affect things :S

Assuming those objects have an orbital radius of 1 meter and an orbital period of 2 seconds, the objects must be travelling π meters every 2 seconds, or rather they must have an orbital velocity of π/2 meters a second.



So you would have to weigh 3.7*10¹⁰ kilograms. That's 3,700,000,000 kilograms (3.7 billion). This is of course not not counting into account Earth's gravity. Since there are two perpendicular forces here, there would be a torque (not to mention a very strong attraction towards the ground), so you wouldn't have much luck anyway in getting an object to an orbit on the same plane as your center of mass, even if you did weigh 3.7 billion kilograms. It also, of course, assumes that the larger mass is spherical with a uniform density (in gravitation, spherical objects with uniform density can be treated as point masses. In reality, density has a lot of implications as gravitation mostly concerns the center of mass). Also, remember here that this very large mass (still very very small compared to the Earth's mass) must be concentrated in the same, small amount of area since the calculations assume an orbital radius of 1 meter, so the density will be enormous (3.7 billion kilograms, assuming one cubic meter, is pretty simply 3.7 trillion grams per cubic meter. Still only 0.4% of the density of a neutron star!)

Speaking of orbiting, the electrostatic force is much, much stronger than gravity. So you could achieve orbit with everyday objects, but once again Earth's gravity ruins things. In free fall, however, the apparent force of gravity is zero (it is not ACTUALLY zero). This is why in orbiting satellites there appears to be zero gravity. Sure enough:



Note: I am NOT an expert, so don't cite me on any of this. I could very well be wrong somewhere in the post.

- - - Updated - - -

Well I had a bad childhood, and while my IQ was above average, unfortunately my grades were not. I dropped out of School in the 10th grade because of personal family reasons and got my GED a few years later. I wish I had payed more attention in school, but its too late now. I feel like I do not know basic things people should as an adult. I even forget how to divide on paper. How pathetic is that. Anyways, I imagine I would get better with stuff like this if I put more time into it, but not understanding things is a turn off.

You could always take an introductory science course at a university/college and afterwards go on from there. School is not the ONLY chance at pursuing a science career. Even then, you can still be enthusiastic about science without having a science career/tertiary science education. Also, a big part of learning science is not understand much/any of it at first

Also, I don't even think 20% of the people in my physics class at university would still be able to do long division. We have been spoiled by calculators . Long division is only really relevant in factorizing polynomials in the mathematics subjects, but even then it's quite different to the long division done in primary school.

- - - Updated - - -

Mass (in theory) can definitely travel at the speed of light according to special relativity, the initial mass would just become infinite. Big bang kinda stuff.

But infinity is not really a defined, achievable quantity. Most mathematicians would agree that it isn't a number by itself. Mass cannot travel at the same speed as c (this is the speed limit of the universe, not just for light. Gravity also "travels" at c (c = 299,792,458 m/s)).

A simplified explanation of complicated physics (outlined by special relativity): movement occurs in both the spacial dimensions (x, y, z) and also through time. Anything without mass has all its movement in space and none in time (from a photon's perspective, travelling from one end of the universe to another happens in an instant!). Objects with mass have their movement "shared" between time and space. Stationary objects have all their movement through time and none through space.

Basically, objects with mass will always have SOME of their movement through time and thus cannot be moving through space alone; they can never travel at the same speed as stuff like photons because photons have ALL of their movement through space.

[Nihilan]

There's a great "Yo mama" joke in here somewhere. Consider the following. The gravity well of every object with mass exerts a pull on every other object with mass in the universe.

So yes, Yo mama so fat she effects the orbit of stars in the Andromeda galaxy 2.5 million light years away*.

Nailed it.





*Even if it is by an almost infinitesimally small amount.

[Reeve]

To op: anything with mass has gravity.

Photons don't have mass. Anything that moves at the speed of light cannot have mass. Therefore they don't have gravity (Something with mass cannot move at the speed of light) Everything is affected by gravity, whether it has mass or not.

Photons don't have rest mass. They do have inertial mass.

[Annoying]

@FpicEail: That post belongs on /r/theydidthemath

[Nihilan]

Photons don't have rest mass. They do have inertial mass.

This is why they can be used to accelerate or push object in space, e.g. solar sails. Even a flashlight has thrust, a tiny amount sure, but it is there.

[Deleted]

Yea if you send a frozen fat person to space, they can capture all kinds of space junk as tiny moons that will start to orbit them.

[iceberg265]

We cant measure it, but surely it must exist. Also, bacteria and even atoms must have their own gravity right?

Gravity is the reason that protons, neutrons, and electrons stick together to form atoms.

[Deleted]

Gravity is the reason that protons, neutrons, and electrons stick together to form atoms.

It most certainly is not.. i mean seriously? If that was the case wed all fall apart

[Reeve]

Gravity is the reason that protons, neutrons, and electrons stick together to form atoms.

No, it's not.

[Adam Jensen]

Gravity is the reason that protons, neutrons, and electrons stick together to form atoms.

No.

The Strong Force holds the quarks in the protons and neutrons together and holds the protons and neutrons in the nucleus together. The positive charge of the nucleus holds the electrons to the atom via the Electromagnetic Force. The Electromagnetic Force is also responsible for covalent bonds, which forms molecules. Gravity causes these items to clump together and form stars and planets.

[Tirivaria]

Gravity is the reason that protons, neutrons, and electrons stick together to form atoms.

http://en.wikipedia.org/wiki/Strong_interaction

[Adam Jensen]

http://en.wikipedia.org/wiki/Strong_interaction

In fact, without the strong interaction, atoms would tear themselves apart due to the electromagnetic force. Positively charged protons don't wanna hang with each other! They hate each other!

[Tradewind]

In fact, without the strong interaction, atoms would tear themselves apart due to the electromagnetic force. Positively charged protons don't wanna hang with each other! They hate each other!

"stop giving away my secrets Adam."