How close could you get to the speed of light due to acceleration by falling into or being in a decaying orbit around a large gravity well (black hole?) [more inside]
I was stumbling around trying to explain to someone that sometimes a black hole is created at the end of a star's life cycle. And they said.... [more inside]
At the same instant, The three year old fan drops the autographed ball Sandy gave him before the game from the same exact height that Sandy released his pitch. Which one will hit the ground first? [more inside]
I'm sure you've all seen the quite obvious and silly "gravity will fail" hoax. It got me wondering...if all the planets, stars, asteroids, comets, black holes, etc (basically all known physical matter) were to somehow align on one side of the planet would the cumulative gravity exceed Earth's? I asked my dad (a doctor of nuclear chemistry) and he was stumped. Exclude dark matter for these purposes.
As a by-product of this FPP about a very large water slide, have just been involved in an inconclusive and heated argument about the physics aspects. Hypothetically, what would happen if, halfway down this very fast waterslide in a raft, you (accidentally or deliberately, it doesn't matter) defecated? [more inside]
Watching the video from this FPP got me wondering. There are countless scenes in movie and TV shows that depict somebody shooting somebody else and that person falling to the ground dead from a rooftop, ledge, etc. (and possibly Wilhelm screaming on the way). Are there any examples where the shooter/killer keeps firing at the gravity-stricken victim while they fall?
After watching Gravity and Europa Report I started to wonder what would happen to an astronaut's body if they floated off in space. Googling reveals information about how long they'd be able to breathe (~8 hours) and that we have little jet packs that can help people maneuver, but nothing about what would happen over thousands or millions of years, assuming there's no way to rescue the astronaut alive or dead and they drift off into outer space, say on an interplanetary mission and not near the Earth's atmosphere to be burned up. [more inside]
I have a question about the film, Gravity, and the geography of its ending. Obviously there are major spoilers if you click through. [more inside]
I just saw Gravity this weekend... [more inside]
Until last night I was unaware that the hollow earth conspiracy was a thing. Since then, I've been driven crazy by trying to imagine the physics of it. What would gravity be like on a shell planet? Details about the exact setup within. [more inside]
I'm looking for a short book or series of books for my 7.5 year old son describing the history of the search to explain planetary motion. [more inside]
My dad built a proper pedestal for our new washing machine and dryer. It is 19 inches high. The challenge is getting the washer up onto the pedestal. The washer weighs 232 lbs. It is just the two of us today. I don't want to throw my back out. Neither does he. What equipment or physics tricks can we employ to get this thing up on the pedestal?
Work in my office has ground to a halt over this question about the physics of fish in space. [more inside]
Settle an argument. A 150 person falls and grabs something as they do. Assuming they have kung-fu grip, how much weight does the thing they grab need to be able to withstand without tearing, breaking, whatever. I say the weight of the person. They say it's their weight and g-forces combined. Who is right and if they are, how do you calculate those g-forces? And if they are twisting as they fall, does torque figure into it?
Could mining the moon destroy the oceans? [more inside]
Would artificial gravity be enough to contain an atmosphere? [more inside]
What's the best way to build a Wordpress feature allowing users to contribute content along the lines of recipes? [more inside]
I have a perfectly spherical lead weight that weighs 1 kilogram. I drop it from the surface of the ocean directly into the Mariana Trench. How long does it take to hit the bottom, and how fast is it traveling when it hits? [more inside]
It's the future and humans live in space stations. What are some ways (real or fictional) that artificial gravity can be created so there will be no weightlessness? [more inside]
The strong nuclear force is ≈10^39 times as strong as gravity. It takes ≈10^39 protons to make a black hole with a Schwarzschild radius about the size of a proton. That's not just a coincidence, right? Why? [more inside]
Help me use a hydrometer to make the perfect sorbet [more inside]
Is my conception of gravity deeply flawed, or is this bad terminology? [more inside]
a "thought experiment" on gravity: Pretend you could "teleport" a huge mass such as the sun into "empty outer space". How long would it take for the gravitational force to reach a distance such as the distance from the earth to the sun?
Wubbo Ockels blew up my brain. Does anyone who actually understands physics have an an educated take on his theory of time and gravity? [more inside]
Is there any way that major fluctuations in the Earth's climate could have an effect on the temperature of the Earth's core? What about its density? Could temperature changes cause some sort of change in the planet's gravity or magnetic fields? Could changing weather have any other effect on the Earth's interior? [more inside]
How was it proved that gravitation was a function of mass? [more inside]
Would it be possible to have a planet with significantly more surface area than the earth and similar gravity (at ground level) by decreasing its density? [more inside]
With the advent of NASA's return to the moon I have a question of whether or not The Apollo astronauts could have recovered from a less than perfect landing. [more inside]
Fictional gravity: Let's say I was the complete master of all things gravity and I wanted to hurl a person into the sun. [more inside]
If my working desk were in space, would I still experience tensions in my back? [more inside]
What is the contradiction in the discussion of gravitational forces in the ... [more inside]
If the earth's gravity was increased by 10%, would sprint runners be slower or faster? [more inside]
Would Tai Chi work in outer space? [more inside]
What are those things called that you see on badge clips and rock climbing walls that automatically retract a nylon cord? [more inside]
Why is the Big Bang possible? [more inside]
You know the playground trick whereby four of you can "levitate" a fifth person using just your fingertips (you first hold your hands over his head and count to 20)? How does that work, then?
How would a metal bar built around the world react to gravity? [more inside]
Imagine a world in which the atmospheric density is somewhat greater than ours, but gravity is somewhat lower. How might our experience be different on that world? [more inside]
Does gravity make small pools of water curve slightly (I’m thinking a small lake size) or is surface tension enough to flatten it out? More importantly - how would I calculate whether the resistance from the surface tension is enough to keep it flat and when/what size that breaks off? [more inside]
Has anyone ever had sex in space? [more inside]
Why do videogames with physics simulation always have things fall too slowly? [more inside]
If General Relativity is accepted as true, why do Physicists talk about (and look for) Gravitons? [more inside]
Gravity/Life/SocietyFilter: So the Earth is all lumpy, with more or less gravity in some places. Has anyone ever corroborated it with life/social/world things? Many questions inside... [more inside]
Science hour question: My niece asked me this and I didn't have a good answer. People in orbit around the earth are "weightless." But what would happen if an object in space were kept stationary at 150-200 miles up? Would an astronaut in such a stationary but very high station in fact feel significant gravity? Is "weightlessness" (in near-Earth space) an artifact of a free-fall orbit? C'mon rocket scientists, I know you're out there.
If the sun's gravity is so strong as to keep whole planets circling it in orbit, how come light and heat can escape?
ScientificIlliterateFilter: If the sun's gravity is so strong as to keep whole planets circling it in orbit (even ones million of miles away), how come light and heat (incredibly fragile things compared to planets) can escape as rays (or whatever they are)?