## Acceleration due to gravity

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?)
posted by blue_beetle on Aug 12, 2016 - 12 answers

## If Light Can't Escape a Black Hole, Why Not Stars of the Same Mass?

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....
posted by justcorbly on Feb 19, 2016 - 13 answers

## Sandy Koufax throws a fast ball... perfectly straight and level....

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?
posted by Jim_Jam on Jan 22, 2016 - 20 answers

## Gravity fail

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.
posted by karst on Jan 6, 2015 - 24 answers

## Poo vs Gravity

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?
posted by Wordshore on May 20, 2014 - 13 answers

## Bad Guy + Gravity = Swiss Cheese

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?
posted by schleppo on Feb 17, 2014 - 4 answers

## What would happen to an astronaut if they floated off in space?

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.
posted by UltraFleece on Dec 29, 2013 - 10 answers

## Help me track down a fictional landing site?

I have a question about the film, Gravity, and the geography of its ending. Obviously there are major spoilers if you click through.
posted by Narrative Priorities on Dec 18, 2013 - 11 answers

## Gravity. Fact check. Potential Spoilers.

I just saw Gravity this weekend...
posted by mazola on Oct 20, 2013 - 14 answers

## Hollow Earth Physics

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.
posted by odinsdream on Aug 17, 2013 - 25 answers

## History of the science of planetary motion for kids

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.
posted by alms on Aug 5, 2013 - 6 answers

## Lifting a Washing Machine onto Pedestal

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?
posted by jasondigitized on Feb 17, 2013 - 16 answers

## FISH IN SPAAAAAACE!

Work in my office has ground to a halt over this question about the physics of fish in space.
posted by stuck on an island on Nov 20, 2012 - 28 answers

## How heavy is it, really?

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?
posted by CollectiveMind on Aug 5, 2012 - 25 answers

## What would happen if large-scale lunar mining operations became commonplace?

Could mining the moon destroy the oceans?
posted by asnider on Feb 27, 2012 - 12 answers

## Gravity of the situation

Would artificial gravity be enough to contain an atmosphere?
posted by fimbulvetr on Feb 24, 2012 - 21 answers

## How to let Wordpress readers submit recipes or other content?

What's the best way to build a Wordpress feature allowing users to contribute content along the lines of recipes?
posted by steinsaltz on Dec 16, 2011 - 14 answers

## Water dissolving and water removing. There is water at the bottom of the ocean.

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?
posted by Cool Papa Bell on May 10, 2011 - 24 answers

## Earth gravity in space? How hard could it be...

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?
posted by thejrt on Apr 27, 2011 - 18 answers

## Is this where I'm supposed to use the phrase "self-appointed defender of the orthodoxy"?

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?
posted by Kid Charlemagne on Mar 30, 2011 - 11 answers

## Sorbet making with hydrometer

Help me use a hydrometer to make the perfect sorbet

## Does gravity really "attract"?

Is my conception of gravity deeply flawed, or is this bad terminology?
posted by curious nu on Oct 23, 2010 - 21 answers

## speed of gravity

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?
posted by santogold on Jun 25, 2010 - 12 answers

## Is Wubbo Ockels a crank or a genius?

Wubbo Ockels blew up my brain. Does anyone who actually understands physics have an an educated take on his theory of time and gravity?
posted by evariste on May 16, 2010 - 11 answers

## "That could never happen." "It so totally could!"

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?
posted by Captain Cardanthian! on Feb 28, 2010 - 12 answers

## How was it proved that mass exerts the gravitic forces?

How was it proved that gravitation was a function of mass?
posted by Lorc on Jul 6, 2009 - 10 answers

## Could there be a planet so big that it is bigger than itself?

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?
posted by blue_beetle on Jun 18, 2009 - 5 answers

## Strong man in the moon?

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.
posted by Gungho on Jun 18, 2009 - 19 answers

## I'm going to throw you right into the sun.

Fictional gravity: Let's say I was the complete master of all things gravity and I wanted to hurl a person into the sun.
posted by Cool Papa Bell on Apr 15, 2009 - 41 answers

## Muscle tensions in space?

If my working desk were in space, would I still experience tensions in my back?
posted by jfricke on Mar 23, 2009 - 8 answers

## There's a problem with (my understanding of) gravity.

What is the contradiction in the discussion of gravitational forces in the ...
posted by woodblock100 on Jan 17, 2009 - 26 answers

## Sprinting in high G

If the earth's gravity was increased by 10%, would sprint runners be slower or faster?
posted by IvyMike on Aug 25, 2008 - 49 answers

## Tai Chi in zero-g?

Would Tai Chi work in outer space?
posted by nímwunnan on Aug 5, 2008 - 6 answers

## Help me avoid gravity...somewhat.

What are those things called that you see on badge clips and rock climbing walls that automatically retract a nylon cord?
posted by ostranenie on May 21, 2008 - 10 answers

## Big Bang Baffles Bonzai

Why is the Big Bang possible?
posted by Bonzai on Feb 20, 2008 - 24 answers

## What mystical powers do four kids have?

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?
posted by bonaldi on Nov 21, 2007 - 20 answers

## How would a metal bar built around the world react to gravity?

How would a metal bar built around the world react to gravity?
posted by studentbaker on Nov 1, 2007 - 36 answers

## Thicker air and lower gravity

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?
posted by Ritchie on Jan 8, 2007 - 16 answers

## How do you get a flat surface of water?

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?
posted by Smedleyman on Oct 11, 2006 - 19 answers

## Sex in Space?

Has anyone ever had sex in space?
posted by blueplasticfish on Sep 22, 2006 - 41 answers

## Life on the moon!

Why do videogames with physics simulation always have things fall too slowly?
posted by terpsichoria on Apr 25, 2006 - 16 answers

## Gravity and relativity.

If General Relativity is accepted as true, why do Physicists talk about (and look for) Gravitons?
posted by grahamwell on Mar 28, 2006 - 14 answers

## Lumpy Earth---gravity's effects on us?

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...
posted by amberglow on Feb 18, 2006 - 33 answers

## Guess the number and win a sculpture!

How does this work?
posted by ~rschram on Mar 10, 2005 - 15 answers

## Is "weightlessness" an artifact of a free-fall orbit?

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.
posted by socratic on Dec 12, 2004 - 20 answers

## 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)?
posted by amberglow on Nov 14, 2004 - 53 answers

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