If space is a vacuum, wouldn't spacecrafts implode rather than explode?
453743
To allow any astronauts  on board to breathe, the cabin would be be pressurized with a breathable atmosphere.  This internal pressure would be greater than the (very tiny) pressure outside the spacecraft.  And just like increasing the pressure inside a balloon by blowing into it causes it to expand, this increased pressure inside the spacecraft would, if there was a catastrophic failure of some kind, cause the space craft to explode rather than implode.  The exact opposite happens to submarines that are deep underwater.  If something happens to a submarine at depth, it will implode as the pressure of the water around it is greater than the pressure of the interior spaces.
18207
You have the right idea, but you actually can fire a gun in space. What causes a gun to fire is actually the sudden impulse delivered by the trigger to the gunpowder causing the gun powder to explode, transferring a lot of energy to the bullet and causing it to shoot out of the barrel of the gun. In order to trigger the explosion of the gun powder, you do need an oxidizer to initiate the chemical reaction, but most gun ammunition comes with its own oxidizer built in so therefore, the gun can fire even without oxygen.  \n\nHowever, you shouldn't believe anything physics-related you see in movies,  What's funny is those huge explosions that happen all the time win movies in space with no oxygen like in star wars and armegeddon.  That definately could not happen.  Being a physics major has ruined my appreciation for movies really, I can't watch one without picking out all of the physics mistakes--and there are a LOT, and not just in space movies.  They should employ a physicist to stand by and tell them what they screw up.  Actually, I wish they did, that would be an awesome job haha.
677264
I just answered this on another question.\n\nActually, there is no such thing as a true vacuum...Period!\nA true vacuum has never been created, anywhere, where the atomic count is zero.\nThere is always atomic content left to fill the "vacuous" space. No one has ever been able to creat a true vacuum.\n\nContrary to popular belief, empty space is not empty, and it is certainly not a vacuum. \nresearch it, its true.\n"Empty" space actually contains an average of 1 hydrogen atom for every 32 cubic centimeters of space, this data is per NASA.\n\nIn our own Milky Way, space is more dense with 1 hydrogen atom for every 1 cubic centimeter.\n\nAs of today, light has NEVER been propagated through a true empty vacuum. \n\nOne day the misinformation of space, or anything else, as a vacuum will finally die out.\n\nSpread the knowledge
238439
Yeah, it's not a jet where air is pushed out.  It is a chemical reaction where chemicals are burned and thrust out the back of the ship.  It's like if you were floating as still as possible in zero G and blew air out hard.  you would move in the opposite direction.  If you held a little bottle of any gas under pressure and opened it, you would move.  Same basic principle. It's not pushing against the surrounding air, it's just pushing away from you regardless of whether it's a vacuum or in air.\n\nIn fact, in air you would get less of a push than you would in a vacuum.
1046649
Space is expanding at an accelerating rate, and carrying everything along with it. The energy that causes this is called dark energy. What it is is unknown, but it may be a property of space itself.\n\nIf it was just the leftover momentum from the big bang, it would gradually slow. The fact that the expansion is accelerating means it's something else.
1097658
"Space air"?\nIt is really hard to decipher what you are trying to ask.\n\n"Space" is pretty close to being a vacuum (for all intensive purposes for us here on Earth), thus there is no "air" in space.\n\nThe concept of there being some type of medium in space which everything travels through (the idea of an "aether", the material which allowed light to propigate through empty space) has since been disproven over well 100 years ago by the Michelson-Morley experiment.
1036106
in space, it is a vaccum.  and on earth, the air pressure keeps your body intact.  there is a lot of pressure coming down upon your body and your body's pressure outward is kept at an equillibrium.  thus preventing you from exploding or imploding, unless you get too deep in the ocean you would implode from the excessive pressure from the water.\n\nin space, a vaccum, there isn't external pressure pushing against the pressure exerted by your body outwards hence causing you to explode.  once you have exploded... if you are far enough from any heat source, you will freeze.  if you are close enough to a heat source you will burn up.\n\nyou can test this vaccum idea by getting a plastic bottle and covering the opening with your mouth.  if you suck and suck really hard the air is removed, hence the bottle will become closer to a vaccum and the outside pressure will crush the less pressured bottle.  but if your tongue or lips are at the tip of the opening, it will hurt b/c that is the pressure from your body pushing outwards towards a less pressured area trying to obtain equilibrium.
402349
Normally you can't fire a bullet in space. Theres no air to burn with the powder.\n\nAssuming you do though, theres nothing to slow the bullet down, it would travel the same speed as it did on earth, and actually further as there is no friction or gravity to slow it down.
897838
Hi. Space is not a complete vacuum. There are a number of hydrogen atoms throughout. A few per cubic meter. But if you think about it, light can reach us through billions of light years of space, so it is a very good vacuum if not a perfect one. And any material should SLOW the light. 'c' is still the fastest speed.
889751
Possible, yes.  Likely, no.  We know the orbits of the satellites we put up pretty well.\n\nHowever, there IS a lot of junk orbiting the Earth - pieces of spacecraft, nuts, bolts, etc - and they are orbiting fast.  Being hit by a fast-moving piece of space trash is something they have to keep in mind and try to account for when building shuttles.
308555
Yes and No, Since a black hole is made of particles, anti-matter could counter and destroy it, on the other hand, most believe it is an actual hole in the fabric of space/time. So can you repair it, not as of yet. 2nd an A-bomb is nothing to a black hole, so it wouldn't do much. 3rd, I've never heard of plasma being able to escape a black hole, theoretical energy, thermal energy, and certain virtual particles are the only thing I know that have been thought that could escape a black hole. 4th, Black holes can merge into 1 really big one, so they continue to live even through themselves.
1057782
If all matter is over 90% empty space, then there should theoretically be small vacuums throughout the entire universe.  However, such a vacuum would be impossible to detect, contain, or sustain.\n\nPerhaps beyond the edge of the universe, a perfect vacuum exists.  All the matter/energy ever can only take up so much space.  However, there is no way to observe or reach that vacuum either.\n\nMmmm... uncertainty!
463058
Planets aren't directly formed from explosions and whatnot, they are formed from gravitational accumulation of mass in dust clouds. They are approximately round for the same reason anything that is approximately fluid that experiences a central force is round. Central forces have circular potential energy wells.\nConsider a cubic planet. A mass on the face of such a planet would be experiencing less force than a mass near a corner of such a planet (The corner has a greater amount of non-cancelling mass "behind" it. If you know the divergence theorem, this can be seen as well.). Since less force is exerted on points on the faces than points near the vertex, the vertex will slowly collapse if the mass is great enough, easily pushing the points on the faces outwards until an equilibrium is reached. This thought experiment works for any polyhedron, with the sphere being the limiting shape. Once the shape is approximately spherical, it is a well known proof that the force experienced by a particle outside the sphere will be the same as the force if the sphere was a point mass at the center of the central force, giving us back the circular potential energy map.
197354
Not to my knowledge but it is an interesting idea. We know that the solarwind pushes on Earths magnetosphere with tremendous force. A spaceship with a magnetic bubble around it would also experience that force which should yield some thrust. The farther from the sun you get the weaker the thrust gets. It should be easy enough to compensate for this by simply expanding the magnetic bubble. \nSuch articficial magnetospheres will probably become standard for spacecraft destined for very longterm missions in the near future. They may not be able to provide all the thrust the spacecraft needs (you might want to inwards in the solarsytem too...) but it could provide valuable extra protection from highenergy particles for the astronauts inside.\n\nThe other way of magnetic propulsion is MagLev, or magnetic levitation. It is used for highspeed trains here on earth. Such a train on, say, the Moon with its absence of an atmosphere should be able to reach escape velocity (2.4 km/s for the moon) and get launched into space with only the electricity needed to run the MagLev track as a propellant.
1126516
Yes, but there will be no sound, because of the vacuum.  It would explode with light, heat and radiation but little else.
834717
It depends what you mean by small and volume.\n\nIf by small you mean mass, then for a black hole to form spontaneously by gravitational collapse it requires a minimum of around 6 solar masses (6 times the mass of our sun). In principle you could forcibly compress matter to form a smaller black hole, but in practice it is not clear how - or whether - you could do this.\n\nVolume is more complex. If you mean the volume contained by the Schwarzchild radius (or event horizon) then this can be very large indeed - many times the volume of our solar system for the black hole belived to be at the centre of the galaxy. \n\nIf you mean the volume of the collapsed matter, then this is zero, because a black hole is a singularity.
453550
It is an incorrect concept that space is full of nothing.  There are dust particles and gas molecules in space.  The solar wind from our sun is always blowing particles into space.  There is also a galactic wind that is blowing particles out into space as well.\n\nSpace is as close as we can get to natural vacuum, or nothingness but it still has a density of one atom per cubic meter.