Mass in Outter Space?
stevebzzzzz
Posts: 38
OK, this is off the wall...but I was wondering this...
We all know what happens when you throw a baseball on the moon. The mass is a lot less, and it flies a lot further. But there is still mass on the moon. What about this scenario:
You are in Deep Space, and floating along side a station. Neither one of you has mass. Now, Imagine in theory, that you are somehow held in place...don't ask how...
If the space station had a handle, would you be able to grab it by the handle, and fling it around like a toy? Would there be any resistance? Could you hurl the space station like a baseball. Now remember, you are being held in place by something (Theory)...
What do you think?
We all know what happens when you throw a baseball on the moon. The mass is a lot less, and it flies a lot further. But there is still mass on the moon. What about this scenario:
You are in Deep Space, and floating along side a station. Neither one of you has mass. Now, Imagine in theory, that you are somehow held in place...don't ask how...
If the space station had a handle, would you be able to grab it by the handle, and fling it around like a toy? Would there be any resistance? Could you hurl the space station like a baseball. Now remember, you are being held in place by something (Theory)...
What do you think?
Comments
Another example: If you run into a wall here at the earth at, say, 20km/h, it will hurt a lot. Due to your mass. If you run into a wall at the same speed on the moon, it'll be exactly the same.
-Tor
I'm astounded. I have no idea how old you might be but is it really possible they have stopped teaching basic physics in school since I left in 1975?
Unfortunately Albert Einstein says no.
-- Gordon
As others are pointing out, the mass of the baseball is the same on the moon or the Earth or in deep space.
This kind of stuff is pretty well understood.
Duane
Unlike the game show...I am NOT smarter than a fifth grader
Actually, I think I got the idea of how mass is typically measured in it's most simplistic state, with a balance. So if on the moon, two 1KG weights placed on opposite sides of a scale, would balance out. Or 1KG of moon rock and a 1KG weight would balance out, just as it would on earth. But in deep space, with no gravity...how could you measure mass?
"It wasn't heavy but it sure was massive."
Well, something like that.
Duane
You know those spring scales for weighing (not massing) fish?
Use one of those scales with a string out to your unknown mass. Swing the mass around at the end of the string. Measure the speed and length of string. Do math. Determine mass.
Edit: Kg are units of mass. N (Newtons) are units of force (weight).
-Phil
??? Haha!
For large bodies, you could measure the amount of gravity the body generates by using a gravimeter. For smaller bodies, you could place the mass at the end of a spring and, after stretching it out, observe the frequency of vibration: larger masses would cause the spring + mass system to oscillate slower than smaller masses.
Well, you CAN divide by zero, it's just that the result is meaningless!
Anyway, taking this to more esoterica than necessary, E = mc2 is for rest mass. By their nature photons are never at rest. As I recall the theory of relativity suggests photons have momentum, but no mass. This is stretching my feeble memory, but I believe the more generally accepted formula to use for photons is E^2 = p^2c^2 + m^2c^4 (the 2's and 4's are superscripted, of course).
I've asked the beam of light coming from my pocket laser to confirm my formula, but so far nothing. I guess to a photon I'm standing still, so it chooses to ignore me.
-- Gordon
Photons have mass, they have zero rest-mass. But since they are never at rest this doesn't really cause problems!
E=mc^2 is universal, your equation is not just for photons. Your equation is relating total energy to rest energy and momentum, BTW: E^2 = p^2c^2 + m0^2c^4 - for a photon p=mc, and m0=0, so E^2 = m^2c^4, take square roots on both sides.
I think that same equation is related to (or a restatement of) the Lorentz transform. See a couple of papers published by Eistein in 1905
The forum software lets you insert superscripts, e.g. [noparse]E = mc2[/noparse] produces E = mc2.
-Phil
@Phil - Your knowledge is massive.
but two n's in inner.
Researching the mass of the "arm" that the Space Shuttle used to secure orbiting satellites will dispense with the "flinging space stations with handles as though they were toys" folly.
Except...When Newton invented the differential calculus he seemed to be dividing by zero quite handily.
To get the slope a curve y=x2, for example, he takes a little change in x, dx, and a little change in y, dy. The slope is then dx/dy.
Problem is that to get the accurate slope of the curve at a particular point you have to make dy and dx vanishingly small as you home in on the point. Then slope = dx/dy = 0/0. At which point I guess most mathematicians gave up (Well, except Liebnitz apparently).
But no, Newton wriggles around it and gets the correct answer that the slope of y=x2 at any point along x is given by: slope = 2x.
Magic!
Otherwise it would be prounounced "eye-nar".
@stevebzzzz
But as for the mass in space posting, I would argue that you could "fling it around like a toy", depending on the mass of the space station and how much force you can bring to bear on it. If you are asking if the normal average human, unassisted, could move a space station (the size or large than the ISS...or even the space shuttle), then it seems unlikely....but I could picture some nifty ways that could work so it is in the realm of possibility (like a rogue space man launched through space at high speed, latching onto a nearby space station as he flies by...).
As two other posts alluded to; watch some of the shuttle mission footage (now history) of astronauts moving communications satellites around, though...pretty cool stuff. If they were on earth they could not do such things.