Can someone explain to me how mass changes as an object approaches the speed of light? Appearently, as an objects velocity increases, its mass does too…and as an object approaches light speed its mass toward infinite. At low speeds the changes seem neglegable…but appearently at higher speeds it becomes substantial. Does this make any sense? But HOW does the mass change? Does the object somehow become bigger? If so, again, how?
Do I have this right? If so, can someone explain it in laymans terms why an object becomes more massive the faster it goes? If this is the case, it seems impossibly to accelerate any object with actual mass anywhere close to light speed…if I have this correct.
This is my second shot in GQ for a question like this. Hoping THIS time to get a response.
(I’m going on the E=M x C(squared) formula and using the M=Mass of an oject at rest divided by 1 minus the velocity of the object squared divided by the speed of light constant squared. Basically as velocity squared approaches the value of the speed of light squared, you essentially get the mass of the object at rest divided by 1-1/1…or the mass of the object at rest divided by zero…thus mass, if I’m understanding this correctly, is infinite as velocity equals the speed of light constant).
The point is that mass is not a fixed quantity, but depends on your reference frame. As I pointed out in your other thread, the object in question does not “notice” a change.
Let’s say you have two guys: XT and XU. XU accelerates to near the speed of light and flies by XT at a constant speed. XT looks at XU and measures a guy with mass increased by the amount of the eqaution in your OP. But, XU measures his own mass as his rest mass and measures XT as having gained in mass by the same amount that XT measures in XU.
It’s all relative to your reference frame. You might very well be travelling at near the speed of light compared to some other point in the universe. Do you feel heavier (or more massive) yet?
i really can’t give you a much better answer than last time unless you make your question much more specific
mass dialtion occurs as momentum must be conserved in all refernce frames the exact derivation is nowhere near as easy as that for deriving time dilation or length contraction from first principles.
Ok, I remember the reference frame part, John. My grasp of this stuff is VERY rusty. So, with respect to myself, if I’m the object thats traveling at near light speed, I don’t notice a change. However, with respect to an outside observer, they would notice a change in mass, correct?
But, to an outside observer, how can mass become infinite as a particle with mass approaches the speed of light?? Wouldn’t an object with mass approaching the speed of light basically fill the entire universe (infinite mass) to an outside observer?? Or, does the theory simply preclude a particle with mass ever going the speed of light, so neatly side steps this aspect??
I’ll look at the other thread MC…I hadn’t noticed that anyone had replied to it, so figured I’d go with this one to see if I could ask the question in a better way (and when I wasn’t drunk) to get a better response.
The answer to your second question is that an objects mass may not be infinite and a massive object must never travel at the speed of light. No an object approaching the speed of light won’t fill the entire universe (as matter of fact it will contract along the axis it is travelling).
Think of mass is just some intrinsic quantity that matter has. There is nothing majic about a given particle having any particualr mass. As you increase in speed, relative to a “stationary” observer, you simply have a different mass. As MC mentioned, there is a change in shape, but the increase in mass is not due to the object getting bigger. Don’t think of mass as some absolute quantity. What you measure depends on your reference frame.
Then I’m still confused. If you use the mass equation I got from my old dusty college second year physics book, won’t you get Mass=Mass of the initial object (a number if the object actually has mass) divided by the square root of 1 minus 1? And, unless I’m misremembering, isn’t any number divided by zero infinity? But what does this infinity MEAN? I have got to be missing something here. I don’t even have massive amounts of achohol as an excuse atm either…damn it.
BTW, John, MC, thanks for slogging through this. Appreciate it.
Your other thread is still on the first page. Please don’t start another thread on the same topic. We don’t mind if you bump an old thread once. Although you might wait until it falls of the first page.
