I asked that question on another forum here. The 2 answers I got before the question was closed by an angry mod said:
You wouldn't understand the answer.
Don't ask that question. Ask about a Riemann sphere instead.
You're too lazy to look up the answer in [a GR textbook that I don't own]...
Ok. But isn't the sloppiness that you say the Doppler shift here reduces the frequency (red/blue) but not the frequency (of strobe pulses)? Light is always c.
A BH can't touch another hole's horizon for the same reason nothing else can: time drags the object to a halt for a distant observer.
Right?
Manifestly not. So are we wrong about gravitational time dilation, or what?
You don't need another object in the universe in order to rotate and feel centrifugal force.
You establish an inertial frame just by sitting there and existing. When you rotate, you rotate relative to that frame, even though the only mass in it is rotating.
Or am I, like, WAY off?
If so...
> Where are all the geeky girls?
there's one in my bed, in central fla (via VPN). She's crazy, but she's sho' 'nuff a geek.
But after an... intense (and long) saturday night, I'm all used up. Go to okcupid.com its amazing.
Yaaack! That was the key.
With your info plus reading about Langrangians and action for the past hour, I've learned as much today as in any college class. That makes me both delighted and excited because it links all the stuff I noticed about cyclic trading of energy between dimensions, like...
> there can be multiple geodesics connecting two events.
But when i drop a ball in a gravity field, it always follows the same geodesic. Is this contradictory?
Yes, but it's not inconsistent with GR.
By Machian, I assume you mean that local inertia is determined by faraway mass.
Well, I'm glad you think it's false. I thought I had to believe it because that physics prof said so in the inertia paper.
I never did see what the problem is with the only...
Look,
The interval length between any two events specified in 4D coordinates is invariant.
If one of those events is the Bang (which absolutely is fixed in 4D), then the age of every event (seconds since BB) is invariant, too.
I'm perfectly willing to believe that this argument invalid, but...
WOH.Action is one of the things I'm currently trying to understand.
So maximizing the proper time is the same as minimizing the action.
That was key info, thx.
I wish I knew how many more of those understanding nuggets I have to collect before I'll understand what the eff is going on--how...
Thanx!
My conclusion, modulo your approval: for an ideal, unyielding wall, the forces are equal. But the one-car will experience less crash force as a function of how much energy the wall absorbs by distortion.