Mirror Questions: Q1, Q2 & Q3 - Reflection Effects

  • Thread starter Thread starter Nickelodeon
  • Start date Start date
  • Tags Tags
    Mirror
Nickelodeon
Messages
180
Reaction score
1
Q1 if you were traveling at .99c and held a mirror at arms length orientated perpendicular to your direction of travel would you see a perfect reflection?

Q2 if you were hovering within a few feet of the event horizon of a black hole and, as before, held a mirror at arms length 'horizontally' would you see a perfect reflection?

Q3 is there any similarity between the effects observed in the Q1 scenario and the Q2 scenario?
 
Physics news on Phys.org
Nickelodeon said:
Q1 if you were traveling at .99c and held a mirror at arms length orientated perpendicular to your direction of travel would you see a perfect reflection?

Q2 if you were hovering within a few feet of the event horizon of a black hole and, as before, held a mirror at arms length 'horizontally' would you see a perfect reflection?

Q3 is there any similarity between the effects observed in the Q1 scenario and the Q2 scenario?

Q1) Essentially yes. Your face would be reflected perfectly, because it is at rest with the mirror. The starry background might look a little weird due to aberration effects that makes it look like most of the background stars are in front of you.

Q2) Imagine that we replace the black hole with a dense body that is very nearly a black hole, so that we could in principle stand on the body and see its surface. Instead of looking like you are standing on the surface of a sphere, it would look like you are standing at the lowest point of a bowled surface. There will be visual distortions making it clear you are in extreme curved spacetime and there will be some some distortions in the mirror, but these might be small due to the short distances considered (arm's length) .

Q3) Not much. If you held the mirror so that the reflection light path is essentially vertical in the gravitational field then there would be some similarities with the (small) distortions you would see in a mirror when you are inside a rocket accelerating in flat space.
 
kev said:
Q2) ... There will be visual distortions making it clear you are in extreme curved spacetime and there will be some some distortions in the mirror, but these might be small due to the short distances considered (arm's length) .

Kev - re. your answer to Q2 what do you think would the be the visual effect if, for arguments sake, the black hole sphere is so large that for all intense and purpose the surface was flat (I'm assuming this would result in flat spacetime)?
 
In Philippe G. Ciarlet's book 'An introduction to differential geometry', He gives the integrability conditions of the differential equations like this: $$ \partial_{i} F_{lj}=L^p_{ij} F_{lp},\,\,\,F_{ij}(x_0)=F^0_{ij}. $$ The integrability conditions for the existence of a global solution ##F_{lj}## is: $$ R^i_{jkl}\equiv\partial_k L^i_{jl}-\partial_l L^i_{jk}+L^h_{jl} L^i_{hk}-L^h_{jk} L^i_{hl}=0 $$ Then from the equation: $$\nabla_b e_a= \Gamma^c_{ab} e_c$$ Using cartesian basis ## e_I...
Thread 'Can this experiment break Lorentz symmetry?'
1. The Big Idea: According to Einstein’s relativity, all motion is relative. You can’t tell if you’re moving at a constant velocity without looking outside. But what if there is a universal “rest frame” (like the old idea of the “ether”)? This experiment tries to find out by looking for tiny, directional differences in how objects move inside a sealed box. 2. How It Works: The Two-Stage Process Imagine a perfectly isolated spacecraft (our lab) moving through space at some unknown speed V...
Insights auto threads is broken atm, so I'm manually creating these for new Insight articles. The Relativator was sold by (as printed) Atomic Laboratories, Inc. 3086 Claremont Ave, Berkeley 5, California , which seems to be a division of Cenco Instruments (Central Scientific Company)... Source: https://www.physicsforums.com/insights/relativator-circular-slide-rule-simulated-with-desmos/ by @robphy

Similar threads

Back
Top