Entrance to the black hole: Talk with Frolov

I am quite unsatisfied with Hollywood movie 'Interstellar' on its physical description as well as its plot. Even not in physics, one blogger described well about what should be considered in the movie.
http://vegaseul.blog.me/220180270224

I want to talk about basic issue which is more certainly confidently to be said true than Thorne's 'picture'. In this article, I want to talk about 'when an object is to be said "absorbed" to the black hole'. I have discussed about this problem with Valeri Frolov in the last winter school, and he introduced the solution which is widely accepted among the black hole physicists. Well, simply said, 'under the Planck length, we cannot distinguish from the horizon'.

Let's think about it more in quantum sense. As an object approaches to the horizon, the radiation or any emission including reflection which may come from the object red-shifts. Thus, for the Schwarzschild at the Schwarzschild frame, the object at \(r=2M+l\) may be seen with redshift of factor \(\sqrt{\frac{l}{2M}}\). If the seen frequency is less than the inverse of the lifetime of the universe which cannot be lived longer by any observer, the energy is totally quantum and out of conservation of energy which now can be explained as a part of the black hole. In the different, the object's frame, the observation is very short time near horizon. A short moment passing the horizon may corresponds to eternity in the Schwarzschild frame. Any observation from the asymptotic rest frame should be committed by emission in such short (proper) time which prevents exact energy measurement. This gives different condition from the 'Planck length' explanation which mentioned in earlier passage, but this makes more sense as we cannot define 'length' well if we still believe equivalence principle.

This also gives somewhat similar intuition with CFT scattering amplitude and particle counting problem. In theory with no mass gap, particle counting is hardly defined. In this situation, as system goes near horizon, energy goes to zero which effectively make the energy gap converge to zero.

How to use easiest version control system

When you lost your data or history by crash or accidently saving process, you might be very frustrated. People usually use Dropbox, but Dropbox cannot sync into custom directories, multiple history branches, and massive collaborators. I will introduce intuitive guide to one of version control system 'git', which supports multi-branch, multi-collaborator projects.

The only point people might hesitate may be that git is open-source-based: mostly you are forced to share your sources you uploaded on the git repositories. There is good service which avoid this license: bitbucket, which gives up to 5 free private repositories per user. This service is provided by Atlassian who also provides git client program with intuitive user interface: SourceTree.

First, you should make your repository on the server e.g. bitbucket. Then, you should clone your server repository into a blank directory of your local disk. When you change your local file, the sourcetree app shows what is changed, and you can 'commit' to make a node to the history line. 'push' pushes the nodes to the server and make changes to the server which are shared to all collaborators. If there are conflicts between collaborators, it automatically merges, or you can fix it in your way. When you transfer into another branch, data of the local repository changes, so you should be aware of it.