## rvgupta Group Title What happens to time at the center of a black hole i.e., at the singularity? one year ago one year ago

1. Carl_Pham

Nobody knows. We don't have a quantum theory of gravity.

2. Decart

it is infinite

3. 009infinity

time stops

4. UnkleRhaukus

everything is in place

5. 009infinity

@avijit007 can explain it better

6. 009infinity

the black whole's centre of gravity constantly pulls the time and space towards itself

7. avijit007

well......mass-density would definetly b vry much bt it won't b enough to stop time........................even in the evet horrizon, time slows down to about 65-75%

8. avijit007

even we are pulling space and time.

9. 009infinity

yes i m also saying that only

10. 009infinity

based on the information given by u i have come to aconclusion that universe constantly expands and contracts

11. avijit007

well, according to general relativity, at gravitational singularity, the space time curvature is infinite.

12. 009infinity

what do u say about big crunch then @avijit007

13. avijit007

what big crunch has to do with this qsn??????

14. 009infinity

because u said that time and space curvature is infinite

15. rvgupta

at the singularity time has no physical meaning, it completely stops. Based on this stephen hawking said that big bang also acts like singularity where time stops so before big bang there was no time and no one creates the universe, it was itself created

16. UnkleRhaukus

but space is expanding faster and faster , there will be no crunch

17. avijit007

at singularity, as asked in the qsn, not in the whole universe space-time is infinite

18. 009infinity

@UnkleRhaukus is there any scintific proof about that bic crunch will not occur

19. avijit007

it would b better if we focus on the qsn n try 2 find out what will happen time when space-time curve is infinite

20. avijit007

yes definetly there are speculations about the big crunch, bt it has nothing to do with space- time curve

21. avijit007

it has been pointed out by the scientists that till dark energy is more than dark matter in the universe , the universe will expand continously

22. rvgupta

big crunch theory is proven wrong by most of the scientist, and a new theory is predicted by the scientist which is inflation. It predicts that universe expand continuously with increasing speed

23. 009infinity

do u know what is dark energy and dark matter

24. avijit007

dark energy is a a hypothetical form of energy that permeates all of space and tends to accelerate the expansion of the universe

25. 009infinity

no its not hypothetical because dark energy are all those black whole which traps even light and dark energy are those radiations which are uninflueced by gravitational pull of black holes

26. UnkleRhaukus

@009infinity The measure is know as the Hubble constant $H_0\sim 71[\text{km}\cdot\text{s}^{-1}\cdot\text{Mpc}^{-1}]$

27. rvgupta

dark energy is a kind of riddle to the scientists which expands the universe covers almost 75% of the universe. Dark matter works like gravity which sticks all the planets to galaxy and galaxy to galaxy in a filament and it is made up of particle called WIPM(weekly interactive massive particle)

28. 009infinity

cosmic energy is also a dark energy which exist

29. avijit007

by hypothetical i mean that its total presence is still to b proven.its properties have been laid down

30. rvgupta

its some of the properties are known as it diverts the path of light when light passes through it. Actually WIMP was discovered on these basis

31. rvgupta

can anyone tell me why it was too hard to detect WIMP

32. 009infinity

it was difficult to detect wimp because may be it was undetectable due to merging in dark universe and due to its weak field .