Astronomy and Space exploration discussion

Imagine a trip into a black hole. This tantalizing thought has excited much creative speculation.There are two ways to consider the issue. One is to "watch" someone or something -- say a small robot spacecraft -- fall into the black hole. The odd thing is it never seems to get there. The closer it approaches the hole's event horizon, the slower it seems to travel. But for the crew inside, there would be no warning of its impending doom.

Let's assume that you start outside the event horizon of the black hole. As you look toward it, you see a circle of perfect darkness. Around the black hole, you see the familiar stars of the night sky. But their pattern is strangely distorted, as the light from distant stars gets bent by the black hole's gravity.

As you fall toward the black hole, you move faster and faster, accelerated by its gravity. Your feet feel a stronger gravitational pull than your head, because they are closer to the black hole. As a result, your body is stretched apart. For small black holes, this stretching is so strong that your body is completely torn apart before you reach the event horizon.

If you fall into a supermassive black hole, your body remains intact, even as you cross the event horizon. But soon thereafter you reach the central singularity, where you are squashed into a single point of infinite density. You have become one with the black hole. Unfortunately, you are unable to write home about the experience.

What actually is singularity ?
A singularity means a point where some property is infinite. For example, at the center of a black hole, according to classical theory, the density is infinite (because a finite mass is compressed to a zero volume). Hence it is a singularity.


What are your thoughts Guys ? Do you still think going into a black hole is exciting? ... Tell me your thoughts

Wow .... i know , its impossible to go into a black hole (even near it ) , but its such a great thinking , i have hear that if any matter goes near a Black hole , black hole converts it into fundamental particles...is that true?

Yes but i wouldnt use the word CONVERT , it doesnt convert anything into anything .....its actually , Black hole's gravitational pull is soooo powerful , it rips of out structure ...Clearly our body or any matter near a black hole continues to stretch and rip off , and this process continues one and one , until, only thing that remains are our atoms .

Truly Nature is Genius . But here's something , what about the information of our Structure, i mean , the information theory isn't conserved Here

what is information theory for god sake?

Its Simple , just like conservation of mass , energy ....there is something called Conservation of Information saying, Information
can neither be created nor destroyed. And Starman ., thats Amazing Question , i had this Doubt long ago , what i know is (i may be wrong) .....the information of the arrangement of atoms of any matter thats gone into the black hole , is liberated in an encrypted way in the form of Radiation , OR maybe there's something on the other side of the Black Hole , Maybe Antimatter universe or something , we still dont know

This has absolutely fascinated me since I was a kid. I'm really interested in the possibility of the conservation of information in the form of radiation/gravitational waves/etc either back from or "through" a Black Hole. That could almost be like a time machine, but instead of traveling anywhen/where, it acted like a history viewer if you could somehow decode the information.

Ha yes , if we somehow learn to decode it (it's near impossible with current technology and knowledge) , we will be able to see our past that a particular black hole has swallowed . It can solve miraculous questions about the Beginning our the universe .

Thats amazing though . Just think about it . if we decode that information we can use it to arrange matter with reference to the information . we can create matter back that was destroyed by the Black hole long long back .

I don’t know why, but I never thought I’d arrange matter back...that would be amazing. The technology alone would be insanely amazing!

Yes . But I am hardly hoping to see it in my lifetime

Second law of Thermodynamic - Entropy of the system always increases. It would take tremendous amount of energy to rearrange the information albeit we get that out of BH.

Question here is how do we retrieve the matter from the point where time is zero and density is infinite? The point where Space time does not exist.

According to Hawking information gets lost in Blackhole - at least he was believing that. However, String theory says otherwise.

Its not about retrieving any matter or creating it . We are talking about the information that may be in the radiation emitted by the black hole . when i say information , its just the pattern of arrangement of atoms in the matter that was lost . We could use that info to arrange similar molecules in similar pattern which in turn is nothing but creating the lost Object or whatever it is ...It's just a faint idea my friend . According to the second law as you said , it may be impossible to retrieve that matter in the first place.

Alok wrote: "Its Simple , just like conservation of mass , energy ....there is something called Conservation of Information saying, Information
can neither be created nor destroyed. And Starman ., thats Amazin..."

Alok wrote: "Its Simple , just like conservation of mass , energy ....there is something called Conservation of Information saying, Information
can neither be created nor destroyed. And Starman ., thats Amazin..."er the Duality Revolution in string/M-theory,

here's something : actually a discovery channel episode, (for lack of a better word ) details the debate between Hawking and a plumber-scientist, whose name escapes me ----like the info in the black hole, showed, by adding red colour to a basin of water and then draining it out, that the info was not lost at all, as hawking had been claiming all along and at last, hawking" conceded defeat while searching for that i have come across something totally different here it is
{"Hawking admitted that the information gets out. It meant that he surrendered in a bet against John Preskill who had correctly argued that the information had to be saved. Kip Thorne who has shared Hawking's incorrect "information is lost" opinion in the bet hasn't admitted his defeat yet. And it makes pretty clear that he never will.

Hawking continued to be heavily interested in this topic. In 2005, he announced that he had explained why the information wasn't lost, after all. The key idea of his argument was that when we describe the black hole formation and evaporation by the Feynman path integral, we should only sum over "topologically trivial" spacetimes and not the spacetimes of a different topology, those with the black hole. and this is something else which is misplaced here nevertheless i am keeping it

he Ancient Egyptians wrote Calendars of Lucky and Unlucky Days that assigned astronomically influenced prognoses for each day of the year. The best preserved of these calendars is the Cairo Calendar (hereafter CC) dated to 1244–1163 B.C. We have presented evidence that the 2.85 days period in the lucky prognoses of CC is equal to that of the eclipsing binary Algol during this historical era. We wanted to find out the vocabulary that represents Algol in the mythological texts of CC. Here we show that Algol was represented as Horus and thus signified both divinity and kingship. The texts describing the actions of Horus are consistent with the course of events witnessed by any naked eye observer of Algol. These descriptions support our claim that CC is the oldest preserved historical document of the discovery of a variable star. The period of the Moon, 29.6 days, has also been discovered in CC. We show that the actions of Seth were connected to this period, which also strongly regulated the times described as lucky for Heaven and for Earth. Now, for the first time, periodicity is discovered in the descriptions of the days in CC. Unlike many previous attempts to uncover the reasoning behind the myths of individual days, we discover the actual rules in the appearance and behaviour of deities during the whole year.