Large Hardon Collider

[Mizango]

YouTube - Neil DeGrasse Tyson - Death By Black Hole

i got your back.

There you go, much love lol.

[Mizango]

Also, his book Death by black hole is amazing.

[Pirian]

Thanks, now I'm watching a million youtube videos on NDT

[Khamsin]

Quick question on the topic of space bending. Is space elastic or plastic? Is it more akin to an infinitely deformable rubber sheet, or an infinitesimally deformable linen sheet? If you were to make a mark on the sheet and then press down next to it, would the mark move when viewed from directly above, or would it merely move up and down but stay in the same apparent spot?

[Wintermute]

YouTube - Neil DeGrasse Tyson - Death By Black Hole

i got your back.

Man fuck you. I watch one tiny YouTube video and it's been over an hour watching Neil DeGrasse Tyson videos.


On-topic, is there any such thing as a Science for Retards book?
The thread is interesting to glance at but all I'm getting is a breeze from the science flying over my head.
Maybe my English Lit educated brain isn't wired for it.

[quannum]

Man fuck you. I watch one tiny YouTube video and it's been over an hour watching Neil DeGrasse Tyson videos.


On-topic, is there any such thing as a Science for Retards book?

you're welcome, NDT is the truth.

i always recommend this playlist YouTube - Broadcast Yourself.

it's light on math without feeling condescending.

[Mizango]

Man fuck you. I watch one tiny YouTube video and it's been over an hour watching Neil DeGrasse Tyson videos.


On-topic, is there any such thing as a Science for Retards book?
The thread is interesting to glance at but all I'm getting is a breeze from the science flying over my head.
Maybe my English Lit educated brain isn't wired for it.

If you are looking for a cheap book an excellent start is Origins: 14 billion years of cosmic evolution. I cant recommend this book enough for beginners.

You can find it really really cheap on Amazon.

Amazon.com: Origins: Fourteen Billion Years of Cosmic Evolution (9780393327588): Neil Degrasse Tyson, Donald Goldsmith: Books

GREAT GREAT read and goes into tremendous depth and is easy to grasp.

[Mizango]

Quick question on the topic of space bending. Is space elastic or plastic? Is it more akin to an infinitely deformable rubber sheet, or an infinitesimally deformable linen sheet? If you were to make a mark on the sheet and then press down next to it, would the mark move when viewed from directly above, or would it merely move up and down but stay in the same apparent spot?

Posting from my phone, I will answer this when I get home. Im sure Neo, Max or Woozie will get to it before then.

[Woozie]

I would answer it if I understood the question. Can you rephrase that somehow, Khamsin?

[zoobernut]

I think he is wondering hypothetically if you had a black hole and its great gravitational force is causing a strong warp in space time, if now that black hole instantly disappeared (hypothetically of course) would space time instantly return to its original shape or does it take time to recover. Is it elastic or stiff?

I hope that is what he was trying to ask. If not I am curious about it anyway.

[Enygma55]

Maybe Khamsin is more wondering what the actual fabric of space would act like visually.

Does it bounce up and down like a rubberband ( or trampoline ? ) or is it more like a foam mattress where it just indents due to the black hole gravity ( bowling ball sitting on a bed ? )

Kinda confused myself lol. If so my opinion is of the ladder. Think when Homer Simpson went into that 3D portal and got sucked into the "Black Hole" vortex.

[Knightmare]

or is it more like a foam mattress where it just indents due to the black hole gravity ( bowling ball sitting on a bed ? )

Kinda confused myself lol. If so my opinion is of the ladder. Think when Homer Simpson went into that 3D portal and got sucked into the "Black Hole" vortex.

Yeah its like a foam matress.

That episode is awesome and is an accurate representation of what a black hole does.

Edit: http://www.youtube.com/watch?v=AAqSCuHA0j8 in case you don't believe me.

[Khamsin]

Well, you know the analogy of space being a sheet you place weighted objects on which deforms the sheet and causes, say a marble you place on the sheet, to roll around the indents toward the low point (as an analogy to gravity)?

My question is whether these "indents" in the fabric of space-time would cause the surrounding fabric to pull in (i.e. not stretch, but get pulled in), or whether it would stretch (i.e. the indent can be as deep as you want, and will only stretch local space but not pull in the surrounding fabric).

Visualize making a mark on the sheet itself and view it directly from above. A linen sheet, for example (like your bedsheet), would pull in and not stretch. If you were to mark the bedsheet then poke your finger down into it, the mark would move toward your finger as the fabric pulls in toward the hole. The surface area of the sheet would remain unchanged.

An infinitely deformable rubber sheet, on the other hand, would stretch thin when you poke your finger down into it, but would not pull the surrounding sheet in with it. The surface area of the sheet would increase because you're stretching it thin. A mark on the sheet would not move in toward your finger, but remain in place as viewed from above. Viewed from the "side" it would move up and down, but not in toward the indent.

By elastic or plastic, I mean whether the fabric stretches (and increases in surface area), or does not stretch (and keeps a constant surface area).

The whole "stretch a sheet out and place a weight on it and watch a marble circle and move in toward the indent" analogy describes how a marble placed on the sheet moves, but does not describe how the sheet itself (or a mark directly on the sheet) deforms.

[Knightmare]

An infinitely deformable rubber sheet, on the other hand, would stretch thin when you poke your finger down into it, but would not pull the surrounding sheet in with it. The surface area of the sheet would increase because you're stretching it thin. A mark on the sheet would not move in toward your finger, but remain in place as viewed from above. Viewed from the "side" it would move up and down, but not in toward the indent.

By elastic or plastic, I mean whether the fabric stretches (and increases in surface area), or does not stretch (and keeps a constant surface area).

Pretty sure this is right.

Source GP-B — Einstein's Spacetime

[Max™]

Black holes aren't just "impressions" in the "sheet".

Consider a grid marking off the actual contours of spacetime throughout the Universe.

In regions where there are gravity wells, the amount of grid within the well is greater than it should be.

It's deeper, Pi measured around the gravity well does not match up against the radius you measure, there is more space in between the hypothetical circumference and the hypothetical origin of that circle.

Feynman described it wonderfully as excess radius.

http://i341.photobucket.com/albums/o...cessradius.jpg

The spacetime around a massive body is curved, such that it is deeper near the bottom of the gravity well.

The term bottom is misleading, but if you were standing ON a spherical surface around the well, towards your feet is the bottom.


A black hole is a point where the extra radius is so great that it tears loose of local spacetime.

Any lines drawn through that excess radius region as presented above would be curved slightly, imagine the r line is curving out of the page towards you. The end on the circle is flat as always, but the origin point is raised somewhat towards you.

The insertion of an event horizon could be viewed as expanding the origin point to a sphere covering the end of the r line.

A straight line from your perspective would not be the same from all perspectives.

An event horizon is a boundary where the curvature is so great that no path which crosses it can cross back out.

Light simply propagates like a note rippling across a guitar string, it doesn't get sucked in literally, the string is just cut at the event horizon.

[Neosutra]

You need to point out that what you just stated is hypothetical. It is a really good guess at this point, but we dont know yet.

[Max™]

Wait what?

The excess radius is the currently accepted implications of general relativity.

The event horizon description as being an extended origin as well.

The note rippling is my personal explanation of light, yes, but it is also Einstein's... I'm gonna go with him.

http://www.astronomynotes.com/evolutn/grwarp.gif

That excess radius pic I drew up there, if you lay it flat with the gridlines in the above picture, the radius line would curve into the well.

You have to remember though, that well is three dimensional (well, four dimensional, but I digress), so it isn't like the 2-D picture shows, with a single sheet being curved in a single directly.

Imagine the grid sheets shown there are on the surfaces of a cube.

The deeper the well, the larger the cube would be.

There would still be grid sheets near the object, but they would be distorted appropriately.

Technically that impression would be rotated all around the object, not just six dents in a cube, but again that isn't helpful for laymen to picture.

The extended radius though, is, which is why Feynman used it, the guy was amazingly good at that.

[Woozie]

I think he is wondering hypothetically if you had a black hole and its great gravitational force is causing a strong warp in space time, if now that black hole instantly disappeared (hypothetically of course) would space time instantly return to its original shape or does it take time to recover. Is it elastic or stiff?

I hope that is what he was trying to ask. If not I am curious about it anyway.

If the black hole disappeared, the space around it would take time to recover. The effects would propagate at the speed of light and create gravity waves.

Visualize making a mark on the sheet itself and view it directly from above. A linen sheet, for example (like your bedsheet), would pull in and not stretch. If you were to mark the bedsheet then poke your finger down into it, the mark would move toward your finger as the fabric pulls in toward the hole...

This one is correct, if I'm understanding your analogy correctly. The Earth would be like an object on the sheet, and objects are like a mark or a dot on the same piece of fabric. The Earth presses the fabric down, and the fabric around it is pulled in towards the indentation, causing objects to fall towards the Earth.

[Woozie]

Also

Sunday at 9PM, the science channel is having a show about the LHC. I figure anyone reading this topic would also be interested in that show as well.

[Max™]

It's deeper towards the center of the earth than it is in some lateral direction from it's surface.

There is more space down there than you would expect if you traced a circle around the earth in some kind of crazy super indelible spacetime marking crayon.

You're trying to traverse a straight path through the Universe, one that requires the least energy to maintain it.

The path of least resistance near the Earth passes inside of it, so you fall towards it.