Thursday, March 10, 2011

Villains in our Universe

Original posted on October 1, 2009


I remember, actually I’ll never forget that day, when I was still a little girl I was intensly watching the Bugs Bunny show “she’sa flat”, “naaaw she’s round.” – “Wassa matta with you she’sa flat lika da pancake!” when my father ever so casually mentioned to my mother; “They found a black hole.” My eyes popped wide open as I tugged on my father’s sleeve insisting on an immediate explanation. “It’s a hole in space” he explained looking far off into the distance. Oh I needed more detailed information. “It’s called a black hole,” he continued at my urging, “because no one can see it until you’ve come too close to it and then it grabs you and you’re forever gone.” Having held my breath the entire time, I finally gasped for air while at the same time blurted out “Oh God, they found hell!”

Years later to this present time if you would ask for an explanation from any astrophysicist to explain a black hole, he’d take a deep breath and with a deep frowned look gaze off into the distance, raise his hands to the level of his chest and with fingers rotating an invisible basketball he’d begin to explain, first by exhaling loudly and then inhaling again. A black hole, it’s a hole in space. If you drop a bowling ball into it, it will fall for a long time and then get crushed to a single point in space time and then it’s gone. (or) A black hole has an invisible monster in it that eats everything, no that’s not it. (or) A black hole is a hole with infinite density if you stick your finger in it, you ain’t getting it back. And this pretty much sums it up. OK not quite.

The reason why astrophysicists haven’t got their heads around the black hole yet is because all laws of physics and equations break down. This is where Einstein’s theory of General Relativity stands on its head. A new law for extreme physics is needed and no one has come up with one yet. I do suspect that the theoretical physicist Edward Witten a genius in mathematics, who also came up with the $tring theory formula will also come up with the extreme physics formula for black holes and other nasty things in space. I do suspect that gravity will possibly be the key for the new formula. Where energy from light is forever in a battle with energy from gravity. So far the black hole is winning, once light goes into a black hole it is trapped. If you could go past the Event Horizon, you’d be blinded from the trapped energy and light and then you would die. The black hole always wins.

Meanwhile Kip Thorne, Physicist, California Institute of Technology explains;

“When a black hole forms by the implosion of a star, which is how most black holes probably form, the matter implodes, and as it gets more and more compact its mass generates the warping of space and time around it; its spin generates the whirling motion of space around it. But the matter continues to shrink smaller and smaller and smaller, shrinks down to the very centre where it gets destroyed in a singularity, a region of infinite warped space and time. And it's gone. When it's gone there is nothing left except the warped space and the warped time. So the common idea that a black hole is just made of very compacted matter—it's wrong. It is just simply wrong. It may have been created from very compacted matter, but the matter is gone. It's been completely destroyed; it no longer exists. And all that's left behind is the warped space and the warped time, and this little nugget of a singularity at the centre of the black hole that we don't understand.” End of quote.

Andrew Hamilton, Astronomer, University of Colorado, Boulder explains;

“What's a black hole? Imagine a waterfall falling over a cliff. It's like that, except it's space itself that's falling over the cliff, and there's a place where the space starts moving faster than light, and then light can't make its way out of that space. What's a black hole? Take a mass and compress it very, very prodigiously. As you do so, the gravity of its surface becomes exceedingly strong, and there comes a point where it's so strong that not even light can escape.” End of quote.

Very adequately explained, the problem is we still don’t know how it works inside a black hole or as my father said many years ago, if you’ve come too close to it, it grabs you and you’re forever gone.

Albert Einstein didn’t like black holes, he thought they were anathema; this was something that nature should avoid. The places where space and time became infinitely twisted up, he thought, "No, nature shouldn't allow that."

Volcanoes as destructive as they are also have its benefits such as it gives nutrients to the earth, alas, many years later. Asteroids can wipe out species but it can also bring gifts such as water, gold, diamonds, nickel and new species to thrive. OK it can also bring bacteria or virus we may or may not find an antibiotic or vaccine for, nevertheless as destructive it is, it is also beneficial. Earthquakes and tsunamis, incredibly destructive but the benefits are that our tectonic plates are moving, if they didn’t our planet would be dead and our magnetosphere would cease to exist and we’d die from space weather. Tsunamis bring fresh nutrients to our earth and this is how more likely than not life began to thrive on our planet. Hurricanes and tornadoes are destructive and as far as I know have no benefits, had Albert looked outside his window occasionally he would realize that nature does allow things us humans have no benefit from suffice to say perhaps to make our species realize and humble ourselves that we are not all knowing and not in control of everything. Nature has the last word here on earth and it seems black holes have the last word in space.

What we know about Black holes:

Far back in time, or best said the beginning of time, because before then there was no time, it all began with the Big Bang. With the Big Bang, the Universe was dark, very dusty and hot and very dense, Gravity stirred this primordial soup mostly made of hydrogen and helium when millions of years after the big bang massive stars began to form. These were super stars; they formed in a massive size hundreds of times bigger than our Sun and burned out quickly. Deep inside the stars, temperatures soar above a billion degrees. Helium and carbon fuse into heavier elements: oxygen, silicon and sulphur. Eventually, the nuclear reaction creates iron, and the core stops burning. Then the star implodes under its own immense gravity, and goes supernova. What's left is a heavy core of subatomic particles, a neutron star, only about 10 miles across, but of incredible density. If the neutron star is heavy enough, three times more massive than our sun or more, the implosion will continue. The result is a black hole.

Our Universe was possibly seeded by black holes; the infant galaxies dance and orbit one another, as gravity pulls them closer. So our Milky Way, our galaxy, was not born in one single event. Instead, it was built, over billions of years, from a swarm of smaller galaxies smashing together, merging. We have over millions and millions of galaxies in our Universe. Galaxies of size such as our own galaxy all have a super massive black hole in the centre. Little galaxies as a rule get eaten; it’s as simple as that. Cannibalism of galaxies goes on all over the Universe and one day our own galaxy will merge with the galaxy Andromeda heading towards us at 700,000 miles per hour where when these two galaxies collide in a few billion years from now, in an elegant dance of galactic cannibalism, it will be a show to behold in awe. Imagine what that might look like from another galaxy. They'll see two grand, beautiful, spiral galaxies moving towards each other, slowly losing their shape. They'll see new avenues where stars and gas can funnel down towards this newly formed centre, feeding this reborn monster. Amid the maelstrom, chances are, our little solar system will either witness a spectacular show or be flung out of the galaxy into the voids of space. The Milky Way will be destroyed, and what about the black hole at its centre? Most likely, it will merge with Andromeda's, and become a monster 50 times larger. Stars and galaxies may come and go, but supermassive black holes just get bigger and Gravity is the key player.

For now our super massive black hole in our galaxy is resting or it went into retirement after having had its youthful years with many snacks and starlit parties. But in about 10 million years from now the beast will waken and snack again. Harvard-Smithsonian Center for Astrophysics are observing the black hole from the South Pole and have observed that there's some of the gas falling in toward the black hole at the galactic centre. Nothing too serious but farther out, about 400 light years from the galactic centre, astrophysicists can see signs of something much more alarming. A vast ring of matter is gradually growing bigger. This storage ring then builds up, until it coagulates into a single gigantic cloud of about 30 million solar masses. When the ring reaches a tipping point, it will condense into a giant cloud, triggering a dramatic starburst event, a storm of stars forming and dying quickly. What's left of the gas cloud will spiral down into the grasp of the black hole. Which then rapidly spirals in and feeds the black hole in the galactic centre, making the Milky Way an active galaxy. When the feasting starts, the fireworks will be seen across the Milky Way.

Time Travel

Approaching a black hole, the gravity is so strong and space is so warped, it distorts the light all around it. Then, soon, you'll be distorted, too, by tremendous "tidal forces" of gravity. The tidal force is the difference between the gravity at your head and your feet. The gravity at your feet, if they're close to the black hole, is a little bit stronger than the gravity at your head, and you feel that as something that is tearing you apart stretching you from head to toe. The tidal forces unrelentingly getting stronger, as they exceed the molecular forces that bind your you snap into two pieces and those two pieces snap into another two pieces and ultimately, will pull your atoms apart moving through space-time like toothpaste squeezed through a straw. You will be, as we say, "spaghettified." Not a wise idea to try and enter a black hole confusing it with a wormhole. A theoretical wormhole.

The gravitational pull warps space time around it with an incredibly deep cone shaped hole. When scientists analyzed X-ray images of super massive black holes they discovered that they were spinning close to speed of light, this causes the space time fabric to be dragged around. Scientists call this frame dragging, space time becomes so distorted that it forms an almost complete circle. This was music to those interested in time travel. Time travelers were just about to strike gold.

J. Richard Gott is a professor of astrophysics at Princeton University, what he found made him make a hypothesis which is based on something which is still theoretical, it’s called a “cosmic string”, they’re left over after the big bang, no wider than an atom. Cosmic strings have colossal density, a string just one mile long would exert more gravity than earth’s, (immense gravity warps space time). According to Professor Gott, if two strings are passing each other at infinite speed you can use it as a time machine. The fast moving strings warp space time as they pass so that they bend it down into a wedge shape. Normally a space ship would have to take the longer route across space time but the time traveler can now take the short cut. By outrunning a light beam he can travel back in time. All Professor Gott would need to do with his space ship is find the two strings and he would be gone and back to before he entered into his space ship. The space time around the two cosmic strings would be so twisted that Gott could circle the strings and come back before he sets off. Here’s how; by traveling through the cosmic strings Gott would be traveling faster than the speed of light. Theoretically a time machine in principle. The path of time is no longer linear; instead it forms something like a circle. But there is a problem with this time travel, the moment his time machine would warp space time into a circle the whole region would fall inside a black hole. And that’s not a good thing. This would be a one way trip, a very short one way trip.

Thinking outside the box:

I have to admit that black holes has been on my mind lately. Not for what I had learned and what I know, but for what has been missed. Not just by me but possibly by all physicists? We already know by observation that stars coming too close to a black hole, are one minute visible and then they are gone. Swallowed up by the black hole. But also it has been observed by astronomers that many stars orbiting near the black hole in fact continue their orbit and do not fall into the black hole but are affected by the black hole nevertheless. Stars have been observed going merrily in their orbit’s designated speeds towards a black hole and as they approach the black hole “whoops” the event horizon of the black hole gives the stars a slingshot effect and they speed off at the speed of over a million miles per hour way past from the black hole and back to their routine orbit. Woooo what a ride! But this is nothing new to use gravity as a booster (slingshot). The astronauts of Apollo 13 used our moon’s gravity as a booster to come back home saving valuable fuel. Also the Cassini space ship used the slingshot effect, two passes of Venus, one of Earth, then one of Jupiter and on to Saturn.

Now if “our” space ship was to head towards a black hole, not to enter it as some do in sci-fi movies, but to ride the edge of the Event Horizon and like a sling shot get catapulted out into space at over a million miles per hour, we could conquer space travel, no wormhole required, no fuel needed for those several thousand light years ahead. In a sense it is time travel because by the time you’d come back your grandchildren would be your ancestors.

We are burning the midnight candle trying to figure out how a black hole works inside. What the extreme physics formula should be to help us figure out the interior of a black hole. Maybe we should be concentrating on the edge of the Event Horizon and the slingshot effect? Just one minor problem and that is to build a space ship that could withstand some intense Mach 9² warp speed and a large spatula to peel us travelers off the spaceship’s interior.

video by true masked wabbit

Wish you all a great week and a very relaxing weekend ahead


No comments:

Post a Comment