New! How to Find Wandering Supermassive Black Holes

Diagram 8

Astronomers have a new place to search for wandering black holes.

At the center of each spiral galaxy is a supermassive black hole. Diagram 8 (right) shows two spiral galaxies seen from Earth in a particular orientation. The two orbital planes of the galaxies are parallel so that the galaxies face each other. Gravity attracts the less massive black hole of the smaller galaxy toward the more massive black hole of the other galaxy.

Now presume that another galaxy or galaxy cluster is beyond the space between the two galaxies of Diagram 8. The background galaxies or clusters are shown in blue and yellow. In other words, the space between the two galaxies is illuminated by another galaxy or cluster in the background.

This scenario offers an excellent opportunity for astronomers to watch a supermassive black hole in motion. Astronomers know that the less massive black hole will be in motion toward the other black hole. They know they can use the optical data analysis technique used to spot extra-solar planets to track the movement of the black hole!

That optical technique is simple. Astronomers fix a telescope on a distant star and record the amount of light received. They analyze the received light on a computer. Whenever they detect slight decreases in light that are systematically moving across the star, they theorize that it's a planet. If the systematic decreases in light are consistent with a planet trajectory, a new planet is announced.

So too in the case of wandering supermassive black holes. When the light from a background light source (a galaxy) decreases, astronomers will know that the supermassive black hole is moving. It blocks light from the background light source.

Alternatively, astronomers may observe a supermassive black hole causing gravitational lensing. The light from the background light source will bend around the supermassive black hole as it moves through space. Some of the light will fall into the black hole.

Either way, astronomers have a new hunting ground. They should search their astronomical data collections for two galaxies oriented as in Diagram 8 that have a background light source like a galaxy or cluster. Then they should fix their telescopes on that position.

This is a revolutionary opportunity to study the movement of supermassive black holes!

Copyright, 2011.

Wade Hobbs, Jr.

Particle Travels Between Galaxies

Professor Kip Thorne of CalTech wrote a remarkable book, “Black Hole and Time Warps: Einstein’s Outrageous Legacy.” According to Thorne, time for a particle just above the event horizon of a black hole slows to a crawl because of gravitational time dilation. (For more information on gravitational time dilation see http://www.search.com/reference/Time_dilation#Gravitational_time_dilation_tests.)

A particle hovering just above such a black hole might travel between galaxies in a short time. Consider two galaxies separated by 1000 light years. Each galaxy has a super massive black hole at center. As gravity pulls the two black holes toward each other, a particle just above the event horizon of one of the black holes might travel to the other galaxy in a short period of time as measured by clocks in its reference frame. For instance, the particle might travel to the other galaxy in ten years as measured by a clock just above the event horizon. (I haven’t worked the equations.)

As long as the particle moves away from the black hole before both collide with matter from the other galaxy, it might survive the intergalactic voyage.

Theoretically, this leads to the possibility that a spacecraft might make the intergalactic leap!

We can simulate on a computer the natural phenomenon of a particle traveling between galaxies in a short time as measured by its clock.

How can a human accelerated particle beat a photon in a race?

Diagram 1

The particle can’t beat the photon if they travel next to each other, but in one scenario, the particle would win.

Light travels faster than everything. That’s one rule from Einstein’s Theory of Relativity. But in one scenario, a human accelerated particle might begin at an imaginary start line and reach an imaginary finish line before a photon.

Consider schematic Diagram 1. Two galaxies are attracted by gravity. The more massive galaxy (left) pulls the less massive galaxy (right). All galaxies have super-massive black holes at center, represented here by the big black dots. Imagine two green lines, a start and finish line respectively.

Diagram 2

Diagram 2 (right) is an enlarged picture of the inset from Diagram 1. Two photons (red dots) start at an imaginary green start line. The photons may be separated by a thousand light years. The top photon is emitted from a star near galaxy center. The bottom photon is emitted from another star a thousand light years away in the galaxy.

Both photons race toward the finish line, the second green line (left). The black hole is moving toward the more massive galaxy. As the black hole moves, it pulls spacetime with it.

But in one scenario, a human accelerated particle might begin at an imaginary start line and reach an imaginary finish line before a photon.

Diagram 3

In Diagram 3 (right), the black hole of the less massive galaxy moves toward the more massive galaxy. It draws the nearby photon (top) with it.

Diagram 4

Diagram 4 (right) shows the inset from Diagram 3. The top photon finishes first because it is being dragged through space by the black hole. Both photons move at light speed, but the top photon finishes first because the nearby black hole is dragging spacetime with it. Nothing can travel faster than light speed, but the top photon wins because of the additional gravitational pull from the black hole.

Both photons move at light speed, but the top photon finishes first because the nearby black hole is dragging spacetime with it.

Diagram 5

Diagram 5 (right) shows the less massive galaxy and its black hole being pulled toward the more massive galaxy over time.

Diagram 6

Now imagine a human accelerated particle substituted for the top photon in Diagram 2. As shown in Diagram 6 at right, the particle (blue) is accelerated from an accelerator near galactic center. Both the particle and photon begin simultaneously at the green start line. The particle is accelerated to relativistic speeds, defined here to be 99.5 per cent of light speed.

Diagram 7

Presume that the black hole is moving toward the more massive galaxy at a speed that makes the particle arrive at the finish line first. The particle beats the photon to the finish line! Again, the black hole pulls the particle by gravity. The photon, which is a thousand light years away, experiences little gravitational pull from the black hole. The photon loses the race, as shown in Diagram 7 (right).

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Copyright, 2011.

W. Hobbs, Jr.