Kugelblitz! Powering a Starship With a Black Hole

space.com ^ | January 16, 2014 | Jeff Lee

[12th_Monkey]

so in reality, we need to find nibbler first

[12th_Monkey]

yes, lots of the point A to B problems would be solved along with the pesky time dilation effects.

But folding space? wouldn’t that require the manipulation of a large singularity?

[GraceG]

[ so the hole is plugged by matter and it evaporates because nothing can get in yo fuel it. ]

It evaporates due to this: http://en.wikipedia.org/wiki/Hawking_radiation

The smaller the hole, the faster it evaporates, unless you add matter at a faster rate than it evaporates.

Basically in empty space there are particles and anti-particles that pop in and out of existence that then combine and annihilate one another.

If they pop into existence close to a black hole one particle gets eaten by the black hole and the other can escape causing the net loss of energy ie. mass to the black hole.

[12th_Monkey]

thanks for the link, I will read it. I’ve heard of hawking radiation, but never read up on it.

You seem very knowledgeable Grace. Is this your field of study?

[commish]

nah, no Obama. I am pretty sure its just Whales and Petunias you have to worry about.

[GraceG]

[ You seem very knowledgeable Grace. Is this your field of study? ]

No, but it is a personal passion and hobby

[SgtHooper]

“Of course when you start talking about speeds close to that of light, it brings up all sorts of weird stuff like time dilation and length contraction.”

Remember, that stuff is only theory! It’s weird only in the math and paperwork. Until we get a machine that reaches out to those speeds, all we can do is talk about it.

[12th_Monkey]

at one time it was mine, but kind of let it go and cluttered my mind with politics and other such frustrating subjects.

Now I just read up on it when subjects like this show up or catch a show on the science or discovery channel.

Perhaps after some of the replies I’ve received, I should pick it up again. Have any suggested reading?

Appreciate your replies Grace

[ETL]

Remember, that stuff is only theory! It’s weird only in the math and paperwork.

Not true. The effects are commonly taken into account and used today in calculations on many devices, including in GPS satellite technology. But in the case of satellites, surprisingly, it's not so much the high speeds that cause most of the effects, but rather the gravitational field of the Earth, which is stronger at the surface than at the altitudes of satellites.

[ETL]

Real-World Relativity: The GPS Navigation System

People often ask me “What good is Relativity?” It is a commonplace to think of Relativity as an abstract and highly arcane mathematical theory that has no consequences for everyday life. This is in fact far from the truth.

Consider for a moment that when you are riding in a commercial airliner, the pilot and crew are navigating to your destination with the aid of the Global Positioning System (GPS). Further, many luxury cars now come with built-in navigation systems that include GPS receivers with digital maps, and you can purchase hand-held GPS navigation units that will give you your position on the Earth (latitude, longitude, and altitude) to an accuracy of 5 to 10 meters that weigh only a few ounces and cost around $100.

GPS was developed by the United States Department of Defense to provide a satellite-based navigation system for the U.S. military. It was later put under joint DoD and Department of Transportation control to provide for both military and civilian navigation uses.

The current GPS configuration consists of a network of 24 satellites in high orbits around the Earth. Each satellite in the GPS constellation orbits at an altitude of about 20,000 km from the ground, and has an orbital speed of about 14,000 km/hour (the orbital period is roughly 12 hours - contrary to popular belief, GPS satellites are not in geosynchronous or geostationary orbits). The satellite orbits are distributed so that at least 4 satellites are always visible from any point on the Earth at any given instant (with up to 12 visible at one time). Each satellite carries with it an atomic clock that “ticks” with an accuracy of 1 nanosecond (1 billionth of a second).

A GPS receiver in an airplane determines its current position and heading by comparing the time signals it receives from a number of the GPS satellites (usually 6 to 12) and triangulating on the known positions of each satellite. The precision is phenomenal: even a simple hand-held GPS receiver can determine your absolute position on the surface of the Earth to within 5 to 10 meters in only a few seconds (with differential techiques that compare two nearby receivers, precisions of order centimeters or millimeters in relative position are often obtained in under an hour or so). A GPS receiver in a car can give accurate readings of position, speed, and heading in real-time!

To achieve this level of precision, the clock ticks from the GPS satellites must be known to an accuracy of 20-30 nanoseconds. However, because the satellites are constantly moving relative to observers on the Earth, effects predicted by the Special and General theories of Relativity must be taken into account to achieve the desired 20-30 nanosecond accuracy.

Because an observer on the ground sees the satellites in motion relative to them, Special Relativity predicts that we should see their clocks ticking more slowly (see the Special Relativity lecture). Special Relativity predicts that the on-board atomic clocks on the satellites should fall behind clocks on the ground by about 7 microseconds per day because of the slower ticking rate due to the time dilation effect of their relative motion.

Further, the satellites are in orbits high above the Earth, where the curvature of spacetime due to the Earth’s mass is less than it is at the Earth’s surface. A prediction of General Relativity is that clocks closer to a massive object will seem to tick more slowly than those located further away (see the Black Holes lecture). As such, when viewed from the surface of the Earth, the clocks on the satellites appear to be ticking faster than identical clocks on the ground. A calculation using General Relativity predicts that the clocks in each GPS satellite should get ahead of ground-based clocks by 45 microseconds per day.

The combination of these two relativitic effects means that the clocks on-board each satellite should tick faster than identical clocks on the ground by about 38 microseconds per day (45-7=38)! This sounds small, but the high-precision required of the GPS system requires nanosecond accuracy, and 38 microseconds is 38,000 nanoseconds. If these effects were not properly taken into account, a navigational fix based on the GPS constellation would be false after only 2 minutes, and errors in global positions would continue to accumulate at a rate of about 10 kilometers each day! The whole system would be utterly worthless for navigation in a very short time. This kind of accumulated error is akin to measuring my location while standing on my front porch in Columbus, Ohio one day, and then making the same measurement a week later and having my GPS receiver tell me that my porch and I are currently about 5000 meters in the air somewhere over Detroit.

The engineers who designed the GPS system included these relativistic effects when they designed and deployed the system. For example, to counteract the General Relativistic effect once on orbit, they slowed down the ticking frequency of the atomic clocks before they were launched so that once they were in their proper orbit stations their clocks would appear to tick at the correct rate as compared to the reference atomic clocks at the GPS ground stations. Further, each GPS receiver has built into it a microcomputer that (among other things) performs the necessary relativistic calculations when determining the user’s location.

Relativity is not just some abstract mathematical theory: understanding it is absolutely essential for our global navigation system to work properly!

http://www.astronomy.ohio-state.edu/~pogge/Ast162/Unit5/gps.html

[ETL]

From Wiki...

Calculation of time dilation

To calculate the amount of daily time dilation experienced by GPS satellites relative to Earth we need to separately determine the amounts due to special relativity (velocity) and general relativity (gravity) and add them together.

The amount due to velocity will be determined using the Lorentz transformation. This will be:

For small values of v/c, by using binomial expansion this approximates to:

The GPS satellites move at 3,874 m/s relative to Earth's center.^[12] We thus determine:

This difference below 1 of 8.349×10⁻¹¹ represents the fraction by which the satellites' clocks move slower than Earth's. It is then multiplied by the number of nanoseconds in a day:

That is, the satellites' clocks lose 7,214 nanoseconds a day due to special relativity effects.

Note that this speed of 3,874 m/s is measured relative to Earth's center rather than its surface where the GPS receivers (and users) are. This is because Earth's equipotential makes net time dilation equal across its geodesic surface.^[15] That is, the combination of Special and General effects make the net time dilation at the equator equal to that of the poles, which in turn are at rest relative to the center. Hence we use the center as a reference point to represent the entire surface.

The amount of dilation due to gravity will be determined using the gravitational time dilation equation:

For small values of M/r, by using binomial expansion this approximates to:

We are again only interested in the fraction below 1, and in the difference between Earth and the satellites. To determine this difference we take:

Earth has a radius of 6,357 km (at the poles) making R_earth = 6,357,000 m and the satellites have an altitude of 20,184 km^[12] making their orbit radius R_gps = 26,541,000 m. Substituting these in the above equation, with M_earth = 5.974×10²⁴, G = 6.674×10⁻¹¹, and c = 2.998×10⁸ (all in SI units), gives:

This represents the fraction by which the satellites' clocks move faster than Earth's. It is then multiplied by the number of nanoseconds in a day:

That is, the satellites' clocks gain 45,850 nanoseconds a day due to general relativity effects. These effects are added together to give (rounded to 10 ns):

45850 – 7210 = 38640 ns

Hence the satellites' clocks gain approximately 38,640 nanoseconds a day or 38.6 μs per day due to relativity effects in total.

In order to compensate for this gain, a GPS clock's frequency needs to be slowed by the fraction:

5.307×10⁻¹⁰ –  8.349×10⁻¹¹ = 4.472×10⁻¹⁰

This fraction is subtracted from 1 and multiplied by the pre-adjusted clock frequency of 10.23 MHz:

(1 –  4.472×10⁻¹⁰) × 10.23 = 10.22999999543

That is, we need to slow the clocks down from 10.23 MHz to 10.22999999543 MHz in order to negate the effects of relativity.

http://en.wikipedia.org/wiki/Error_analysis_for_the_Global_Positioning_System#Calculation_of_time_dilation

[SgtHooper]

Understand, and thanks for all your work. But for the most part we live in Newtonian physics. Until we can provide propulsion systems that get us waaay up there, it is only on paper as to the actual effects. I have no quarrel with the math and the physics—I love the stuff. And I understand that interpolation to the far edge is fun to think about and explore. It’s how things get invented. It just irritates me a bit when peeps think that the SOL is the limit—it’s based only on our science at THIS time. And who can say we truly are on the right path and not building on false models that will eventually dead end. However, it is all we have to work with for now.

While I enjoy watching the channels on TV about the planets, wormholes, time travel, universe, big bang (now evidently a fact!!), etc., they come off as being so sure this is the way it is. I find that a height of hubris, when 2 months from now, a discovery may blow that idea out of the water.

[Svartalfiar]

All black holes eventually evaporate (though it may take billions-trillions of years), the smaller/less dense ones are just that much faster decomposing, especially on a atomic-level size.

Of course, most research on this is hypothetical, as we haven’t actually seen any of this, especially in a controlled laboratory setting. Any observations have minimal vision, and are from long ago.

[ETL]

Absolutely, for the most part Relativity doesn’t apply in our everyday lives. Yet there are situations where it must be applied. Same for quantum mechanics. And I agree that quite a few of today’s theories may turn out to be less than perfect, and in several cases perhaps way off base, particularly the current theories involving the evolution of the universe: big bang, inflation, dark energy, dark matter, etc. The history of science is riddled with theories that were flawed.

[Bubba_Leroy]

So you are in a spaceship already moving just under the speed of light when you pass me in my stationary space station. One year later (my time) you are just under one light year away. You keep on going so there is no acceleration or deceleration involved.

If you have experienced time dilation relative to me, then from your point of view less than a year has passed. Are you still a light year away? If so, then from your point of view you had to move faster than the speed of light, but that is impossible because you cannot move faster than the speed of light relative to anything else.

Then there is the issue of the other guy going just under the speed of light in the opposite direction who passed me at the same time that you did. How fast are you going relative to each other? In a year, you are each just under one light year away from me (in opposite directions). How far are you from each other?

I could go on, but my headache is getting worse.

[InterceptPoint]

Yes, that is true. You can even say that it hadn't even moved, since its travel distance would have contracted to zero by virtue of its traveling at light speed. ...

Yes, this is true as well. It actually explains why the Speed of Light is limited: You can't compress space to less than zero. Once that is done moving faster just wouldn't make any sense.

Unless maybe by doing so you come out on the "other side" where time and maybe space are "imaginary". Hmmm.

[ETL]

Unless maybe by doing so you come out on the "other side" where time and maybe space are "imaginary". Hmmm.

Well, the theory doesn't actually state that nothing can travel faster than light, only that nothing (with mass) can be accelerated TO the speed of light, as it would require an infinite amount of energy to get it there. In theory, if something were already traveling faster than light, there would be no problem. Tacyons are believed to travel faster than light. And in the world of quantum physics, there is "spooky action at a distance", where communications seem to occur instantaneously, regardless of the distance between two entangled quantum entities.

[InterceptPoint]

And in the world of quantum physics, there is “spooky action at a distance”, where communications seem to occur instantaneously, regardless of the distance between two entangled quantum entities.
+++++++
Well, if the Spooky particles are photons then “the distance” is ZERO. Nothing spooky about that. Even I can go that far in mere nanoseconds.

So ... Do we see this Spooky action for particles with mass?

[ETL]

you are in a spaceship already moving just under the speed of light when you pass me in my stationary space station. One year later (my time) you are just under one light year away. You keep on going so there is no acceleration or deceleration involved. If you have experienced time dilation relative to me, then from your point of view less than a year has passed. Are you still a light year away?

If I understand the question, each of the observers would see the distance between points A and B differently. The observer who is stationary with respect to distance A-B will perceive it as it actually is. The one in motion with respect to points A and B (and the stationary observer) will see the distance shortened by virtue of his high-speed motion. The stationary observer will perceive the moving observer's clock ticking out time more slowly than his own. Not sure if I answered your question, or even made sense, but it's about the best I can do at the moment. Just ate a pretty good sized meal and am getting sweepy. Yaaaawn.... :)

[ETL]

Do we see this Spooky action for particles with mass?

Apparently so...

"This behavior is consistent with quantum theory, and has been demonstrated experimentally with photons, electrons, molecules the size of buckyballs,[8][9] and even small diamonds.[10][11]"

Quantum entanglement:
Quantum entanglement is a physical phenomenon that occurs when pairs (or groups) of particles are generated or interact in ways such that the quantum state of each member must subsequently be described relative to the other.

Quantum entanglement is a product of quantum superposition. However, the state of each member is indefinite in terms of physical properties such as position,[1] momentum, spin, polarization, etc. in a manner distinct from the intrinsic uncertainty of quantum superposition. When a measurement is made on one member of an entangled pair and the outcome is thus known (e.g., clockwise spin), the other member of the pair is at any subsequent time[2] always found (when measured) to have taken the appropriately correlated value (e.g., counterclockwise spin). There is thus a correlation between the results of measurements performed on entangled pairs, and this correlation is observed even though the entangled pair may be separated by arbitrarily large distances.[3]

Repeated experiments have verified that this works even when the measurements are performed more quickly than light could travel between the sites of measurement: there is no lightspeed or slower influence that can pass between the entangled particles.[4] Recent experiments have measured entangled particles within less than one part in 10,000 of the light travel time between them;[5] according to the formalism of quantum theory, the effect of measurement happens instantly.[6][7]

This behavior is consistent with quantum theory, and has been demonstrated experimentally with photons, electrons, molecules the size of buckyballs,[8][9] and even small diamonds.[10][11]

It is an area of extremely active research by the physics community. However, there is some heated debate[12] about whether a possible classical underlying mechanism could explain entanglement. The difference in opinion derives from espousal of various interpretations of quantum mechanics.

Research into quantum entanglement was initiated by a 1935 paper by Albert Einstein, Boris Podolsky, and Nathan Rosen describing the EPR paradox[13] and several papers by Erwin Schrödinger shortly thereafter.[14][15] Although these first studies focused on the counterintuitive properties of entanglement, with the aim of criticizing quantum mechanics, eventually entanglement was verified experimentally,[16] and recognized as a valid, fundamental feature of quantum mechanics. The focus of the research has now changed to its utilization as a resource for communication and computation.

http://en.wikipedia.org/wiki/Quantum_entanglement