Conventionally, physicists have assumed that if the black hole is large enough, the gravitational forces won’t become extreme until you approach the singularity. There, the gravitational pull will be so much stronger on your feet than your head, that you will be ‘spaghettified’. Now, a new theory proposes that instead of spaghettification, you will encounter a massive wall of fire that will incinerate you on the spot, before you get close to turning into vermicelli.
It’s over an hour long, so grab a coffee.
Black Holes are prime examples of the fact that Physics went off the rails about a century ago. When one finds a theory that results in a Singularity one should reject the theory.
Finding a black hole is like dividing by zero–an impossible operation.
Dan Kurt
Several catch concepts here should set off the Quack-o-meter”- such as: “thought experiments” and quantum mech. dealing with unmeasurable/undetectable issues.
As an engineer my discipline demands that anything which cannot be measured cannot be confirmed as fact – so in essence what we see here are scientists running the equivalent of a fantasy football game which is all premised on “what if”.
Theories are easy to conceptualize, the real heavy lifting involves devising methods to confirm/measure the hypothesis. Black holes are a favorite of the scientific nattering class because of the endless opportunity to theorize on a vast little known unmeasurable phenomena. This drives the “is universe is expanding or contracting” controversy which will probably never be understood fully in our lifetime – unless we can rid ourselves of the malignant politics and leadership which are retarding our evolution as a species.
While “anything which cannot be measured cannot be confirmed as fact” is technically correct, there are a lot scientific facts that can and have been confirmed via indirect measurements, measurements of corollaries to the original theory.
E.g. I am not sure quantum theory is directly measurable, but indirectly it has been confirmed again and again, and is thus no longer controversial.
Black holes I assume has also been “detected” via measurements that are (at least) consistent with the black hole theory. (This is of course weaker than confirming something.)
There is nothing wrong with scientific speculation, as long as it is based on solid science.
When I talk about black holes … which is very rarely since I don’t know shit about them other than what is flogged in the media and in the movies … I just like saying ‘event horizon’. Sound so cool like you know something ….
Further … I like What Occam said and how true it is … unless we can rid ourselves of the malignant politics and leadership which are retarding our evolution as a species.
Black holes exist, genius.
Cygnus X-1 was the firt one to be discovered.
Old newtonian physics also has a singularity at the center of a black hole.
Look up “fuzball”, and look at some of Leonard Susskind’s vids. on the matter.
I know, math is hard.
Both quantum theory and the existence of black holes has been verified.
More than half of the particles that exist were predicted to exist by theory before they were ever found in nature.
Quantum mechanis is the most precisly verified theory in history.
The universe is clearly expanding.
Black holes…. I was expecting something about Sharpton, Holder and Obama. Oh well, carry on…
Johan – measuring the effect of a hidden physical action is in essence proof it happens – example in macro mechanics: we can’t see the pistons functioning in an operating internal combustion engine but we can measure the air they displace doing this. so we can measure the efficiency of the the action of compression and decompression – this is confirmation, not on faith, but on a measurable effect the pistons travel as predicted in the cylinders – the closest QM have is trying to measure the amount of distortion of the reflected light off objects close to a suspected black hole but this is no very reliable yet. Using the previous example, this would be like saying the pistons function because we see heatwaves on the engine hood ( there are other things that can distort light).
We have enough evidence to suggest negative mass exists because we can witness some effects on light travel but the full array of properties and characteristics is not available to confirm as fact because we know little of the effects or have no way of determining the effects let alone measuring them – and so the hypothesizing goes on – the scientific community is as fragmented on the properties and characteristics of black holes as they are on few other subjects.
“There, the gravitational pull will be so much stronger on your feet than your head, that you will be ‘spaghettified'”
C’mon, you only have to do your taxes once a year!
Black holes, or collapsars to give them their proper name, are measured by two effects. The first is gravitation, nearby planetary or stellar masses affected by the gravitational pull of another mass which cannot be directly observed. The second is high energy XRays, the only energy which can escape the event horizon of a black hole. This is what theory predicted, and this is in fact what’s been observed in cases like Cygnus X-1 and others.
Conventional cosmologic theory is that at the centre of all spiral galaxies like ours is a central collapsar of about 100 million solar masses or so which provides the galaxy with its spin. Observational evidence from Andromeda tends to confirm that this is the case.
Occam’s example of hidden effects is entirely correct. Most subatomic particles were discovered, not by being directly observed but by their effects on other objects which could be observed in very specific ways.
Wow!
What a terrible speaker.
And the hands.
THE HANDS!!!!!
Two minutes seemed like two hours.
the scientific community is as fragmented on the properties and characteristics of black holes as they are on few other subjects
If you really want to see mental masturbation at work in science, then look at the field of string theory and all the discussion of branes and the possibility of dimensional travel. There is real concern in the physics community that the efforts of an entire generation of theoretical physicists has been squandered on string theory.
I think we need an entirely new concept in Physics to do away with singularities. The idea I currently favor is that space itself is quantized, and that there is a maximum energy density for a quantum of space (Planck energy divided by Planck volume). This would imply a radius on the order of 10^-22 m for a 5 solar mass black hole; thus no division by zero errors. However, I’ve only just started working on this idea, and there’s a lot of ways it could be wrong.
So is starlight measurable? Do you believe in stars?
Most of the stars have line spectra. The lines correspond to the line spectra shown by hot atoms and ions
in flames in labs, often slightly and regularly shifted. Does this suggest anything?
Assignment 1: look up the uses of spectroscopy in Engineering.
Assignment 2: look up “Doppler shift”.
Re Cyg X-1: this designates an X-ray source, which is quite measurable, in the constellation Cygnus.
It is in fact the most intense X-ray source in that constellation. It appears to be a point source (which BTW doesn’t
prove a great deal). It coincides with a blue giant which is known as HDE 226868. HDE226868 has a period of 5.6 da.
Cyg X-1 also alternates between a “high” (or relatively hard X-rays) and “low” (relatively soft X-rays). The switch is not
very regular. That at least, is not understood.
The distance to Cyg X-1 and HDE 226868 is determinable by parallax.
Cyg X-1 actually designates an X-ray source. It is extremely compact, and it emits a mess of radiation, in particular
X-rays.
The compact source at the centre of NGC 1068 has been studied in detail by the Chandra X-ray observatory and does,
indeed, show a very compact source; the closer to the source the hotter the emissions.
General relativity (GR) is a theory of space-time and gravitation which has passed all weak-field tests, possible on Earth.
It is used in GPS. The weak-field tests include differences in clock rates between sites at different altitudes.
GR has been used for the accurate prediction of the changes in the orbital parameters of the binary pulsar PSR B1913+16.
This is a nice strong-field test but still is an indirect test, and so is not as solid as the weak-field tests.
GR predicts singularities in spacetime, with no-return boundaries outside of them. The infalling of gas into them would
certainly lead to very high temperatures, from friction outside the no-return boundaries, and this in turn would lead to the
emission of copious quantities of X-rays.
So there it stands. An explanation of a large number of observations can be constructed on the basis of gas falling into
something corresponding to mathematical black holes. Other explanations haven’t worked out, but the evidence remains
somewhat indirect. Alternative explanations would involve objects even weirder to everyday experience than mathematical
black holes.
It is useful at this point to keep in mind the set of observations which I call “black hole phenomenology”,
and the set of theoretical constructs, mathematical black holes and gas movement into them. They are different things,
indeed, different kinds of things The connection is still somewhat speculative, and that is worth bearing in mind.
So if there is a maximum energy density per space quantum, then what would be observed if energy collected around a region to the point that that energy density would be exceeded? Would a “repulsive” force have to exist for bosons beyond a critical density? Would energy be repelled from any point that current theories say would produce a singularity?
Conjectures built on theories, constructed from Math equations. At one time they though light traveled at one speed universally. That the universe was infinite.All for naught. If you can’t measure, or see it, than repeat it. For me its just though day dreams.
A thought kept coming to the fore as I listened to this lecture about something invisible, vastly distant and unapproachable….
Conjecture on steroids, supported by assumptions….Google “Castle Bravo”…….
there are some in here who are out of their intellectual element, so they spout nonsense.
Engineering is about constructing physical things, or methods on how to construct, or finding reasons for failure of constructed elements. Now theoretical physics is about asking questions, even hypothetical ones. Often these questions only generate more questions rather than answers….it’s called science
as to singularities, there are powerfull gravitational fields that express themselves, and the result can be observed and measured. But they are not fully understood, so, more questions
you got that Occam?????
I don’t know. I’ve only just started bouncing this idea around in my head over the last few months, after reading the Snowflake Universe. However, if space itself really is quantized, then the questions you are asking show a path to developing some testable ideas about the behavior of gravity at the quantum scale.
Occam has a valid point, NME. Physics went off the rails with Superstring theory. An entire generation of physicists have wasted their careers chasing multidimensional strings that can’t be measured. Another significant group has been flagellating about with Dark Matter and Dark Energy, neither of which has ever been observed. The whole field needs to be reseeded.