Yep, itís time for another edition of Tylerís Random Science Topics:
One of the most elusive and most misunderstood space objects to the everyday person is the concept of black holes. Still not fully understood by science, nor will it be for quite some time, todayís understanding is becoming more and more complete advanced of these amazing and violent beasts.
Black hole with corona, X-ray source (artist's concept).(Credit Wikipedia Commons)
What is a black hole? Now that is a very difficult question to answer with just a single definition.
Why? Because a black hole can be many things, and none of these things.
Wait, what? Exactly, let me try to explain.
In the simplest definition, it is an area of space-time that exhibits an extreme gravitational distortion. The gravitational distortion being so strong such that particles and even electromagnetic radiation (light) cannot escape the distortion and become trapped or effected by this gravitational effect.
The interesting thing to note here, is at the center of our very own milky way galaxy in which our own solar system is nestled, there is what is called a ďSuper Massive Black HoleĒ with the mass of roughly 4 million times that of our own Sun. Donít worry though, we are billions and billions of years away from ever having to worry about that black hole. We are on a collision course with the nearby galaxy Andromeda in only 4 billions of years of which in computer modeling, our own solar system will be flung out of our galaxy. But, again, donít worry about that, our Sun will run out of nuclear fuel and go dark way before that and destroy Earth in that process.
Now, I discussed the warping of space-time by gravitationally massive objects in my General Relativity email. We can see this in light on a massive scale around massive black holes below:
This lensing effect is cause by light passing around and being warped by the black holes gravity. Some of the light does fall in and get trapped, but some is basically distorted from its direct path and creates this view to us when view the night sky with a powerful telescope. This is also one means that scientist can indirectly detect black holes, as direct observation is near impossible as black holes do not reflect any light, rather than absorb or warp it.
Now, Iím sure most of you have heard of the ďEvent HorizonĒ, which is a snazzy way of saying the point of no return from a black hole for both mass objects and light. An observer outside the event horizon cannot detect any events that occur inside this event horizon as that information (light) never escapes this region, so the observer never sees it. So as an object passes this point, its light information fades away from the observerís perspective.
Next month, I will continue this discussion, to provide what it would be like for a person in a spacesuit to fall into a black hole and what this would look like to an observer orbiting the black hole outside of the event horizon. This is where physics gets really weird.
Todayís Science Topic is dedicated to the Crew of STS-51-L (Challenger) which lost their lives 30 years ago today (January 28, 1986):
Francis R. Scobee, Commander
Michael J. Smith, Pilot
Ronald McNair, Mission Specialist
Ellison Onizuka, Mission Specialist
Judith Resnik, Mission Specialist
Gregory Jarvis, Payload Specialist
Christa McAuliffe, Payload Specialist