Spacetime - Blog Posts

oh yeah what I meant by this! watched Interstellar with my brothers last night. two of them are science nerds! so well one has seen it and one hadn't before

so afterward I sat at a table with the one that hadn't priorly seen it and asked scale of 1 to 10 how realistic he felt it was. he got immediately hung up on the mathematics of the time as portrayed on screen, we jabbered about that for a while

... and second brother comes in. "Okay what you NEED to know," he says, and he's apparently talked this over with the fandom several times over, and he just takes off in this conversation and here I am sitting between two brothers who are going off about the science of well everything practically

inwardly I'm kinda making this face :D because I miss these sorts of arguments (and also I get to be a part of it)

and bro

okay yeah I could go into the whole wormholes and black hole/white hole and time shift and that sort of thing, it was a good conversation, but I'll save that for another time

and there was the whole me bringing up The Martian as more realistic and then us picking it apart too (tbh it's very good tho) but again not the point of tonight's tale

the point being

loved ones are so precious

loved ones are so precious when they're engaging in the thing they love

love languages can be arguing over science technicalities in science fiction and cinema

I love these people so much and I love that I get to be theirs.

bringing back the interstellar fandom one cranky science nerd at a time

What are Gravitational Waves?

Today, the National Science Foundation (NSF) announced the detection of gravitational waves by the Laser Interferometer Gravitational-Wave Observatory (LIGO), a pair of ground-based observatories. But...what are gravitational waves? Let us explain:

Gravitational waves are disturbances in space-time, the very fabric of the universe, that travel at the speed of light. The waves are emitted by any mass that is changing speed or direction. The simplest example is a binary system, where a pair of stars or compact objects (like black holes) orbit their common center of mass.

We can think of gravitational effects as curvatures in space-time. Earth’s gravity is constant and produces a static curve in space-time. A gravitational wave is a curvature that moves through space-time much like a water wave moves across the surface of a lake. It is generated only when masses are speeding up, slowing down or changing direction.

Did you know Earth also gives off gravitational waves? Earth orbits the sun, which means its direction is always changing, so it does generate gravitational waves, although extremely weak and faint.

What do we learn from these waves?

Observing gravitational waves would be a huge step forward in our understanding of the evolution of the universe, and how large-scale structures, like galaxies and galaxy clusters, are formed.

Gravitational waves can travel across the universe without being impeded by intervening dust and gas. These waves could also provide information about massive objects, such as black holes, that do not themselves emit light and would be undetectable with traditional telescopes.

Just as we need both ground-based and space-based optical telescopes, we need both kinds of gravitational wave observatories to study different wavelengths. Each type complements the other.

Ground-based: For optical telescopes, Earth’s atmosphere prevents some wavelengths from reaching the ground and distorts the light that does.

Space-based: Telescopes in space have a clear, steady view. That said, telescopes on the ground can be much larger than anything ever launched into space, so they can capture more light from faint objects.

How does this relate to Einstein’s theory of relativity?

The direct detection of gravitational waves is the last major prediction of Einstein’s theory to be proven. Direct detection of these waves will allow scientists to test specific predictions of the theory under conditions that have not been observed to date, such as in very strong gravitational fields.

In everyday language, “theory” means something different than it does to scientists. For scientists, the word refers to a system of ideas that explains observations and experimental results through independent general principles. Isaac Newton's theory of gravity has limitations we can measure by, say, long-term observations of the motion of the planet Mercury. Einstein's relativity theory explains these and other measurements. We recognize that Newton's theory is incomplete when we make sufficiently sensitive measurements. This is likely also true for relativity, and gravitational waves may help us understand where it becomes incomplete.

Make sure to follow us on Tumblr for your regular dose of space: http://nasa.tumblr.com