Post: #1

Link to article in Science.

Thought this might interest some guys on here.

The media are currently screaming Nobel Prize and scientific discovery of the decade.

Just how significant is this?

Post: #2

Very, very significant. Gravity has been the most mysterious of the four major forces (strong nuclear force, weak nuclear force, electromagnetism, and gravity) for a long time. So this is a major step in understanding how it all fits together.

(I've been on an Einstein kick lately...last month I finished a great biography of him by Walter Isaacson).

This is a great link explaining what the waves are:

https://www.sciencenews.org/article/grav...-explained

Post: #3

Thanks to OP and Quintos for links,you ve provided me with night time reading!

Post: #4

I watched the NSF conference live. Pretty incredible. What's especially cool is how they can obtain so much information about the emitting objects (here two black holes that collided) just from the waves emitted by their collision.

Basically, this is an entirely new way to observe the universe. I think in 1995 the first extra-solar planets were confirmed, and after that, planets are popping up all over the place. I suspect something similar will happen here, although the types of events that can generate detectable waves are probably less prevalent than planets around other stars. But we will see!

I wonder if this will shed any light (heh) on dark matter. Exciting times.

Post: #5

Looks like there's reading to do over the weekend.

Can we expect an article on Einstein in the near future Quintus? Thanks for the link by the way.

Menace, it would be great if this could lead to a breakthrough in the study of dark matter. It still remains a 99 % on the WTF-scale for science, from that I understand.

Just imagine the kind of questions today's discovery will lead to... But those questions will ever so slightly shift the needle towards an answer to the riddle that is our universe. Exciting times indeed!

Post: #6

In this NY Times article you can see a video worth looking:

http://www.nytimes.com/2016/02/12/scienc....html?_r=0

Post: #7

(02-11-2016 03:05 PM)DarianFrey Wrote:  Looks like there's reading to do over the weekend.

Can we expect an article on Einstein in the near future Quintus? Thanks for the link by the way.

Menace, it would be great if this could lead to a breakthrough in the study of dark matter. It still remains a 99 % on the WTF-scale for science, from that I understand.

Just imagine the kind of questions today's discovery will lead to... But those questions will ever so slightly shift the needle towards an answer to the riddle that is our universe. Exciting times indeed!

Einstein is such a vast subject, that I'd have to focus on something specific about his career, views, or discoveries. I'll have to give it some thought.

Post: #8

Gravity is such an interesting subject. I believe it's directly correlated to time.

From my understanding the two things that can alter time ( time relativity) are speed and gravity.

The higher the speed and closer to light speed and/ or the more intense the gravitational field, the slower time passes for the individual experiencing either.

Post: #9

While I generally think "science media" is bullshit, since it's journalists are usually geeky loners too dumb or lazy to hack the math necessary to get into the field, so stuff generally ends up completely ass backwards or flat out wrong. This journalist has a doctorate in particle physics (thankfully enough) so it has a lot more credibility methinks.

Quote:The signal exceeds the “five-sigma” standard of statistical significance that physicists use to claim a discovery, LIGO researchers report in a paper scheduled to be published in Physical Review Letters to coincide with the press conference. It’s so strong it can be seen in the raw data, says Gabriela González, a physicist at Louisiana State University, Baton Rouge, and spokesperson for the LIGO scientific collaboration. “If you filter the data, the signal is obvious to the eye,” she says.

This is cool as hell.

Post: #10

As amazing a discovery as this is, what sort of shirts were these guys wearing when they made the announcement?

Post: #11

(02-11-2016 09:12 PM)robreke Wrote:  Gravity is such an interesting subject. I believe it's directly correlated to time.

From my understanding the two things that can alter time ( time relativity) are speed and gravity.

The higher the speed and closer to light speed and/ or the more intense the gravitational field, the slower time passes for the individual experiencing either.

I once saw a TV programme that used atomic clocks to show that over 3 days, time passed about 0.00000000000026 seconds more quickly at the top of a mountain compared to sea level.

Think about that for a second. It is literally mind bending. 2 clocks that are very accurate, running on the same counting/timing mechanism, 1 is slower.

Post: #12

(02-12-2016 04:18 AM)britchard Wrote:  

(02-11-2016 09:12 PM)robreke Wrote:  Gravity is such an interesting subject. I believe it's directly correlated to time.

From my understanding the two things that can alter time ( time relativity) are speed and gravity.

The higher the speed and closer to light speed and/ or the more intense the gravitational field, the slower time passes for the individual experiencing either.

I once saw a TV programme that used atomic clocks to show that over 3 days, time passed about 0.00000000000026 seconds more quickly at the top of a mountain compared to sea level.

Think about that for a second. It is literally mind bending. 2 clocks that are very accurate, running on the same counting/timing mechanism, 1 is slower.

Yes, I've seen this before. It also goes for airplanes traveling at high altitudes. The airplane's clock goes, ever so slightly, more quickly.

Gravity is stronger on the Earth's surface than at altitude.

Post: #13

Here is the best, most easily understood explanation/demonstration of the whole thing I have seen thus far. Really made me grasp it conceptually. Plus the presenter chick has a great rack. WB with the force of two black holes colliding.

Post: #14

(02-12-2016 10:00 AM)VolandoVengoVolandoVoy Wrote:  Here is the best, most easily understood explanation/demonstration of the whole thing I have seen thus far. Really made me grasp it conceptually. Plus the presenter chick has a great rack. WB with the force of two black holes colliding.

WB also. She seems to have a boner inducing mixture of intelligence and passion...

That said, it is truly amazing that gravitational waves caused by a collision of a pair of black holes reached the earth from millions or (billions?) of light years away, and us having the sophisticated equipment to detect a wave with a width of less than 1/10000th of a proton!

What's even more amazing is that Einstein predicted this.

Post: #15

This discovery might be the first step towards something even bigger than merely changing the way we view the universe. Imagine if at some point in the future mankind develops a way to actually manipulate gravity waves? Things like anti-gravity propulsion suddenly don't seem like science-fiction anymore.

Post: #16

The explanation of spacetime as a rubber sheet is funny, because it's circular. This comes up every now and then when I run into mentally energetic nerds who mean well but like to pontificate about things they don't necessarily understand.

- " This is how gravity in spacetime works, it's like a rubber sheet with bowling balls and ball bearings"
- " So you're telling me that you need gravity to explain why or how gravity works"
- "No, no, see, the ball bearings orbit the bowling balls just like planets"
- "The sheet deforms because the objects are pulled down. If you need gravity to explain gravity, then you didn't explain gravity"
- "Ffffuuuuuuu"

The video (above) with the big tittied redhead is typically misleading science journalism. We don't know why gravity works, and we don't know how. The rubber sheet analogy is just an analogy. The why and how of gravity is a lot bigger than observable phenomena like gravity waves. If you can figure that out then you get the next eight or ten Nobel prizes, probably.

IIRC (correct me if I'm wrong), gravitational waves came about due to general relativity. Under Einstein's postulates, nothing moves faster than light. I still recall the lecture on the thought experiment Einstein did.

Einstein's Thought Experiment Wrote:Given that the Earth is millions of miles away from the Sun, light takes several minutes to reach the Earth from the Sun.
Suppose Galactus got his balls up and decided to make the Sun disappear in a plot to kill Superman again.

Q: What would happen to the Earth ?

A: Since nothing moves faster than light, it stands to reason that the Earth would continue orbiting a sun that wasn't there for eight minutes, until the (lack of) light reached the Earth's surface. Assuming that gravity moves close to the speed of light, there would be no gravity shortly afterwards.

Once there were no gravity waves (by extension, no gravity), the Earth would just move in a straight line tangent to its orbit into the cosmos.

Under Newtonian mechanics, field forces are instantaneous, so if the Sun were to disappear, the Earth would just fuck off right out of it's orbit while there was still light emitted from the Sun to reach Earth. This is not the case.

Post: #17

So this confirms that Gravity also travels at C?

No FTL then. Even with exotic matter.

Post: #18

(02-13-2016 03:38 AM)Aurini Wrote:  So this confirms that Gravity also travels at C?

No FTL then. Even with exotic matter.

It's entirely possible that whoever is theorizing FTL knows more about it that I do. I guess the answer of the speed of gravity propagation is not as clear as I figured. Not really sure what to conclude after reading this, I'll go over it in the morning.

http://www.metaresearch.org/cosmology/sp...ravity.asp

Post: #19

(02-13-2016 01:01 AM)Hades Wrote:  The explanation of spacetime as a rubber sheet is funny, because it's circular.

I have a hard time visualizing this.

In most videos that try to explain gravity and space time, they go with the rubber sheet analogy. Smaller objects circulate larger objects on a given geometrical plane because of gravity.

But space is 3-dimensional. So objects above and below each other affect each other as well. But no video or explanation I've seen yet takes this into account. For instance, the whole concept of space time "folding" when hypothetical worm holes are created is jarring to me. Same with the rubber sheet analogy, it just shows "one plane". Isn't that like saying that our universe is kind of flat?

The way I've understood it is that the universe is a large, expanding sphere. Do we exist on an infinite number of geometrical planes, which makes the universe spherical, or is the universe a mind-fuckingly large circular plane?

I'm not very knowledgeable about mathematics and physics, and am rather right-brained, so please have patience with my questions. I even have a hard time putting them into words.

Post: #20

Quote:But space is 3-dimensional. So objects above and below each other affect each other as well.

It's just a representation, because your brain can't picture four dimensions (which would be required to show three dimensional bending.)

Post: #21

(02-12-2016 04:18 AM)britchard Wrote:  

(02-11-2016 09:12 PM)robreke Wrote:  Gravity is such an interesting subject. I believe it's directly correlated to time.

From my understanding the two things that can alter time ( time relativity) are speed and gravity.

The higher the speed and closer to light speed and/ or the more intense the gravitational field, the slower time passes for the individual experiencing either.

I once saw a TV programme that used atomic clocks to show that over 3 days, time passed about 0.00000000000026 seconds more quickly at the top of a mountain compared to sea level.

Think about that for a second. It is literally mind bending. 2 clocks that are very accurate, running on the same counting/timing mechanism, 1 is slower.

This is a relatively recent discovery:

Wikipedia Wrote:The SI second was defined in terms of the caesium atom in 1967, and in 1971 the name International Atomic Time (TAI) was assigned to a time scale based on SI seconds with no leap seconds.[10] During this time, irregularities in the atomic time were detected and corrected. In 1967 it was suggested that nearby masses caused clocks to operate at different rates, but this was disproven in 1968.[11]

In the 1970s, it became clear that the clocks participating in TAI were ticking at different rates due to gravitational time dilation, and the combined TAI scale therefore corresponded to an average of the altitudes of the various clocks. Starting from Julian Date 2443144.5 (1 January 1977 00:00:00), corrections were applied to the output of all participating clocks, so that TAI would correspond to proper time at mean sea level (the geoid). Because the clocks had been on average well above sea level, this meant that TAI slowed down, by about one part in a trillion. The former uncorrected time scale continues to be published, under the name EAL (Echelle Atomique Libre, meaning Free Atomic Scale).[12]

https://en.wikipedia.org/wiki/International_Atomic_Time

The clocks in GPS satellites are actually set to run a little slow (38 microseconds per day) on the ground so that they'll run at the correct speed when in orbit .

Post: #22

I don't really understand what the significance of this is?

Does it proves the existence of a fourth dimension? How will this actually help technological advances going forward? I thought the theory of relativity was always considered true so now that's it proven that doesn't mean anything since modern physics has always been based on it as true?

And the theory of relativity is no longer a theory but no the "law of relativity"?

Post: #23

(02-13-2016 06:36 AM)DarianFrey Wrote:  

(02-13-2016 01:01 AM)Hades Wrote:  The explanation of spacetime as a rubber sheet is funny, because it's circular.

I have a hard time visualizing this.

In most videos that try to explain gravity and space time, they go with the rubber sheet analogy. Smaller objects circulate larger objects on a given geometrical plane because of gravity.

But space is 3-dimensional. So objects above and below each other affect each other as well. But no video or explanation I've seen yet takes this into account. For instance, the whole concept of space time "folding" when hypothetical worm holes are created is jarring to me. Same with the rubber sheet analogy, it just shows "one plane". Isn't that like saying that our universe is kind of flat?

The way I've understood it is that the universe is a large, expanding sphere. Do we exist on an infinite number of geometrical planes, which makes the universe spherical, or is the universe a mind-fuckingly large circular plane?

Like you said, it is just one geometrical plane, you can imagine the same thing happening in all possible directions. The rubber sheet is just one slice of the 3D space where it is happening.

Post: #24

(02-13-2016 01:53 PM)monster Wrote:  I don't really understand what the significance of this is?

Does it proves the existence of a fourth dimension? How will this actually help technological advances going forward? I thought the theory of relativity was always considered true so now that's it proven that doesn't mean anything since modern physics has always been based on it as true?

And the theory of relativity is no longer a theory but no the "law of relativity"?

There's no such thing as a 'true' scientific law. Theorists make predictions about phenomena that should exist in the world and experimentalists go try and measure them. When those predictions are born out they expand the useful domain over which a theory can be applied, when they're contradicted they provide limits to how a theory can be applied. For instance we still use Newton's Laws of Motion even though we now know that they are only valid in certain circumstances.

So on a fundamental level this provides validation on the one corner of relativity that had yet to be measured. It also opens up the door to measuring new phenomena which no theory predicts yet.

On a secondary level the amount of precision LIGO has is incredible. It may seem like nobody needs that level of precision but remember that computer (or cellphone) you're reading this on has nanometer scale features - a length scale that was unmeasurable until roughly 100 years ago. That alone has exciting implications for everyday life.

Post: #25

(02-13-2016 01:53 PM)monster Wrote:  I don't really understand what the significance of this is?

Does it proves the existence of a fourth dimension? How will this actually help technological advances going forward? I thought the theory of relativity was always considered true so now that's it proven that doesn't mean anything since modern physics has always been based on it as true?

Personally I think the significance of this discovery can't be over stated. The difference between theoretical and actual is perhaps analogous to the actual detection of radio waves in the late 18th century and the resultant applications since

Quote:Radio waves were first predicted by mathematical work done in 1867 by Scottish mathematical physicist James Clerk Maxwell. Maxwell noticed wavelike properties of light and similarities in electrical and magnetic observations. His mathematical theory, now called Maxwell's equations, described light waves and radio waves as waves of electromagnetism that travel in space, radiated by a charged particle as it undergoes acceleration. In 1887, Heinrich Hertz demonstrated the reality of Maxwell's electromagnetic waves by experimentally generating radio waves in his laboratory, showing that they exhibited the same wave properties as light: standing waves, refraction, diffraction, and polarization. Radio waves were first used for communication in the mid 1890s by Guglielmo Marconi, who developed the first practical radio transmitters and receivers.

Think of the astounding number of applications for radio waves that came along subsequently

It won't happen in our lifetime but this is the inception of a paradigm shift in the history of humanity.