Quantum Physics

It's at least where Gremlins hide.

Actually talking about an extra dimension is just a handy way to help visualize things.  It's never used for any calculational purposes.  The only time I've heard of it is through this one professor, nobody else mentions it.  I think they just do the math and nod their heads.

You do hear about gravity as being like a rubber sheet, where we are in 2 dimensions on the sheet and the gravity is in the third as the sheet is deformed by a mass sitting on it; by simple extension there must be an extra dimension for our 3D world, but it's never discussed as 4 dimensional space for some reason. Only time is mentioned as a 4th dimension, but that doesn't seem to be what's going on here.

Right, lets see if I got this- you cant go faster than the speed of light because the faster you go the shorter the distance you are going becomes whislt at the same time staying exactly the same distance?
And that if you try going even faster you will never get passed light speed because the distances will keep getting shorter, relative to you? I am nowhere near drunk enough for this yet

speed = distance/time. But we have to realize there are two speeds we are talking about: the speed of the train your friend is on, and the speed of what ever your friend is doing on the train. The speed of the train shrinks distances in the direction of the train's motion. So when your friend throws a ball in that direction, the speed will be slower. This prevents the speed of the ball, when added to the speed of the train, to exceed the speed of light.

The train itself will never exceed the speed of light because it becomes increasingly more massive with speed, making it harder to accelerate, but that's even harder to demonstrate.

Yeah, bucky doesn't really help. What it takes is relentless logic and faith that the equations that give us the speed of light can't change, hence the speed of light can't change, even if we have to sacrifice concepts of space and time. makes it damn hard to intuit your way through.

Pettytyrant101 wrote:Consider a spinning disk. If you are old enough consider LP playing.

I've read this Calvin and Hobbes strip.

Yep, that one's an old classic. But then, nearly every Calvin and Hobbes cartoon is a classic.

Pettytyrant101 wrote:

Consider a spinning disk. If you are old enough consider LP playing.

And if you had a massive disk- I mean ginormous, and you got the centre to spin at just under the speed of light- what happens at the edge?

Well first, you shouldn't be spinning your LP's that fast. Neither the records nor the needles are made for that kind of use. And besides they sound incredibly high and squeaky.

If you play your disks at 33 1/3 RPM like you're supposed to, you won't have any trouble with the speed of light unless you have disks that are more than 106,000 miles in diameter.

Not entirely sure how accurate this all is, it seems reasonably balanced but there other stuff seems a bit conspiracy themed, fortunately this isn't-

That should be labelled as "possibilities for" not "signs of" extraterrestrial life.

Good news! After 7 months its back to life!

'The European Space Agency (Esa) says its comet lander, Philae, has woken up and contacted Earth.'

Welcome back to awareness Phiale!

Its amazing to think we have a probe riding a comet through space and telling us whats going on as it does so. Mind boggling.

Great engineering for it to have survived at all this long, especially as the temperatures plummeted.
But now the comets nearer the sun Philae has got some fresh juice and come back online.

"Philae is doing very well. It has an operating temperature of -35C and has 24 watts available," said Philae project manager Stephan Ulamec."
Philae was carrying large amounts of data that scientists hoped to download once they made contact again, he said.
"I think we're optimistic now that it's awake that we'll have several months of scientific data to pore over," he added.

Huh, what? How'd I miss this? That's great news.

Glad to hear it's sticking in there and continuing to function.

http://hplusmagazine.com/2015/07/20/heres-what-you-need-to-know-about-the-large-hadron-colliders-latest-discovery-the-pentaquark/

http://www.huffingtonpost.com/sheldon-stone/pentaquarks-a-new-state-o_b_7820000.html

Pentaquarks!!!!

{{{{not a clue what it all implies, but it makes me happy }}}}

From a very simple minded reading, all you are looking for is combinations of +/- 2/3 and 1/3 charges that add up to unity or zero.  The mesons (2 quarks) are always a quark and anti-quark, while the baryons (3 quarks) add to zero or one. They have spin 1/2, so that two are always spinning one way and one the other way to add to 1/2 spin for the baryons.  By the Pauli exclusion principle, two of the same quarks must spin in opposite directions in the ground state.

The up quark is +2/3 charge, the down is -1/3.  The others we rarely see so won't worry about.   A proton is two up and one down (adds to 1), a neutron is 1 up and two down (adds to 0).

Since if you try with up and down to put 5 quarks together at least 3 must be the same, yet only two spin directions, one of them must be an anti-quark in the ground state.  So a pentaquark is basically just a meson and baryon combined.  This makes pentaquarks a little less exciting, but the fact that 5 quarks can be in one particle is rather interesting.

There's color charge too, but that doesn't really bear on this discussion.

This was the part of the story that pleased me the most. You rarely hear about the grad students.

Huff Post/Sheldon Stone wrote:The background process had the Λb decaying into a J/ψ plus a proton and a negatively charged kaon. This decay had never been seen before. The graduate student who was working on the B meson decay for his thesis was asked to look for the background and he begrudgingly went off and did it. He returned with a smile. He had found a very large signal. It was immediately used to measure the Λb lifetime which had be an outstanding issue for twenty years

Most science comes from grad students and post docs (big important work is mainly post docs). Professors don't have time to do much science. It was a nice moment to show a grad student going from tedium to success.

An accidental discovery that could lead to some interesting applications-

'Engineers and physicists have discovered a property of silicon which could aid the development of faster computers.
"Photonic" and "spintronic" computing is the principle of transferring information by light or electron spin.
This new property means that silicon-based light detectors identify spin, so more information can be transferred.
Spin is a property of sub-atomic particles, which influences the ordering of electrons and nuclei in atoms and molecules.
The discovered property is usually observed in materials containing heavy elements, which are difficult to integrate into existing computing systems that are composed mainly of silicon.
Silicon is a highly symmetrical crystal, but by changing the geometry of it, the team was able to impart "chiral" properties to it. Something is chiral if the mirror image of the object cannot be superimposed on the original.
This chirality means that silicon-based detectors are able to detect the spin of electrons and light, and as a result allow more information to be transmitted.
"This is only around five years away from now. The technology already exists, but this can bring added functionality."
The discovery was made by accident, while investigating heavier materials.
As well as discovering chirality in silicon, this study has wider implications for materials science.
This is a step towards engineering new, useful properties by changing the geometry of a material. "- BBC Science

Love this, very Doctor Who- any Americans of the right age to remember the Berenstein, sorry Berenstain, Bears care to chip in?- do your memories tally with reality!

http://woodbetweenworlds.blogspot.co.uk/2012/08/the-berenstein-bears-we-are-living-in.html

And if it turns out you definetly remember the BerenstEin's then don't worry- the Doctor can explain it for you-

That explains sooooooooooo much!

I can definitely see the attraction to Amy Pond here. Wonderful acting from both of them.

First stage of a practical working tractor beam?

http://www.bbc.co.uk/news/science-environment-34647921

I can understand a force away from a source of sound, but towards it I have problems wrapping my head around. I'd have to see a more technical description, plus a half day to figure it out. Very interesting.

I think its more the sounds create shapes, so its not so much its pulling towards it as moving the shape about and changing it affects the boundaries holding it in place and it moves about sort of 'inside' the sound shape. That was my reading of the article at least.

I can see how the interference pattern can be made to propagate towards the source, so that does begin to make sense. But I still think of it as areas of zero sound pressure versus pressure directed away from the source. Even if the zero pressure areas move towards the source, I don't see how it can be used to lift against gravity towards the source. Maybe the 'UFO' they showed was not the source they just made it look like that?

No the UFO is the source- they put the equipment inside it to show it worked from any side, top sides and bottom.
Thats the bit I find most amazing- and why it could be so applicable in time- you dont need something surrounding the object to do it, just pointing the device at the subject from one side or another or from above or below.