Category Archives: Physics

It's About Time: More NPR Physics Discussions

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A Light Take On The Gravity-Time Relationship

Brian Greene explains the link between gravity and time.

Greene has written a short (less than 40 cardboard pages) new picture book called Icarus at the Edge of Time. It tells the story of a young boy who slips off in a space ship and cruises over to a black hole, only to discover that he’s made a terrible mistake: He forgot one of Einstein’s fundamental observations, which is that time is not the same for everybody everywhere.

[…]

Einstein’s theories posit that as one gets closer to a center of gravity, time will “slow down.” So if you spend the rest of your life closer to the Earth’s center of gravity on 34th Street while I spend the rest of my life at the top of the Empire State Building, time for you will tick a teeny, teeny bit more slowly than time for me.

Einstein meant this not poetically, but literally. If you and I each had a watch, ticking off hundred-billionths of seconds, the watch on your wrist down below on the street would tick fewer times than the watch I was wearing up in the sky. It wouldn’t be a big difference — a few billionths of a second over 20 years — but it would be a real difference. If we decided after several decades to meet and compare watches, we’d see that they would literally differ, that time for the two of us had indeed ticked differently.

via Physics Buzz

There's One Thing That's Perpetual

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Credulous media will apparently never run out.

Blacklight Power bolsters its impossible claims of a new renewable energy source

It’s difficult to pay attention to these claims, because scientific history is littered with ambitious, revolutionary theories that turned out to be groundless. But Blacklight is an interesting case. Its “hydrino” theory isn’t put forth by a single crackpot; instead, the company employs a good handful of high-level scientists who would presumably rebel if the idea was totally false.

No, not really. Creationism, for example, has a few credentialed scientists among its ranks. Pons and Fleischmann really thought they had fusion. Scientists in any field will cover a spectrum — there will always be some on the fringe. A lot of outlandish “theories” have the backing of somebody with a degree. That’s not the right metric for measurement.

As I noted in May, it would be odd, if Blacklight were a complete sham, for Mills to place himself in an end game in which he would be definitively proven wrong within just a year or two. So there does seem to be something deeper here.

As with the above, this isn’t the right way to look at it. There are numerous free-energy advocates out there, convinced they are right, with a working model just around the corner (or so they claim), or gee, it was working yesterday, right before I was going to show it off. Remember Steorn?

Proof here is a working model, producing energy. I’m not holding my breath.

A Slice of PI

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What We Research at the Perimeter Institute for Theoretical Physics.

Researchers at PI build on the two great revolutionary advances of 20th century physics – the relativity and quantum theories:

Einstein discovered that space and time are not separate entities, but are different aspects of a single geometrical entity called spacetime, which dynamically twists and warps as it dances with matter and energy. This dance, called gravity, governs the behaviour of the universe on large scales, from the solar system and galaxies to the entire cosmos as a whole.

The fathers of quantum theory, on the other hand, such as Bohr, Heisenberg, and Schrödinger, discovered strange new laws that were eventually seen to govern the behaviour of all matter and forces on very small scales – the atomic and subatomic worlds, with the exception of gravity, whose quantum nature continues to elude physicists.Both are profoundly powerful theories which not only explain, with extraordinary accuracy, many previously puzzling aspects of the universe, but have also successfully predicted a wealth of completely unexpected new phenomena, from black holes and gravitational waves to lasers and quantum teleportation.

Links to Quantum Gravity, Superstring Theory, Quantum Foundations, Quantum Information, Cosmology and Particle Physics.

Superman Already Knew This

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Sticky tape generates X-rays

Researchers at the University of California, Los Angeles, have shown that simply peeling ordinary sticky tape in a vacuum can generate enough X-rays to take an image — of one of the scientists’ own fingers

Only when you do it in a vacuum, though. Not clear (the concept, not the tape) if that is because the atmosphere degrades the charge buildup on the tape or if the occasional x-rays just scatter in the atmosphere, or some third option or a combination. I’ve seen bluish light when I’ve peeled adhesives before, so the mechanoluminescent properties aren’t a surprise, but the energy of them is.

Hear Here

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Ran across this while Googling for something else. NPR interviewed some of my colleagues about the master clock a while back. This aired in January 2007.

The Atomic Secrets of Accurate Time Keeping

I keep forgetting to use the bell ringing analogy when I explain how clocks work. (oh, and when the interviewer says “and his colleagues” near the end, she’s referring, in part, to me. Better than lackey or minion, I suppose.)

The Politics of Physics. Or is it The Physics of Politics?

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McCain’s Cosmological Breakthrough: Unreality Is Expanding

Gov. Sarah Palin, campaigning, she said, in “real America,” which apparently includes part of North Carolina, Rep. Michelle Bachmann, calling for a media investigation to determine whether Americans are real or not, and today, McCain all-around best surrogate Nancy Pfotenhauer (pronounced — Foe-Ten-How-er, like proton power), said that parts of the state of Virginia, heretofore universally assumed to be in America, were not, in fact, in the country.

Extra dimensions can apparently account for the “unreal America”

I find this especially interesting, because, according to the article, I live in the place that is “real America” but is in danger of becoming “unreal” when we collapse the wave function in November.

If you think that’s special, then think about this. Pfotenhauer said that she lives in a place called Oakton, Va. Oakton is located in Fairfax County. Pfotenhauer implied that the country was part of “real America” because it was open to the possibility of electing John McCain. Here’s the problem: Fairfax County, like its neighbors, are in the process of turning colors. (We can detect this with a special version of a mass spectrometer called a “ballot box.”)

Heh. Oakton’s about 8 miles away. I’ve never noticed any changes when I’ve driven in that direction.

via physics and physicists

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Since we’re on the topic of politics anyway, check out Ian’s Lessons from the Cold War: understanding ideologies over at Quantum Moxie.

I believe the hatred that has slowly taken the place of respectful disagreement between the “left” and “right” has its origins in the inability of either side to comprehend the other side’s motivation. Some might say it is an unwillingness rather than an inability and the truth is likely a mixture of both. But, quite clearly, there are times when there is simply an inability, for whatever reason, to grasp a motivating principle if it is so entirely foreign to us.

I certainly have observed people from both sides that simply hate the other side, no matter what. Which is really dangerous, because then nobody will listen to each other, but is also self-defeating, because you become a hypocrite for decrying behavior when the opponent does it, but not when your friend does.

I ran across an example just today, in what was an otherwise much more reasonable discussion about why an electrical transmission project in California is a bad idea, and an entreaty to do something about it if you live there.

You can also, if you choose, point out that Arnold has a good record on environmental issues (which, I am pained to report, he really does, for a Republican) and that he has a chance to keep that record intact here.

Why does it pain you to report this? It’s almost as if the poster wants to hate him, and is upset that this is preventing him from doing so. This is part of the problem outlined above.

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And finally, a few tidbits

This resonated with me in the recent endorsements of Obama by the Chicago Tribune

We know first-hand that Obama seeks out and listens carefully and respectfully to people who disagree with him.

This would be a welcome change from the current administration.

And, finally, Yes

Frozen Waterfalls

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10 Most Incredible Waterfalls of Ice

BP (before physics) I used to wonder how waterfalls could freeze. But if one looks at the physics, it’s apparent that the motion of water moving in a stream, river or waterfall is small compared to the thermal motion, so this motion really has little effect.

Take a peek at picture #5, showing the frozen outer cylinder, with water still falling inside of it.