Tag Archives: physics

A load of science

If you are into science videos this will interest you. It’s a collection of 100 science lectures given by top scientists.

They are divided into the following groups:

  • General,
  • Science and engineering,
  • Biology and medicine,
  • Chemistry,
  • Physics and astronomy,
  • Earth and environment,
  • Technology and computer science,
  • Science and the future,
  • Science and business, and
  • Miscellaneous

Some are several years old – but they look interesting. And they certainly cover a range of interests within science.

Thanks to Shirley Zeilinger for pointing me to 100 More Incredible Lectures From the World’s Top Scientists.

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The trouble with physics?

Scientists working on the Atlas experiment at the Large Hadron Collider ( Photo: REX FEATURES & The Telegraph)

No, this is not an in-depth critique of string theory along the lines of Lee Smolin’s The Trouble With Physics: The Rise of String Theory, The Fall of a Science, and What Comes Next or Peter Woit’s Not Even Wrong: The Failure of String Theory and the Search for Unity in Physical Law. It’s more along the lines of how do you know when a physicist is joking?

I think part of the attraction of modern physical theories and speculations are their non-intuitive nature. I buy that – and don’t find myself rejecting ideas just because they violate “common sense.” But I have often through that this non-intuitive nature does leave the field wide open to bullshit.

OK – I am aware that pseudo-science uses this to it’s own advantage to sell products and ideologies. But here’s a more practical problem I face – who do you believe when you read stories about physical discoveries on or around April 1 every year?

For example – I am pretty sure that the CERN Newsletter editors were pulling my leg when they reported – CERN scientists report sidereal influence on the behaviour of antimatter:

CERN scientists today reported an unexpected effect in the behaviour of antiprotons in the ALPHA experiment’s particle trap. ALPHA traps antiprotons from the laboratory’s Antiproton Decelerator and mixes them with positrons to form antihydrogen.

The experiment’s ultimate goal is to perform spectroscopic measurements on antihydrogen atoms in order to investigate nature’s preference for matter over antimatter. ALPHA reported an important step forward last month with the announcement that they had succeeded in changing the internal state of antihydrogen atoms using microwaves.

One of the key stages in CERN’s antimatter programme is slowing the antiprotons down as much as possible, a process known as cooling. In all measurements to date, the ALPHA experiment has cooled the antiprotons to a temperature of just 0.5 Kelvin. However, when the experiment ran on Monday 26 March, they observed antiprotons cooled to 0.4 Kelvin: in other words, they were moving more slowly than usual. Another curious phenomenon was that the temperatures of the antiprotons followed a Poisson distribution instead of the usual Gaussian. The following day, the antiprotons were back to their normal temperature of 0.5 Kelvin.

“We took a long time to figure this one out,” explained collaboration spokesperson, Jeffrey Hangst. “On Monday, the antiprotons were particularly cold, but they responded well to microwave warming, allowing us to conclude the run. On Tuesday, our antiprotons were back to normal.”

The solution came from an unexpected direction.

“There was something else strange about Monday’s run,” said Hangst. “Our run coordinator Niels Madsen arrived an hour late, which is very uncharacteristic behaviour for him.”

This provided the clue the ALPHA collaboration needed.

“I’d forgotten that the time changed over the weekend,” said Madsen. “And of course no one had told the antiprotons that the clocks went forward either, so they were just a little more slow than usual. By the time we got to Tuesday, they’d adjusted to Central European Summer Time.”

But what about this from Jon Butterworth – a physics professor at University College London and a member of the High Energy Physics group on the Atlas experiment at Cern’s Large Hadron Collider. He’s normally a serious guy but reported in his Guardian Blog Life and Physics recently (April 1 actually) that “a bug in the software used to model the detectors at the Large Hadron Collider could have been covering up evidence for extra space time dimensions” (see  First evidence for string theory at the Large Hadron Collider):

Complex software models are used to understand the results from the Large Hadron Collider. These include simulations of the particle physics in the proton-proton collisions, as well as of the material and geometry of the detectors and the strength of the various magnetic fields. As more data are accumulated, the required precision of this software increases.

A recent review recommended that the number of decimal places used to represent numbers in the software should be increased. This means all mathematical constants such as e and pi, as well as physical constants and the measured dimensions of the detectors. So far, so routine. But when adding more precision to pi, a strange effect was noticed. The alignment of charged particle tracks across detector boundaries actually got worse when a more precise value was used. In addition, the agreement between simulation and data also got slightly worse.

This really should not happen – more precision should mean better alignment and better agreement.

Boring scientists say this is probably evidence that some physicists don’t know how to write proper code. However, string theorists have pointed out that a firm prediction of string theory is the existence of extra space-time dimensions. In a space which is curved into a higher dimension, the apparent value of pi can deviate from that seen in real life. And thus the LHC may have proved that they were right all along. More data are needed before we can be sure.

Well, I don’t know. Sounds as credible as most of the stories coming from the LHC and the scientists working there.

Perhaps a hint that the story is an April Fool’s joke comes from the last sentence:

Less welcome news for CERN is that since they have been near to the beams for two years, the values of pi used in those parts of the ATLAS which were built in the UK are now hot, and therefore as of today will attract VAT.

Or perhaps it’s only the last sentence which is the joke?

That’s the trouble with modern physics. When should we take it seriously.

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Another lousy photo of the sun?

As a photo of the sun this doesn’t look very impressive – until you realise it was taken using neutrinos!

And also that it was taken through the earth – when the sun was on the other side of the earth!

An exposure of 503 day was used and neutrinos detected using a 50 000-ton water pool located 1 km underground. Neutrinos have an extremely weak interaction with other matter. Most of them pass through the earth without interaction and the detection relies on Cherenkov radiation emitted during a rare interaction with an electron in the water.

Thanks to: The Sun seen through the Earth in “neutrino light”

Comprehending reality – Should we give up so easily?

The Edge question is an annual event. Publisher John Brockman poses an interesting question to a large number of scientists, thinkers, academics and writers. He publishes their answers on the Edge website and usually, later,  as a book*

The 2012 question is:

What Is Your Favorite Deep, Elegant, Or Beautiful Explanation? Continue reading

Fine-tuning fallacies

In Fiddling with “fine-tuning” I discussed the way theologians and philosophers of religion have used claims of fine-tuning of the cosmological constant erroneously. That they have taken the fact that the value of the measured cosmological constant is 120 orders of magnitude different to the value of vacuum energy used to explain it. This has been described as the “worst calculation in physics history.” But never mind, these apologists have just utilised the huge mistake to claim that the cosmological constant is fine-tuned to 1 part in 10120! So there god must be responsible.

This is what happens when you use scientific knowledge opportunistically. Like a drunk uses a lamppost – more for support than illumination. Because the problem with the theological approach is that there is no interest in understanding the world around us – just in using science to support any argument they can drag up to “prove” the existence of their particular god.

Mind you, some non-theists also find the fine tuning concept beguiling. And they can also uncritically accept some of the fine-tuning claims that circulate. The idea that many of the physical and cosmological constants in our universe are extremely delicately balanced to values necessary for life to exist. The so-called anthropic principle.

So, Victor Stenger’s new book The Fallacy of Fine-Tuning: Why the Universe Is Not Designed for Us will be very useful for anyone attempting to check out these arguments by actually considering the science. He describes the physical and cosmological background to the constants, or parameters as he prefers to call them, usually used in fine-tuning arguments. And then he considers, one by one, just how valid – or invalid – the fine-tuning arguments are.

Here I will just deal with two “fine-tuned” constants – the “Hoyle resonance” for carbon nuclei and the “nuclear efficiency.” I think they illustrate two common mistakes made in estimating the degree of fine-tuning.

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Art in science

Elusive ... subatomic neutrino tracks showing electrons and muons. Photograph: Dan Mccoy/Rainbow/Science Faction/Corbis

The process of science is very creative in itself. But I think creativity in science  takes on a deeper meaning, and provide a wider communication, when it involves other art forms like writing, music and the graphic arts.

Spare a thought

So I enjoyed this little song by Andrew Pontzen (a theoretical cosmologist – @apontzen) commenting on  the recent news of neutrinos caught travelling faster than light.

It’s called Spare a Thought – and to my limited appreciation of the subject he seems to hint at the underlying physics of the situation.

Thanks to Geek Pop Podcast: The Live Sessions at geek pop.

Some NZ poetry

And I have just found out that SciBlogsNZ has its own resident poet. The chemist Michael Edmonds who writes the blog Molecular Matters.

He has just posted two poems Wolf in Sheep’s Clothing and A New Scientific Revolution. Both are very relevant to the issues we face today.

Hawking’s grand design – lessons for apologists?

I managed to get my own copy of  The Grand Design (co-authored by Stephen Hawking and Leonard Mlodinow) the other day. Talk about luck. I was on one of my rare visits to the big smoke and inquired at Borders. It had just come in that day and wasn’t yet on the shelves!

 

Victor Stenger

 

Obviously I won’t comment in depth until I have read the book. I get the impression that I may find the discussions of philosophy more interesting then the physics, though. And I guess it is the philosophical aspects of the book which have provoked the most criticism, or at least the theological criticism. (Mathematicians and physicists like Peter Woit, of course are making their criticisms – but hardly making the newspapers with them – see for example Hawking gives up).

However, I am aware the Victor Stenger is reviewing the book and look forward to his views. He has some standing in cosmology and philosophy, and his writing in these areas are excellent.

So far he has made only limited comments based on other reviews (see Hawking and the Multiverse). I feel he makes an important, point in his conclusion. It does seem obvious to me, but then again the extreme theological reaction to news of the book suggests it may not be to some others. Victor says:

So, at least according to the reviews, Hawking and Mlodinow haven’t said much that physicists and cosmologists haven’t already heard before. However, thanks to Hawking’s notoriety, at least more people will now have heard that science has plausible answers to how the universe came about naturally without the need for a creator. Hopefully this will include those theologians and apologists who continue to wrongfully insist that modern science has demonstrated a need for God.

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Not about Einstein

Book Review: Einstein’s God: Conversations About Science and the Human Spirit by Krista Tippett

Price: US$10.88; NZ$12.97
Paperback:
304 pages
Publisher:
Penguin (Non-Classics) (February 23, 2010)
Language:
English
ISBN-10:
0143116770
ISBN-13:
978-0143116776

The media reports of Stephen Hawking’s new book with co-author Leonard Mlodinow (The Grand Design) attracted hostile reaction from some theological quarters (see The Grand Design – neither God nor 42). This reminds me of similar treatment meted out to Albert Einstein in his time.

Einstein had many religious critics for an article of his on the philosophy of religion in 1940. An Episcopalian responded “to give up the doctrine of a personal God . . . .  shows the good Doctor, when it comes to the practicalities of life, is full of jellybeans”. He was accused of providing fuel for the fanatical antisemitism of religious bigots and told that he should “stick to his science” and stop delving into philosophy (sound familiar). And this from the founder of the Calvary tabernacle Association in Oklahoma City “Professor Einstein, every Christian in America will immediately reply to you, ‘Take your crazy, fallacious theory of evolution and go back to Germany where you came from.”

Perhaps some of today’s scientists who hesitate to respond to their theological critics could learn from Einstein’s reaction. While criticising atheist reaction he described his theological critics as “numerous dogs who are earning their food guarding ignorance and superstition for the benefit of those who profit from it.”

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What is matter? What is materialism?

I have often thought most philosophers vague when they talk about matter. And especially when they use the word “materialism.”And this includes some who call themselves “philosophers of science.”

And try to hunt down the definitions. Answers for example describes matter as “something that has mass and exists as a solid, liquid, gas, or plasma.” In Wikipedia we find: Matter is the substrate from which physical existence is derived, remaining more or less constant amid changes. Anything that occupies space and has mass and weight.” Search for clarification usually produces the circular definitions that matter has substance and substances are matter.

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Fallacy of Fine Tuning

I just picked up in my browsing that Victor Stenger is working on a new book The Fallacy of Fine-Tuning: How the Universe is Not Designed for Us. Its planned for publication early next year.

Continue reading