April 23, 2011

Physicists at a Party

 This is an exceptionally good physics joke, taken shamelessly from the web.

 At the Party with the Physicists

One day, all of the world's famous physicists decided to get together for a party (ok, there were some non-physicists too who crashed the party). Fortunately, the doorman was a grad student, and able to observe some of the guests...


  • Everyone gravitated toward Newton, but he just kept moving around at a constant velocity and showed no reaction.
  • Einstein thought it was a relatively good time.
  • Coulomb got a real charge out of the whole thing.
  • Cauchy, being the mathematician, still managed to integrate well with everyone.
  • Thompson enjoyed the plum pudding.
  • Pauli came late, but was mostly excluded from things, so he split.
  • Pascal was under too much pressure to enjoy himself.
  • Ohm spent most of the time resisting Ampere's opinions on current events.
  • Hamilton went to the buffet tables exactly once.
  • Volta thought the social had a lot of potential.
  • Hilbert was pretty spaced out for most of it.
  • Heisenberg may or may not have been there.
  • Feynman got from the door to the buffet table by taking every possible path
  • The Curies were there and just glowed the whole time.
  • van der Waals forced himeself to mingle.
  • Wien radiated a colourful personality.
  • Millikan dropped his Italian oil dressing.
  • de Broglie mostly just stood in the corner and waved.
  • Hollerith liked the hole idea.
  • Stefan and Boltzman got into some hot debates.
  • Everyone was attracted to Tesla's magnetic personality.
  • Compton was a little scatter-brained at times.
  • Bohr ate too much and got atomic ache.
  • Watt turned out to be a powerful speaker.
  • Hertz went back to the buffet table several times a minute.
  • Faraday had quite a capacity for food.
  • Oppenheimer got bombed.
  • The microwave started radiating in the background when Penzias and Wilson showed up.
  • After one bite Chandrasekhar reached his limit.
  • Gamow left the party early with a big bang while Hoyle stayed late in a steady state.
  • For Schrodinger this was more a wave function rather than a social function.
  • Skorucak wanted to put everybody on his web site.
  • Erdos was sad no epsilons were invited.
  • Born thought the probability of enjoying himself was pretty high.
  • Instead of coming through the front door Josephson tunnelled through.
  • Groucho refused to attend any party that would invite him in the first place.
  • Niccolò Tartaglia kept stammering throughout the evening.
  • Pauling wanted to bond with everyone.
  • Keynes was keen to question the marginal utility of this party.
  • Shakespeare could not decide whether to be or not to be at the party.
  • John Forbes Nash wanted to play a n-person zero sum game.
  • Pavlov brought his dog; which promptly chased after Schrodinger's cat.
  • Zeno of Elea came with two friends - Achilles and the tortoise.
  • Bill Gates came to install windows.
  • Bertrand Russell kept wondering if the cook only cooks for the guests, who cooks for the cook?
  • Witten bought a present all tied up with superstrings.
  • The food was beautifully laid out by Mendeleyev on the periodic table.
  • Riemann hypothesised about who would arrive next; to which Newton retorted, ' hypotheses non fingo.'
  • Chadwick was handing out neutrons free of charge.
  • Everyone was amazed at Bell's inequality.
  • Watson and Crick danced the Double Helix.
  • While Fermat sang, 'Save the Last Theorem for me.'
  • Maxwell's demon argued with Dawkin's friend, the selfish Gene.
  • Russell and Whitehead insisted on checking the bill for completeness and consistency. Godel said it was incomplete and it can never be proved otherwise.
  • Epimenides the Cretan announced that only non-Cretans spoke the truth.
  • Rontgen saw through everybody.
  • Descartes cogitated, 'I think I am drunk. Therefore I am at the party.' 
Source: www.physlink.com

Oh yeah.

April 20, 2011

Vanishing Water Trick

Go on, finish the video. You need to~

Aw, isn't he nice? He seems like a very likable person, charming, and very charismatic. He'd make a perfect insurance salesman.

Ahem.

So, what we've just seen in the video was that the water apparently disappears. To the common, untrained person, this magic trick is almost impossible to crack. However, we have the power of science on our side.

The key ingredient in this trick are chemicals known as Super absorbent polymers. These cross-linked acrylic polymers are referred to as "Super Absorbents" and "Water Crystals", and are used in baby diapers. From our findings, we can infer that the magician laced his cup with super absorbent crystals, and naturally, due to its ability to hold lots of water (sodium polyacrylate holds 800+ml of water per gram!) the water apparently disappears.

Sodium Polyacrylate can be extracted from baby diapers, or purchased from your local garden store. You might need a few extra cups though.

Also, magically, the reaction can be reversed with a few spoons of sodium chloride.

April 18, 2011

Dehydration of Sugar

Wow?

What happens in the above video is an exothermic reaction involving the monosaccharide and a strong acid. In this case, we witnessed the action of Sulphuric Acid + Sucrose.

Observation:
When the acid is added to the sugar, the sugar transforms, expands and an effervescence of steam is observed. This reaction is clearly exothermic since the acid and the sugar were originally at room temperature.

Dehydration reactions are reactions where the H2O molecule is removed from the carbonyl compound and in balancing the equation, the acid is hydrated. This water transfer is the source of the heat in this reaction. The water and the acid create very strong hydrogen bonds, which in turn give off energy in the form of heat. When bonds break, and new bonds are formed, some bonds are easier to form than others, so often the excess energy that doesn’t go into making bonds, gives off heat as the product.

In this reaction when hydrogen and oxygen are removed from sugar, all we have left is graphite(carbon). The water escapes mostly as steam, and like most reactions, not everything is able to react, so we often have the leftover, unreacted acid evaporating with the water.

Note: This is a very dangerous experiment. Only proceed under proper supervision.

The full equation is actually pretty simple:
C12H22O11 (Sucrose) + H2SO4 (Sulphuric Acid) → 12C (Graphite) + 11H2O (Water)

Oh, if you insist on doing this experiment, kindly check your insurance policies on scientific accidents coverage, or whatever they say.