Your spit contains a painkiller that can be 6 times more powerful than morphine 

Human saliva contains a natural painkiller called opiorphin. Due to its powerful painkilling ability, scientists are trying to synthesize a new natural painkiller  from opiorphin. It is great, because it doesn’t have the same addicting attributes that morphine does and would work better with the body. 

In a study, 1 milligram of opiorphin gave the same results as 3 milligrams of morphine did. In another study, involving rats standing on pins, they needed 6 times more morphine than opiorphin to make them oblivious to the pain. 

Opiorphin works in the nerve cells of the spine. It stops the usual destruction of natural pain killing opiates in the spine called enkephalins. It is such a simple molecule, that scientists believe it’ll be possible to synthesize it and produce large quantities of it without needing to isolate it from saliva. Another approach is to find a drug that will make the body produce more opiorphin to manage pain.

source:

http://www.newscientist.com/article/dn10514-naturalborn-painkiller-found-in-human-saliva.html 

can you look back in time?

you actually can!

here is how

if you look at the sun right now your technically looking back at the sun ...

it takes 8 mins for the sun light to travel to earth

so when you look at it ...you are actually looking at the sun like it was 8 mins ago :)

the equation to plot a heart symbol:

(x² y²-1)³-x²y³=0 

It should look like this:

You can also depict a heart symbol with a cardioid like r = 1 - sinΘ, but it doesn’t look as good.  

source 

http://en.wikipedia.org/wiki/Heart_(symbol) 

You can measure the speed of light by using a bunch of marshmallows and a microwave

You can measure the speed of light by using a bunch of marshmallows and a microwave!

Place one layer of marshmallows in a casserole dish. The dish should be completely covered in marshmallows. Put the dish in the microwave without a turntable and cook on low heat. Continue heating the marshmallows until the layer starts to melt in 4 or 5 different places. Microwaves do not cook evenly, so you have to allow for several places to begin melting.
Take the dish out of the microwave and observe the melted spots. Use a ruler to measure the distance between the melted marshmallows. Check the back of the microwave for its frequency. There will be a consistent distance between the melted spots of marshmallow and this distance is half the wavelength of the microwave. Finally, all you have to do is multiply the microwave frequency by the wavelength. The product is the speed of light!

Velocity = Frequency ´ Wavelength 

then you get to eat the marshmallows :D

source:

http://www.physics.umd.edu/icpe/newsletters/n34/marshmal.htm