8 things you didn't know who to ask

Does hair grow back thicker after shaving?

If that's true, you would have legs and armpits like Gorillas. New-grown stubble seems thicker than uncut hair. But the truth is, all hair growth takes place below the skin, down in the hair follicle. The section of hair we lop off, is just dead protein. If shaving caused faster or thicker hair, men suffering from male pattern baldness would be hacking away at their shiny pates with the latest five-bladed razor, from dawn till dusk.

Can cockroaches survive an atomic blast?

Though loathsome cockroaches are chased from one corner of the earth to the other by brandished shoes and rolled-up magazines, you need to give the vermin their due. A human being exposed to the radiation in excess of about 800 rems is most likely to die, but tiny cockroaches can survive the radiation in a thermonuclear blast. The killer dose for an American cockroach is 67,500 rems and that for a German cockroach is about 1,00,000 rems. The more complex and longer living the organism is, the more vulnerable it is to the effects of radiation. And cockroaches don't live long enough to develop cancers linked to radiation exposure, like humans do.

Why shouldn't pregnant women dye their hair?

You can opt for a change of look while you are pregnant, but avoid full blown change of colour scheme. A link was found between maternal hair dyes and childhood diseases like brain tumors. Besides, too much of it can lead to hair loss. It is fine to get an occasional colour rinse, but you should avoid soaking your head in a vat of dye.

How does Aspirin find the pain?

Do you wonder how Aspirin, the magical pill associated with strokes and heart disease, locate your aching area, and start working on it? The answer is, it doesn't. Say you drop a bowling ball on your toe. Although the pain is felt in the throbbing toe, it's really processed in the brain. After the ball crushes the toe, damaged cells and nerve endings release chemicals like prostaglandins, that send a message of pain to the brain. Aspirin is not a pain-seeking bloodhound it appears to be. When you pop it, it stops the cells from making prostaglandins. The result temporary relief from pain and inflammation.

Does falling in love really cause chemical changes in your brain?

Do you feel that people in love, especially teenagers, turn deranged, volatile and self-centered psychos in dire need of an exorcism? Research says, when you avidly gaze at your lover's photograph, your ventral tegmental area and the caudate nucleus is lit up. Serotonin (In the central nervous system, Serotonin plays an important role as a neurotransmitter in the modulation of anger, aggression, body temperature, mood, sleep, human sexuality, appetite, and metabolism) levels in love-struck people were as low as those in people with Obsessive Compulsive Disorder, a study found. In case you are feeling madly in love, there is valid scientific reason for it.

When you pull out a grey hair, do two come back in its place?

If you pull out a grey hair and wait the three months it usually takes for a hair to grow back, and an additional three months it takes to grow long enough for you to notice, you will probably have one. So it's nonsense if you concoct spurious misconceptions like two-grey-hair-for-each-one-plucked.

Can friends synchronise their menstrual cycles?

Have you ever noticed that your menstrual cycle times perfectly with your best friend's cycle? Yes, it's possible. A research says women who spend a lot of time together can synchronise their menstrual cycles. In 1971, Martha McClintok, a psychologist first reported this phenomenon. But there is no physiological reason for it; it might happen simply by coincidence as some overlap of periods can be expected in any group of friends.

Some hormonal changes occur with orgasm, and this could be one of the reasons behind the snoozing habits of men. After orgasm, both, men and women release chemicals like Oxytocin and Prolactin. They secrete them in equal proportions but it has a greater effect on men, since they orgasm more frequently. These hormones contribute to the roll-over-and-snore feeling. Oxytocin is called the cuddling hormone, since it elicits the need to be close and bond, but not in a sexual way. It could make men feel satiated and rested after a good romp. Prolactin stimulates milk production and takes your mind off sex, so, it could be another culprit.