Lokesh: Kya hum ghar me ya shop me bhagwad geeta rakh sakte hai?
Swami Ram Swarup: Han! Aap ghar ya shop kahin bhi Bhagwad Geeta rakh sakte hain.

Aman: Things need to make hawan?
Swami Ram Swarup: Preparing Havan Samagri

Hawan samagri is prepared from four matters which can be further hundred , two-hundred or as many as you want. Otherwise twenty-one are enough. It may be even eight to ten etc, but main four are:
(1) Sweet like jaggery, honey etc.
(2) Nutritive like ghee, dry fruits, black daal (mah ki daal), black til etc, flour.
(3) Fragrant like dried leaves of flowers like rose petals, sandal wood powder etc.
(4) Antiseptic like gyol etc.

First of all, hawan samagri to perform agnihotra should be purchased from market. In case of inavailability of hawan samagri in market, you can prepare it at home from the following matters—–

21 best herbs for Havan

Jatin: Acharyaji Ved ek ishwariya vaani hai aur sirf sun ke prapt hoti hai. Kya yeh kewal sanskrit bhasha mein hi hoti hai.Ya phir alag alag bhasha mein.
Swami Ram Swarup: Ved vanni kewal sadaa divya Sanskrit bhasha mein hee hotee hai.

Anonymous: Hindu hawan vidhi.
Swami Ram Swarup: Havan vidhi is mentioned below in English:

How to do havan

Please sit in the morning to perform havan. Havan must be performed in sunlight then it is more beneficial. Half a bowl of fresh water with a tablespoon must be with you with small twigs especially of mango tree if possible, havan samagri, ghee, camphor and match box must be there with you. Please sit on sukh asan on four times folded blanket and blanket must be kept on mat.

Sukh asan i.e., sit on duly folded feet in comfortable position. First close your eyes and concentrate between two eyebrows and chant Gayatri mantra three times within heart and not by mouth. Then open your eyes.

Take one spoon of water in right palm. Chant this mantra, OM AMRITO UPASTRANMASI SWAHA and drink the water which you have put in your palm. Then again take the spoon of water in right palm then chant the next mantra, OM AMRITA APIDHANMASI SWAHA, and drink the water. Then again take the water in right palm and chant the mantra, OM SATYAM YASHAH SHRI MAYI SHRI SHRAYTAAM SWAHA, and drink the water. Then wash the right palm while sitting, with the same water kept in bowl.

Now, put the twigs into havan kund with one piece of camphor and burn it. During this process chant the Gaaytri mantra again and again till such time the fire is lighted sufficiently. Then chant the Gayatri mantra and at the last add the word Swaha and offer ghee with tablespoon, quantity equivalent to 4 to 5 drops. And if you are alone then also offer in fire pinch of havan samagri from your right hand’s fingers and thumb avoiding forefinger. So this offering may be of 11 times, 21 times or 51 times as the time suits. It is the simplest way and I have not quoted the complete method of Yajyen. The havan with Ved mantras are always offered as the best worship of God only please. Do havan daily and both times.

However, ACD/VCD performing havan are also available along with book containing ved mantras which are pronounced to perform daily agnihotra. It can be sent on receipt of your postal address, if you desire,

Rohit: Gravitation ke khilaf koi force hai?
Swami Ram Swarup: Nahin hai.