Here is a concise summary of the provided text:
**Video Content Summary**
* **Segments:**
1. **Snowflakes under a microscope** (observed outdoors due to melting issue indoors)
2. **Fish Scales** (structure and function)
3. **Comparison of Fresh and Used Car Oil** (microscopic examination revealing contaminants in used oil)
4. **Tangerine Peel** (mysterious holes or "craters" observed)
5. **Human Fingernail** (composition and growth rate)
6. **Sausage/Frankfurter Contents** (debunking a viral video claiming to show garbage and hairs; no evidence found under microscope)
* **Additional Note:** Brief promotion of the online game "War Thunder" and a commentary on the prevalence of fake content on social media platforms.
Here are the key facts extracted from the text, keeping each fact as a short sentence and excluding opinions:
**1.** The video explores multiple topics under a microscope, including human fingernails, fish scales, car oil, snowflakes, tangerine peels, and sausages.
**2.** To observe snowflakes under a microscope, the filming had to be done outside in the cold because the indoor temperature was above zero.
**3.** Snowflakes were collected on a piece of paper held under falling snow to obtain undamaged specimens.
**4.** The shape of snowflakes depends on the temperature and humidity conditions along their path from cloud to ground.
**5.** Fish scales are made of transparent plates with grooves, resembling human fingerprints.
**6.** Fish scales provide a streamlined body, reducing water resistance, and offer protective functions.
**7.** A comparison was made between fresh and used car motor oil under a microscope.
**8.** Used car motor oil contains visible debris, possibly metal scraps and fuel combustion products.
**9.** The engine oil filter collects dirt and filters the oil in a car engine.
**10.** Human fingernails are dense, horny plates that protect fingers from mechanical damage.
**11.** Fingernails grow approximately 1-2 millimeters per week.
**12.** An experiment was conducted to verify claims of debris in sausages by examining them under a microscope.
**13.** The examined sausages and frankfurters showed no visible garbage under the microscope, contradicting a video claiming otherwise.
**14.** The suspicious video likely placed debris on top of the sausage sample to fake the presence of garbage inside.