1. Science of Scuba Diving Spicer Bak Stevens Institute of Technology This material is based upon work supported by the National Science Foundation under Grant No. NSF DGE-0742462

2. Overview Magnification Light Pressure Boyles Law Nitrogen Narcosis

3. Magnification Objects appear 33% larger – 25% closer 3 m long object – 4 m away – 33% larger – 33% of 3m is 1m = 4m – Looking up at 45% 4m tall at distance of 4m – 25% closer, appears 3m tall at distance 3m (3m tall at distance of 3m)

4. Science of Scuba Diving

5. Light Absorption

6. Boyle’s Law

7. Boyles Law P 1 *V 1 =P 2 *V 2 – Pressure = P – Volume = V – As Pressure Increases Volume Decreases Applied to: – BC – Lungs – Mask – Body

8. Pressure With Depth, Pressure Increases Even in lungs and At Depth = 99 ft.. – 1 breath = 4xmolecules of air of normal breath DepthPressureVolumeAir Density Sea Level1 ATM121x 33'2 ATM62x 66'3 ATM43x 99'4 ATM34x 132'5 ATM2.45x

9. Boyles Law Decompression Sickness – High Pressure increases nitrogen concentration in blood Turns Gas -> Liquid – Dissolves in blood – Come to surface too quickly Nitrogen goes from Liquid to Gas in blood stream (like opening coke) Embolism – Decompression Stops Stop at various depths during surface to reach equilibrium Emergency Surface – Take Deep breath and blow out slowly as rise to the surface Gas expands, always have air

10. Nitrogen Narcosis

11. With depth increases nitrogen in blood stream – Under High Pressure Nitrogen Dissolves into blood – CausesNitrogen narcosis Effects – Similar to Alcohol Intoxication

12. Nitrogen Narcosis Signs and symptoms of narcosis (breathing air) Pressure (bar) Depth (m) Depth (ft.) Comments 1–20–100-33 Unnoticeable small symptoms, or no symptoms at all. 2–410–3033–100 Mild impairment of performance of unpracticed tasks. Mildly impaired reasoning. Mild euphoria possible.impairmenteuphoria 4–630–50 100–165 Delayed response to visual and auditory stimuli. Reasoning and immediate memory affected more than motor coordination. Calculation errors and wrong choices. Idea fixation. Over-confidence and sense of well-being. Laughter and loquacity (in chambers) which may be overcome by self control. Anxiety (common in cold murky water).loquacitychambers

13. Narcosis 6–850–70165–230 Sleepiness, impaired judgment, confusion. Hallucinations. Severe delay in response to signals, instructions and other stimuli. Occasional dizziness. Uncontrolled laughter. Terror in some.Hallucinations 8–1070–90230–300 Poor concentration and mental confusion. Stupefaction with some decrease in dexterity and judgment. Loss of memory, increased excitability.Stupefactiondexterity 10+90+300+ Hallucinations. Increased intensity of vision and hearing. Sense of impending blackout, euphoria, dizziness, disorganization of the sense of time, changes in facial appearance. Unconsciousness. Death.

14. Nitrogen Narcosis - Solutions Normal – 78% nitrogen – 21% Oxygen Nitrox – Mixes with higher oxygen content – Very specific types of dives 68% N – 32% O 2 Others designed Oxygen Toxicity – VENTID-C Vision (blurriness) Ears-Ringing Nausea Twitching Irritability Dizziness Convulsions

15. Nitrogen Narcosis Does Free Diving have same Risks as Scuba Diving? Eg. Nitrogen Narcosis, The bends?