A lot of spells seem possible without magic. Charm Person can be done with a good diplomacy check and Stinking Cloud can be done with some terrible flatulence.

In this way, spells would be learned as effects created by devices, serums, and other such items of science fiction. Obviously, more vague or directly magical abilities such as Wish or Antimagic Field could not function with these alterations, but for the most part nearly any spell can be converted into a science fiction creation.

In addition to the below alterations, each spell has a specific knowledge it is tied to based on the created effects. I’m sure an experienced DM can think of on a spell-by-spell basis.
you can create your own alteration by just replacing “arcana” and “spell” with “technology”.

I'm open to suggestions and ideas as to other methods of converting magic into science fiction or even just ideas as to how to mix it with standard fantasy concepts.

Abjuration and Evocation Spells
You have special devices with you which generate energy fields or blasts. You must have your device and its energy source (focus and spell components) to use its effects. The device usually weighs a number of pounds equal to (1 + spell level)2 and can be crafted with a Craft (mechanics/electronics) check DC15 + spell level taking an amount of gold equal to (1 + spell level)2 x 100 gold and 1 week per 1000 gold to craft (1/4 this cost/time to repair if damaged). Each device can hold many different spells although its weight and craft DC/time is always dependent upon the highest level spell and its cost is accumulative between all the spells. Activating the device and wielding it works just like normal spellcasting, although if it weighs too much you may be required to use it as a vehicle as well (adding a Fly or Floating Disk or other spell to it to allow it mobility). This trades time, gold, and focus dependency in order to make things which are normally impossible without magic, possible. Because of the difficulty of lugging around these devices, they usually allow x1.5 the normal uses per day (not including bonus spells).

Conjuration and Non-mind affecting Illusion and Necromancy Spells
You can craft anything given the right time and material. You can cast any conjuration spell with a check DC15 + (2 x spell level) taking an amount of gold equal to (1 + spell level)2 x 10 gold and 1 day per 100 gold to craft (1/4 this cost/time to repair if damaged). The check is dependent upon the conjuration. Usually Craft (alchemy) for energy-based conjuration or conjuration resembling evocation, Craft (item being created), or Heal for summoning and necromancy spells. Because of the increased time to craft, all durations of the conjuration spells are multiplied by 2. A crafter may also choose to leave their craft unfinished and add the final components (normal spell components) at the last second to activate their creation. Each spell saved this way weighs an amount of pounds equal to (1 + spell level)2 until it is cast and transforms into the intended conjured item or creature. They may also reuse the remains of their broken creations at 1/4 value.

Divination and Mind-affecting Enchantment, Illusion, and Necromancy Spells
Your wit and charm has a way of confusing, charming, or baffling others. With a successful Charisma-based skill check DC15 + (2 x spell level) taking a number of minutes of uninterrupted social intercourse to perform equal to 1+ spell level, you can recreate the effects of any mind affecting spell without using magic. This trades spell components for time. Fear affects use Intimidate, compulsion effects use Diplomacy, Divination spells use Gather Information or Search, and all other effects use a Perform check.

Transmutation and Other Enchantment Spells
You can manipulate the physical properties of things with a simple injection of one of your serums or ingestion of potions. This simply allows the effects of any Transmutation or Enchantment spell to be made into a potion or injury poison. Fortitude resists spell effects when injected though a second save is needed 1 round later to avoid taking 1 point of Con damage per spell level for resisting the effects. Characters failing the first Fortitude save don’t suffer this Con damage. To create such a brew requires a Craft (alchemy) check DC15 + (2 x spell level) taking an amount of gold equal to (1 + spell level)2 x 10 gold and 1 day per 100 gold to craft and a number of ranks in Heal or Knowledge (nature) equal to the spell level.